Advances in biomaterials and clinical techniqueshave facilitated significant expansion in the indi-

cations for dental implant therapy. In the beginning,the replacement of already missing teeth, eg, in eden-tulous patients, dominated daily practice. Today,many patients present for treatment to replace teeththat first need to be extracted before implants can beplaced. This provides clinicians with the opportunityto decide on the timing of implant placement aftertooth extraction.1,2 This decision is critical, since it hasa significant influence on treatment outcome.2 Arecent systematic review of randomized controlled

trials (RCTs) identified only two studies of immediateimplants that fulfilled the inclusion criteria.3 Althoughthis review concluded that implants placed into freshor healing sockets was a viable treatment option,more research was required.

The aim of this paper was to review the literaturepertaining to implants placed in postextraction sites,and to identify the level of evidence and clinical out-comes for the different time points of implant place-ment following extraction.

MATERIALS AND METHODS

An electronic search of the dental literature usingPubMed was undertaken to identify papers pub-lished in English between January 1990 and May2008, using the following search terms: dentalimplant, extraction, socket, immediate implant, immedi-ate placement, delayed implant, delayed placement,and late placement. A hand search of the followingjournals was undertaken: Clinical Oral ImplantsResearch, International Journal of Oral & MaxillofacialImplants, International Journal of Periodontics &Restorative Dentistry, Journal of Periodontology, Journalof Clinical Periodontology and Clinical Oral Implants

186 Volume 24, Supplement, 2009

1Senior Fellow, Periodontics, School of Dental Science, Universityof Melbourne, Parkville, Victoria, Australia.

2Professor and Chairman, Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern,Bern, Switzerland.

The authors reported no conflict of interest.

Correspondence to: Dr Stephen Chen, 223 Whitehorse Road,Balwyn, VIC 3103, Australia. Fax: +61 3 9817 6122. Email:schen@balwynperio.com.au

This review paper is part of the Proceedings of the Fourth ITI Con-sensus Conference, sponsored by the International Team for Implan-tology (ITI) and held August 26–28, 2008, in Stuttgart, Germany.

Clinical and Esthetic Outcomes of Implants Placed in Postextraction Sites

Stephen T. Chen, BDS, MDSc, PhD1/Daniel Buser, DMD, Prof Dr Med Dent2

Purpose: The aim of this review was to evaluate the clinical outcomes for the different time points ofimplant placement following tooth extraction. Materials and Methods: A PubMed search and a handsearch of selected journals were performed to identify clinical studies published in English thatreported on outcomes of implants in postextraction sites. Only studies that included 10 or morepatients were accepted. For implant success/survival outcomes, only studies with a mean follow-upperiod of at least 12 months from the time of implant placement were included. The following out-comes were identified: (1) change in peri-implant defect dimension, (2) implant survival and success,and (3) esthetic outcomes. Results and Conclusions: Of 1,107 abstracts and 170 full-text articles con-sidered, 91 studies met the inclusion criteria for this review. Bone augmentation procedures are effec-tive in promoting bone fill and defect resolution at implants in postextraction sites, and are moresuccessful with immediate (type 1) and early placement (type 2 and type 3) than with late placement(type 4). The majority of studies reported survival rates of over 95%. Similar survival rates wereobserved for immediate (type 1) and early (type 2) placement. Recession of the facial mucosal marginis common with immediate (type 1) placement. Risk indicators included a thin tissue biotype, a facialmalposition of the implant, and a thin or damaged facial bone wall. Early implant placement (type 2and type 3) is associated with a lower frequency of mucosal recession compared to immediate place-ment (type 1). INT J ORAL MAXILLOFAC IMPLANTS 2009;24(SUPPL):186–217

Key words: bone grafts, early implant placement, esthetics, immediate implant, implant survival

186_4a_Chen.qxd 9/10/09 10:16 AM Page 186

and Related Research. In addition, the reference lists ofrecent review papers were searched for additionalcitations.1,2,4–8 Papers accepted for publication werealso included.

Selection of StudiesAll clinical studies of implants in postextraction sitesthat included 10 or more treated patients were evalu-ated. For studies reporting on success and survivaloutcomes, only studies with a mean follow-up periodof at least 12 months from the time of implant place-ment were included.Where a follow-up publication ofa previous study was identified, the most recent studywas included.

Studies were excluded if the mean follow-upperiod was not stated. In studies that reported oncases with different implant placement times aftertooth extraction, studies were excluded if the datadid not permit a differentiation of the placementtime in subjects and sites.

Evaluation of Treatment OutcomeThe following treatment outcomes were recorded:

• Change in peri-implant defect dimension, either as areduction in defect area (mm2 or %), defect height,width, and/or depth (mm or %), or as the changein the number of exposed implant threads. The fol-lowing parameters were recorded: study design,implant surface, number of patients and implantsites, timing of implant placement after toothextraction, implant sites, augmentation method,healing protocol (whether submerged or transmu-cosal), concomitant use of systemic antibiotics,healing time from implant placement to surgicalreentry, and postoperative complications.

• Implant survival, recorded either as an overall sur-vival rate or cumulative survival rate. Loading pro-tocol and complications during the follow-upperiod were also recorded, in addition to the para-meters listed above.

• Esthetic outcomes. The following parameters wererecorded: descriptive soft tissue outcomes,esthetic indices, recession of the mucosa andpapillae (in mm or % change), changes in probingdepths or attachment levels, radiographic changesof the proximal bone, loading protocol, patient-evaluated esthetic outcomes, and complicationsduring the follow-up period.

DefinitionsIn the literature, a number of descriptive terms havebeen used to describe when implants are placed aftertooth extraction.The terms immediate, recent, delayed,

and mature were introduced to describe the timingof placement in relation to soft tissue healing and thepredictability of guided bone regeneration.9 The termlate was used to describe time intervals of 6 monthsor more after extraction.10 More recently, the termearly has been used to describe implant placementafter initial soft and hard tissue healing but beforecomplete healing of the socket has occurred.5,11,12

The imprecise nature of these descriptive terms inthe dental literature was discussed at the Third ITIConsensus Conference in 2003, and a new classifica-tion system for timing of implant placement aftertooth extraction was proposed.13 A slight modifica-tion to the classification was made in a 2008 ITI publi-cation, the ITI Treatment Guide, Vol 3 (Table 1).2 Thisclassification system was based on the desired clinicaloutcome of the wound-healing process, rather thanon descriptive terms or rigid time frames followingextraction. Type 1 placement refers to placement ofan implant on the same day as tooth extraction andas part of the same surgical procedure. Type 2 place-ment occurs when the implant is placed after soft tis-sue healing, but before any clinically significant bonefill occurs within the socket. In contrast, type 3 place-ment is defined as placement of an implant followingsignificant clinical and/or radiographic bone filling ofthe socket. In type 4 placement, the implant is placedinto a fully healed site. This classification was vali-dated in a recent review paper.1 The authors of thepaper felt that the classification was an appropriatemeans for describing the timing of implant place-ment in postextraction sites, as it accounted for varia-tions in the healing capacity of individuals.

Although this classification system has clarifiedthe terminology for implant placement in postextrac-tion sites, various descriptive terms remain in wideuse in the dental implant literature. Therefore, to

The International Journal of Oral & Maxillofacial Implants 187

Group 4

Table 1 Classification and Descriptive Terms forTiming of Implant Placement After Tooth Extraction(from Chen and Buser2)

Classifi- Descriptive Desired clinical cation terminology outcome

Type 1 Immediate placement An extraction socket with nohealing of bone or soft tissues

Type 2 Early placement-with A postextraction site withsoft tissue healing healed soft tissues but without(typically 4 to 8 wk of significant bone healinghealing)

Type 3 Early placement-with A postextraction site withpartial bone healing healed soft tissues and with(typically 12 to 16 wk significant bone healingof healing)

Type 4 Late placement (more A fully healed socketthan 6 mo of healing)

186_4a_Chen.qxd 9/10/09 10:16 AM Page 187

avoid ambiguity with respect to the timing of implantplacement after extraction, the descriptive terms andclassification adopted in the Third ITI TreatmentGuide, Vol 3, were used simultaneously in this review.2

The term postextraction sites was used to describecollectively fresh and healing extraction sites thatpermit implants to be placed immediately (type 1),early after soft tissue healing (type 2), and early afterpartial bone healing (type 3).

RESULTS

A total of 1,107 abstracts and 170 full-text articleswere evaluated. Of these, 91 studies met the inclusioncriteria for this review. Data were extracted from thestudies and tabulated.

Regenerative Outcomes of PostextractionImplantsThere were 28 studies reporting on healing of peri-implant defects in postextraction sites ( Table 2).Eleven comparative studies were identified, of which7 were RCTs.14–20 Four were prospective and retro-spective studies.21–24 The remaining 17 studies wereprospective and retrospective case series, the major-ity of which investigated immediate placement (type1).25–38 Three studies reported on treatment out-comes with early placement (type 2).39–41

How Effective Are Bone Augmentation Proce-dures? The majority of studies used combinations ofbone grafts and/or barrier membranes to promotebone regeneration in peri-implant defects. The mostcommonly used augmentation material was depro-teinized bovine bone mineral (DBBM), eitheralone31,33 or in conjunction with expanded polytetra-fluoroethylene (e-PTFE) membranes15 or collagenmembranes.21,22,24,30,32,40,41 Other augmentationmaterials included autogenous bone alone,17,26

e-PTFE barrier membrane alone,27,29 freeze-drieddemineralized laminar cortical bone membrane,34

composite graft of polymethyl methacrylate and cal-cium hydroxide,36 and hydroxyapatite alone.16

Despite the heterogeneity of the evaluated bone-augmentation techniques and variations in methodsfor quantifying defect fill, all studies reported signifi-cant fill of the peri-implant defects, resulting in clini-cally acceptable resolution of the defects.

Five RCTs have provided data to compare differentaugmentation techniques (Table 3).14–16,19,20 In a studycomparing defect height changes with immediateplacement (type 1), defect reduction was significantlygreater when an e-PTFE membrane was combinedwith demineralized freeze-dried bone allograft(DFDBA) than for an e-PTFE membrane alone after 6

months of submerged healing (5.68 ± 1.4 mm vs 3.18± 2.8 mm; P < .04).14 In a study of 83 patients compar-ing a hydroxyapatite graft and a resorbable polymermembrane with immediate placement (type 1) andsubmerged healing, no significant differences wereobserved in defect height resolution. Residual defectheight for both groups was between 0.70 and 0.80mm (P = .772).16 In a study comparing four differentaugmentation techniques (e-PTFE membrane alone,e-PTFE membrane and autogenous bone, resorbablepolymer membrane and autogenous bone, and auto-genous bone alone) with a nonaugmented controlgroup, no significant differences were observed withrespect to reduction in defect height and orofacialdefect depth after 6 months of healing with immedi-ate placement (type 1).19 However, sites treated withthe addition of a membrane (e-PTFE or resorbablepolymer) showed greater reduction in the mesiodistalwidth of the peri-implant defect. A study of immedi-ate placement (type 1) with transmucosal healingreported no significant differences in defect heightand depth reduction when comparing two augmen-tation methods (DBBM and collagen membrane, andDBBM alone) to a nonaugmented control group.20

The results of these controlled clinical studies aresupported by retrospective and prospective casesseries studies with immediate (type 1) and early (type2) implant placement. Without exception, these stud-ies showed statistically and clinically significant reso-lution of the peri-implant defects. There is strongevidence to suggest that bone augmentation proce-dures are effective in promoting bone fill and defectresolution in peri-implant defects with both surgicalapproaches—immediate (type 1) and early (type 2)placement.

Are Bone Augmentation Procedures Necessary?Recently, several studies reported on healing out-comes without the use of barrier membranes andbone grafts within the peri-implant defects in postex-traction sites.19,20,23,35,37–39 In two separate studies,Chen et al reported that various combinations of bar-rier membranes and/or bone grafts and substitutesachieved similar defect resolution when compared tononaugmented control sites that were allowed toheal with a blood clot alone.19,20 Defect height reduc-tions between 68% and 83% were reported. Nir-Hadar et al reported that after 3 to 6 months ofsubmerged healing, the residual vertical defect wasless than 0.5 mm with early placement (type 2), irre-spective of whether an initial orofacial defect waspresent or not.39 Complete defect resolution wasobserved with immediate placement in a prospectivestudy in 10 patients.35 In this study, the peri-implantdefects were less than 2 mm in the orofacial dimen-sion. The same authors compared the outcomes of

188 Volume 24, Supplement, 2009

Chen/Buser

186_4a_Chen.qxd 9/10/09 10:16 AM Page 188

The International Journal of Oral & Maxillofacial Implants 189

Group 4

Tabl

e 2

C

linic

al S

tudi

es R

epor

ting

on

Hea

ling

of P

eri-i

mpl

ant

Def

ects

Ass

ocia

ted

wit

h Im

plan

ts in

Pos

text

ract

ion

Sit

es

No.

of

Pla

cem

ent

pati

ents

tim

eS

tudy

Impl

ant

(No.

of

afte

r A

ugm

enta

tion

H

ealin

gD

efec

t

Stu

dyde

sign

surf

ace

impl

ants

)ex

trac

tion

met

hod

prot

ocol

chan

ges

Gel

b (1

99

3)2

5

Bec

ker

et a

l (1

99

4)2

6

Lang

et a

l (1

99

4)2

7

Bec

ker

et a

l (1

99

4)2

8

Nir-

Had

ar e

t al

(19

98

)39

Häm

mer

le e

t al

(19

98

)29

Nem

covs

ky e

t al

(19

99

)30

Nem

covs

ky e

t al

(20

00

)31

Nem

covs

ky e

t al

(20

00

)40

Nem

covs

ky e

t al

(20

00

)32

Van

Ste

enbe

rghe

et a

l (2

00

0)3

3

Pros

p C

S

Pros

p C

S

Pros

p C

S

Mul

ticen

ter

Pros

p C

oS

Pros

p C

S

Pros

p C

S

Pros

p C

S

Pros

p C

S

Pros

p C

S

Pros

p C

S

Pros

p C

S

Turn

ed

Turn

ed

TPS

Turn

ed

Turn

ed

TPS

TPS

and

HA

SB

E an

d TP

S

SB

E an

d TP

S

Vario

us (m

icro

-te

xtur

ed, T

PSan

d H

A)Tu

rned

35

(50

)

30

(54

)

16 (2

1)

40

(49

)

14 (2

1)

10 (1

1)

29

(33

)

24

(26

)

21 (2

8)

61 (6

1)

15

(21

)

Type

1

Type

1

Type

1

Type

1

Type

2(6

to 8

wee

ks)

Type

1

Type

1

Type

1

Type

2(5

to 7

wee

ks)

Type

1

Type

1

e-PT

FE m

embr

ane,

DFD

BA

graf

t or

e-PT

FE m

embr

ane

+ D

FDB

A gr

aft

Auto

geno

us b

one

chip

s

e-PT

FE m

embr

ane

only

e-PT

FE m

embr

ane

only

No

augm

enta

tion

e-PT

FE m

embr

ane

only

DB

BM

onl

y in

sm

all (

size

of d

efec

tsno

t spe

cifie

d) d

efec

ts

DB

BM

and

reso

rbab

le c

olla

gen

mem

-br

ane

in d

ehis

cenc

e de

fect

s >

4 m

mD

BB

M o

nly;

inta

ct b

one

wal

ls

DB

BM

and

reso

rbab

le c

olla

gen

mem

-br

ane;

deh

isce

nce

defe

cts

wer

e al

l >

4 m

m o

r ha

d >

25

% o

f the

impl

ant

surf

ace

expo

sed

DB

BM

and

reso

rbab

le c

olla

gen

mem

-br

ane

(mem

bran

e no

t use

d w

hen

all

bone

wal

ls w

ere

inta

ct)

DB

BM

with

no

mem

bran

e

Sub

mer

ged

Sub

mer

ged

Tran

smuc

osal

Sub

mer

ged

Sub

mer

ged

Tran

smuc

osal

Sub

mer

ged

Sub

mer

ged

Sub

mer

ged

Sub

mer

ged

Sub

mer

ged

100

% th

read

cov

erag

e fo

r al

l tec

hniq

ues

exce

pt in

one

cas

e of

a n

o-w

all d

efec

t tre

ated

with

DFD

BA

graf

t onl

y, 7

6%

cov

erag

eM

ean

initi

al d

efec

t hei

ght 5

.5 ±

3.0

mm

redu

ced

to 0

.5 ±

1.0

mm

at

reen

try*

Mea

n in

itial

oro

faci

al d

efec

t wid

th 3

.7 ±

2.1

mm

redu

ced

to 0

.2 ±

0.8

mm

*2

0/2

1 s

ites

with

com

plet

e bo

ne re

gene

ratio

n

At s

ites

with

no

early

mem

bran

e re

mov

al (N

= 2

9):

mea

n in

itial

defe

ct h

eigh

t of 4

.9 ±

2.5

mm

redu

ced

to 0

.1 ±

0.4

mm

at r

eent

ry†

At s

ites

with

ear

ly m

embr

ane

rem

oval

(N =

20

): m

ean

initi

al d

efec

the

ight

of 6

.4 ±

4.3

mm

redu

ced

to 2

.4 ±

3.3

mm

†

Mea

n in

itial

ver

tical

def

ect 2

.5 ±

0.3

7 m

m re

duce

d to

0.3

6 ±

0.6

4m

m w

hen

a ho

rizon

tal (

orof

acia

l) de

fect

was

pre

sent

*M

ean

initi

al v

ertic

al d

efec

t 3.8

6 ±

0.5

8 m

m re

duce

d to

0.4

8 ±

0.2

5m

m w

hen

a ho

rizon

tal (

orof

acia

l) de

fect

was

abs

ent*

Mea

n in

itial

hor

izon

tal (

orof

acia

l) de

fect

1.6

± 1

.73

mm

redu

ced

to0

.02

± 0

.02

mm

*M

ean

initi

al v

ertic

al d

efec

t 4.7

± 1

.3 m

m re

duce

d to

2.1

± 0

.8 m

mat

reen

try†

94

% d

efec

t vol

ume

fill†

No

mem

bran

e si

tes:

Mea

n in

itial

def

ect h

eigh

t 1.9

± 1

.16

mm

redu

ced

to 0

.3 ±

0.4

6 m

m a

t ree

ntry

†

Mem

bran

e si

tes:

Mea

n in

itial

def

ect h

eigh

t 4.6

± 1

.18

mm

redu

ced

to 0

.7 ±

0.7

mm

at r

eent

ry†

Mea

n in

itial

def

ect h

eigh

t 2.6

± 1

.72

mm

redu

ced

to 0

.6 ±

0.7

0 m

m†

For

sing

le im

plan

ts: M

ean

initi

al d

efec

t hei

ght 6

.7 ±

2.2

3 m

mre

duce

d to

0.6

± 0

.69

mm

at r

eent

ry

Mea

n in

itial

def

ect a

rea

23

.7 ±

11

.49

mm

2re

duce

d to

0.7

± 0

.99

mm

2at

reen

try

For

adja

cent

impl

ants

: Mea

n in

itial

def

ect h

eigh

t 6.4

± 1

.03

mm

redu

ced

to 0

.8 ±

0.2

7 m

m a

t ree

ntry

Mea

n in

itial

def

ect a

rea

20

.67

± 4

.4 m

m2

redu

ced

to 0

.6 ±

0.4

0m

m2

at re

entr

yVe

rtic

al g

ain

in b

one

betw

een

1.5

and

3.6

mm

Mea

n in

itial

def

ect h

eigh

t 3.8

± 0

.6 m

m re

duce

d to

1.1

± 0

.3 m

m a

tre

entr

y

186_4a_Chen.qxd 9/10/09 10:16 AM Page 189

190 Volume 24, Supplement, 2009

Chen/Buser

Tabl

e 2

con

tinu

ed

Clin

ical

Stu

dies

Rep

orti

ng o

n H

ealin

g of

Per

i-im

plan

t D

efec

ts A

ssoc

iate

d w

ith

Impl

ants

in P

oste

xtra

ctio

n S

ites

No.

of

Pla

cem

ent

pati

ents

tim

eS

tudy

Impl

ant

(No.

of

afte

r A

ugm

enta

tion

H

ealin

gD

efec

t

Stu

dyde

sign

surf

ace

impl

ants

)ex

trac

tion

met

hod

prot

ocol

chan

ges

Ros

enqu

ist a

ndAh

med

(20

00

)34

Häm

mer

le a

nd

Lang

(20

01)41

Cov

ani e

t al

(20

03

)35

Yukn

a et

al

(20

03

)36

Bot

ticel

li et

al

(20

04

)37

Cov

ani e

t al

(20

07

)38

Stu

dy d

esig

n: P

rosp

= p

rosp

ectiv

e; C

oS =

coh

ort

stud

y; C

S =

cas

e se

ries.

Impl

ant

surf

ace:

tur

ned

= e

quiv

alen

t to

mac

hine

d su

rfac

e; T

PS

= t

itani

um p

lasm

a-sp

raye

d; H

A =

hyd

roxy

apat

ite-c

oate

d; S

LA =

sur

face

san

dbla

sted

with

larg

e-gr

it an

d ac

id-e

tche

d;S

BE

= s

andb

last

ed a

nd a

cid-

etch

ed.

Pla

cem

ent

time

afte

r ex

trac

tion:

Typ

e 1

= im

med

iate

pla

cem

ent

at t

he t

ime

of e

xtra

ctio

n; T

ype

2 =

ear

ly p

lace

men

t af

ter

initi

al s

oft

tissu

e he

alin

g; T

ype

3 =

ear

ly p

lace

men

t af

ter

subs

tant

ial b

one

heal

ing;

Type

4 =

late

pla

cem

ent

afte

r co

mpl

ete

heal

ing

of t

he r

idge

.A

ugm

enta

tion

met

hod:

e-P

TFE

= e

xpan

ded

poly

tetr

aflu

oroe

thyl

ene

mem

bran

e; D

BB

M =

dem

iner

aliz

ed b

ovin

e bo

ne m

iner

al; D

FDB

A =

dem

iner

aliz

ed f

reez

e-dr

ied

bone

allo

graf

t.*S

igni

fican

t w

ithin

-gro

up c

hang

e fr

om b

asel

ine

(P<

.05)

.† S

igni

fican

t w

ithin

-gro

up c

hang

e fr

om b

asel

ine

(P<

.01)

.

Pros

p C

S

Pros

p C

S

Pros

p C

S

Pros

p C

S

Pros

p C

S

Pros

p C

S

Turn

ed

TPS

SB

E an

d TP

S

HA

SLA

TPS

25

(34

)

10 (1

0)

10 (1

5)

23

(30

)

18

(21

)

20

(20

)

Type

1

Type

2(8

to 1

4w

eeks

)

Type

1

Type

1

Type

1

Type

1

Free

ze-d

ried

dem

iner

aliz

ed h

uman

lam

inar

cor

tical

bon

e us

ed a

s a

bar-

rier

mem

bran

eD

BB

M a

nd re

sorb

able

col

lage

n m

em-

bran

e

No

augm

enta

tion;

mar

gina

l def

ects

betw

een

sock

et w

all a

nd im

plan

tw

ere

no m

ore

than

2 m

mC

ompo

site

of p

olym

ethy

l met

hacr

y-la

te a

nd c

alci

um h

ydro

xide

No

augm

enta

tion

No

augm

enta

tion

Mem

bran

e le

ftex

pose

d

Tran

smuc

osal

Sub

mer

ged

Sub

mer

ged

Sem

isub

mer

ged

Sub

mer

ged

Mea

n in

itial

def

ect h

eigh

t of 8

.5 m

m re

duce

d to

0.3

mm

at r

eent

ry

Mea

n in

itial

ver

tical

def

ect h

eigh

t red

uced

from

7.8

± 1

.9 m

m to

2.5

± 0

.6 m

m†

Def

ect a

rea

redu

ctio

n of

86

± 3

3%

; 8/1

0 s

ites

had

100

% d

efec

tar

ea re

duct

ion

No

resi

dual

bon

e de

fect

s ob

serv

ed; d

ista

nce

betw

een

faci

al a

nd li

n-gu

al b

one

wal

ls re

duce

d fr

om 1

0.5

± 1

.5 m

m to

6.8

± 1

.3 m

m (3

5%

chan

ge)

Oro

faci

al in

tern

al s

ocke

t dim

ensi

on re

duce

d fr

om 6

.9 to

0 m

mEx

tern

al r

idge

wid

th d

ecre

ased

from

9.1

± 2

.4 m

m to

8.4

± 1

.9 m

m(P

= .0

8)

Def

ect h

eigh

t red

uctio

n: m

esia

l 1.6

± 3

.8 m

m; f

acia

l 5.5

± 2

.3 m

m;

dist

al 0

.4 ±

2.3

mm

; lin

gual

3.5

± 2

.7 m

mD

efec

t wid

th re

duct

ion:

mes

ial 0

.3 ±

0.8

mm

; fac

ial 1

.5 ±

0.7

mm

;di

stal

0.1

± 0

.8 m

m; l

ingu

al 1

.1 ±

0.8

mm

Mea

n re

duct

ion

in c

rest

al b

one

heig

ht w

as 0

.8 m

m (0

mm

in 3

8%

of

site

s, >

0 to

1 m

m in

47

% o

f site

s, >

1 to

2 m

m in

15

% o

f site

s)

186_4a_Chen.qxd 9/10/09 10:16 AM Page 190

The International Journal of Oral & Maxillofacial Implants 191

Group 4

Tabl

e 3

C

ontr

olle

d C

linic

al S

tudi

es C

ompa

ring

Dif

fere

nt A

ugm

enta

tion

Met

hods

Use

d w

ith

Impl

ants

Pla

ced

into

Pos

text

rati

on S

ites

Pla

cem

ent

Expe

rim

enta

lpr

otoc

ol/

Stu

dy a

im/

grou

ps a

ndR

eent

ry p

erio

dIm

plan

the

alin

g pr

otoc

ol/

outc

ome

augm

enta

tion

N

o. o

fN

o. o

f fo

llow

ing

Stu

dysu

rfac

ecl

inic

al in

dica

tion

sva

riab

les

met

hods

pati

ents

impl

ants

plac

emen

tR

esul

ts

Ghe

r et

al

(19

94

)14

Zitz

man

n et

al (

19

97

)15

Pros

per

et a

l (2

00

3)16

TPS

and

HA

Turn

ed

San

d-bl

aste

d

Type

1/S

ubm

erge

d/M

axill

ary

ante

rior

and

prem

olar

site

s;m

andi

bula

r can

ine,

prem

olar

and

mol

arsi

tes

Type

1, 2

, 3, 4

/Sub

-m

erge

d/M

axill

ary

and

man

dibu

lar

site

s-al

l loc

atio

ns

Type

1/

Sub

mer

ged/

Max

illar

y an

dm

andi

bula

r m

olar

site

s

RC

T/To

com

pare

two

bone

aug

men

-ta

tion

met

hods

at

two

impl

ant s

ur-

face

s/C

hang

e in

defe

ct h

eigh

t and

cres

tal b

one

leve

ls

RC

T/To

com

pare

bone

aug

men

tatio

nus

ing

a re

sorb

able

colla

gen

mem

bran

ew

ith a

non

re-

sorb

able

e-P

TFE

mem

bran

e in

asp

lit-m

outh

ran

dom

-iz

ed s

tudy

/Cha

nge

in d

efec

t are

a

RC

T/To

com

pare

two

bone

aug

men

ta-

tion

met

hods

in c

on-

junc

tion

with

aw

ide-

diam

eter

impl

ant (

5.9

mm

)/Pr

imar

y ou

tcom

eva

riabl

e-ch

ange

inde

fect

hei

ght

Gro

up 1

: TPS

sur

face

and

e-PT

FE m

embr

ane

only

Gro

up 2

: TPS

sur

face

and

e-PT

FE p

lus

DFD

BA

Gro

up 3

: HA

surf

ace

and

e-PT

FE m

embr

ane

only

Gro

up 4

: HA

surf

ace

and

e-PT

FE p

lus

DFD

BA

Each

pat

ient

requ

ired

atle

ast t

wo

imm

edia

teim

plan

ts; o

ne s

ite ra

n-do

mly

rece

ived

are

sorb

able

col

lage

nm

embr

ane

and

the

othe

r site

a n

onre

-so

rbab

le e

-PTF

E m

em-

bran

e (p

rovi

ded

ther

ew

as 1

4 m

m o

f spa

cebe

twee

n th

e tw

o si

tes;

ifle

ss th

an 1

4 m

m th

esa

me

mem

bran

e w

asus

ed fo

r bot

h si

tes)

.D

BB

M w

as g

raft

ed a

tbo

th s

ites

Gro

up 1

: HA

graf

t onl

yG

roup

2: R

esor

babl

epo

lym

er m

embr

ane

only

Gro

up 1

= 1

0G

roup

2 =

10

Gro

up 3

= 1

0G

roup

4 =

10

25

83

pat

ient

sto

tal

No.

of p

atie

nts

in e

ach

grou

pno

t sta

ted;

all

patie

nts

belo

nged

toth

e sa

me

trea

t-m

ent g

roup

/S

ome

patie

nts

rece

ived

mor

eth

an 1

impl

ant

Gro

up 1

= 1

1G

roup

2 =

12

Gro

up 3

= 1

0G

roup

4 =

10

84

Type

1 =

27

Type

2, 3

, 4(b

etw

een

6 w

kan

d 6

mo

afte

rto

oth

extr

ac-

tion)

= 1

7H

eale

d si

te(m

ore

than

6m

o af

ter e

x-tr

actio

n) =

40

Gro

up 1

= 5

6G

roup

2 =

55

6 m

o

4 m

o in

the

man

dibl

ean

d 6

mo

in th

e m

axill

a

4 y

from

plac

emen

t;al

l pat

ient

sco

mpl

eted

the

4-y

fol-

low

-up

No

diff

eren

ces

betw

een

impl

ant s

urfa

ces

Mea

n de

fect

hei

ght r

educ

tion:

Non

-DFD

BA

graf

ted

=3

.18

± 2

.83

mm

; DFD

BA

graf

ted

= 5

.68

± 3

.45

mm

(P

< .0

4)

Mea

n cr

esta

l bon

e lo

ss fr

om m

ost c

oron

al b

one

cres

t:N

on-D

FDB

A gr

afte

d =

1.5

9 ±

1.6

6 m

m; D

FDB

A gr

afte

d=

1.5

3 ±

1.3

8 (N

S)

Mea

n cr

esta

l bon

e lo

ss fr

om m

ost a

pica

l par

t of c

rest

:N

on-D

FDB

A gr

afte

d =

0.1

1 ±

2.7

6 m

m; D

FDB

A gr

afte

d=

–1.3

9 ±

2.7

6 (i

e, g

ain

in c

rest

al b

one

heig

ht)

(P<

.02

)M

ean

defe

ct a

rea

redu

ctio

n:

e-PT

FE m

embr

ane:

78

± 5

0.2

%C

olla

gen

mem

bran

e: 9

2 ±

19

.3%

(P<

.00

01)

Mea

n de

fect

are

a re

duct

ion

in th

e pr

esen

ce o

f aw

ound

deh

isce

nce:

Fo

r co

llage

n m

embr

ane

No

dehi

scen

ce (n

= 3

9):

94

± 1

9.0

%;

Deh

isce

nce

(n =

4):

87

± 1

8.9

% (N

S)

For

e-PT

FE m

embr

ane

No

dehi

scen

ce (n

= 2

3):

98

± 9

.8%

Deh

isce

nce

(n =

18

): 6

5 ±

68

.4%

(P=

.01

)

Res

idua

l ver

tical

def

ect h

eigh

t:G

roup

1: r

ange

0.7

0 to

0.8

0 m

m

Gro

up 2

: ran

ge 0

.73

to 0

.80

mm

(P

= .7

72

)

186_4a_Chen.qxd 9/10/09 10:16 AM Page 191

192 Volume 24, Supplement, 2009

Chen/Buser

Tabl

e 3

con

tinu

ed

Con

trol

led

Clin

ical

Stu

dies

Com

pari

ng D

iffe

rent

Aug

men

tati

on M

etho

ds U

sed

wit

h Im

plan

ts P

lace

d in

to P

oste

xtra

tion

Sit

es

Pla

cem

ent

Expe

rim

enta

lpr

otoc

ol/

Stu

dy a

im/

grou

ps a

ndR

eent

ry p

erio

dIm

plan

the

alin

g pr

otoc

ol/

outc

ome

augm

enta

tion

N

o. o

fN

o. o

f fo

llow

ing

Stu

dysu

rfac

ecl

inic

al in

dica

tion

sva

riab

les

met

hods

pati

ents

impl

ants

plac

emen

tR

esul

ts

Cor

nelin

i et a

l(2

00

4)1

8

Che

n et

al

(20

05

)19

Che

n et

al

(20

07

)20

Impl

ant s

urfa

ce: T

urne

d =

equi

vale

nt to

mac

hine

d su

rfac

e; T

PS =

tita

nium

pla

sma-

spra

yed;

HA

= hy

drox

yapa

tite-

coat

ed, S

LA =

sur

face

san

dbla

sted

with

larg

e-gr

it an

d ac

id-e

tche

d.Pl

acem

ent p

roto

col (

plac

emen

t tim

e af

ter

extr

actio

n): T

ype

1 =

imm

edia

te p

lace

men

t at t

he ti

me

of e

xtra

ctio

n; T

ype

2 =

ear

ly p

lace

men

t aft

er in

itial

sof

t tis

sue

heal

ing;

Typ

e 3

= e

arly

pla

cem

ent

afte

r su

bsta

ntia

l bon

e he

alin

g; T

ype

4 =

late

pla

cem

ent a

fter

com

plet

e he

alin

g of

the

ridge

. Stu

dy d

esig

n: R

CT

= ra

ndom

ized

con

trol

led

tria

l; C

CS

= c

ontr

olle

d cl

inic

al s

tudy

; CoS

= c

ohor

t stu

dy;

CS

= c

ase

serie

s. A

ugm

enta

tion

met

hod:

e-P

TFE

= ex

pand

ed p

olyt

etra

fluor

oeth

ylen

e m

embr

ane;

DB

BM

= d

emin

eral

ized

bov

ine

bone

min

eral

; DFD

BA

= de

min

eral

ized

free

ze-d

ried

bone

allo

graf

t;TC

P =

beta

tric

alci

um p

hosp

hate

.*T

he a

utho

rs re

port

ed s

tand

ard

erro

r; s

tand

ard

devi

atio

n w

as d

eriv

ed fr

om d

ata

pres

ente

d in

the

pape

r.

SLA

Turn

ed

SLA

Type

1/T

rans

mu-

cosa

l/M

axill

ary

and

man

dibu

lar

cani

nes

and

prem

olar

s

Type

1/S

ub-

mer

ged/

Sin

gle-

toot

h im

plan

ts in

the

max

illar

y an

te-

rior

and

prem

olar

regi

ons

Type

1/T

rans

mu-

cosa

l/S

ingl

e-to

oth

impl

ants

in m

axil-

lary

ant

erio

r an

d pr

emol

ar s

ites

RC

T/To

com

pare

the

effe

ct o

f dem

-in

eral

ized

bov

ine

bone

as

an a

djun

ctto

reso

rbab

le c

olla

-ge

n fo

r bo

ne a

ug-

men

tatio

n at

imm

edia

te im

plan

ts

RC

T/To

com

pare

the

effe

ct o

f var

ious

bone

aug

men

tatio

npr

oced

ures

on

heal

-in

g of

the

peri-

impl

ant m

argi

nal

defe

ct/P

rimar

y ou

t-co

me

varia

bles

-de

fect

hei

ght,

wid

th,

and

dept

h ch

ange

san

d re

sorp

tion

ofth

e fa

cial

bon

e w

all

RC

T/To

com

pare

the

effe

ct o

f var

ious

bone

aug

men

tatio

npr

oced

ures

on

heal

-in

g of

the

peri-

impl

ant m

argi

nal

defe

ct/P

rimar

y ou

t-co

me

varia

bles

-ch

ange

in d

efec

the

ight

, wid

th, a

ndde

pth,

and

faci

alcr

esta

l bon

e

Test

gro

up: D

BB

M a

ndre

sorb

able

col

lage

nm

embr

ane

Con

trol

gro

up:

Res

orba

ble

colla

gen

mem

bran

e on

ly

Gro

up 1

: e-P

TFE

mem

-br

ane

only

Gro

up 2

: Res

orba

ble

poly

mer

mem

bran

eon

lyG

roup

3: R

esor

babl

epo

lym

er m

embr

ane

and

auto

geno

us b

one

Gro

up 4

: Aut

ogen

ous

bone

onl

yG

roup

5: N

o au

gmen

ta-

tion;

con

trol

Max

illar

y an

terio

r an

dpr

emol

ar s

ites

Gro

up 1

(n =

10

):D

BB

MG

roup

2 (n

= 1

0):

DB

BM

and

reso

rbab

leco

llage

n m

embr

ane

Gro

up 3

(n=1

0):

No

augm

enta

tion;

con

trol

Test

gro

up =

10

Con

trol

gro

up=

10

Gro

up 1

= 1

2G

roup

2 =

11

Gro

up 3

= 1

2G

roup

4 =

14

Gro

up 5

= 1

2To

tal =

62

Gro

up 1

= 1

0G

roup

2 =

10

Gro

up 3

= 1

0

Test

gro

up =

10 Con

trol

gro

up=

10

Gro

up 1

= 1

2G

roup

2 =

11

Gro

up 3

= 1

2G

roup

4 =

14

Gro

up 5

= 1

2To

tal =

62

Gro

up 1

= 1

0G

roup

2 =

10

Gro

up 3

= 1

0

6 m

o

2 y

aft

erlo

adin

g

6 m

o

Mea

n ra

diog

raph

ic c

rest

al b

one

loca

tion

from

impl

ant

shou

lder

, bas

elin

e to

6 m

o:Te

st g

roup

: 1.7

mm

vs

1.8

mm

Con

trol

gro

up: 2

.2 m

m v

s 2

.1 m

mM

ean

prox

imal

muc

osal

mar

gin

leve

ls c

oron

al to

the

shou

l-de

r at 6

mo:

Buc

cal

Test

gro

up: 2

.6 m

m

Con

trol

gro

up: 2

.3 m

m (P

< .0

1)

Ling

ual

Test

gro

up: 1

.3 m

mC

ontr

ol g

roup

: 1.1

mm

(P<

.01

)M

ean

bucc

al m

ucos

al m

argi

n le

vels

cor

onal

to th

e sh

ould

erat

6 m

o:Te

st g

roup

: 2.1

mm

Con

trol

gro

up: 0

.9 m

m (P

< .0

5)

Def

ect h

eigh

t red

uctio

n (%

):G

roup

1: 7

4.9

± 2

7.8

*; G

roup

2: 6

9.1

± 2

7.6

; Gro

up 3

: 83

.1±

23

.8; G

roup

4: 7

5.3

± 2

0.9

; Gro

up 5

: 73

.6 ±

24

.1 (N

S)D

efec

t dep

th (o

rofa

cial

) red

uctio

n (%

):G

roup

1: 7

3.6

± 3

0.3

; Gro

up 2

: 75

.8 ±

34

.3; G

roup

3: 8

9.7

± 19

.9; G

roup

4: 7

5.6

± 2

6.0

; Gro

up 5

: 69

.7 ±

44

.2 (

NS)

Def

ect w

idth

(mes

iodi

stal

) red

uctio

n (%

):G

roup

1: 6

7.3

± 2

3.6

; Gro

up 2

: 60

.6 ±

35

.9; G

roup

3: 7

1.2

± 2

9.2

; Gro

up 4

: 34

.1 ±

28

.3; G

roup

5: 7

3.6

± 2

4.1

(P<

.01

betw

een

grou

ps; G

roup

1 d

iffer

ent f

rom

Gro

ups

4 a

nd 5

,G

roup

2 d

iffer

ent f

rom

Gro

up 4

, Gro

up 3

diff

eren

t fro

mG

roup

s 4

and

5)

Mea

n ch

ange

in v

ertic

al d

efec

t hei

ght:

Gro

up 1

: 81.

2 ±

5.0

%; G

roup

2: 7

0.5

± 1

7.4

%; G

roup

3: 6

8.2

± 1

6.6

% (N

S)M

ean

chan

ge in

def

ect d

epth

(oro

faci

al):

Gro

up 1

: 71.

7 ±

34

.3%

; Gro

up 2

: 81.

7 ±

33

.7%

; Gro

up 3

: 55

.0 ±

28

.4%

(NS)

At s

ites

with

inta

ct b

one

wal

ls, m

ean

chan

ge in

faci

al c

res-

tal b

one

heig

ht: G

roup

1: 1

.1 ±

1.2

mm

; Gro

up 2

: 1.0

± 0

.6m

m; G

roup

3: 1

.3 ±

0.9

mm

(NS)

At s

ites

with

inta

ct b

one

wal

ls, m

ean

horiz

onta

l res

orpt

ion

of th

e fa

cial

bon

e: G

roup

1: 1

3.9

± 1

6.7

%; G

roup

2: 2

3.8

±2

3.4

%; G

roup

3: 4

8.3

± 9

.5%

(P=

.015

; Gro

up 3

sig

nifi-

cant

ly g

reat

er th

an G

roup

s 1

and

2)

186_4a_Chen.qxd 9/10/09 10:16 AM Page 192

type 1 and type 2 placement, and concluded thatboth approaches resulted in complete defect fill.23 Ahuman histologic study confirmed that spontaneousbone regeneration occurred in experimental peri-implant defects that were less than 2 mm in width,and that the newly regenerated bone became inte-grated with the previously exposed implant surface.42

Covani and coworkers observed that completedefect fill occurred in the peri-implant gaps followingtype 1 and type 2 implant placement.23,35 The initialperi-implant gaps were 2 mm or less, and all sites hadintact bone walls. These observations are corrobo-rated by human histologic studies that have shownspontaneous bone regeneration and osseointegra-tion when peri-implant defects were less than 2 mmin a horizontal dimension.42–44 In contrast, two stud-ies examining healing outcomes when the initial peri-implant gaps were more than 2 mm reported thatnot all sites healed with complete bone fill. Botticelliet al demonstrated that 25% of sites with initial orofa-cial gaps of 2 to 3 mm healed completely, comparedto 78% of sites with initial gaps of less than 2 mm.37

Schropp et al observed that only 52% of sites with aninitial orofacial defect depth of 4 to 5 mm healedspontaneously in the presence of intact bone walls.17

Summarizing these studies, there is evidence toshow that peri-implant defects with gaps of less than2 mm following type 1 and type 2 implant placementmay heal with spontaneous bone regeneration anddefect resolution. However, gaps of 2 mm or more inthe orofacial dimension show clearly reduced pre-dictability for spontaneous bone regeneration.

Do Implants Prevent Resorption of the Ridge inPostextraction Sites? Recent clinical and experimen-tal studies have demonstrated that healing in postex-traction sites is characterized by bone regenerationwithin the socket and external dimensional changesdue to bone resorption and bone modeling.45–47 Aseries of well-designed experimental studies in acanine model have demonstrated that implantsplaced into extraction sockets of mandibular premo-lar teeth did not prevent these resorptive and model-ing changes from taking place.48,49 The result is areduction in the orofacial dimension of the ridge anda loss of crestal bone height, predominantly at thefacial aspect of the ridge.

Several studies have provided clinical data on thedimensional changes that occur adjacent to implantsin postextraction sockets when no augmentation wasperformed.35,37,38 In a prospective study, the distancebetween the facial and lingual bone walls changedfrom 10.5 ± 1.5 mm to 6.8 ± 1.3 mm (35% reduction ininitial orofacial width) after 6 months of submergedhealing.35 In this study, implants were placed intoextraction sockets (type 1 implant placement) in max-

illary and mandibular anterior and premolar sites. Afurther prospective study reported on type 1 place-ment of 21 implants in 18 patients.37 Implant siteswere confined to maxillary and mandibular anteriorand premolar sites. After 4 months of submergedhealing, the implant sites were reentered andchanges in the dimensions of the ridges wererecorded. External bone resorption and modelingresulted in a reduction in the orofacial crest width of56% on the facial aspect and 30% on the lingualaspect. The height of the crestal bone was reduced by0.2 to 0.6 mm. In a similar prospective study, Covaniand coworkers reported a mean loss in facial crestalbone height of 0.8 mm after 6 months of submergedhealing following type 1 placement in 20 patients.38

Implant sites included maxillary and mandibular ante-rior and premolar sites. Although 38% of the sitesshowed no change, 47% had between 0 mm and 1mm of loss, and 15% had between 1 and 2 mm of loss.

These studies provide strong evidence that type 1placement per se does not prevent vertical or hori-zontal resorption of the ridges in postextraction sites.

Does Bone Augmentation Prevent Ridge Resorp-tion with Postextraction Implants? Three RCTs14,19,20

and one prospective clinical case series36 reported onthe effect of bone augmentation on external dimen-sional changes with postextraction implant placement.

In a study of 40 patients, vertical resorption of thefacial crestal bone was similar for sites treated with ane-PTFE membrane alone or an e-PTFE membrane andDFDBA (1.59 ± 1.7 mm vs 1.53 ± 1.4 mm) for type 1placement after 6 months of submerged healing.14

Similar changes in facial crestal bone height wereobserved in a study of 30 patients who received 30immediate implants and transmucosal healing.20

After a healing time of 6 months, vertical resorptionof the facial bone was 1.1 ± 1.2 mm for peri-implantdefects grafted with DBBM, 1.0 ± 0.6 mm for sitesaugmented with DBBM and collagen membrane, and1.3 ± 0.9 mm for nonaugmented control sites. Therewere no significant differences between groups. Theresults of these two studies are similar to results fromstudies of nongrafted postextraction implant siteswith respect to vertical crestal bone resorption.37,38

A study of various augmentation techniques withtype 1 placement showed that although defect fillwas similar, dehiscence defects showed significantlygreater horizontal resorption than sites with intactbone walls.19 In another study by the same authors,significantly less horizontal resorption of the facialbone occurred when the peri-implant defects weregrafted with DBBM (13.9% to 23.8%) compared to thenonaugmented control group (48.3%).20 Similarly,Yukna and Castellon reported that following type 1placement and grafting of the peri-implant defects

The International Journal of Oral & Maxillofacial Implants 193

Group 4

186_4a_Chen.qxd 9/10/09 10:16 AM Page 193

with a composite of polymethyl methacrylate andcalcium hydroxide, the external dimensions of thesockets changed only slightly, from 9.1 ± 2.4 mm to8.4 ± 1.9 mm (an 8% reduction in orofacial ridgewidth) after 6 months.36 Both these studies usedbone fillers with a low substitution rate.

These studies provide strong evidence that boneaugmentation following type 1 placement reduceshorizontal resorption of the facial bone. However,these augmentation procedures appear not to influ-ence vertical resorption of the facial bone.

Does Damage to or Loss of the Facial Bone AffectRegenerative Outcomes? In postextraction sites, lossof one or more of the socket walls is a common obser-vation. In a retrospective study of 75 patients, only 10out of 31 extraction sites (32%) had intact bonewalls.21 The majority of extraction sites presentedwith damage to the socket walls, with two-wall (52%of sites) or no-wall/one-wall (16% of sites) defects.Theauthors also reported that the proportion of two- andthree-wall defects diminished as the time after toothextraction increased. In an RCT, 60 out of 92 type 3and type 4 implant placement sites had peri-implantdefects. Of these, 48 were three-wall defects and 12were dehiscence or two-wall defects.17

Several studies were identified that reported ontreatment outcomes in postextraction sites in the pres-ence of dehiscences of the socket walls.17,19,20,25,30,40 Intwo RCTs of type 1 placement using various augmen-tation techniques, sites with dehiscence defectsachieved similar defect fill compared to intact sites.19,20

However, greater horizontal resorption of the facialbone occurred in the presence of a dehiscence, despitebone augmentation.19 In a prospective study of type 1placement in 35 patients, 100% implant thread cover-age was achieved in all sites except one site with a no-wall defect morphology, which achieved only 76%coverage.25 In this study, DFDBA was used alone or incombination with an e-PTFE membrane. A study oftype 1 implant placement in 29 patients receiving 33implants showed significant gain in crestal boneheight at dehiscence sites using DBBM and collagenmembrane.30 The resultant ridge height was similar tothat observed in sites that initially had intact bonewalls. In a study of type 2 implant placement in whichall 28 implant sites in 21 patients presented with dehis-cence defects, a defect area reduction of 97% wasreported using DBBM and collagen membrane.40 Again in crestal bone height of 6 to 7 mm was recorded.

In contrast to these studies, Schropp et al reportedthat a trend toward greater bone fill was observed atsites with intact bone walls compared to sites withdehiscence defects.17

These studies provide strong evidence that boneaugmentation following type 1 and type 2 placement

is effective in reconstructing the damaged facialbone. However, with type 1 placement, greaterresorption of the facial bone was shown to occur inone RCT. This may have significant implications foresthetic outcomes. A recent study reported a highincidence of recession of the facial mucosa in thepresence of defects of the facial bone with type 1placement, despite bone augmentation using DBBMand collagen membranes.50

Does Timing of Implant Placement Affect theRegenerative Outcome? There were six studies thatprovided comparative data on the effect of timing ofimplant placement on regenerative outcomes (Table4).15,17,21–24

Three studies compared immediate (type 1), early(type 2 or 3), and late (type 4) implant placement. In asplit-mouth randomized study of dehiscence defectsaugmented with DBBM, Zitzmann et al reported lessdefect area reduction with healed sites (80% fore-PTFE membrane and 90% for collagen membrane)compared to immediate and healing sites (85% to94% for e-PTFE membrane and 95% to 97% for colla-gen membrane) in 25 patients.15 Similarly, in a retro-spective study of 75 patients by the same authors,defect area reduction was significantly better withtype 1 and types 2 and 3 implant placement (92% ±20.8% and 92% ± 20.7%, respectively) compared totype 4 (80% ± 34.1%).21 The authors suggested thatthe difference was attributable to the greater propor-tion of one-wall/no-wall defects found with type 4placement compared to immediate and early place-ments, which had a greater proportion of two-walland three-wall defects. In another retrospective study,the use of DBBM and collagen membrane resulted inless defect area reduction with type 4 placement(87.6% ± 11.5%) compared to type 1 (90.2% ± 9.1%)and type 2 (95.6% ± 8.7%) placement.24 Type 2 place-ment achieved the best regenerative outcome in thisstudy.

Two studies compared types 1 and 2 implant place-ment. In a prospective study using DBBM and collagenmembrane to manage dehiscence defects, signifi-cantly greater defect area reduction was observedwith type 2 placement (91.2% ± 9.1%) compared toimmediate placement (type 1; 77.4% ± 17.0%) in maxil-lary molar sites.22 Covani et al reported that both type1 and type 2 placement in sites with intact bone wallsachieved complete defect fill in the absence of simul-taneous bone augmentation procedures.23

One RCT compared early placement in 46 patientswho received single-tooth implants in maxillary andmandibular anterior and premolar sites.17 Implantswere placed a mean of 10 days after extraction (range3 to 35 days) in the test sites (23 implants in 23patients). In control sites (23 implants in 23 patients),

194 Volume 24, Supplement, 2009

Chen/Buser

186_4a_Chen.qxd 9/10/09 10:16 AM Page 194

The International Journal of Oral & Maxillofacial Implants 195

Group 4

Tabl

e 4

Clin

ical

Stu

dies

Com

pari

ng D

iffe

rent

Tim

es A

fter

Ext

ract

ion

and

Thei

r Ef

fect

on

Hea

ling

of P

eri-I

mpl

ant

Def

ects

No.

of p

atie

nts

(No.

of i

mpl

ants

) by

plac

emen

tR

esul

ts fo

r pl

acem

ent

tim

e af

ter

toot

h ex

trac

tion

tim

es a

fter

too

th e

xtra

ctio

nmet

hod

Stu

dy

Impl

ant

Type

s 2

(h

ealin

g O

bser

vati

on

Type

s 2

S

tudy

desi

gnsu

rfac

eTy

pe 1

and

3Ty

pe 4

prot

ocol

)pe

riod

Type

1an

d 3

Type

4

Zitz

man

n et

al

(19

97

)15

Zitz

man

n et

al

(19

99

)21

Nem

covs

ky

and

Artz

i (2

00

2)2

2

Cov

ani e

t al

(20

04

)23

Nem

covs

ky

et a

l (2

00

2)2

4

RC

T

Ret

ro C

S

Ret

ro C

S

Pros

p C

S

Ret

ro C

S

Turn

ed

Turn

ed

Mic

roro

ugh,

HA

and

TPS

NR

HA

and

TPS

25

* (2

7)

75

* (3

1)

19

(23

)

33

(20

)

19

/23

25

* (1

7)

75

* (2

3) (

plac

e-m

ent t

ime

afte

rex

trac

tion

from

6w

k to

6 m

o)

24

(31

)(4

to 6

wk)

33

(20

) (6

to 8

wk)

25

/39

(4 to

6 w

k)

25*

(40)

75*

(48)

(pla

cem

ent

time

afte

rex

trac

tion

> 6

mo)

– –

22

/40

DB

BM

and

eith

er n

on-

reso

rbab

lee-

PTFE

or

reso

rbab

leco

llage

n m

em-

bran

e (ra

ndom

lyal

loca

ted)

DB

BM

and

reso

rbab

le c

olla

-ge

n m

embr

ane

(sub

mer

ged)

DB

BM

and

reso

rbab

le c

olla

-ge

n m

embr

ane

(sub

mer

ged)

No

augm

enta

-tio

n(s

ubm

erge

d)

DB

BM

and

reso

rbab

le c

olla

-ge

n m

embr

ane

(sub

mer

ged)

4 to

6 m

o

4 to

6 m

o

6 to

8 m

o

4 m

o m

an-

dibl

e, 6

mo

max

illa

6 to

8 m

o

Def

ect a

rea

redu

ctio

n85

% fo

r e-P

TFE;

95%

for c

olla

gen

mem

-br

ane

Def

ect a

rea

redu

ctio

n92

% ±

20.

8%

Def

ect m

orph

olog

y:no

-wal

l/1-

wal

l def

ect:

16%

2-w

all d

efec

t: 52

%

3-w

all d

efec

t: 3

2%

Def

ect h

eigh

t red

uc-

tion

77.4

% ±

17.

0%§

Def

ect a

rea

redu

ctio

n90

.2%

± 9

.1%

§

(All

site

s pr

esen

ted

ini-

tially

with

deh

isce

nce

defe

cts)

Faci

al to

ling

ual r

idge

wid

th c

hang

e fr

om10

.0 ±

1.5

mm

to8.

1 ±

1.3

mm

†

Com

plet

e de

fect

fill

Def

ect h

eigh

t red

uc-

tion

77.4

% ±

16.

9%§

Def

ect a

rea

redu

ctio

n90

.2%

± 9

.1%

§

Def

ect a

rea

redu

ctio

n 94

% fo

re-

PTFE

; 97%

for c

olla

gen

mem

bran

e

Def

ect a

rea

redu

ctio

n9

2%

± 2

0.7

%

Def

ect m

orph

olog

y:no

-wal

l/1

-wal

l def

ect:

39

%2

-wal

l def

ect:

55

%3

-wal

l def

ect:

6%

Def

ect h

eigh

t red

uctio

n91

.2 %

± 9

.1%

§

Def

ect a

rea

redu

ctio

n 9

7.2

% ±

3.9

%§

(All

site

s pr

esen

ted

initi

ally

with

dehi

scen

ce d

efec

ts)

Faci

al to

ling

ual r

idge

wid

thch

ange

from

8.9

± 2

.4 m

m to

5.8

± 1

.3 m

m†

Com

plet

e de

fect

fill

Def

ect h

eigh

t red

uctio

n88

.8%

± 1

5.3%

§

Def

ect a

rea

redu

ctio

n95

.6%

± 8

.7%

§

Sign

ifica

ntly

gre

ater

def

ect a

rea

and

heig

ht re

duct

ion

reco

rded

for

early

pla

cem

ent (

type

2) c

om-

pare

d to

the

othe

r 2 tr

eatm

ent

grou

ps

Def

ect a

rea

redu

c-tio

n 80

% fo

r e-P

TFE;

90%

for c

olla

gen

mem

bran

e

Def

ect a

rea

redu

c-tio

n 8

0%

± 3

4.1

%

Def

ect m

orph

olog

y:no

-wal

l/1

-wal

lde

fect

: 92

%Tr

end

tow

ard

less

succ

essf

ul o

utco

me

of ty

pe 4

com

pare

dto

type

s 2

/3 a

ndty

pe 1

pla

cem

ents

com

bine

d (P

= .0

5)

– –

Def

ect h

eigh

t red

uc-

tion

75

.2%

± 1

8.0

%§

Def

ect a

rea

redu

c-tio

n 8

7.6

% ±

11.

5%

§

Aug

men

tati

onm

etho

d

186_4a_Chen.qxd 9/10/09 10:16 AM Page 195

196 Volume 24, Supplement, 2009

Chen/Buser

Tabl

e 4

con

tinu

ed C

linic

al S

tudi

es C

ompa

ring

Dif

fere

nt T

imes

Aft

er E

xtra

ctio

n an

d Th

eir

Effe

ct o

n H

ealin

g of

Per

i-Im

plan

t D

efec

ts

No.

of p

atie

nts

(No.

of i

mpl

ants

) by

plac

emen

tA

ugm

enta

tion

R

esul

ts fo

r pl

acem

ent

tim

e af

ter

toot

h ex

trac

tion

met

hod

tim

es a

fter

too

th e

xtra

ctio

n

Stu

dy

Impl

ant

Type

s 2

(h

ealin

g O

bser

vati

on

Type

s 2

S

tudy

desi

gnsu

rfac

eTy

pe 1

and

3Ty

pe 4

prot

ocol

)pe

riod

Type

1an

d 3

Type

4

Sch

ropp

et a

l (2

00

3)17

Stu

dy d

esig

n: R

etro

= r

etro

spec

tive;

Pro

sp =

pro

spec

tive;

RC

T =

ran

dom

ized

con

trol

led

tria

l; C

S =

cas

e se

ries.

Impl

ant

surf

ace:

Tur

ned

= e

quiv

alen

t to

mac

hine

d su

rfac

e; T

PS

= t

itani

um p

lasm

a-sp

raye

d; H

A =

hyd

roxy

apat

ite-c

oate

d; S

LA =

sur

face

san

dbla

sted

with

larg

e gr

it an

d ac

id-e

tche

d.P

lace

men

t tim

e af

ter

extr

actio

n: T

ype

1 =

imm

edia

te p

lace

men

t at

the

tim

e of

ext

ract

ion;

Typ

e 2

= e

arly

pla

cem

ent

afte

r in

itial

sof

t tis

sue

heal

ing;

Typ

e 3

= e

arly

pla

cem

ent

afte

r su

bsta

ntia

l bon

e he

alin

g;Ty

pe 4

= la

te p

lace

men

t af

ter

com

plet

e he

alin

g of

the

rid

ge.

Aug

men

tatio

n m

etho

d: e

-PTF

E =

exp

ande

d po

lyte

traf

luor

oeth

ylen

e m

embr

ane;

DB

BM

= d

emin

eral

ized

bov

ine

bone

min

eral

; DFD

BA

= d

emin

eral

ized

free

ze-d

ried

bone

allo

graf

t; TC

P =

bet

a tr

ical

cium

pho

spha

te.

– =

Due

to

the

stud

y de

sign

, the

re w

ere

no d

ata

for

this

par

amet

er.

NR

= n

ot r

epor

ted.

* In

dica

tes

tota

l num

ber

of p

atie

nts

in t

he s

tudy

.†

Sig

nific

ant

with

in-g

roup

diff

eren

ces

(P<

.05)

.‡

Sig

nific

ant

with

in-g

roup

cha

nge

from

bas

elin

e (P

< .0

1).

§S

igni

fican

t be

twee

n-gr

oup

diff

eren

ce (P

< .0

5).

RC

TAc

id-e

tche

d–

Gro

up 1

: 23

(23

)ea

rly p

lace

men

t(m

ean

10 d

; ran

ge3

to 1

5 d

aft

erto

oth

extr

actio

n)

Gro

up 2

: 23

(23

)ea

rly p

lace

men

t(t

ype

3 -

mea

n14

.1 w

k; r

ange

65

to 1

38

d a

fter

toot

h ex

trac

tion)

–Au

toge

nous

bone

in d

ehis

-ce

nce

site

s(s

ubm

erge

d)

3 m

o–

Def

ect h

eigh

t red

uctio

n:G

roup

1: 4

8%

Gro

up 2

: 34

% (n

o si

gnifi

cant

dif-

fere

nces

bet

wee

n gr

oups

)D

efec

t wid

th (m

esio

dist

al) r

educ

-tio

n:G

roup

1: 4

8%

Gro

up 2

: 39

% (n

o si

gnifi

cant

dif-

fere

nces

bet

wee

n gr

oups

)D

efec

t dep

th (o

rofa

cial

) red

uctio

n(fo

r site

s w

ith in

tact

faci

al b

one,

ie, 3

-wal

l def

ects

onl

y):

Gro

up 1

: 59

%G

roup

2: 7

7%

(no

sign

ifica

nt d

if-fe

renc

es b

etw

een

grou

ps)

–

186_4a_Chen.qxd 9/10/09 10:16 AM Page 196

implants were placed a mean of 14.1 weeks followingextraction (range 9.3 to 19.7 weeks). Most sites didnot receive bone grafts or membranes; three controlsites received autogenous bone chips to cover dehis-cences of the facial bone. The authors reported nostatistically significant differences in defect height,width, and depth reduction between the two groups.

These studies provide strong evidence that aug-mentation procedures are more successful withimmediate (type 1) and early (types 2 and 3) implantplacement than with late placement (type 4). There issome evidence to show that regenerative outcomesare better with type 2 placement compared to type 1placement in the presence of dehiscence defects ofthe bone. However, with intact bone walls, type 1 andtype 2 placement achieve similar results with respectto fill of the peri-implant defect.

Does the Healing Protocol (Submerged VersusTransmucosal Healing) Affect Treatment Outcome?Most studies used a submerged healing protocol fol-lowing implant placement. In five studies that used atransmucosal healing protocol,18,20,27,29,41 the healingoutcomes appeared to be similar to reports fromstudies using a submerged approach. No studieswere identified that directly compared submergedwith transmucosal healing for postextractionimplants.

Evidence is lacking to demonstrate the superiorityof one healing protocol over the other with respectto healing of peri-implant defects with postextractionimplants.

What Are the Postoperative Complications withPostextraction Implants? The majority of studieswith postextraction implants reported the occur-rence of postoperative complications. Although notcommon, the most clinically significant complicationwith type 1 placement was postoperative infection orabscess formation leading to implant loss.19,51–56

The most common complication reported wasdehiscence of the wound and exposure of e-PTFEmembranes when submerged healing was used withimmediate implants.15,19,25,28,30,31,33–35,52,57–60 Threestudies reported on the rate of complications with e-PTFE membranes,58,59,61 which ranged from 4.3% to48% of sites. Studies with reentry defect data showedthat this complication was associated with impairedhealing and reduced bone fill in the peri-implantdefects.15,28 Premature membrane exposure andinfections in 15% to 20% of sites were reported instudies of type 1 placement using transmucosal heal-ing when e-PTFE membranes were used.27,29 In stud-ies using collagen membranes combined with bonegrafts and bone substitutes, wound dehiscences werealso reported.30–35,62,63 These studies reported com-plication rates ranging from 4.2% to 36.7%.

Since 1998, there has been a clear trend in studydesigns to use resorbable collagen membranesrather than e-PTFE membranes for bone augmenta-tion. In the event of wound dehiscences, collagenmembranes have been associated with less adversehealing outcomes. A split-mouth study which com-pared e-PTFE membranes with collagen membranesdemonstrated that when wound dehiscencesoccurred, bone fill was significantly better in siteswith collagen membranes than in sites with e-PTFEmembranes.15 Furthermore, the healing outcomeswere similar in sites with collagen membranes,whether or not a wound dehiscence occurred.

Other complications reported with type 1 place-ment included postoperative pain,38,52,64 sloughing ofthe flaps,30,31 postoperative bleeding,31 and temporaryparesthesia.65,66 Absence of complications with type 1implants was reported in only seven studies.26,38,67–71

Only two studies reported on complications withtype 2 placement. These included postoperativeinfection and necrosis of the flap in 2 out of 10patients (20%)41 and postoperative bleeding.31 Nocomplications were reported in two studies with type2 placement and submerged healing.39,72

Two studies provided comparative data on post-operative complications with postextraction implantsplaced with submerged healing. In a split-mouthstudy comparing type 1 and type 4 placement, pre-mature implant exposure occurred in 7 out of 14 sites(50%) with type 1 placement compared to 4 out of 14sites (28.8%) with type 4 placement. Bone augmenta-tion with particulate hydroxyapatite was under-taken.73 In a retrospective study in which autogenousbone chips were grafted into peri-implant defects,premature implant exposure occurred in 10.2% ofsites with type 1 placement compared to 11.8% ofsites with type 4 placement.74

There were no studies that compared the rate ofpostoperative complications between type 1 andtype 2 or 3 implant placements.

The evidence is clear that postoperative complica-tions are common with immediate placement. Themost common complication is dehiscence of thewound when either collagen or e-PTFE membranes areused in conjunction with submerged healing. There isstrong evidence to show that in the presence of awound dehiscence, collagen membranes result in bet-ter bone regeneration and defect fill compared to e-PTFE membranes. There were no comparative data forcomplication rates between type 1 and type 2 or 3implant placements.

Do Systemic Antibiotics Enhance the TreatmentOutcome? The majority of studies included systemicantibiotics that were prescribed perioperativelyand/or postoperatively. Amoxicillin was the most

The International Journal of Oral & Maxillofacial Implants 197

Group 4

186_4a_Chen.qxd 9/10/09 10:16 AM Page 197

commonly prescribed antibiotic. There were no stud-ies that reported on the influence of systemic anti-biotics on the outcome of bone augmentationprocedures, or on the occurrence of postoperativecomplications.

Survival Outcomes of Postextraction ImplantsA total of 54 papers reporting on survival out-comes of postextraction implants were identified(Table 5). There were 24 prospective and 11 retro-spective studies; of these, the majority reported onsurvival outcomes with type 1 implant place-ment.25,27,50–52,54–56,58,59,61,63,64,67–71,75–85 Four studiesprovided data on type 2 placement.11,39,72,86

There were 19 studies that provided data com-paring different placement times after extraction(Table 6). Of these, only two were RCTs87,88 and twowere controlled clinical studies.73,89 The remainingstudies were prospective and retrospective caseseries studies.53,57,65,66,74,90-99

What Are the Survival Outcomes of Postextrac-tion Implants? The data on survival outcomes of pos-textraction implants were predominantly derivedfrom studies with type 1 implant placement. Moststudies (35 studies) were short term, with mean obser-vation periods of 1 to 3 years. Survival rates rangedfrom 65% to 100% (median 99%), with 25 studiesreporting survival rates of 95% or higher. Ten studieshad mean follow-up periods of 3 to 5 years. Survivalrates over this period ranged from 90% to 100%(median 95.5%). Only 3 studies were published withfollow-up periods of greater than 5 years; survivalrates for these studies ranged from 92% to 97%(median 95%).

Seven studies reported on survival after earlyimplant placement (type 2), six of which were short-term studies of 1 to 3 years. One study provided com-parative data between type 1 and type 2 placementover 4 years. The survival rates for type 2 placementranged from 91% to 100% (median 100%).

There were only two studies that reported data onearly implant placement with partial bone healing(type 3).The survival rates were 96% and 100%.

Due to the heterogeneity of the studies withrespect to implant surfaces, loading protocols, andthe relatively short-term observation period for themajority of studies, the data should be interpretedcautiously. However, it appears that survival rates forpostextraction implants are high, with the majority ofstudies reporting survival rates of over 95%.

Does Timing of Implant Placement Influence Sur-vival Outcomes? Of the 19 studies with comparativedata, most compared type 1 and type 4 implantplacement (11 studies). Three studies compared type1 and type 2 implant placement. Two studies com-

pared type 2 and type 3 implant placement, and onestudy compared type 1 and type 3 implant place-ment (two of these studies were RCTs).87,88 One studyhad comparative data on type 1, type 2, and type 4placement. The majority were short-term studies.Four studies reported follow-up periods of 3 to 5years, whereas only one study had a follow-up time ofover 5 years. In one retrospective study with compar-ative data, it was unclear when implants were placedafter tooth extraction.94

Type 1 Versus Type 4 Implant Placement. All studiescomparing type 1 to type 4 implant placement wereeither retrospective or prospective cohort or caseseries studies. In seven studies with conventional ordelayed loading, survival rates of type 1 implantsranged from 90% to 100% (median 99%) compared to60% to 100% (median 94%) for implants with type 4placement.64,73,90,91,96–98 In six studies of immediaterestoration of single-tooth, short-span, and full-archreplacements, the survival rates of immediate implants(type 1 placement) was 65% to 100% (median 91%)compared to 94% to 100% (median 95%) for implantswith type 4 placement.53,66,92,96,98,99 In one retrospec-tive study providing data on three placement proto-cols, type 1 and type 2 implant placement had highersurvival rates (99% and 100%, respectively) than type 4implant placement (81.8%).57

There is evidence to show that postextractionimplants have survival rates similar to implants inhealed sites. With immediate loading, type 1 implantsmay have lower survival rates than implants placedinto healed sites.

Type 1 Versus Type 2 Implant Placement. Two short-term retrospective studies57,95 and one prospectivecohort study with a 5-year follow-up65 provided com-parative data on type 1 and type 2 placement. Sur-vival rates for type 1 implant placement ranged from90% to 99% (median 90%) compared to a range of90% to 100% (median 94%) for type 2 placement.Thus, implants placed with an immediate or early(type 2) protocol appear to have a similar survivaloutcome. In two studies, increased failure rates werenoted in patients with a history of periodontitis.65,94

Type 1 Versus Type 3 Implant Placement. Compara-tive data for type 1 and type 3 implant placementwere examined in only one study, which was anRCT.88 A total of 50 patients were selected, each witha single tooth site with radiographic evidence ofchronic apical periodontitis. The patients were ran-domly allocated to receive either immediate place-ment or placement 12 weeks after extraction (type 3).A submerged healing protocol was used and patientswere followed up for 12 months. The survival rates ofimplants placed immediately were 92% and 100% fortype 1 and type 3 placement, respectively.

198 Volume 24, Supplement, 2009

Chen/Buser

186_4a_Chen.qxd 9/10/09 10:16 AM Page 198

The International Journal of Oral & Maxillofacial Implants 199

Group 4

Tabl

e 5

Clin

ical

Stu

dies

Rep

orti

ng o

n S

urvi

val O

utco

mes

wit

h P

oste

xtra

ctio

n Im

plan

ts

Stu

dy d

esig

n/N

o. o

fP

lace

men

tpa

tien

tsti

me

afte

r Im

plan

t (N

o. o

fIm

plan

t A

ugm

enta

tion

met

hod/

Load

ing

prot

ocol

/ O

bser

vati

on

Sur

viva

l S

tudy

toot

h ex

trac

tion

surf

ace

impl

ants

)si

tes

Hea

ling

prot

ocol

Res

tora

tion

typ

epe

riod

rate

(%)

Gel

b (1

99

3)2

5

Lang

et a

l (1

99

4)2

7

Ros

enqu

ist

and

Gre

nthe

(1

99

6)51

Peco

ra e

t al

(19

96

)52

Cos

ci a

nd

Cos

ci (1

99

7)5

8

Sch

war

tz-A

rad

and

Cha

ushu

(1

99

7)6

2

Nir-

Had

ar e

t al

(19

98

)39

Bec

ker

et a

l (1

99

9)5

9*

Gru

nder

(2

00

0)8

6

Sch

war

tz-A

rad

et a

l (2

00

0)6

3

Huy

s (2

001

)67

Pros

p C

S/

Type

1

Pros

p C

S/

Type

1

Ret

ro C

S/

Type

1

Ret

ro C

S/

Type

1

Ret

ro C

S/

Type

1

Ret

ro C

S/

Type

1

Pros

p C

S /

Type

2

(4 to

8 w

k af

ter

extr

actio

n)Pr

osp

mul

ticen

-te

r C

oS/T

ype

1Pr

osp

CS

/Ty

pe 2

(8 w

kaf

ter

extr

actio

n)R

etro

CS

/Ty

pe 1

Ret

ro C

S/

Type

1

Turn

ed

TPS

Turn

ed

TPS

HA

Turn

ed a

ndH

A

Turn

ed

Turn

ed

Turn

ed

Turn

ed a

ndH

A

TPS

35

(50

)

16 (2

1)

51 (1

09

)

31 (3

2)

35

3 (4

23

)

49

(85

)

14 (2

1)

40

(49

)

10 (1

0)

43

(56

)

147

(55

6)

Max

illar

y an

d m

andi

bula

ran

terio

r tee

th a

nd p

rem

o-la

rs, a

nd m

andi

bula

r mol

ars

Max

illar

y in

ciso

rs, c

anin

es,

prem

olar

s, a

nd m

andi

bula

rpr

emol

ars

NR

Max

illar

y an

d m

andi

bula

rin

ciso

r, ca

nine

, pre

mol

ar,

and

mol

ar s

ites

NR

Max

illar

y an

d m

andi

bula

ran

terio

r, pr

emol

ar, a

nd m

olar

site

sAl

l are

as

All a

reas

Sing

le-to

oth

repl

acem

ent

Max

illar

y ce

ntra

l and

late

ral

inci

sors

Max

illar

y an

d m

andi

bula

rm

olar

site

s on

ly

NR

e-PT

FE m

embr

ane

alon

e, o

r D

FDB

Agr

aft a

lone

, or

e-PT

FE m

embr

ane

com

bine

d w

ith D

FDB

A gr

aft/

Sub

mer

ged

e-PT

FE m

embr

ane

alon

e/Tr

ansm

ucos

al

No

augm

enta

tion

in m

ost c

ases

;e-

PTFE

mem

bran

e in

5 p

atie

nts/

Sub

mer

ged

e-PT

FE m

embr

ane

in 1

0 s

ites/

Sub

mer

ged

e-PT

FE m

embr

ane

for

site

s w

ithin

tact

bon

e w

alls

; hyd

roxy

apat

ite o

rD

FDB

A gr

aft a

nd c

olla

gen

mem

-br

ane

for

sock

et w

all d

efec

ts o

rap

ical

fene

stra

tion/

Sub

mer

ged

Auto

geno

us b

one

chip

s/S

ubm

erge

d

No

augm

enta

tion/

Sub

mer

ged

e-PT

FE m

embr

ane

alon

e/S

ubm

erge

de-

PTFE

mem

bran

e an

d D

BB

M/

Sub

mer

ged

Auto

geno

us b

one

whe

n re

quire

d;e-

PTFE

(2 s

ites)

and

col

lage

n m

em-

bran

es (6

site

s) /

Sub

mer

ged

Com

posi

te p

olym

er g

raft

/S

ubm

erge

d

Conv

entio

nal/

Sing

le-to

oth

rest

orat

ions

Del

ayed

/Sin

gle-

toot

h,sh

ort-s

pan

pros

thes

es,

shor

t-spa

n to

oth-

impl

ant

pros

thes

esCo

nven

tiona

l in

the

man

-di

ble;

del

ayed

in th

e m

ax-

illa/

Res

tora

tion

type

NR

NR

/Sin

gle-

toot

h re

stor

a-tio

ns

NR

/Res

tora

tion

type

NR

NR

/Res

tora

tion

type

NR

Del

ayed

/NR

NP/

Sing

le-to

oth

repl

ace-

men

tsD

elay

ed/S

ingl

e-to

oth

repl

acem

ents

Del

ayed

/Sin

gle-

toot

h an

dsh

ort s

pans

Conv

entio

nal/

Bal

l-re

tain

ed o

verd

entu

res,

shor

t-spa

n pr

osth

eses

,im

plan

t-too

th p

rost

hese

s,si

ngle

cro

wns

Mea

n 17

mo

(ran

ge 8

to4

4 m

o)

Mea

n 3

0.3

mo

(ran

ge21

to 4

2 m

o)

Mea

n 3

0.5

mo

(ran

ge 1

to 6

7 m

o)

Mea

n 16

.3 m

o af

ter

load

ing

Ran

ge 1

to 7

y

Ran

ge 4

to 7

y

12

mo

5 y

1 y

aft

er lo

adin

g

Mea

n 15

mo

(ran

ge 4

to6

0 m

o)

Ran

ge 7

to 1

0 y

98

100

93

.6

96

.9

99

.5

95

aft

er5

y

95

.2

93

.9

100

89

.3

96

.6

186_4a_Chen.qxd 9/10/09 10:16 AM Page 199

200 Volume 24, Supplement, 2009

Chen/Buser

Tabl

e 5

con

tinu

ed C

linic

al S

tudi

es R

epor

ting

on

Sur

viva

l Out

com

es w

ith

Pos

text

ract

ion

Impl

ants

Stu

dy d

esig

n/N

o. o

fP

lace

men

tpa

tien

tsti

me

afte

r Im

plan

t (N

o. o

fIm

plan

t A

ugm

enta

tion

met

hod/

Load

ing

prot

ocol

/ O

bser

vati

on

Sur

viva

l S

tudy

toot

h ex

trac

tion

surf

ace

impl

ants

)si

tes

Hea

ling

prot

ocol

Res

tora

tion

typ

epe

riod

rate

(%)

Gom

ez-R

oman

et

al (

20

01)61

†

Gol

dste

in e

t al

(20

02

)68

Artz

i et a

l (2

00

3)6

9

Kan

et a

l (2

00

3)76

Cov

ani e

t al

(20

04

)54

Bia

nchi

and

S

anfil

ippo

(2

00

4)10

6

Can

gini

and

C

orne

lini (

20

05

)77

Cor

nelin

i et a

l (2

00

5)7

0

Vand

en B

ogae

rde

et a

l (2

00

5)5

5

Bar

one

et a

l (2

00

6)5

6

Ferr

ara

et a

l (2

00

6)7

8

Fuga

zzot

to

(20

06

)79

Pros

p C

S/

Type

1

Pros

p C

S/

Type

1Pr

osp

CS

/Ty

pe 1

Pros

p C

S/

Type

1

Pros

p C

S/

Type

1

Ret

ro C

S/

Type

1

Pros

p C

CS

/Ty

pe 1

Pros

p C

S/

Type

1

Pros

p C

S/

Type

1

Pros

p C

S/

Type

1

Pros

p C

S/

Type

1

Pros

p C

S/

Type

1

Grit

bla

sted

and

acid

-et

ched

Turn

ed

TCP

blas

ted

HA

TPS

TPS

SLA

SLA

Tita

nium

oxid

e co

ated

TPS

Grit

-bla

sted

/ac

id-e

tche

d

SLA

104

(12

4)

38

(47

)

10 (1

2)

35

(35

)

95

(16

4)

116

(116

)

32

(32

)

22

(22

)

19

(50

)

18

(18

)

33

(33

)

83

(83

)

All s

ites

Max

illar

y si

tes

Max

illar

y m

olar

site

s on

ly

Max

illar

y in

ciso

r and

can

ine

site

s

Max

illar

y an

d m

andi

bula

rin

ciso

r, ca

nine

, and

pre

mol

arsi

tes

All s

ites

Max

illar

y an

d m

andi

bula

rin

ciso

r, ca

nine

, and

pre

mol

arsi

tes;

all

teet

h ha

d pe

riodo

n-ta

l def

ects

Max

illar

y an

d m

andi

bula

rin

ciso

r, ca

nine

, and

pre

mol

arsi

tes

Max

illar

y an

terio

r and

pre

-m

olar

site

s, a

nd m

andi

bula

rpr

emol

ar a

nd m

olar

site

s

Max

illar

y an

d m

andi

bula

rin

ciso

r, ca

nine

, and

pre

mol

arsi

tes

Max

illar

y an

d m

andi

bula

rin

ciso

r, ca

nine

, and

pre

mol

arsi

tes

Max

illar

y fir

st a

nd s

econ

dm

olar

s

Auto

geno

us b

one

(9 s

ites)

, HA

(24

site

s), e

-PTF

E m

embr

ane

(17

site

s)/T

rans

muc

osal

DFD

BA

and

reso

rbab

le p

olym

erba

rrie

r m

embr

ane/

Sub

mer

ged

DB

BM

or

TCP/

Sub

mer

ged

No

augm

enta

tion/

Tran

smuc

osal

No

augm

enta

tion

at 5

8 s

ites

with

inta

ct b

one

wal

ls; a

utog

enou

s bo

nech

ips

and

reso

rbab

le m

embr

anes

in 1

05

site

s w

ith d

ehis

cenc

e an

dfe

nest

ratio

n de

fect

s/Tr

ansm

ucos

alN

R/S

ubm

erge

d

Enam

el m

atrix

der

ivat

ive

(18

site

s);

reso

rbab

le c

olla

gen

mem

bran

e (1

4si

tes)

/Tra

nsm

ucos

al

Res

orba

ble

colla

gen

mem

bran

e/Tr

ansm

ucos

al

Auto

geno

us b

one

in 3

-wal

l def

ects

;au

toge

nous

bon

e an

d re

sorb

able

poly

mer

mem

bran

e fo

r 1

- and

2-

wal

l def

ects

/Tra

nsm

ucos

alN

o au

gmen

tatio

n (a

ll si

tes

with

inta

ct b

one

wal

ls a

nd m

argi

nal

gaps

< 2

mm

)/Tr

ansm

ucos

alO

sseo

us c

oagu

lum

if a

mar

gina

lga

p w

as p

rese

nt/T

rans

muc

osal

Oss

eous

coa

gulu

m o

r de

min

eral

-iz

ed b

one

mat

rix p

aste

with

reso

rbab

le o

r tit

aniu

m-re

info

rced

e-

PTFE

mem

bran

e/S

ubm

erge

d

NR

/Sin

gle-

toot

h, p

artia

l,an

d fu

ll ar

ches

NR

/Sin

gle-

toot

h re

plac

e-m

ents

NR

/Sin

gle-

toot

h an

dex

tend

ed s

pans

Imm

edia

te re

stor

atio

n/Si

n-gl

e-to

oth

repl

acem

ents

Imm

edia

te re

stor

atio

n/Si

ngle

-toot

h re

plac

emen

ts

Del

ayed

/Sin

gle-

toot

hre

plac

emen

ts

Del

ayed

/Sin

gle-

toot

hre

plac

emen

ts

Imm

edia

te re

stor

atio

n/

Sing

le-to

oth

repl

acem

ents

Imm

edia

te a

nd e

arly

load

-in

g/Sh

ort-s

pan

to fu

ll-ar

chre

stor

atio

ns

Imm

edia

te re

stor

atio

n/Si

ngle

-toot

h re

stor

atio

ns

Imm

edia

te re

stor

atio

n/Si

ngle

-toot

h re

stor

atio

ns

Del

ayed

/Sin

gle

rest

ora-

tions

Mea

n 2

.6 y

(up

to 6

.3 y

)

Mea

n 3

9.4

mo

(ran

ge 1

to 5

y)

2 y

1 y

4 y

1 to

9 y

12

mo

12

mo

18 m

o

12

mo

4 y

Mea

n 1

2.4

mo

infu

nctio

n

97

100

100

100

97

100

100

100

100

94

.5

94

.0

100

186_4a_Chen.qxd 9/10/09 10:16 AM Page 200

The International Journal of Oral & Maxillofacial Implants 201

Group 4

Tabl

e 5

con

tinu

ed C

linic

al S

tudi

es R

epor

ting

on

Sur

viva

l Out

com

es w

ith

Pos

text

ract

ion

Impl

ants

Stu

dy d

esig

n/N

o. o

fP

lace

men

tpa

tien

tsti

me

afte

r Im

plan

t (N

o. o

fIm

plan

t A

ugm

enta

tion

met

hod/

Load

ing

prot

ocol

/ O

bser

vati

on

Sur

viva

l S

tudy

toot

h ex

trac

tion

surf

ace

impl

ants

)si

tes

Hea

ling

prot

ocol

Res

tora

tion

typ

epe

riod

rate

(%)

De

Kok

et a

l (2

00

6)8

0

Wag

enbe

rg a

nd

Frou

m (2

00

6)81

‡

Cov

ani e

t al

(20

07

)82

Juod

zbal

ys a

nd

Wan

g (2

00

7)8

3

Sam

mar

tino

et a

l (2

00

7)71

Kan

et a

l (2

00

7)5

0

Sch

war

tz-A

rad

et a

l (2

00

7)6

4

Cre

spi e

t al

(20

07

)12

3

Villa

and

Ran

gert

(2

00

7)8

4

Caf

iero

et a

l (2

00

8)10

0

Fuga

zzot

to

(20

08

)60

Fuga

zzot

to

(20

08

)101

Ret

ro C

S/

Type

1

Ret

ro C

S/

Type

1

Pros

p C

S/

Type

1

Pros

p C

S/

Type

1R

etro

CS

/Ty

pe 1

Pros

p C

S/

Type

1

Ret

ro C

S/

Type

1

Pros

p C

S/

Type

1

Pros

p C

S/

Type

1

Pros

p C

oS/

Type

1

Ret

ro C

S/

Type

1

Ret

ro C

S/

Type

1

Tita

nium

-ox

ide

grit-

blas

ted

Turn

ed a

ndun

spec

ified

roug

h-su

r-fa

ced

impl

ants

San

dbla

sted

and

acid

-et

ched

NR

SLA

(53

im-

plan

ts) a

ndgr

it-bl

aste

d/ac

id-e

tche

d(3

4 im

plan

ts)

Tita

nium

oxid

e co

ated

NR

TPS

Tita

nium

oxid

e co

ated

SLA

SLA

SLA

28

(43

)

591

(1,0

91)

10 (1

0)

12

(14

)

55

(83

)

23

(23

)

87

(210

)

27

(15

0)

33

(10

0)

82

(82

)

38

6 (3

91)

33

5 (3

41)

Max

illar

y an

terio

r and

pre

-m

olar

site

s

Max

illar

y an

d m

andi

bula

rin

ciso

r, ca

nine

, and

pre

mol

arsi

tes

Max

illar

y an

d m

andi

bula

rin

ciso

r, ca

nine

, and

pre

mol

arsi

tes

Max

illar

y ce

ntra

l and

late

ral

inci

sors

Max

illar

y an

d m

andi

bula

rin

ciso

r, ca

nine

, and

pre

mol

arsi

tes

Max

illar

y ce

ntra

l and

late

ral

inci

sors

, and

can

ines

Max

illar

y an

d m

andi

bula

ran

terio

r tee

th a

nd p

rem

o-la

rs, a

nd m

axill

ary

mol

ars

All s

ites

Max

illar

y in

ciso

rs, c

anin

es,

and

prem

olar

s

Max

illar

y an

d m

andi

bula

rm

olar

s

Max

illar

y fir

st a

nd s

econ

dm

olar

s

Man

dibu

lar f

irst a

nd s

econ

dm

olar

s

NR

/Tra

nsm

ucos

al

Min

eral

ized

FD

BA

and

reso

rbab

lepo

lym

er m

embr

ane/

Sub

mer

ged

NR

/Sub

mer

ged

DB

BM

and

reso

rbab

le c

olla

gen

mem

bran

e/S

ubm

erge

dN

o au

gmen

tatio

n (a

ll m

argi

nal

gaps

wer

e ≤

2 m

m)/

Tra

nsm

ucos

al

Auto

geno

us b

one

or D

BB

M a

ndre

sorb

able

col

lage

n m

embr

ane/

Tran

smuc

osal

DB

BM

and

aut

ogen

ous

bone

mix

-tu

re/

Tran

smuc

osal

Auto

geno

us b

one

chip

s/Tr

ansm

ucos

al

Auto

geno

us b

one

and

DB

BM

/Tr

ansm

ucos

al

DB

BM

and

reso

rbab

le c

olla

gen

mem

bran

e w

hen

mar

gina

l gap

s >

1m

m/

Tran

smuc

osal

DB

BM

or

dem

iner

aliz

ed b

one

putt

y,an

d tit

aniu

m re

info

rced

e-P

TFE

mem

bran

e/S

ubm

erge

dD

BB

M o

r de

min

eral

ized

bon

e pu

tty,

and

titan

ium

-rein

forc

ed e

-PTF

Em

embr

ane

at s

ites

with

mar

gina

lga

ps >

3 m

m/S

ubm

erge

d

Imm

edia

te re

stor

atio

n/

Sing

le-to

oth

rest

orat

ions

Del

ayed

/ R

esto

ratio

n ty

pe N

R

Del

ayed

/ Si

ngle

rest

orat

ions

Del

ayed

/ Si

ngle

rest

orat

ions

Early

/Sin

gle-

and

mul

tiple

-to

oth

repl

acem

ents

Imm

edia

te re

stor

atio

n/

Sing

le-to

oth

rest

orat

ions

Imm

edia

te re

stor

atio

n/

Sing

le-to

oth

and

shor

t-sp

an re

stor

atio

nsIm

med

iate

load

ing/

Fu

ll-ar

ch m

axill

ary

and

man

dibu

lar r

esto

ratio

nsIm

med

iate

and

ear

ly lo

ad-

ing/

Sing

le-to

oth,

par

tial,

and

full-

arch

rest

orat

ions

Early

/Sin

gle-

toot

h re

stor

a-tio

ns

NR

/Sin

gle

(387

impl

ants

)an

d sp

linte

d re

stor

atio

ns(4

impl

ants

)N

R/S

ingl

e-to

oth

and

splin

ted

rest

orat

ions

12

to 3

0 m

o (n

o m

ean)

35

% fo

r 1 y

46

% fo

r 2 to

5 y

19%

for 5

to 1

1 y

12

mo

12

mo

afte

r loa

ding

2 y

12

mo

Mea

n 15

.6 ±

12

.6 m

o(r

ange

6 to

52

mo)

18 m

o

12

mo

12

mo

Mea

n 4

0.3

mo

Mea

n 3

0.8

mo

90

.7

95

100

100

96

.6

100

97.

6

100

97.

4§

100

99

.5

99

.1

186_4a_Chen.qxd 9/10/09 10:16 AM Page 201

202 Volume 24, Supplement, 2009

Chen/Buser

Tabl

e 5

con

tinu

ed C

linic

al S

tudi

es R

epor

ting

on

Sur

viva

l Out

com

es w

ith

Pos

text

ract

ion

Impl

ants

Stu

dy d

esig

n/N

o. o

fP

lace

men

tpa

tien

tsti

me

afte

r Im

plan

t (N

o. o

fIm

plan

t A

ugm

enta

tion

met

hod/

Load

ing

prot

ocol

/ O

bser

vati

on

Sur

viva

l S

tudy

toot

h ex

trac

tion

surf

ace

impl

ants

)si

tes

Hea

ling

prot

ocol

Res

tora

tion

typ

epe

riod

rate

(%)

Bus

er e

t al

(20

08

)11

Bar

one

et a

l (2

00

8)8

5

Bus

er e

t al

(20

09

)72

Stu

dy d

esig

n: P

rosp

= p

rosp

ectiv

e; R

etro

= re

tros

pect

ive;

RC

T =

rand

omiz

ed c

ontr

olle

d tr

ial;

CC

S =

con

trol

led

clin

ical

stu

dy; C

oS =

coh

ort s

tudy

; CS

= c

ase

serie

s.Im

plan

t sur

face

: Tur

ned

= eq

uiva

lent

to m

achi

ned

surf

ace;

TPS

= ti

tani

um p

lasm

a-sp

raye

d; H

A =

hydr

oxya

patit

e-co

ated

; SLA

= s

urfa

ce s

andb

last

ed w

ith la

rge-

grit

and

acid

-etc

hed.

Plac

emen

t tim

e af

ter

extr

actio

n: T

ype

1 =

imm

edia

te im

plan

t pla

cem

ent;

Type

2 =

ear

ly im

plan

t pla

cem

ent w

ith s

oft t

issu

e he

alin

g; T

ype

3 =

ear

ly im

plan

t pla

cem

ent w

ith p

artia

l bon

e he

alin

g;Ty

pe 4

= la

te p

lace

men

t in

a fu

lly h

eale

d si

te.

Augm

enta

tion

met

hod:

e-P

TFE

= ex

pand

ed p

olyt

etra

fluor

oeth

ylen

e m

embr

ane;

DB

BM

= d

emin

eral

ized

bov

ine

bone

min

eral

; DFD

BA

= de

min

eral

ized

free

ze-d

ried

bone

allo

graf

t;FD

BA

= fr

eeze

-drie

d bo

ne a

llogr

aft;

TCP

= be

ta tr

ical

cium

pho

spha

te.

Load

ing

prot

ocol

: acc

ordi

ng to

the

ITI C

onse

nsus

Con

fere

nce

(20

03

).12

4N

R =

not

repo

rted

.*

This

stu

dy re

pres

ents

the

5-y

ear

follo

w-u

p; 1

-yea

r re

sults

wer

e pu

blis

hed

in B

ecke

r et

al (

19

94

).28

‡Th

is s

tudy

incl

udes

dat

a fr

om a

pre

viou

s re

port

by

the

sam

e au

thor

s: W

agen

berg

and

Gin

sber

g (2

001

).12

6

§S

urvi

val r

ate

is fo

r a

subs

et o

f 76

out

of 1

00

impl

ants

in 3

3 p

atie

nts,

that

wer

e pl

aced

in in

fect

ed e

xtra

ctio

n so

cket

s.

Ret

ro C

S /

Type

2 (4

to 8

wk

afte

r ex

trac

tion)

Pros

p C

S/

Type

1

Pros

p C

S /

Typ

e2

(4 to

8 w

k af

ter

extr

actio

n)

SLA

TPS

SLA

45

(45

)

12

(12

)

20

(20

)

Max

illar

y an

terio

r and

pre

-m

olar

teet

h

Max

illar

y pr

emol

ar s

ites;

all

site

s re

quire

d si

mul

tane

ous

sinu

s flo

or e

leva

tion

usin

gos

teot

omes

Max

illar

y an

terio

r and

pre

-m

olar

teet

h

DB

BM

and

col

lage

n m

embr

ane;

graf

t app

lied

to m

argi

nal d

efec

tsan

d ex

tern

al s

urfa

ce o

f the

faci

albo

ne/S

ubm

erge

dC

ortic

o-ca

ncel

lous

por

cine

bon

ean

d co

llage

n ge

l, an

d re

sorb

able

mem

bran

e/Tr

ansm

ucos

al

DB

BM

and

col

lage

n m

embr

ane;

graf

t app

lied

to m

argi

nal d

efec

tsan

d ex

tern

al s

urfa

ce o

f the

faci

albo

ne/S

ubm

erge

d

Early

/Sin

gle-

toot

h re

stor

a-tio

ns

Del

ayed

/Sin

gle-

toot

hre

stor

atio

ns a

nd m

ultip

leim

plan

t pro

sthe

ses

Early

/Sin

gle-

toot

h re

stor

a-tio

ns

23

pat

ient

s fo

r 2 y

16 p

atie

nts

for 3

y6

pat

ient

s fo

r 4 y

18 m

o

12

mo

100

91.7

100

186_4a_Chen.qxd 9/10/09 10:16 AM Page 202

The International Journal of Oral & Maxillofacial Implants 203

Group 4

Tabl

e 6

Clin

ical

Stu

dies

wit

h C

ompa

rati

ve D

ata

on S

urvi

val O

utco

mes

wit

h D

iffe

rent

Impl

ant

Pla

cem

ent

Tim

es A

fter

Ext

ract

ion

No.

of p

atie

nts

Aug

men

tati

on

Load

ing

(No.

of i

mpl

ants

)m

etho

dpr

otoc

ol/

Sur

viva

l rat

e (%

)

Stu

dy

Impl

ant

Type

s 2

(h

ealin

g re

stor

atio

nO

bser

vati

on

Type

s 2

S

tudy

desi

gnsu

rfac

eTy

pe 1

and

3Ty

pe 4

prot

ocol

)ty

pepe

riod

Type

1an

d 3

Type

4

Yukn

a

(19

91)7

3

Cra

nin

et a

l (1

99

3)9

0

Wat

zek

et a

l (1

99

5)5

7

Poliz

zi e

t al

(20

00

)65

†

Sch

war

tz-A

rad

et a

l (2

00

0)74

Jo e

t al

(20

01)91

Cha

ushu

et a

l (2

001

)53

Mal

o et

al

(20

03

)66

Nor

ton

(20

04

)92

Got

fred

sen

(20

04

)93

Evia

n et

al

(20

04

)94

Perr

y an

d Le

nche

wsk

i (2

00

4)9

5

Pros

p C

CS

Pros

p C

CS

Ret

ro C

S

Pros

p C

oS

Ret

ro

Ret

ro C

S

Ret

ro

Pros

p C

S

Pros

p C

S

Pros

p C

S

Ret

ro C

S

Ret

ro C

S

HA

Poly

crys

talli

neAl

umin

aC

eram

icH

A an

dtu

rned

Turn

ed

Turn

ed a

ndH

A

NR

HA

Turn

ed

Tita

nium

oxid

e gr

it-bl

aste

d

Tita

nium

oxid

e gr

it-bl

aste

d

HA

and

turn

ed

NR

14 (1

4)

30

* (2

5)

20

* (9

7)

143

* (1

46

)

43

* (1

17)

75

* (8

1)

20

* (1

9)

76*

(22

)

25

* (1

6)

–

100

(10

0)

44

2*

(32

2)

– –

20*

(26)

(6 to

8 w

k af

ter

extr

actio

n)14

3* (3

4)(3

to 5

wk

afte

rex

trac

tion) – – – – –

Gro

up A

: 10

(10)

4 w

k af

ter e

xtra

c-tio

nG

roup

B: 1

0 (1

0)12

wk

afte

rex

trac

tion

49 (4

9) (p

lace

-m

ent t

ime

afte

rex

trac

tion

NR

)44

2* (7

77)

(8 to

12

wk

afte

rex

trac

tion)

14 (1

4)

30*

(5)

20*

(11)

–

43*

(263

)

75*

(205

)

20*

(9)

76*

(94)

25*

(12)

– – –

HA/

Sub

mer

ged

No

augm

enta

tion/

Tran

smuc

osal

e-PT

FE m

embr

ane

with

DB

BM

or

hydr

oxya

patit

egr

afts

/Sub

mer

ged

Com

bina

tions

of e

-PTF

Ean

d co

llage

n m

em-

bran

es, a

utog

enou

s bo

nean

d D

FDB

A/S

ubm

erge

dAu

toge

nous

bon

e/S

ubm

erge

d

No

augm

enta

tion/

Tran

smuc

osal

Auto

geno

us b

one/

Tran

smuc

osal

NR

/Tra

nsm

ucos

al

NR

/Tra

nsm

ucos

al

e-PT

FE m

embr

ane

only

/S

ubm

erge

d

NR

/Sub

mer

ged

NR

/Sub

mer

ged

Del

ayed

/Spl

inte

d br

idge

s

Del

ayed

/Res

tora

tion

type

NR

Del

ayed

in th

e m

axill

a; c

on-

vent

iona

l in

the

man

dibl

e/Fu

ll-ar

ch fi

xed

rest

orat

ions

Del

ayed

in th

e m

axill

a; C

on-

vent

iona

l in

the

man

dibl

e/Si

ngle

-toot

h, p

artia

l and

full-

arch

rest

orat

ions

Conv

entio

nal l

oadi

ng in

the

man

dibl

e; d

elay

ed in

the

max

-ill

a/Fu

ll-ar

ch re

stor

atio

nsIm

med

iate

and

del

ayed

load

-in

g pr

otoc

ols

used

/R

esto

ratio

n ty

pe N

RIm

med

iate

rest

orat

ion/

Sing

le-to

oth

rest

orat

ions

;si

tes

NR

Imm

edia

te re

stor

atio

n in

73

patie

nts/

Sing

le-to

oth

and

shor

t spa

nsIm

med

iate

rest

orat

ion/

Sing

le-to

oth

rest

orat

ions

Del

ayed

/Sin

gle-

toot

h re

stor

a-tio

ns

Conv

entio

nal/

Res

tora

tion

type

NR

Conv

entio

nal/

Res

tora

tion

type

NR

Mea

n 16

mo

(rang

e8

to 2

4 m

o)M

ean

85 m

o (ra

nge

not s

tate

d)

Mea

n 27

.1 m

o(ra

nge

4 to

83

mo)

60 m

o af

ter f

unc-

tiona

l loa

ding

5 y

Mea

n 40

mo

Mea

n 13

mo

(rang

e6

to 2

4 m

o)

1 y

Mea

n 20

.3 m

o(ra

nge

13 to

30

mo)

In fu

nctio

n fo

r 15.

7m

o (ra

nge

8 to

27

mo)

5 y

Mea

n 2.

6 y

34.5

mo

(rang

e 5.

8to

67.

4 m

o)

– –

100

93

.6 – – – – –

100

85

.7

90

100

92

.0

98

.9

90

.4

96

98

.9

82

.4

100

97.

6 –

85

90

100

60

.0

81.8 –

89

.4

93

.9

100

94

.7

95

.2 – – –

186_4a_Chen.qxd 9/10/09 10:16 AM Page 203

204 Volume 24, Supplement, 2009

Chen/Buser

Tabl

e 6

con

tinu

ed C

linic

al S

tudi

es w

ith

Com

para

tive

Dat

a on

Sur

viva

l Out

com

es w

ith

Dif

fere

nt Im

plan

t P

lace

men

t Ti

mes

Aft

er E

xtra

ctio

n

No.

of p

atie

nts

Aug

men

tati

on

Load

ing

(No.

of i

mpl

ants

)m

etho

dpr

otoc

ol/

Sur

viva

l rat

e (%

)

Stu

dy

Impl

ant

Type

s 2

(h

ealin

g re

stor

atio

nO

bser

vati

on

Type

s 2

S

tudy

desi

gnsu

rfac

eTy

pe 1

and

3Ty

pe 4

prot

ocol

)ty

pepe

riod

Type

1an

d 3

Type

4

Sch

ropp

et a

l (2

00

5)8

7

Deg

idi e

t al

(20

06

)96

Lind

eboo

m

et a

l (2

00

6)8

8

Fuga

zzot

to

et a

l (2

00

7)9

7

Deg

idi e

t al

(20

07

)98

Sie

gent

hale

r et

al (

20

07

)89

Hor

witz

et a

l(2

00

7)9

9

Stu

dy d

esig

n: P

rosp

= p

rosp

ectiv

e; R

etro

= r

etro

spec

tive;

RC

T =

ran

dom

ized

con

trol

led

tria

l; C

CS

= c

ontr

olle

d cl

inic

al s

tudy

; CoS

= c

ohor

t st

udy;

CS

= c

ase

serie

s.Im

plan

t su

rfac

e: T

urne

d =

equ

ival

ent

to m

achi

ned

surf

ace;

TP

S =

tita

nium

pla

sma-

spra

yed;

HA

= h

ydro

xyap

atite

-coa

ted;

SLA

= s

andb

last

ed w

ith la

rge-

size

d gr

it an

d ac

id-e

tche

d su

rfac

e;S

BE

= s

andb

last

ed a

nd a

cid-

etch

ed.

Pla

cem

ent

time

afte

r ex

trac

tion:

Typ

e 1

= im

med

iate

pla

cem

ent

at t

he t

ime

of e

xtra

ctio

n; T

ype

2 =

ear

ly p

lace

men

t af

ter

initi

al s

oft

tissu

e he

alin

g; T

ype

3 =

ear

ly p

lace

men

t af

ter

subs

tant

ial b

one

heal

ing;

Type

4 =

late

pla

cem

ent

afte

r co

mpl

ete

heal

ing

of t

he r

idge

.A

ugm

enta

tion

met

hod:

e-P

TFE

= e

xpan

ded

poly

tetr

aflu

oroe

thyl

ene

mem

bran

e; D

BB

M =

dep

rote

iniz

ed b

ovin

e bo

ne m

iner

al; D

FDB

A =

dem

iner

aliz

ed f

reez

e-dr

ied

bone

allo

graf

t; H

A =

hyd

roxy

apat

ite.

Load

ing

prot

ocol

s ac

cord

ing

to t

he IT

I Con

sens

us C

onfe

renc

e (2

003)

.124

– =

due

to

the

stud

y de

sign

, the

re w

ere

no d

ata

for

this

par

amet

er.

NR

= n

ot r

epor

ted.

*Ind

icat

es t

otal

num

ber

of p

atie

nts

in t

he s

tudy

.† T

his

stud

y re

pres

ents

the

5-y

ear

follo

w-u

p; 3

-yea

r re

sults

wer

e pu

blis

hed

in G

rund

er e

t al

(199

9).1

27

RC

T

Pros

p C

S

RC

T

Ret

ro C

S

Ret

ro C

S

Pros

p C

CT

Acid

-etc

hed

Mix

ed: t

urne

d,TP

S an

d ac

id-

etch

edSB

E

SLA

Vario

us s

ur-

face

s

SLA

Sand

blas

ted

and

acid

-et

ched

23

(23

)M

ean

10 d

afte

r ex

trac

-tio

n (r

ange

3–1

5 d

)6

7 (6

7)

25

(25

)

22

(39

)

1,06

4*(4

16)

34

(34

)

19

* (4

1)

23 (2

3)(3

mo

afte

rex

trac

tion)

–

25 (2

5)(1

2 w

k af

ter

extr

actio

n)

– – – –

–

44 (4

4) –

39 (1

30)

All p

atie

nts

on b

isph

os-

phon

ate

ther

apy

1,06

4*(6

58) –

19*

(33)

Type

1—

no a

ugm

enta

tion;

Type

3—

aut

ogen

ous

bone

par

ticle

s if

defe

cts

pres

ent/

Sub

mer

ged

NR

/Tra

nsm

ucos

al

Part

icul

ate

auto

geno

usca

ncel

lous

bon

e an

dre

sorb

able

col

lage

nm

embr

ane/

Sub

mer

ged

Dem

iner

aliz

ed b

one

mat

rixbl

ocks

with

type

1 p

lace

-m

ent,

and

reso

rbab

le o

re-

PTFE

mem

bran

es

NR

/Tra

nsm

ucos

al

DB

BM

and

reso

rbab

leco

llage

n m

embr

ane

NR

/Tra

nsm

ucos

al

Conv

entio

nal/

Sing

le-to

oth

rest

orat

ions

Imm

edia

te re

stor

atio

n/Si

ngle

-toot

h re

stor

atio

ns

Del

ayed

/Sin

gle-

toot

h re

stor

a-tio

ns

NR

Imm

edia

te re

stor

atio

n/R

esto

ratio

n ty

pe N

R

Conv

entio

nal/

Sing

le-to

oth

rest

orat

ions

Imm

edia

te lo

adin

g/

Sing

le-to

oth,

par

tial a

nd fu

ll-ar

ch re

stor

atio

ns

2 y

5 y

12 m

o

12 to

24

mo

Mea

n 3

y

12 m

o

12 m

o

96 –

100 – – – –

91 92

.5

92

100

90

.2

100

65

–

100

P<

.05

–

100

93

.9 –

94

186_4a_Chen.qxd 9/10/09 10:16 AM Page 204

Type 2 Versus Type 3 Implant Placement. One studycompared the outcomes of 10 implants placed4 weeks after extraction in 10 patients, with 10implants placed 12 weeks after extraction in anothergroup of 10 individuals.93 The survival rate was 100%for both groups after 5 years of function. One RCTcompared the outcomes of different early placementtimes over a 2-year observation period.87 A total of 46subjects each received a single implant, either 3 to 15days (mean 10 days) or 3 months after extraction(type 3 placement). The survival rates were 91% fortype 2 and 96% for type 3. It should be noted thatimplant placement between 3 and 15 days afterextraction is unlikely to have been accompanied bycomplete soft tissue healing, and therefore does notfulfill the definition of early placement with soft tis-sue healing (type 2) adopted in this review.

Does Implant Surface Affect Implant Survival? Avariety of implant surfaces were used in the studiesreviewed, with many studies reporting the use ofmixed implant systems and surfaces. Implants with amachined surface were widely used prior to the year2000; subsequently, the majority of studies utilizedroughened surfaces. Survival rates for machinedimplant sur faces ranged from 93.6% to 100%(median 95%).25,39,51,59,65,66,68,86 Survival rates forhydroxyapatite (HA)-coated implants were 82.4% to100% (median 99.5%).53,58,73,76 Survival rates reportedin studies that used implants with a titanium plasma-sprayed surface (TPS) ranged from 94.5% to 100%(median 97%).27,52,56,67 In studies using implants witha sandblasted and acid-etched surface (SLA), survivalrates of 99.1% to 100% (median 100%) werereported.23,60,70,77,79,89,97,100,101

Due to differences in study design and follow-upperiods, no direct conclusions can be drawn from thedata. However, there was a trend toward slightlylower survival rates for implants with a machined sur-face (median survival rate 95%) and highest survivalrates for implants with an SLA surface (median sur-vival rate 100%). No studies were designed to com-pare the survival of implants with different surfaces inpostextraction sites. One retrospective studyreported no differences in survival outcomesbetween implants with machined and roughenedsurfaces.81

Does Systemic Antibiotic Therapy Improve Sur-vival Outcomes? The majority of studies reported thatsystemic antibiotics were prescribed. However, theantibiotic regimen varied considerably between stud-ies. Penicillin was the most common antibiotic pre-scribed. There were no studies that evaluated survivaloutcomes with and without systemic antibiotic ther-apy. In one retrospective study, implant survival wassignificantly influenced by choice of antibiotics.81 Fail-

ure rates were higher in patients who were allergic topenicillin and were prescribed alternative antibiotics.

What Are the Potential Risk Indicators for Sur-vival of Postextraction Implants? Several factorshave been considered as potential risk indicators forfailure of postextraction implants.

Chronic Periodontitis. In a retrospective study of1,091 implants in 591 patients who were observed fora period of 1 to 11 years, an overall survival rate of 95%was reported.81 The authors reported that there weresignificantly more failures in men than in women, inthose who were prescribed alternative antibiotics topenicillin, in implants in mandibular anterior sites, andin tooth sites with chronic periodontitis. Three otherstudies identified chronic periodontitis as a risk indica-tor.51,65,94 A higher failure rate was also noted in peri-odontitis sites irrespective of the timing of placementafter extraction.65,94 In a study of implants placed into76 extraction sites with infection (55 chronic peri-odontitis, 15 endodontic pathology, and 6 root frac-tures) in 33 patients, two implants failed during the12-month follow-up. The failed implants were in sitesaffected by chronic periodontitis.84

Periapical Pathology . The data for survival ofimplants in sites with apical pathology are contradic-tory. Two controlled studies have been publishedcomparing sites with periapical pathology. In the RCTof Lindeboom et al described previously, the authorsreported that the survival rate was lower for type 1compared to type 3 implant placement.88 In a con-trolled clinical study, type 1 implant placement wascompared in 17 tooth sites with apical pathology and17 sites without apical pathology in 32 subjects.89

After 12 months, the survival rates for both groupswere 100%. It should be noted that 5 sites (4 with api-cal pathology and 1 without apical pathology) werewithdrawn due to lack of initial implant stability.

Immediate Loading. The data on survival of imme-diately loaded implants placed into postextractionsites are unclear. Although high survival rates rangingfrom 91% to 100% (median 100%) were reported in anumber of prospective case series studies of immedi-ate restoration of single-tooth, short-span, and full-arch cases,55,56,64,70,76,78,80,102 comparative studieshave reported lower survival rates of 65% to 100%(median 91%) for type 1 implants compared to 94%to 100% (median 95%) for implants with type 4 place-ment for similar clinical indications.53,66,92,96,98,99 In astudy in which implants were placed into extractionsockets of teeth with chronic periodontitis, a muchlower survival rate was observed with type 1 place-ment (65%) compared to implants placed into healed(type 4) placement sites (94%).99

Implant Sites. The majority of reports with type 1placement were confined to single-root extraction

The International Journal of Oral & Maxillofacial Implants 205

Group 4

186_4a_Chen.qxd 9/10/09 10:16 AM Page 205

sites in the maxillary and mandibular anterior andpremolar regions. Several studies provided data onimplants placed into multiroot extractionsites.60,63,69,79,100,101 The survival rates of 89% to 100%(median 99.5%) were similar to the results forimplants in single-root extraction sites.

Systemic Risk Factors. One study reporting on theeffect of systemic conditions on postextractionimplant survival was identified.97 In this retrospectivestudy comparing type 1 and type 4 implant place-ment, no postoperative complications or implant fail-ures were observed in 61 patients who were on oralbisphosphonate therapy.

Esthetic Outcomes of Postextraction ImplantsEsthetic outcomes of postextraction implants werereported in 17 prospective20,50,56,66,70,72,76–78,82,

83,86,88,93,103–105 and 7 retrospective studies.11,80,106–110

(Table 7).Esthetic outcomes were reported as changes in

the position of the midfacial mucosa and papillae,width of keratinized mucosa, radiographic location ofthe proximal bone, esthetic indices, and patient- andclinician-rated esthetic results. The majority of studiesreported on outcomes with single-tooth implantrestorations, predominantly in the maxillary anteriorand premolar regions.

The majority of studies were short term, with fol-low-up periods of 12 to 24 months. Three studiesreported on esthetic outcomes after mean observa-tion periods of 4 to 5 years.20,78,93 One study provideddata on a subset of patients who were followed for 6to 9 years.106

What Tissue Alterations Occur with PostextractionImplants? Changes in the level of the midfacialmucosa and height of the papillae have been reportedin studies using different placement protocols.

Midfacial Mucosa. Three studies reported thatmean recession of the midfacial mucosa rangingfrom 0.5 to 0.9 mm (median 0.75 mm) occurred withtype 1 implant placement.70,76,107 One of these stud-ies used an immediate restoration protocol in whichimplants were placed without elevation of surgicalflaps.76 In a retrospective study of type 1 implantplacement without flap elevation in 85 single maxil-lary central and lateral incisor sites in 85 patients,mean recession of 4.6% of the length of the adjacentmaxillary central incisor was reported.110 With type 2placement, one study reported 0.6 mm of recessionof the facial mucosa.86 In a study comparing type 2and type 3 placement, mean recession of 0.6 mm and0.7 mm was reported, respectively. Over 5 years, fur-ther recession of 0.3 mm occurred in the type 2placement group, whereas a reduction in recession of0.3 mm was observed in the type 3 placement

group.93 These dimensional changes are similar tothose found in reports of single-tooth implants inhealed sites (type 4 implant placement).111–113

In addition to mean values, which express the mag-nitude of change, frequency analyses provide a usefulway to examine the trends in soft tissue recession.107

Frequency of recession with type 1 placement wasreported in eight studies.20,50,83,88,103,104,107,110 Reces-sion was reported in a high proportion of sites, rang-ing from 8.7% to 45.2% (median 39%). Five studiesreported that recession of 1 mm or greater wasobserved in 8% to 40.5% (median 21.4%) ofsites.50,83,88,103,107 In one study in which type 1implants were placed without elevation of surgicalflaps and restored 3 months later, recession of morethan 10% of the length of the adjacent reference max-illary central incisor occurred in 18% of sites.110

One retrospective case series study with 45 single-tooth implants using early placement (type 2)showed a low incidence of recession after 2 to 4 yearsof follow-up.11 This low incidence of recession wasconfirmed in a prospective study of type 2 placementby the same authors.72 Only one out of 20 sites (5%)exhibited recession, and this was between 0.5 and 1.0mm. In contrast, a prospective pilot study comparingtype 2 and type 3 placement reported a much higherfrequency of recession in both treatment groups. Theauthors observed that the clinical crowns of theimplant restorations were longer than the contralat-eral natural teeth in 9 of 10 and 8 of 10 sites, respec-tively. The difference in frequency of recessionreported in these studies may be due to the differentapproaches to bone augmentation used by theauthors. Gotfredsen used e-PTFE membranes whendefects of the facial bone were present, but with noadjunctive bone grafts.93 In addition, the utilizationof e-PTFE membranes required a second open flapprocedure for membrane removal, causing additionalmorbidity and local bone resorption. In contrast,Buser and coworkers grafted the peri-implant defectsand external surfaces of the facial bone with DBBMand covered the graft with a resorbable collagenmembrane, which did not require a second open-flapprocedure.12,72 DBBM is a xenograft reported to havea low substitution rate114 and therefore exhibits lowdimensional change over time.

There were three studies of type 1 placement withimmediate restoration that reported on changes tothe midfacial mucosa. Kan et al reported that meanrecession of 0.5 ± 0.53 mm occurred after 12months.76 Wohrle observed that recession of 1 mm to1.5 mm occurred in 2 out of 14 (14.3%) sites.103 In aprospective study in which type 1 implants withdefects of the facial aspect were immediatelyrestored, recession of greater than 1.5 mm was

206 Volume 24, Supplement, 2009

Chen/Buser

186_4a_Chen.qxd 9/10/09 10:16 AM Page 206

The International Journal of Oral & Maxillofacial Implants 207

Group 4

Tabl

e 7

Clin

ical

Stu

dies

Rep

orti

ng o

n Es

thet

ic P

aram

eter

s w

ith

Pos

text

ract

ion

Impl

ants

Hea

ling

No.

of

prot

ocol

/pa

tien

tsC

hang

e in

mid

faci

al m

ucos

aC

hang

e in

Stu

dy

Pla

cem

ent

load

ing

(No.

of

Follo

w-u

ppa

pilla

e Es

thet

ic

Stu

dyde

sign

prot

ocol

prot

ocol

impl

ants

)pe

riod

Freq

uenc

yM

ean

heig

htou

tcom

es

Woh

rle

(19

98

)103

Gru

nder

(2

00

0)8

6

Kan

et a

l (2

00

3)76

Mal

o et

al

(20

03

)66

Bia

nchi

and

S

anfil

ippo

(2

00

4)10

6

Got

fred

sen

(20

04

)93

Pros

p C

S

Pros

p C

S

Pros

p C

S

Pros

p C

S

Ret

ro C

S

Pros

p C

S

Type

1

Type

1

Type

1

Type

1

Type

1

Type

2 (4

wk

afte

rex

trac

tion)

and

Type

3 (1

2 w

kaf

ter

extr

actio

n)

Tran

smuc

osal

/Im

med

iate

rest

orat

ion

Subm

erge

d/D

elay

ed

Tran

smuc

osal

/Im

med

iate

rest

orat

ion

Tran

smuc

osal

/Im

med

iate

rest

orat

ion

Subm

erge

d/D

elay

ed

Subm

erge

d/D

elay

ed

14 (1

4)

10 (1

0)

35 (3

5)

67 (8

5)

22 (2

2) te

stsi

tes

(con

-ne

ctiv

e tis

-su

e gr

afts

at th

e tim

eof

impl

ant

plac

emen

t)20

(20)

cont

rol s

ites

Type

2: 1

0(1

0)

Type

3: 1

0(1

0)

1 to

3 y

12

mo

12

mo

12

mo

6 to

9 y

5 y

14.3

%; r

eces

sion

1 to

1.5

mm

NR

NR

Muc

osal

rece

ssio

nob

serv

ed in

1 p

atie

nt

6- to

9-y

ear f

ollo

w-u

p:R

eces

sion

> 1

mm

in5%

of t

est a

nd 2

0% o

fco

ntro

l site

s

Rec

essi

on a

t bas

elin

e:Ty

pe 2

: 9/1

0 cr

owns

long

er th

an c

ontr

ol to

oth

Type

3: 8

/10

crow

nslo

nger

than

con

trol

teet

h

NR

0.6

mm

(med

ian

0.5

mm

;ra

nge

0 to

1.5

mm

)

0.5

± 0.

53 m

m

NR

NR

Type

2: 0

.6 ±

1.2

mm

incr

ease

d by

0.3

± 0

.5m

m a

fter

5 y

Type

3: 0

.7 ±

1.4

mm

redu

ced

by 0

.3 ±

0.6

mm

afte

r 5 y

NR

NR

Patie

nt e

valu

atio

n of

est

hetic

out

-co

me

(Rat

ing

0 to

10

; 0 =

tota

llyun

satis

fied,

10

= to

tally

sat

isfie

d):

33

/35

pat

ient

s w

ere

tota

lly s

atis

fied

with

the

esth

etic

out

com

e (r

ated

10

)2/

35 p

atie

nts

rate

d th

e ou

tcom

e as

9M

ean

patie

nt-ra

ted

esth

etic

out

-co

me

9.9

Den

tist e

valu

atio

n at

1 y

:Ex

celle

nt 1

8/6

7 p

atie

nts

Goo

d 41

/67

Acce

ptab

le 6

/67

Una

ccep

tabl

e 2

/67

Patie

nt e

valu

atio

n at

1 y

:Al

l pat

ient

s w

ere

satis

fied

with

the

esth

etic

out

com

e N

R

Patie

nt e

valu

atio

n ba

sed

on a

Vis

ual

Anal

og S

cale

(VAS

):Ty

pe 2

: 9.8

(ran

ge 9

.1-1

0.0

)Ty

pe 3

: 8.8

(ran

ge 5

.1-1

0.0

)D

entis

t eva

luat

ion

usin

g th

e sa

me

VAS:

Type

2: 5

.9 (r

ange

2.9

-9.5

)Ty

pe 3

: 8.4

(ran

ge 6

.1-9

.7)

NR

Mea

n re

cess

ion

ofpa

pilla

0.4

mm

(med

ian

0.5

mm

;ra

nge

0 to

1 m

m)

Mea

n re

cess

ion

ofpa

pilla

0.5

3 ±

0. 4

mm

(mes

ial);

0.3

9 ±

0.4

mm

(dis

tal)

NR

NR

Gai

n in

pap

illa

heig

htof

0.3

± 0

.4 m

m fo

rty

pe 2

; gai

n of

1.0

±0.

7 m

m fo

r typ

e 3

betw

een

base

line

and

5 y

186_4a_Chen.qxd 9/10/09 10:16 AM Page 207

208 Volume 24, Supplement, 2009

Chen/Buser

Tabl

e 7

con

tinu

edC

linic

al S

tudi

es R

epor

ting

on

Esth

etic

Par

amet

ers

wit

h P

oste

xtra

ctio

n Im

plan

ts

Hea

ling

No.

of

prot

ocol

/pa

tien

tsC

hang

e in

mid

faci

al m

ucos

aC

hang

e in

Stu

dy

Pla

cem

ent

load

ing

(No.

of

Follo

w-u

ppa

pilla

e Es

thet

ic

Stu

dyde

sign

prot

ocol

prot

ocol

impl

ants

)pe

riod

Freq

uenc

yM

ean

heig

htou

tcom

es

Can

gini

and

C

orne

lini

(20

05

)77

Cor

nelin

i et a

l (2

00

5)7

0

Sch

ropp

et a

l (2

00

5)10

4

Bar

one

et a

l (2

00

6)5

6

Lind

eboo

m

et a

l (2

00

6)8

8

De

Kok

et a

l (2

00

6)8

0

Ferr

ara

et a

l (2

00

6)7

8

Che

n et

al

(20

07

)20

Juod

zbal

ys a

ndW

ang

(20

07

)83

Pros

p C

CS

Pros

p C

S

RC

T

Pros

p C

S

RC

T

Ret

ro C

S

Pros

p C

S

RC

T

Pros

p C

S

Type

1

Type

1

Mea

n 10

d po

stex

-tr

actio

nTy

pe 3

Type

1

Type

1 a

ndTy

pe 3

Type

1

Type

1

Type

1

Type

1

Tran

smuc

osal

/D

elay

ed

Tran

smuc

osal

/Im

med

iate

rest

orat

ion

Subm

erge

d/Co

nven

tiona

l

Tran

smuc

osal

/Im

med

iate

rest

orat

ion

Subm

erge

d/D

elay

ed

Tran

smuc

osal

/Im

med

iate

rest

orat

ion

Tran

smuc

osal

/Im

med

iate

rest

orat

ion

Subm

erge

d/Co

nven

tiona

lSu

bmer

ged/

Del

ayed

32 (3

2)

22 (2

2)

Mea

n 10

dpo

stex

trac

-tio

n 23

(23)

Type

3: 2

3(2

3)18

(18)

Type

1: 2

5(2

5)Ty

pe 3

: 25

(25)

20 (2

5)

33 (3

3)

19 (1

9)

12 (1

4)

12

mo

12

mo

2 y

12

mo

Mea

n1

2.4

mo

6 to

30

mo

4 y

4 y

12

mo

NR

NR

8.7%

exp

osur

e of

met

alm

argi

n

Wid

th o

f ker

atin

ized

muc

osa

3.3

± 0.

5 m

m; n

osi

gnifi

cant

cha

nge

from

base

line

26%

site

s w

ith re

cess

ion

No

rece

ssio

n in

56%

of

type

1 p

lace

men

ts a

nd84

% o

f typ

e 3

Rec

essi

on 0

to 1

mm

in28

% o

f typ

e 1

plac

emen

tsan

d 16

% o

f typ

e 3

Rec

essi

on 1

to 2

mm

in8%

of t

ype

1 pl

acem

ents

(non

e fo

r typ

e 3)

NR

NR

33.3

% o

f site

s w

ith re

ces-

sion

21.4

% w

ith re

cess

ion

of 1

to 2

mm

0.2

± 1.

5 m

m a

t site

str

eate

d w

ith e

nam

elm

atrix

der

ivat

ive

and

0.9

± 1.

3 m

m a

t site

s w

ith c

ol-

lage

n m

embr

ane

Mea

n re

cess

ion

0.75

mm

NR

NR

NR

NR

NR

NR

NR

NR

NR

All p

atie

nts

wer

e hi

ghly

sat

isfie

dw

ith th

e es

thet

ic o

utco

me

All p

aten

ts w

ere

satis

fied

with

the

esth

etic

out

com

e

NR

NR

Patie

nt-ra

ted

esth

etic

out

com

e;S

core

of 9

.3 ±

0.6

5 (u

sing

a 1

0-

poin

t sca

le, w

ith 0

= c

ompl

etel

yun

satis

fact

ory

and

10 =

com

plet

ely

satis

fact

ory)

NR

Pink

Est

hetic

Sco

re (P

ES)†

of 1

1.1

64

.3%

of c

ases

with

inco

mpl

ete

mes

ial a

nd d

ista

l pap

illae

42

.9%

of c

ases

with

alv

eola

rpr

oces

s de

ficie

ncy

NR

Jem

t Pap

illa

Inde

x*:

Scor

e 2:

61%

of p

apill

aeSc

ore

3: 3

9% o

f pap

illae

No

scor

es o

f 0, 1

, and

4

Jem

t Pap

illa

Inde

x*:

Sco

re 2

: 33

% o

f pap

il-la

eS

core

3: 8

% o

f pap

illae

NR

Jem

t Pap

illa

Inde

x*:

Scor

e 2

in 2

2% o

f typ

e1

and

28%

of t

ype

3im

plan

t pla

cem

ent s

ites

Scor

e 3

in 7

8% o

f typ

e1

and

72%

of t

ype

3im

plan

t pla

cem

ent s

ites

Jem

t Pap

illa

Inde

x*:

Scor

e 1:

64%

of p

apill

aeSc

ore

2: 3

2% o

f pap

illae

Scor

e 3:

4%

of p

apill

aePa

pilla

e w

hen

initi

ally

pres

ent w

ere

neve

r los

t

NR

Jem

t Pap

illa

Inde

x*:

Scor

e 2:

64%

of p

apill

aeSc

ore

3: 3

6% o

f pap

illae

186_4a_Chen.qxd 9/10/09 10:16 AM Page 208

The International Journal of Oral & Maxillofacial Implants 209

Group 4

Tabl

e 7

con

tinu

edC

linic

al S

tudi

es R

epor

ting

on

Esth

etic

Par

amet

ers

wit

h P

oste

xtra

ctio

n Im

plan

ts

Hea

ling

No.

of

prot

ocol

/pa

tien

tsC

hang

e in

mid

faci

al m

ucos

aC

hang

e in

Stu

dy

Pla

cem

ent

load

ing

(No.

of

Follo

w-u

ppa

pilla

e Es

thet

ic

Stu

dyde

sign

prot

ocol

prot

ocol

impl

ants

)pe

riod

Freq

uenc

yM

ean

heig

htou

tcom

es

Cov

ani e

t al

(20

08

)82

Kan

et a

l (2

00

7)5

0

Ste

igm

ann

et a

l (2

00

7)10

5

Evan

s an

d C

hen

(20

08

)107

Deg

idi e

t al

(20

08

)108

Deg

idi e

t al

(20

08

)10

9

Bus

er e

t al

(20

08

)11

Bus

er e

t al

(20

09

)72

Pros

p C

S

Pros

p C

S

Pros

p C

S

Ret

ro C

S

Ret

ro C

S

Ret

ro C

S

Ret

ro C

S

Pros

p C

S

Type

1

Type

1

Type

1

Type

1

Type

1/

Type

4

Type

1

Type

2

Type

2

Subm

erge

d/D

elay

ed

Tran

smuc

osal

/Im

med

iate

rest

orat

ion

Tran

smuc

osal

/Im

med

iate

rest

orat

ion

NR

/Con

vent

iona

l

Tran

smuc

osal

/Im

med

iate

rest

orat

ion

Tran

smuc

osal

/Im

med

iate

rest

orat

ion

Subm

erge

d/Ea

rly

Subm

erge

d/Ea

rly

10 (1

0)

23 (2

3)

10 (1

0)

42 (4

2)

45 (5

2)

49 (1

52)

45 (4

5)

20 (2

0)

12

mo

12

mo

24

mo

Mea

n1

9 m

o

2 to

6 y

24

mo

2 to

4 y

12

mo

Mea

n 4.

1 m

m w

idth

of

kera

tiniz

ed m

ucos

a on

the

faci

al a

spec

t34

.8%

rec

essi

on ≥

1.5

mm

; 8.3

% o

f site

s w

ithV-

shap

ed d

efec

ts o

f the

faci

al b

one‡

42.8

% o

fsi

tes

with

U-s

hape

dde

fect

s of

the

faci

al b

one;

100%

of s

ites

with

UU

-sh

aped

def

ects

of t

hefa

cial

bon

eN

R

45.2

% re

cess

ion

0.5

mm

21.4

% r

eces

sion

1.0

mm

19.1

% re

cess

ion

≥ 1.

5m

mN

R

NR

NR

NR

NR

NR

NR

Mea

n re

cess

ion

0.9

±0.

78 m

m

NR

NR

NR

Mea

n di

ffere

nce

betw

een

test

and

con

tral

ater

al n

at-

ural

teet

h 0.

18 m

mO

ne s

ite w

ith re

cess

ion

of0.

5 to

1.0

mm

NR

NR

All p

atie

nts

extr

emel

y sa

tisfie

d w

ithth

e es

thet

ic o

utco

me

Sub

ject

ive

Esth

etic

Sco

re (S

ES)§

82

% s

atis

fact

ory

(sco

res

I and

II)

18%

uns

atis

fact

ory

(sco

res

III a

nd IV

)

NR

Mul

tiple

adj

acen

t im

plan

ts

No

rece

ssio

n of

the

mid

faci

alm

ucos

a w

as o

bser

ved

Mea

n m

odifi

ed P

ES||

of 8

.1(o

ut o

f 10

)M

ean

WES

¶of

8.6

5(o

ut o

f 10

)

NR

NR

9/1

0 s

ites

with

slig

htbl

untin

g of

the

papi

llae

Mea

n re

cess

ion

ofpa

pilla

0.5

± 0

. 52

mm

(mes

ial);

0.5

± 1

.0 m

m(d

ista

l)Je

mt P

apill

a In

dex

for

type

1 a

nd ty

pe 4

impl

ant p

lace

men

t com

-bi

ned:

Scor

e 1

: 14

.5%

of

papi

llae

Scor

e 2:

50%

of p

apill

aeSc

ore

3: 3

5.5

% o

fpa

pilla

eC

ombi

ned

Jem

t Pap

illa

Inde

x sc

ores

2 a

nd 3

decr

ease

d w

hen

two

impl

ants

wer

e pl

aced

≥ 4

mm

apa

rt w

hen

the

bone

cre

st to

con

tact

poin

t bet

wee

n to

impl

ant c

row

ns w

as

> 6

mm

NR

NR

186_4a_Chen.qxd 9/10/09 10:16 AM Page 209

210 Volume 24, Supplement, 2009

Chen/Buser

Tabl

e 7

cont

inue

dC

linic

al S

tudi

es R

epor

ting

on

Esth

etic

Par

amet

ers

wit

h P

oste

xtra

ctio

n Im

plan

ts

Hea

ling

No.

of

prot

ocol

/pa

tien

tsC

hang

e in

mid

faci

al m

ucos

aC

hang

e in

Stu

dy

Pla

cem

ent

load

ing

(No.

of

Follo

w-u

ppa

pilla

e Es

thet

ic

Stu

dyde

sign

prot

ocol

prot

ocol

impl

ants

)pe

riod

Freq

uenc

yM

ean

heig

htou

tcom

es

Che

n et

al

(20

09

)110

Stu

dy d

esig

n: P

rosp

= p

rosp

ectiv

e; R

etro

= r

etro

spec

tive;

RC

T =

ran

dom

ized

con

trol

led

tria

l; C

CS

= c

ontr

olle

d cl

inic

al s

tudy

; CS

= c

ase

serie

s.P

lace

men

t tim

e af

ter

extr

actio

n: T

ype

1 =

imm

edia

te p

lace

men

t at

the

tim

e of

ext

ract

ion;

Typ

e 2

= e

arly

pla

cem

ent

afte

r in

itial

sof

t tis

sue

heal

ing;

Typ

e 3

= e

arly

pla

cem

ent

afte

r su

bsta

ntia

l bon

e he

alin

g;Ty

pe 4

= la

te p

lace

men

t af

ter

com

plet

e he

alin

g of

the

rid

ge.

Aug

men

tatio

n m

etho

d: e

-PTF

E =

exp

ande

d po

lyte

traf

luor

oeth

ylen

e m

embr

ane;

DB

BM

= d

epro

tein

ized

bov

ine

bone

min

eral

; DFD

BA

= d

emin

eral

ized

fre

eze-

drie

d bo

ne a

llogr

aft;

HA

= h

ydro

xyap

atite

.Lo

adin

g pr

otoc

ols

acco

rdin

g to

the

ITI C

onse

nsus

Con

fere

nce

(200

3).12

4

NR

= n

ot r

epor

ted.

*Pap

illa

Inde

x S

core

as

desc

ribed

by

Jem

t (1

997)

.118

† PE

S =

Pin

k E

sthe

tic S

core

of

Furh

ause

r et

al (

2005

): S

even

var

iabl

es a

sses

sed

in r

elat

ion

to r

efer

ence

too

th a

nd a

ssig

ned

scor

es o

f 0,

1, o

r 2

out

of a

tot

al p

ossi

ble

scor

e of

14,

for

i, s

hape

of

mes

ial p

apill

a;ii,

sha

pe o

f di

stal

pap

illa;

iii,

leve

l of

soft

tis

sue

mar

gin;

iv, s

oft

tissu

e co

ntou

r; v

, alv

eola

r pr

oces

s de

ficie

ncy;

vi,

soft

tis

sue

colo

r; v

ii, s

oft

tissu

e te

xtur

e.12

1

‡ Deh

isce

nce

defe

ct o

n fa

cial

asp

ect

of t

he im

plan

t cl

assi

fied

as: V

-sha

ped,

nar

row

def

ect

isol

ated

to

faci

al s

urfa

ce o

f im

plan

t on

ly; U

-sha

ped,

wid

e de

fect

ext

endi

ng p

roxi

mal

ly in

to t

he m

esia

l or

dist

al a

spec

ts o

fth

e to

oth

to b

e ex

trac

ted;

UU

def

ect,

wid

e de

fect

ext

endi

ng t

o an

d in

clud

ing

the

mes

ial o

r di

stal

sur

face

s of

the

adj

acen

t te

eth.

102

§ S

ubje

ctiv

e E

sthe

tic S

core

(SE

S):10

7I =

ver

tical

fac

ial c

hang

e w

as 0

.5 m

m o

r le

ss a

nd la

bial

tis

sue

fulln

ess

was

in h

arm

ony

with

the

adj

acen

t te

eth;

II =

ver

tical

fac

ial c

hang

e w

as b

etw

een

0.5

and

1.0

mm

and

the

faci

al t

issu

e fu

llnes

s w

as in

har

mon

y; II

I = v

ertic

al f

acia

l cha

nge

was

bet

wee

n 1.

0 an

d 1.

5 m

m o

r th

e fa

cial

tis

sue

appe

ars

defic

ient

in c

onto

ur; I

V =

ver

tical

fac

ial c

hang

e w

as g

reat

er t

han

1.5

mm

and

ade

ficie

ncy

in f

acia

l tis

sue

cont

our

was

not

ed.

|| Mod

ified

Pin

k E

sthe

tic S

core

(mod

PE

S) o

f Fu

rhau

ser

et a

l (20

05)12

1 : F

ive

varia

bles

ass

esse

d in

rel

atio

n to

ref

eren

ce t

ooth

and

ass

igne

d sc

ores

of

0 , 1

, or

2 ou

t of

a t

otal

pos

sibl

e sc

ore

of 1

0, f

or i,

sha

pe o

fm

esia

l and

dis

tal p

apill

ae; i

i, le

vel o

f so

ft t

issu

e m

argi

n; ii

i, so

ft t

issu

e co

ntou

r; iv

, alv

eola

r pr

oces

s; v

, sof

t tis

sue

colo

r an

d te

xtur

e.¶

Whi

te E

sthe

tic S

core

(WE

S):

Sco

res

of 0

, 1, a

nd 2

ass

igne

d ou

t of

a t

otal

pos

sibl

e sc

ore

of 1

0, f

or I,

too

th f

orm

; ii,

toot

h vo

lum

e/ou

tline

; iii,

col

or; i

v, s

urfa

ce t

extu

re; a

nd v

, tra

nslu

cenc

y.72

# Tis

sue

leve

l cha

nge

expr

esse

d as

a p

erce

ntag

e of

the

leng

th o

f th

e ad

jace

nt m

axill

ary

cent

ral i

ncis

or w

hich

ser

ved

as t

he r

efer

ence

.

Ret

ro C

STy

pe 1

Tran

smuc

osal

/Ea

rly85

(85)

26

mo

At 4

4 si

tes

with

initi

al g

in-

giva

l mar

gins

leve

l with

adja

cent

max

illar

y ce

ntra

lin

ciso

r: 2

0.5%

rece

ssio

n5

to 1

0%;1

8% re

cess

ion

of >

10%

Mea

n re

cess

ion

of 4

.6 ±

6.6%

#

Subj

ectiv

e Es

thet

ic S

core

(SES

)§

42.4

% g

ood

(sco

re I)

38.8

% a

ccep

tabl

e (s

core

II)

9.4%

uns

atis

fact

ory

(sco

res

III a

nd IV

)M

ean

PES†

of 1

0.95

(out

of 1

4)

21.2

% o

ptim

um (s

core

s 13

and

14

)56

.5%

goo

d (s

core

s 10

to 1

2)22

.3%

sub

optim

al (s

core

8 o

r 9)

Mea

n re

cess

ion

ofpa

pilla

e 6

.2%

± 6

.8%

(mes

ial)#

; 7.4

% ±

7.5

%(d

ista

l)#

186_4a_Chen.qxd 9/10/09 10:16 AM Page 210

observed in 34.8% of sites.50 Chen et al observed thatmucosal recession occurred soon after restoration ofthe implants, and then remained stable between the1-year and 3-year recall periods.20

One RCT compared type 1 and type 3 placementin sites with radiographic evidence of chronic periapi-cal periodontitis.88 Absence of recession was noted inonly 56% of immediate implant (type 1) sites, com-pared to 84% for early placement (type 3). Recessionof 1 to 2 mm was observed in 8% of type 1 implantsites. In contrast, there were no sites with recession of1 to 2 mm in the type 3 placement group.

In an RCT comparing implant placement soonafter tooth extraction (mean 10 days) with earlyplacement after partial bone healing (type 3), reces-sion of the mucosal margin resulting in exposure ofthe metal margin of the implants was observed in8.7% of implants in each of the two groups after 2years.104 The height of the implant crowns was sub-jectively determined to be too long in 17% of the 10-day postextraction sites and 20% of type 3 implantplacement sites, and too short in 30% of type 3implant placement sites. The crowns were of anappropriate height in 83% of the 10-day postextrac-tion sites and only 50% of type 3 implant sites.

Data on long-term outcomes are limited. However,one study provided data on a subset of patients whowere followed for 6 to 9 years, with implants placed inboth anterior and posterior sites.106 Twenty-twopatients received 22 single-tooth type 1 implants thatwere submerged at the time of surgery using connec-tive tissue grafts. Twenty patients with 20 immediateimplants that were placed without the use of connec-tive tissue (CT) grafts served as controls. Between 6and 9 years following surgery, the proportion of siteswith recession greater than 1 mm (in relation to adja-cent teeth) was 5% in test sites compared to 20% incontrol sites. It was not possible to distinguishbetween anterior and posterior sites from the study.

From these studies, it can be concluded that reces-sion of the midfacial mucosa, even when combinedwith grafts of bone or bone substitutes, is a commoncomplication with type 1 placement. The recessionoccurs soon after restoration of the implants. Reces-sion of 1 mm or more was observed in a high propor-tion (range 8% to 40.5%; median 21.4%) of sites. Thisdimensional change may lie within the visual thresh-old of detecting a difference in mucosal levels.115

Mucosal recession would therefore be expected tohave an adverse effect on esthetic outcomes, as moststudies reported that implants were placed in themaxillary anterior and premolar sites. Recession wasalso observed with immediate restoration ofimplants, and implants placed without elevation ofsurgical flaps.

Early placement (type 2 and type 3) may also beassociated with recession. However, there is evidenceto suggest that early placement with soft tissue heal-ing (type 2) is associated with a relatively low inci-dence of recession when implant placement iscombined with GBR procedures using DBBM. There isevidence that early placement with partial bone heal-ing (type 3) is associated with a lower frequency ofrecession compared to type 1 placement.

Papillae. With type 1 placement, a mean loss ofpapilla height of between 0.5 and 0.6 mm wasreported in three studies.76,86,107 Changes in papillaheight were similar for conventional loading andimmediate restoration protocols. In a prospectivestudy of type 1 placement using the crown of thenatural tooth as an immediate restoration, slightblunting of the papilla was reported in 9 out of 10treated sites.105 In a retrospective study of type 1placement with immediate restoration, 64% of sitesachieved a satisfactory papilla form.80 Loss of papillaheight was accompanied by a reduction in the heightof the proximal crestal bone of 0.3 to 1.9 mm (median1.2 mm).56,66,70,76,83,105 Less than ideal papilla fill wasreported for adjacent implants when the interimplantdistance was less than 2 mm.109

Four studies used the Papilla Index of Jemt todescribe the form of the papillae with immediateplacement.70,83,88,108 The results were variable. In thefour studies, a score of 3 (indicating complete fill ofthe proximal embrasure space) was recorded in 35%to 78% (median 37%) of sites. A score of 2 (indicatingthat half or more of the papilla height was present,but not 100%) was recorded in 22% to 64% (median55%) of sites. A score of 1 (indicating that less thanhalf of the papilla height was present) was onlyrecorded in one study, affecting 14.5% of sites108;three studies reported that no sites recorded a scoreof 1. In studies of immediate restoration ofimplants70,108 there was no clear advantage overstudies using conventional loading protocols83,114

according to this index.Two studies provided comparative data on differ-

ent placement times after extraction. One RCTreported that the risk of a missing papilla or negativepapilla form at the time of restoration was 7.2 timesgreater for type 3 compared to type 2 implant place-ment (33% of sites vs 8% of sites, respectively).104

However, after 1.5 years there was no differencebetween the groups (8% for type 2 placement and 3%for type 3 placement). Overall, 5% of sites had a scoreof 0, 35% had a score of 1, and 60% had a score of 2.Another RCT comparing type 1 and type 2 implantplacement showed no difference between treatmentgroups.88 Studies of type 4 implant placement havereported similar variations in papilla fill.116,117

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The main disadvantage of the Papilla Index ofJemt118 is that scores are based on the degree of fillof the embrasure space after the crown has beenattached to the implant, and not on a comparisonwith the pretreatment form and height of the papillaprior to tooth extraction. Implant crowns will oftenhave an altered width and contact area to compen-sate for a reduction in height of the papilla.119 Thismakes it difficult to compare results between studieswith this index. Several studies reported that the formof the papilla improved over time with postextractionimplants,80,104 a phenomenon also reported withtype 4 placement.116–118

The results of these studies show that type 1placement is associated with recession of the papil-lae.The majority of sites achieved fill of the interproxi-mal embrasure space of at least half of the height, butachieving complete fill was variable.There is evidenceto suggest that the final form of the papillae withtype 1 placement using immediate restoration andconventional loading is similar. Similar outcomeshave been reported with type 4 placement. Two RCTsprovide strong evidence that the final form of thepapillae is independent of the timing of implantplacement after tooth extraction.

Width of Keratinized Mucosa. Three studiesreported on the width of the keratinized mucosa onthe facial aspect following type 1 placement. Themean width was 3.3 mm and 4.1 mm in two stud-ies.56,82 In a third study, 92.9% of sites had a width ofkeratinized mucosa greater than 2 mm.83 Thesedimensions are in accord with studies of type 4implant placement.116,119 The width of keratinizedmucosa was greater when type 1 implants were sub-merged using connective tissue (CT) grafts, com-pared to sites that did not receive CT grafts.106

What Factors Are Associated with Recession ofthe Mucosa? Several factors have been associatedwith recession of the peri-implant mucosa.

Tissue Biotype. With type 1 placement, sites with athin tissue biotype had a higher frequency of reces-sion of > 1 mm than sites with a thick tissue bio-type.20,76,107

Facial Bone Wall. Kan et al reported that damage tothe facial bone wall encountered at the time of type 1placement represented a significant risk factor formucosal recession.50 In 23 patients, implants wereplaced into fresh extraction sites with a damagedfacial bone wall. The defects were grafted with DBBMand covered with a resorbable membrane. The resultsindicate that the risk of recession increased with thewidth of the dehiscence of the facial bone. Only 8.3%of sites with narrow (V-shaped) defects exhibitedrecession of 0.5 mm or more. Recession for sites withwide (U-shaped) defects and defects that involved

the adjacent teeth (UU-shaped defects) was 42.8%and 100%, respectively.

The thickness of the facial bone at the time ofimplant placement may be an important factor. In anRCT, Chen et al noted three residual defect types fol-lowing type 1 placement.20 Sites that healed withcomplete bone fill or a residual craterlike defect hadan initial thickness of the facial bone of 0.7 to 0.9 mmand recorded vertical loss of crestal bone height of0.3 to 0.9 mm at reentry. In contrast, sites that healedwith a dehiscence defect initially had a facial bonethickness of 0.5 mm and recorded vertical crestalbone loss of 2.1 mm at reentry. Thus extraction sock-ets with thin facial bone lost more vertical height andhad less bone fill than sites with thicker bone.

Orofacial Position of the Implant Shoulder. The orofa-cial position of the implant shoulder in the extractionsocket with type 1 placement is strongly associatedwith mucosal recession. In three studies, implants thatwere placed facially within the sockets had a higherfrequency and greater magnitude of recession thansites where implants were more palatally posi-tioned.20,107,110 At sites with recession, the implantshad a significantly greater orofacial defect depth of2.3 mm compared to 1.1 mm for sites with no reces-sion.20 This is consistent with the observation that aperi-implant gap with type 1 implant placement isrequired to minimize compression of the facial bonewall on inserting the implant, and to allow boneregeneration in the gap to establish a thicker facialbone wall.120 These clinical observations have beencorroborated in an experimental study of implants infresh extraction sockets in a canine model.49 Less ver-tical crestal bone loss was observed when the peri-implant defects were wide, compared to sites wherethe defects were less than 2 mm in width.

What Are the Outcomes Based on EstheticIndices? Esthetic indices were used in four studies.Based on the Pink Esthetic Score (PES),121 a meanscore of 11.1 (out of a maximum 14) was reported in aprospective study of 14 immediate implants in 12patients.83 In this study, 64.3% of cases had incom-plete fill of the papillae, and 42.9% had deficiencies inthe alveolar process. In a retrospective study of 85maxillary central and lateral incisors, a mean PES of10.95 was recorded.110 Optimum esthetic results wereachieved in 21.23% of sites (PES scores of 13 and 14).Suboptimal esthetic outcomes (PES scores of 8 and 9)were seen in 22.3% of sites. Using an alternative scor-ing system, 82% of sites had a satisfactory estheticoutcome with type 1 placement in a retrospectivestudy of 42 implants in 42 patients.107 A total of 18%of sites had an unsatisfactory outcome, mainly due torecession of the midfacial mucosa. In a prospectivecase series study with 20 single-tooth implants using

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early placement (type 2), the 12-month results exhib-ited a mean modified PES index of 8.1, and a meanWES index of 8.65 (both out of a maximum of 10).72

Studies reporting on patient-evaluated estheticoutcomes generally reported that patients werehighly satisfied with the results with immediate (type1) placement56,66,76,105 and early placement (type 2and type 3)104 irrespective of the loading protocol.

Although there has been increased interest in andreporting of esthetic outcomes with postextractionimplants since the Third ITI Consensus Conference in2003, there are still relatively few studies at the cur-rent time that evaluate esthetic outcomes usingobjective parameters.

CONCLUSIONS

Regenerative Outcomes of PostextractionImplantsFrom the studies reviewed, it can be concluded that:

• Bone augmentation procedures are effective inpromoting bone fill and defect resolution in peri-implant defects following immediate (type 1) andearly (type 2) placement.

• Peri-implant defects associated with immediate(type 1) and early (type 2) placement may healspontaneously when the peri-implant defect isless than 2 mm in width and the facial bone wall isintact.

• Immediate placement does not prevent vertical orhorizontal resorption of the ridges.

• Bone augmentation combined with immediateplacement may reduce horizontal resorption, butdoes not prevent vertical resorption of the facialbone.

• Bone augmentation procedures are more success-ful in combination with immediate (type 1) andearly (type 2 and type 3) placement compared tolate placement (type 4).

• Evidence is lacking to demonstrate the superiorityof one placement protocol over the other withrespect to healing of peri-implant defects withpostextraction implants. However, there is someevidence to show that regenerative outcomes arebetter with early placement (type 2) compared toimmediate placement (type 1) in the presence ofdehiscence defects of the facial bone wall.

• Postoperative complications are common withimmediate placement.

• The efficacy of concomitant antibiotic therapywith regard to healing of postextraction implantshas not been demonstrated.

Survival Outcomes of Postextraction Implants

• The survival rates for postextraction implants arehigh, with the majority of studies reporting ratesof over 95%.

• Immediate (type 1) and early (type 2) placementprotocols have similar survival rates.

• There is some evidence to suggest that implantswith a machined surface have a lower survival out-come than implants with a roughened surface.

• There is no evidence to show that systemic antibi-otics affect the survival outcome of postextractionimplants.

• A history of chronic periodontitis is a risk indicatorfor survival of postextraction implants.The evidencefor periapical pathology and immediate restorationas risk indicators is contradictory. Evidence for sys-temic factors as risks for implant survival is lacking.

Esthetic Outcomes of Postextraction Implants

• Tissue alterations leading to recession of the facialmucosa and papillae are common with immediateplacement.

• There is evidence that early placement (type 2 andtype 3) is associated with a lower frequency ofmucosal recession compared to immediate place-ment (type 1).

• Risk indicators for recession with immediate place-ment include a thin tissue biotype, a facial malpo-sition of the implant, and a thin or damaged facialbone wall.

• There is evidence to suggest that immediaterestoration and conventional loading protocolsappear to have similar outcomes with respect tosoft tissue alterations.

• Although patient-evaluated esthetic outcomeswith postextraction implants are generally favor-able, there are relatively few studies that evaluateesthetic outcomes using objective parameters.

REFERENCES

1. Schropp L, Isidor F.Timing of implant placement relative totooth extraction. J Oral Rehabil 2008;35(suppl 1):33–43.

2. Chen S, Buser D. Implants in post-extraction sites: A literatureupdate. In: Buser D, Belser U, Wismeijer D (eds). ITI TreatmentGuide. Vol 3: Implants in extraction sockets. Berlin: Quintes-sence, 2008.

3. Esposito M, Grusovin MG, Worthington HV, Coulthard P. Inter-ventions for replacing missing teeth: Bone augmentationtechniques for dental implant treatment. Cochrane DatabaseSyst Rev 2006;(1):CD003607.

4. Penarrocha M, Uribe R, Balaguer J. Immediate implants afterextraction. A review of the current situation. Med Oral2004;9:234–242.

The International Journal of Oral & Maxillofacial Implants 213

Group 4

186_4a_Chen.qxd 9/10/09 10:16 AM Page 213

5. Chen ST, Wilson TG Jr, Hammerle CH. Immediate or earlyplacement of implants following tooth extraction: Review ofbiologic basis, clinical procedures, and outcomes. Int J OralMaxillofac Implants 2004;19(suppl):12–25.

6. Fugazzotto PA.Treatment options following single-rootedtooth removal: A literature review and proposed hierarchy oftreatment selection. J Periodontol 2005;76:821–831.

7. Beagle JR.The immediate placement of endosseous dentalimplants in fresh extraction sites. Dent Clin North Am2006;50:375–389.

8. Quirynen M, Van Assche N, Botticelli D, Berglundh T. Howdoes the timing of implant placement to extraction affectoutcome? Int J Oral Maxillofac Implants 2007;22(suppl):203–223.

9. Wilson TG, Weber HP. Classification of and therapy for areas ofdeficient bony housing prior to dental implant placement. IntJ Periodontics Restorative Dent 1993;13:451–459.

10. Mayfield LJA. Immediate, delayed and late submerged andtransmucosal implants. In: Lang NP, Karring T, Lindhe J (eds).Proceedings of the 3rd European Workshop on Periodontol-ogy: Implant Dentistry. Berlin: Quntessence, 1999:520–534.

11. Buser D, Bornstein MM, Weber HP, Grütter L, Schmid B, BelserUC. Early implant placement with simultaneous guided boneregeneration following single tooth extraction in the estheticzone: A cross-sectional, retrospective study in 45 patientswith a 2- to 4-year follow-up. J Periodontol2008;79:1773–1781.

12. Buser D, Chen ST, Weber HP, Belser UC. Early implant place-ment following single-tooth extraction in the esthetic zone:Biologic rationale and surgical procedures. Int J PeriodonticsRestorative Dent 2008;28:441–451.

13. Hämmerle CH, Chen ST, Wilson TG Jr. Consensus statementsand recommended clinical procedures regarding the place-ment of implants in extraction sockets. Int J Oral MaxillofacImplants 2004;19(suppl):26–28.

14. Gher ME, Quintero G, Assad D, Monaco E, Richardson AC. Bonegrafting and guided bone regeneration for immediate dentalimplants in humans. J Periodontol 1994;65:881–891.

15. Zitzmann NU, Naef R, Schärer P. Resorbable versus nonre-sorbable membranes in combination with Bio-Oss for guidedbone regeneration. Int J Oral Maxillofac Implants1997;12:844–852.

16. Prosper L, Gherlone EF, Redaelli S, Quaranta M. Four-year fol-low-up of larger diameter implants placed in fresh extractionsockets using a resorbable membrane or a resorbable allo-plastic material. Int J Oral Maxillofac Implants2003;18:856–864.

17. Schropp L, Kostopoulos L, Wenzel A. Bone healing followingimmediate versus delayed placement of titanium implantsinto extraction sockets: A prospective clinical study. Int J OralMaxillofac Implants 2003;18:189–199.

18. Cornelini R, Cangini F, Martuscelli G, Wennstrom J. Depro-teinized bovine bone and biodegradable barrier membranesto support healing following immediate placement of trans-mucosal implants: A short-term controlled clinical trial. Int JPeriodontics Restorative Dent 2004;24:555–563.

19. Chen ST, Darby IB, Adams GG, Reynolds EC. A prospective clin-ical study of bone augmentation techniques at immediateimplants. Clin Oral Implants Res 2005;16:176–184.

20. Chen ST, Darby IB, Reynolds EC. A prospective clinical study ofnon-submerged immediate implants: Clinical outcomes andesthetic results. Clin Oral Implants Res 2007;18:552–562.

21. Zitzmann NU, Schärer P, Marinello CP. Factors influencing thesuccess of GBR. Smoking, timing of implant placement,implant location, bone quality and provisional restoration. JClin Periodontol 1999;26:673–682.

22. Nemcovsky CE, Artzi Z. Comparative study of buccal dehis-cence defects in immediate, delayed, and late maxillaryimplant placement with collagen membranes: Clinical heal-ing between placement and second-stage surgery. J Peri-odontol 2002;73:754–761.

23. Covani U, Bortolaia C, Barone A, Sbordone L. Bucco-lingualcrestal bone changes after immediate and delayed implantplacement. J Periodontol 2004;75:1605–1612.

24. Nemcovsky CE, Artzi Z, Moses O, Gelernter I. Healing of mar-ginal defects at implants placed in fresh extraction sockets orafter 4-6 weeks of healing. A comparative study. Clin OralImplants Res 2002;13:410–419.

25. Gelb DA. Immediate implant surgery: Three-year retrospec-tive evaluation of 50 consecutive cases. Int J Oral MaxillofacImplants 1993;8:388–399.

26. Becker W, Becker BE, Polizzi G, Bergström C. Autogenous bonegrafting of bone defects adjacent to implants placed intoimmediate extraction sockets in patients: A prospectivestudy. Int J Oral Maxillofac Implants 1994;9:389–396.

27. Lang NP, Bragger U, Hämmerle CH, Sutter F. Immediate trans-mucosal implants using the principle of guided tissue regen-eration. I. Rationale, clinical procedures and 30-month results.Clin Oral Implants Res 1994;5:154–163.

28. Becker W, Dahlin C, Becker BE, et al.The use of e-PTFE barriermembranes for bone promotion around titanium implantsplaced into extraction sockets: A prospective multicenterstudy. Int J Oral Maxillofac Implants 1994;9:31–40.

29. Hämmerle CH, Bragger U, Schmid B, Lang NP. Successful boneformation at immediate transmucosal implants: A clinicalreport. Int J Oral Maxillofac Implants 1998;13:522–530.

30. Nemcovsky CE, Artzi Z, Moses O. Rotated split palatal flap forsoft tissue primary coverage over extraction sites with imme-diate implant placement. Description of the surgical proce-dure and clinical results. J Periodontol 1999;70:926–934.

31. Nemcovsky CE, Artzi Z, Moses O. Rotated palatal flap in imme-diate implant procedures. Clinical evaluation of 26 consecu-tive cases. Clin Oral Implants Res 2000;11:83–90.

32. Nemcovsky CE, Moses O, Artzi Z, Gelernter I. Clinical coverageof dehiscence defects in immediate implant procedures:Three surgical modalities to achieve primary soft tissue clo-sure. Int J Oral Maxillofac Implants 2000;15:843–852.

33. Van Steenberghe D, Callens A, Geers L, Jacobs R.The clinicaluse of deproteinized bovine bone mineral on bone regenera-tion in conjunction with immediate implant installation. ClinOral Implants Res 2000;11:210–216.

34. Rosenquist B, Ahmed M.The immediate replacement of teethby dental implants using homologous bone membranes toseal the sockets: Clinical and radiographic findings. Clin OralImplants Res 2000;11:572–582.

35. Covani U, Cornelini R, Barone A. Bucco-lingual bone remodel-ing around implants placed into immediate extraction sock-ets: A case series. J Periodontol 2003;74:268–273.

36. Yukna RA, Castellon P, Saenz-Nasr AM, et al. Evaluation of hardtissue replacement composite graft material as a ridgepreservation/augmentation material in conjunction withimmediate hydroxyapatite-coated dental implants. J Peri-odontol 2003;74:679–686.

37. Botticelli D, Berglundh T, Lindhe J. Hard-tissue alterations fol-lowing immediate implant placement in extraction sites. JClin Periodontol 2004;31:820–828.

38. Covani U, Cornelini R, Barone A. Vertical crestal bone changesaround implants placed into fresh extraction sockets. J Peri-odontol 2007;78:810–815.

39. Nir-Hadar O, Palmer M, Soskolne WA. Delayed immediateimplants: Alveolar bone changes during the healing period.Clin Oral Implants Res 1998;9:26–33.

214 Volume 24, Supplement, 2009

Chen/Buser

186_4a_Chen.qxd 9/10/09 10:16 AM Page 214

40. Nemcovsky CE, Artzi Z, Moses O, Gelernter I. Healing of dehis-cence defects at delayed-immediate implant sites primarilyclosed by a rotated palatal flap following extraction. Int J OralMaxillofac Implants 2000;15:550–558.

41. Hämmerle CH, Lang NP. Single stage surgery combiningtransmucosal implant placement with guided bone regener-ation and bioresorbable materials. Clin Oral Implants Res2001;12:9–18.

42. Paolantonio M, Dolci M, Scarano A, et al. Immediate implanta-tion in fresh extraction sockets. A controlled clinical and his-tological study in man. J Periodontol 2001;72:1560–1571.

43. Wilson TG Jr, Schenk R, Buser D, Cochran D. Implants placed inimmediate extraction sites: A report of histologic and histo-metric analyses of human biopsies. Int J Oral MaxillofacImplants 1998;13:333–341.

44. Cornelini R, Scarano A, Covani U, Petrone G, Piattelli A. Imme-diate one-stage postextraction implant: A human clinical andhistologic case report. Int J Oral Maxillofac Implants2000;15:432–437.

45. Camargo PM, Lekovic V, Weinlaender M, et al. Influence ofbioactive glass on changes in alveolar process dimensionsafter exodontia. Oral Surg Oral Med Oral Pathol Oral RadiolEndod 2000;90:581–586.

46. Iasella JM, Greenwell H, Miller RL, et al. Ridge preservationwith freeze-dried bone allograft and a collagen membranecompared to extraction alone for implant site development:A clinical and histologic study in humans. J Periodontol2003;74:990–999.

47. Araujo MG, Lindhe J. Dimensional ridge alterations followingtooth extraction. An experimental study in the dog. J ClinPeriodontol 2005;32:212–218.

48. Araujo MG, Sukekava F, Wennstrom JL, Lindhe J. Ridge alter-ations following implant placement in fresh extraction sock-ets: An experimental study in the dog. J Clin Periodontol2005;32:645–652.

49. Araujo MG, Wennstrom JL, Lindhe J. Modeling of the buccaland lingual bone walls of fresh extraction sites followingimplant installation. Clin Oral Implants Res 2006;17:606–614.

50. Kan JYK, Rungcharassaeng K, Sclar A, Lozada JL. Effects of thefacial osseous defect morphology on gingival dynamics afterimmediate tooth replacement and guided bone regenera-tion: 1-year results. J Oral Maxillofac Surg 2007;65(suppl1):13–19.

51. Rosenquist B, Grenthe B. Immediate placement of implantsinto extraction sockets: Implant survival. Int J Oral MaxillofacImplants 1996;11:205–209.

52. Pecora G, Andreana S, Covani U, De Leonardis D, Schifferle RE.New directions in surgical endodontics; immediate implanta-tion into an extraction site. J Endod 1996;22:135–139.

53. Chaushu G, Chaushu S, Tzohar A, Dayan D. Immediate loadingof single-tooth implants: Immediate versus non-immediateimplantation. A clinical report. Int J Oral Maxillofac Implants2001;16:267–272.

54. Covani U, Crespi R, Cornelini R, Barone A. Immediate implantssupporting single crown restoration: A 4-year prospectivestudy. J Periodontol 2004;75:982–988.

55. Vanden Bogaerde L, Rangert B, Wendelhag I. Immediate/earlyfunction of Bränemark System TiUnite implants in freshextraction sockets in maxillae and posterior mandibles: An18-month prospective clinical study. Clin Implant Dent RelatRes 2005;7(suppl 1):S121–S130.

56. Barone A, Rispoli L, Vozza I, Quaranta A, Covani U. Immediaterestoration of single implants placed immediately after toothextraction. J Periodontol 2006;77:1914–1920.

57. Watzek G, Haider R, Mensdorff-Pouilly N, Haas R. Immediateand delayed implantation for complete restoration of the jawfollowing extraction of all residual teeth: A retrospectivestudy comparing different types of serial immediate implan-tation. Int J Oral Maxillofac Implants 1995;10:561–567.

58. Cosci F, Cosci B. A 7-year retrospective study of 423 immedi-ate implants. Compend Contin Educ Dent 1997;18:940–942.

59. Becker W, Dahlin C, Lekholm U, et al. Five-year evaluation ofimplants placed at extraction and with dehiscences and fen-estration defects augmented with ePTFE membranes: Resultsfrom a prospective multicenter study. Clin Implant Dent RelatRes 1999;1:27–32.

60. Fugazzotto PA. Implant placement at the time of maxillarymolar extraction: Treatment protocols and report of results.J Periodontol 2008;79:216–223.

61. Gomez-Roman G, Kruppenbacher M, Weber H, Schulte W.Immediate postextraction implant placement with root-ana-log stepped implants: Surgical procedure and statistical out-come after 6 years. Int J Oral Maxillofac Implants2001;16:503–513.

62. Schwartz-Arad D, Chaushu G. Placement of implants intofresh extraction sites: 4 to 7 years retrospective evaluation of95 immediate implants. J Periodontol 1997;68:1110–1116.

63. Schwartz-Arad D, Grossman Y, Chaushu G.The clinical effec-tiveness of implants placed immediately into fresh extractionsites of molar teeth. J Periodontol 2000;71:839–844.

64. Schwartz-Arad D, Laviv A, Levin L. Survival of immediatelyprovisionalized dental implants placed immediately intofresh extraction sockets. J Periodontol 2007;78:219–223.

65. Polizzi G, Grunder U, Goene R, et al. Immediate and delayedimplant placement into extraction sockets: A 5-year report.Clin Implant Dent Relat Res 2000;2:93–99.

66. Malo P, Friberg B, Polizzi G, Gualini F, Vighagen T, Rangert B.Immediate and early function of Bränemark System implantsplaced in the esthetic zone: A 1-year prospective clinical mul-ticenter study. Clin Implant Dent Relat Res 2003;5(suppl1):37–46.

67. Huys LW. Replacement therapy and the immediate post-extraction dental implant. Implant Dent 2001;10:93–102.

68. Goldstein M, Boyan BD, Schwartz Z.The palatal advanced flap:A pedicle flap for primary coverage of immediately placedimplants. Clin Oral Implants Res 2002;13:644–650.

69. Artzi Z, Parson A, Nemcovsky CE. Wide-diameter implantplacement and internal sinus membrane elevation in theimmediate postextraction phase: Clinical and radiographicobservations in 12 consecutive molar sites. Int J Oral Maxillofac Implants 2003;18:242–249.

70. Cornelini R, Cangini F, Covani U, Wilson TG Jr. Immediaterestoration of implants placed into fresh extraction socketsfor single-tooth replacement: A prospective clinical study. IntJ Periodontics Restorative Dent 2005;25:439–447.

71. Sammartino G, Marenzi G, di Lauro AE, Paolantoni G. Aesthet-ics in oral implantology: Biological, clinical, surgical, and pros-thetic aspects. Implant Dent 2007;16:54–65.

72. Buser D, Hart C, Bornstein M, Grütter L, Chappuis V, Belser UC.Early implant placement with simultaneous GBR followingsingle-tooth extraction in the esthetic zone: 12-month resultsof a prospective study with 20 consecutive patients. J Peri-odontol 2009;80:152–162.

73. Yukna RA. Clinical comparison of hydroxyapatite coated tita-nium dental implants placed in fresh extraction sockets andhealed sites. J Periodontol 1991;62:468–472.

74. Schwartz-Arad D, Gulayev N, Chaushu G. Immediate versusnon-immediate implantation for full-arch fixed reconstruc-tion following extraction of all residual teeth: A retrospectivecomparative study. J Periodontol 2000;71:923–928.

The International Journal of Oral & Maxillofacial Implants 215

Group 4

186_4a_Chen.qxd 9/10/09 10:16 AM Page 215

75. Schwartz-Arad D, Chaushu G.The ways and wherefores ofimmediate placement of implants into fresh extraction sites:A literature review. J Periodontol 1997;68:915–923.

76. Kan JY, Rungcharassaeng K, Lozada J. Immediate placementand provisionalization of maxillary anterior single implants:1-year prospective study. Int J Oral Maxillofac Implants2003;18:31–39.

77. Cangini F, Cornelini R. A comparison between enamel matrixderivative and a bioabsorbable membrane to enhance heal-ing around transmucosal immediate post-extractionimplants. J Periodontol 2005;76:1785–1792.

78. Ferrara A, Galli C, Mauro G, Macaluso GM. Immediate provi-sional restoration of postextraction implants for maxillarysingle-tooth replacement. Int J Periodontics Restorative Dent2006;26:371–377.

79. Fugazzotto PA. Implant placement at the time of maxillarymolar extraction: Technique and report of preliminary resultsof 83 sites. J Periodontol 2006;77:302–309.

80. De Kok IJ, Chang SS, Moriarty JD, Cooper LF. A retrospectiveanalysis of peri-implant tissue responses at immediateload/provisionalized microthreaded implants. Int J Oral Max-illofac Implants 2006;21:405–412.

81. Wagenberg B, Froum SJ. A retrospective study of 1925 con-secutively placed immediate implants from 1988 to 2004. IntJ Oral Maxillofac Implants 2006;21:71–80.

82. Covani U, Marconcini S, Galassini G, Cornelini R, Santini S,Barone A. Connective tissue graft used as a biologic barrier tocover an immediate implant. J Periodontol2007;78:1644–1649.

83. Juodzbalys G, Wang HL. Soft and hard tissue assessment ofimmediate implant placement: A case series. Clin OralImplants Res 2007;18:237–243.

84. Villa R, Rangert B. Immediate and early function of implantsplaced in extraction sockets of maxillary infected teeth: Apilot study. J Prosthet Dent 2007;97:S96–S108.

85. Barone A, Cornelini R, Ciaglia R, Covani U. Implant placementin fresh extraction sockets and simultaneous osteotomesinus floor elevation: A case series. Int J Periodontics Restora-tive Dent 2008;28:283–289.

86. Grunder U. Stability of the mucosal topography around sin-gle-tooth implants and adjacent teeth: 1-year results. Int JPeriodontics Restorative Dent 2000;20:11–17.

87. Schropp L, Kostopoulos L, Wenzel A, Isidor F. Clinical and radi-ographic performance of delayed-immediate single-toothimplant placement associated with peri-implant bonedefects. A 2-year prospective, controlled, randomized follow-up report. J Clin Periodontol 2005;32:480–487.

88. Lindeboom JA, Tjiook Y, Kroon FH. Immediate placement ofimplants in periapical infected sites: A prospective random-ized study in 50 patients. Oral Surg Oral Med Oral Pathol OralRadiol Endod 2006;101:705–710.

89. Siegenthaler DW, Jung RE, Holderegger C, Roos M, HammerleCH. Replacement of teeth exhibiting periapical pathology byimmediate implants. A prospective, controlled clinical trial.Clin Oral Implants Res 2007;18:727–737.

90. Cranin AN, Heimke G, Gelbman J, Simons A, Klein M, SirakianA. Clinical trials with a polycrystalline alumina dental implant.J Oral Implantol 1993;19:221–227.

91. Jo HY, Hobo PK, Hobo S. Freestanding and multiunit immedi-ate loading of the expandable implant: An up-to-40-monthprospective survival study. J Prosthet Dent 2001;85:148–155.

92. Norton MR. A short-term clinical evaluation of immediatelyrestored maxillary TiOblast single-tooth implants. Int J OralMaxillofac Implants 2004;19:274–281.

93. Gotfredsen K. A 5-year prospective study of single-toothreplacements supported by the Astra Tech implant: A pilotstudy. Clin Implant Dent Relat Res 2004;6:1–8.

94. Evian CI, Emling R, Rosenberg ES, et al. Retrospective analysisof implant survival and the influence of periodontal diseaseand immediate placement on long-term results. Int J OralMaxillofac Implants 2004;19:393–398.

95. Perry J, Lenchewski E. Clinical performance and 5-year retro-spective evaluation of Frialit-2 implants. Int J Oral MaxillofacImplants 2004;19:887–891.

96. Degidi M, Piattelli A, Gehrke P, Felice P, Carinci F. Five-year out-come of 111 immediate nonfunctional single restorations. JOral Implantol 2006;32:277–285.

97. Fugazzotto PA, Lightfoot WS, Jaffin R, Kumar A. Implant place-ment with or without simultaneous tooth extraction inpatients taking oral bisphosphonates: Postoperative healing,early follow-up, and the incidence of complications in twoprivate practices. J Periodontol 2007;78:1664–1669.

98. Degidi M, Piattelli A, Carinci F. Immediate loaded dentalimplants: Comparison between fixtures inserted in postex-tractive and healed bone sites. J Craniofac Surg2007;18:965–971.

99. Horwitz J, Zuabi O, Peled M, Machtei EE. Immediate anddelayed restoration of dental implants in periodontally sus-ceptible patients: 1-year results. Int J Oral Maxillofac Implants2007;22:423–429.

100. Cafiero C, Annibali S, Gherlone E, et al. Immediate transmu-cosal implant placement in molar extraction sites: A 12-month prospective multicenter cohort study. Clin OralImplants Res 2008;19:476–482.

101. Fugazzotto PA. Implant placement at the time of mandibularmolar extraction: Description of technique and preliminaryresults of 341 cases. J Periodontol 2008;79:737–747.

102. Kan JY, Rungcharassaeng K, Liddelow G, Henry P, Goodacre CJ.Periimplant tissue response following immediate provisionalrestoration of scalloped implants in the esthetic zone: A one-year pilot prospective multicenter study. J Prosthet Dent2007;97:S109–S118.

103. Wohrle PS. Single-tooth replacement in the aesthetic zonewith immediate provisionalization: Fourteen consecutivecase reports. Pract Periodontics Aesthet Dent1998;10:1107–1114.

104. Schropp L, Isidor F, Kostopoulos L, Wenzel A. Interproximalpapilla levels following early versus delayed placement ofsingle-tooth implants: A controlled clinical trial. Int J OralMaxillofac Implants 2005;20:753–761.

105. Steigmann M, Cooke J, Wang HL. Use of the natural tooth forsoft tissue development: A case series. Int J PeriodonticsRestorative Dent 2007;27:603–608.

106. Bianchi AE, Sanfilippo F. Single-tooth replacement by imme-diate implant and connective tissue graft: A 1-9-year clinicalevaluation. Clin Oral Implants Res 2004;15:269–277.

107. Evans CJD, Chen ST. Esthetic outcomes of immediate implantplacements. Clin Oral Implants Res 2008;19:73–80.

108. Degidi M, Nardi D, Piattelli A. Peri-implant tissue and radi-ographic bone levels in the immediately restored single-tooth implant: A retrospective analysis. J Periodontol2008;79:252–259.

109. Degidi M, Novaes AB, Nardi D, Piattelli A. Outcome analysis ofimmediately placed, immediately restored implants in theesthetic area: The clinical relevance of different interimplantdistances. J Periodontol 2008;79:1056–1061.

110. Chen S, Darby I, Reynolds E, Clement J. Immediate implantplacement post-extraction without flap elevation: A caseseries. J Periodontol 2009;80:163–172.

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111. Bengazi F, Wennstrom JL, Lekholm U. Recession of the soft tis-sue margin at oral implants. A 2-year longitudinal prospec-tive study. Clin Oral Implants Res 1996;7:303–310.

112. Small PN, Tarnow DP. Gingival recession around implants: A 1-year longitudinal prospective study. Int J Oral MaxillofacImplants 2000;15:527–532.

113. Oates TW, West J, Jones J, Kaiser D, Cochran DL. Long-termchanges in soft tissue height on the facial surface of dentalimplants. Implant Dent 2002;11:272–279.

114. Lindeboom JA, Frenken JW, Dubois L, Frank M, Abbink I, KroonFH. Immediate loading versus immediate provisionalizationof maxillary single-tooth replacements: A prospective ran-domized study with BioComp implants. J Oral Maxillofac Surg2006;64:936–942.

115. Kokich VO, Kokich VG, Kiyak HA. Perceptions of dental profes-sionals and laypersons to altered dental esthetics: Asymmet-ric and symmetric situations. Am J Orthod DentofacialOrthop 2006;130:141–151.

116. Cardaropoli G, Lekholm U, Wennström JL.Tissue alterations atimplant-supported single-tooth replacements: A 1-yearprospective clinical study. Clin Oral Implants Res2006;17:165–171.

117. Henriksson K, Jemt T. Measurements of soft tissue volume inassociation with single-implant restorations: A 1-year com-parative study after abutment connection surgery. ClinImplant Dent Relat Res 2004;6:181–189.

118. Jemt T. Regeneration of gingival papillae after single-implanttreatment. Int J Periodontics Restorative Dent1997;17:326–333.

119. Chang M, Wennström JL, Odman P, Andersson B. Implant sup-ported single-tooth replacements compared to contralateralnatural teeth. Crown and soft tissue dimensions. Clin OralImplants Res 1999;10:185–194.

120. Kan JY, Rungcharassaeng K. Immediate placement and provi-sionalization of maxillary anterior single implants: A surgicaland prosthodontic rationale. Pract Periodontics Aesthet Dent2000;12:817–824.

121. Furhauser R, Florescu D, Benesch T, Haas R, Mailath G, WatzekG. Evaluation of soft tissue around single-tooth implantcrowns: The pink esthetic score. Clin Oral Implants Res2005;16:639–644.

122. Gher ME, Quintero G, Sandifer JB, Tabacco M, Richardson AC.Combined dental implant and guided tissue regenerationtherapy in humans. Int J Periodontics Restorative Dent1994;14:332–347.

123. Crespi R, Cappare P, Gherlone E, Romanos GE. Immediateocclusal loading of implants placed in fresh sockets aftertooth extraction. Int J Oral Maxillofac Implants2007;22:955–962.

124. Cochran DL, Morton D, Weber HP. Consensus statements andrecommended clinical procedures regarding loading proto-cols for endosseous dental implants. Int J Oral MaxillofacImplants 2004;19(suppl):109–113.

125. Gomez-Roman G, Schulte W, d’Hoedt B, Axman-Kremar D.TheFrialit-2 implant system: Five-year clinical experience in sin-gle-tooth and immediately postextraction applications. Int JOral Maxillofac Implants 1997;12:299–309.

126. Wagenberg BD, Ginsburg TR. Immediate implant placementon removal of the natural tooth: Retrospective analysis of1,081 implants. Compend Contin Educ Dent2001;22:399–404, 406, 408 passim.

127. Grunder U, Polizzi G, Goene R, et al. A 3-year prospective mul-ticenter follow-up report on the immediate and delayed-immediate placement of implants. Int J Oral MaxillofacImplants 1999;14:210–216.

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