the autogenous immediate implant supported single-tooth restoration- a 5-ye

CASE REPORT

382THE EUROPEAN JOURNAL OF ESTHETIC DENTISTRY

The autogenous immediate implant

supported single-tooth restoration:

a 5-year follow-up

Jacopo Castelnuovo, DDS, MSD

Affiliate Assistant Professor, Graduate Prosthodontics, School of Dentistry,

University of Washington, Seattle, WA, USA

Prosthodontist, Private Practice, Rome, Italy

Ayse Burçin Sönmez, DDS, MSc

Resident, PhD Program, Department of Pedodontics, School of Dentistry,

University of Rome – La Sapienza, Italy

Private Practice, Istanbul, Turkey

Correspondence to: Dr Jacopo Castelnuovo

COR – Center for Oral Rehabilitation, Via dei Monti Parioli #12, 00197 Rome, Italy.

Tel: +39-06.32.60.9501; Fax: +39-06.32.60.9509; E-mail: [email protected]/[email protected]

CASTELNUOVO/SÖNMEZ


Abstract

When replacing a missing tooth in the

esthetic zone, the implant supported

single tooth restoration can result in a

very natural and pleasing solution for

the patient, being also a conservative

procedure that preserves the adjacent

remaining dentition.

Immediate implant placement with an

immediate provisional crown can avoid

stressful and uncomfortable healing time

for the patient who no longer has to wear

an interim removable appliance. In se-

lected clinical situations, excellent tooth

esthetics for implant supported single

tooth restorations can be achieved by

using the natural extracted tooth as both

provisional and final restoration. No long-

term data is available today as far as the

survival rate of such restorations and the

predictability of such a treatment modal-

ity. This case report describes a tech-

nique for utilizing the patient’s extracted

tooth for the fabrication of an inconspic-

uous final anterior restoration, reporting

a 5-year follow-up.

(Eur J Esthet Dent 2012;7:382–395)


CASE REPORT


Introduction

Implant supported single tooth restor-

ation is a predictable dental proced-

ure for both anterior and posterior sex-

tants. Complications associated with

this treatment modality are biological

failure (peri-implantitis), biomechanical

failure (screw fracture; screw loosening;

implant fracture; ceramic fracture), and

esthetic failure. Nonetheless, the surviv-

al rate of implant supported single tooth

restorations is reported as being 96.5%

after five years.5

Esthetical failures are due to: poor

implant site development; poor implant

placement; anatomical limitations, such

as inadequate bone level and presence

of bone resorption; soft tissue biotype

and stability; tooth form; and contour.6

The ultimate goal of a dental reconstruc-

tion is the strict reproduction of nature in

order to provide the patient with a func-

tional and inconspicuous prostheses.

When replacing a missing tooth in the

esthetic zone, the single tooth implant

restoration – still a technically sensitive

procedure7 – can result in a very natural

and pleasing solution for the patient, as

well as being a conservative one by pre-

serving the adjacent remaining dentition.

As stated by De Van back in 1952,

every dentist’s objective should be “the

punctual preservation of what remains

rather than the meticulous restoration of

what is missing”.8

When a patient is about to receive a

dental extraction in the anterior region,

an immediate post-extractive implant,

immediately restored with a provisional

crown will eliminate the patient’s discom-

fort from wearing an interim provisional

removable partial denture.

With the advent of immediate provi-

sional protocol, implant supported sin-

gle tooth restorations have been taken

to the next level. In contemporary im-

plant dentistry, osseointegration is not a

Fig 1 Preoperative image of fractured maxillary

left central incisor.

Fig 2 Periapical ra-

diograph of maxillary left

central incisor depicting

oblique fracture passing

through CEJ, and short

roots.

CASTELNUOVO/SÖNMEZ


question anymore. Today the focus is on

esthetics: the implant as a matter of fact

will integrate, but in order to be success-

ful it will also have to be pleasing from an

esthetic point of view once it is restored.

The latter is not always an easy task.

According to the immediate provi-

sional protocol, following implant surgi-

cal placement a temporary acrylic resin

crown is delivered during the same ap-

pointment. The temporary crown will

then be replaced by the final metal-

ceramic or all-ceramic crown. When

other previously described esthetical

factors are kept under control, then the

challenge for this treatment option is to

master the manipulation of dental mate-

rials, such as ceramics and acrylic res-

ins. In fact, by using different masses,

several build-ups, codified stratification

techniques the dental technician will at-

tempt to reproduce not only the anatomy

of the extracted tooth but also its opti-

cal properties.9–11 In many patient situ-

ations, a clinician’s frustration will arise

when facing the fact that no artificial

crown will perfectly match the tooth that

was extracted, and even when the goal

is reached it still won’t be possible to

elude metamerism of dental ceramics.

Paradigm shift

In a somewhat near future the dental

community will benefit from stem cell

research and cloned spare dentition;

today it is possible to benefit from the

extracted tooth.

When extracting a root-fractured

tooth or a periodontally failing tooth with

sound structure, an option could be its

immediate reinsertion by connecting it

to an implant. The final outcome can be

considered as a tissue bioengineering

procedure: not a conventional implant

supported single-tooth restoration and

not a natural tooth reimplantation, but a

hybrid new entity.

With such a procedure, the clinician

will replace what is missing (the root),

but will also preserve natural tooth struc-

ture: the anatomical crown.

This article describes a technique for

preservation of natural tooth structure in

restoring single implants.

Patient situation

and technique

slightly tender mobile maxillary left cen-

tral incisor (Fig 1). The tooth had received

root canal therapy four years before.

A periapical radiograph of the maxil-

lary left central incisor showed the pres-

ence of an oblique root fracture passing

through the CEJ (Fig 2).

Orthodontic extrusion and creation

of a ferrule in order to restore the tooth

with a full contour single crown was not

considered a viable option due to the

inadequate length of the residual root

structure.

The treatment plan for the maxillary

left central incisor was then extraction,

surgical immediate post-extractive im-

plant placement, and immediate implant

restoration utilizing the autogenous nat-

ural tooth structure.

CT scan

The preoperative computerised tomog-

raphy (CT) scan carried out to assess

CASE REPORT


the thickness of the alveolar ridge did

not show bone loss or resorption of the

buccal cortical wall. For this reason it

was decided to perform a flapless sur-

gical procedure. The radiographic exam

was performed without a radiographic

template because the tooth was still in

the mouth.

Surgical template

The use of a surgical template for a sin-

gle implant placement is of utmost im-

portance for the amount of information

it conveys, and should be considered

as an indispensable diagnostic surgical

tool as the surgical template for com-

pletely edentulous patients.12 -

tracting the upper left central incisor, a

preoperative diagnostic phase was car-

ried out. Study models were mounted on

a semi-adjustable articulator to fabricate

the surgical template. A silicone index

was fabricated on the study cast in or-

der to duplicate the maxillary left central

incisor before simulating the extraction

on the model with an orthodontic saw.

The extraction site on the cast was modi-

fied with a laboratory carbide bur (H77E;

3.0 mm depth of postextraction alveo-

-

tic resin (polymer and clear monomer)

(Orthoresin clear; Dentsply Limited) and

Caesar and Loretz) was poured both

into the simulated postextraction socket

on the lubricated model and into the sili-

cone index. The index was then seated

back on the cast, stabilized with a rub-

ber band, and the assembly placed in

a pressure pot (Ivomat IP3, Ivoclar Vi-

vadent) for 10 minutes to obtain a rep-

lica of the central incisor. Since the CT

scan was taken before the clinical ex-

traction of the maxillary left central inci-

sor and therefore without a radiographic

template, the barium sulphate powder

was used exclusively to have a better

vision of the tooth during surgery. The

duplicated tooth was then repositioned

on the cast and the retentive portion of

the stent was waxed from the cingulum

of the maxillary left central incisor to the

Fig 3 Surgical template seated on the study

model.

Fig 4 Atraumatic extraction of residual fractured

root portion.

CASTELNUOVO/SÖNMEZ


crown was extracted first while the frac-

Particular care was taken in order not to

create any additional damage to the cor-

onal tooth structure since the tooth was

going to be used as the final restoration.

Immediately after extraction, the tooth

was stored in physiologic solution while

the implant surgical placement was car-

ried out (Fig 5).

Implant placement

and abutment connection

Following extraction, the surgical tem-

plate was tried in the mouth. A 3.0 mm

-

care) (Fig 6) was first used as a pilot

drill through the surgical template, and

then a 5 x 13 mm Drill Tapered surgi-

the final implant site. As decided at the

preoperative evaluation of the CT scan,

a 5.0 x 13 mm Replace Select Tapered

-

ed (Fig 7). The head of the implant was

placed 1.5 mm apical to the free gingival

adjacent teeth, all the way back to the

upper left first molar including all occlus-

al surfaces. The wax was then converted

into clear orthodontic acrylic resin. The

surgical template, seated back on the

study model, was then modified under

the surveyor by using a 3.0 mm surgi-

set the implant trajectory and guide the

osteotomy during surgery (Fig 3).

Tooth extraction

Tooth extraction should always be an

atraumatic procedure leading to pres-

ervation of the buccal cortical wall and

prevention of well documented ridge

deformities.13 –15 Whenever an extrac-

tion is performed in the esthetic zone, a

palatal approach is mandatory for tooth

luxation. Once the tooth has been freed

from the supracrestal periodontal liga-

ment fibers and the alveolar bone has

been compressed enough, then the for-

ceps can be used passively to take the

tooth out of the mouth. In this patient situ-

ation the extraction was uneventful, the

Fig 5 Extracted tooth fragments. Fig 6 Osteotomy guided by surgical template.

CASE REPORT


margin (Fig 8). Particular care was taken

to avoid stripping the osteotomy site and

thus jeopardize implant primary stabil-

ity. A WP Easy Abutment 1.5 mm (Nobel

the implant (Fig 9). A 32 Ncm torque was

delivered by a Manual Torque Wrench

and confirm the implant primary stability.

Tooth structure preparation

and conditioning

Under abundant irrigation the crown

portion was then hollowed out using a

-

sele) to the minimum extent to passively

accommodate the laboratory abutment

replica corresponding to the abutment

connected on the implant in the mouth

(Fig 10). The crown had to accommo-

date the abutment not only in its width,

but also in its length and according to

the correct incisal edge position in the

face of the patient. For this reason, while

hollowing out the crown in an apical-cor-

onal direction, the tooth was constantly

tried on the implant in the mouth to as-

sess the amount of tooth structure to be

removed internally towards the incisal

edge. The next step consisted in the hy-

bridization of the hollowed crown por-

tion. Acid etching was performed with

37.5% phosphoric acid (Gel Etchant;

Kerr Italia) for 20 seconds. The gel was

applied internally and slightly on the ex-

ternal surface of the CEJ to establish an

etched collar of about 2 mm (Fig 11).

Following water rinsing, the adhesive

was applied over the wet etched sur-

faces and according to the manufac-

turer’s instructions (Adper Scotchbond

MP; 3M ESPE) before being light cured.

Fig 7 Immediate postextractive flapless implant

placement.

Fig 8 Implant head placed 1.5 mm apical to free

gingival margin.

Fig 9 Following surgical implant placement, a sol-

id abutment is immediately connected and torqued

to 32 Ncm.

CASTELNUOVO/SÖNMEZ


When bonding to dentin and/or cement,

a multistep adhesive bonding system

is suggested in order to achieve better

bond strength and reduce microleak-

age.16,17 A hybrid composite resin (XRV

Herculyte Dentin A2; Kerr) was then lay-

ered over the bonded surfaces in thin

increments. Following light curing, the

composite resin was finished with high

During this phase, the laboratory abut-

ment replica fit into the root was consist-

ently checked for passivity.

It therefore produced a layered pas-

sive provisional shell, with tooth struc-

ture on the outside and composite resin

on the inside, ready to be relined in the

mouth (Fig 12).

Relining the autogenous crown

A slurry mix of acrylic resin monomer

and polymer (Jet Kit, Lang Dental MFG)

shade 77 was poured into a plastic

Group) and injected inside the auto-

genous provisional shell. The tooth was

then seated on the implant abutment in

the mouth and an “on-off” technique was

used, for which the provisional is seated

and removed several times under copi-

ous irrigation until setting of the acrylic

resin. The irrigation was used to prevent

heat damage to the surrounding soft tis-

sues due to temperature rise generated

by the acrylic resin.18 If the original pre-

extraction tooth position is correct in the

face of the patient, then a rigid index

anchored to the adjacent teeth can be

made on the cast before simulating the

extraction. This index will be used to re-

line the natural crown. Once ready to be

relined in the mouth over the implant, the

Fig 10 Hollowing natural crown.

Fig 11 Acid-etching autogenous crown with

37.5% phosphoric acid.

Fig 12 Composite resin inner build-up prior to

relining.

CASE REPORT


CASE REPORT

extracted tooth is repositioned into the

index. The acrylic resin is then poured

inside the autogenous crown carried by

the index itself into the mouth. This pro-

cedure will facilitate the placing of the

tooth back in the exact original pre-ex-

tractive position during relining.

Acrylic resin finishing

and polishing

Upon setting of the acrylic resin, the re-

lined tooth was removed from the mouth

and seated back on to the laboratory im-

plant replica. Acrylic resin was then add-

ed with a “salt and pepper” technique

to refine marginal adaptation (Fig 13).

Acrylic resin excess was then removed

with laboratory acrylic burs and lathe

polished with water and pumice slurry at

slow speed followed by polishing paste

Cementation

The relined crown was tried in (Fig 15)

and then cemented using temporary

(Fig 16). Particular care was used not to

use too much cement in order to avoid

excess that could interfere with the heal-

ing process.

Occlusal adjustments

Heavy occlusal loading both in centric

occlusion and protrusive movements

were adjusted to avoid overloading of

the implant.

Postoperative early re-evaluation

No abnormal inflammation was detected

at 15 days postsurgery and the occlusal

contacts remained stable. High patient

satisfaction was recorded.

Contingency plan

Due to the patient’s satisfaction, it was

decided to elect the autogenous crown

as the final restoration. The lack of sci-

entific evidence on the reliability of such

a procedure and on the survival rate of

Fig 13 Optimizing marginal adaptation with acryl-

ic resin on implant replica.

Fig 14 Relined autogenous crown finished and

polished.

CASTELNUOVO/SÖNMEZ


Fig 15 Immediate autogenous single-tooth im-

plant supported restoration tried in.

Fig 16 Luting with temporary cement.

Fig 17 5-year follow-up image depicts soft tissue

stability and esthetical integration of autogenous im-

mediate single-tooth implant supported restoration.

such a restoration implied that a contin-

gency plan had to be carried out. The

plan consisted in fabricating a metal

ceramic single implant restoration for

the maxillary left central incisor for the

patient to store and use in case of emer-

gency due to failure of the autogenous

crown.

Impression making

Six months after surgical placement of

the implant, it was decided to proceed

with the final impression. In order to

avoid trauma to the peri-implant soft tis-

sue, the prefabricated Easy Abutment

was not removed from the implant and

a conventional impression was taken

utilizing ad hoc snap-on plastic coping

Five-year follow-up

Clinical evaluation

The patient was regularly coming to the

office every 6 months for oral hygiene

according to the office recall program.

Spontaneous decementation of the au-

togenous crown had not occurred dur-

ing the past 5 years.

Soft tissue maturation and health

conditions were evaluated. No inflam-

mation was detected and no bleeding

occurred during inspection procedures.

Soft tissue coloration and consistency

was registered as normal. Facial and

interdental tissues were considered

stable. The crown itself did not show

any discoloration or colour change, ad-

ditional wear, decay or decalcification

(Fig 17).

CASE REPORT


Radiographic evaluation

The periapical radiograph did not show

any bone loss around the implant over

the last 5 years (Fig 18).

The presence of natural tooth structure

(cementum; cemento-enamel junction

(CEJ); enamel) underneath the marginal

soft tissues might promote hemidesmo-

some reattachment from the supracrestal

apparatus as it happens during the heal-

ing phases of conventional periodontal

treatment. Histological evidence is ne-

cessary to validate such an assumption.

The likely presence of a new supracr-

estal attachment may enhance soft tis-

sue stability over time19,20 reducing the

risk of gingival recession and esthetical

failure.21 For these reasons, once the

autogenous crown is cemented over the

implant it should not be removed for any

reason unless needed, to avoid disrup-

tion of the dentogingival complex.

Contraindications

As for all clinical procedures and tech-

niques, a few contraindications can be

highlighted:

�� Inappropriate root diameter and crown

dimensions: Root diameter for anter-

ior teeth decreases from CEJ towards

the apex. In periodontally involved

teeth with advanced attachment loss,

a good portion of the root will be vis-

ible (supragingival) and therefore will

have to be maintained when relin-

ing the natural tooth over the implant

abutment. A discrepancy between

the implant abutment diameter and

the deficient root diameter will make

it impossible for the tooth structure

to accommodate the abutment. The

same concept can be applied to the

dimensions of anatomical crowns,

and a preoperative assessment is al-

ways mandatory. Most difficulties are

encountered with mandibular incisors

and lateral maxillary incisors, as they

are the smallest teeth.

�� Decay, endodontic treatment and pre-

existing restorations: The presence of

decay, decalcification, pre-existing

direct and indirect restorations and

endodontic treatment may compro-

mise the biomechanical properties

of the natural tooth structure that is

going to be preserved and recycled.

Tooth fracture, micro and macro-

leakage of restorations, secondary

decays can all be expected and will

ultimately lead to failure. The amount

of residual tooth structure should be

carefully evaluated before selecting

such a treatment option.

�� Tooth discoloration, unpleasing anat-

omy: The rational behind this tech-

Fig 18 5-year follow-

up periapical radiograph

of autogenous immedi-

ate single-tooth implant

supported restoration. No

implant bone loss is de-

picted.

CASTELNUOVO/SÖNMEZ


nique is to enhance the aesthetic final

outcome for the patient. If the tooth

in need of replacement doesn’t fulfil

basic esthetical requirements for its

preservation, such as pleasing anato-

my and colour matching with the adja-

cent dentition, then a conventional all-

ceramic or metal-ceramic restoration

should be preferred.

Possible long-term

complications

The possible long-term complications

for this procedure are linked to the pres-

ence of natural tooth structure in the

mouth of the patient.

Tooth fracture

Due to the need of hollowing-out the re-

sidual tooth structure for relining, tooth

fracture might occur. This would be

more likely in the case of periodontally

involved teeth because of the reduced

wall thickness of the root versus the

thickness of an anatomical crown.

Discoloration

Change in colour over time can be ex-

pected. Extrinsic discoloration will be

detected in the same fashion for all the

dentition of a given patient due to dietary

habits, smoking and drinking. On the

other hand, intrinsic discoloration might

occur for the autogenous implant sup-

ported restoration due to degradation

products of the pulp left enchased but

sealed into the tooth structure. In this par-

ticular patient situation, at 5-year recall,

no internal discoloration was recorded.

Decay

The amount and incidence of decay for

such a restoration can be considered as

comparable to that of the rest of the den-

tition of a given patient, and are therefore

related to the patient’s caries receptivity,

oral hygiene and dietary habits.

Practice builder effect

Tooth loss is often followed by psycho-

logical implications for the patients. Such

a condition becomes even more sensi-

tive when the esthetic zone is involved.

The possibility of reassuring a patient

losing a central incisor that he will be

able to retain his very own tooth walking

out of the office with it the same day is

rewarding for both the patient and the

clinician. The fact that only the injured

or diseased root is replaced while the

crown remains the original natural one,

will make a patient extremely apprecia-

tive.

Fig 19 Preoperative

radiograph of periodon-

tally involved maxillary left

central incisor.

CASE REPORT


Conclusions

The technique described herein might

be considered a good alternative to con-

ventional implant supported single tooth

restorations in the esthetic zone. The

patient situation presented herein rep-

resents one of four patients treated with

this technique by the authors. The follow-

ups range from the most recent (1 year)

to the least recent (8 years) performed

on a patient with a well maintained gen-

Fig 20 Relined autogenous crown finished and

polished on implant replica.

Fig 21 8-year follow-

up periapical radiograph

of autogenous immedi-

ate single-tooth implant

supported restoration. No

implant bone loss is de-

picted.

eralized moderate adult periodontitis

(Figs 19–21), and they are all success-

ful. Larger sample size and longer-term

follow-ups are needed to evaluate the

predictability of such a procedure. When

more positive results are recorded in the

future, then a contingency plan such as

the one described in this article might

not be necessary anymore, reducing the

treatment costs and time for the patient

and enhancing the esthetical outcome

in many clinical situations.

CASTELNUOVO/SÖNMEZ


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