42010

i s sn 1868-3207 Vol. 11 • Issue 4/2010

| researchIn vitro wear of human enamel opposing YTZP zirconia

| user report3-D alveolar ridge reconstruction in a case withsevere bone loss

| meetingsAfter 40 years, DGZI is in its prime

implantsinternational magazine of oral implantology

Osstem_A4_IM410.pdf 23.11.2010 9:45:56 Uhr

I 03

editorial _ implants I

implants4_2010

Dr Friedhelm Heinemann

Dear colleagues,

I think I can honestly say that we made history early in October at DGZI’s 40th InternationalAnnual Congress in Berlin. Like no other implantological association, DGZI represents the ex-traordinarily successful development of implantology from an “unorthodox” treatment, facedwith many opponents and supported by only a few enthusiasts, to a modern, renowned and sci-entifically-documented dental discipline.

In his speech, the President of the German Dental Medical Association, colleague Peter En-gel, noted in particular the achievements of dental practitioners, while DGI’s President, colleagueHendrik Terheyden, commented that he does not see any contradiction between scientific re-search and dental practice, and on the contrary, a close relationship between the two has led toa very productive cooperation.

The expert associations keep in frequent and cooperative contact with each other, particu-larly through the Consensus Conference, whose current President is Mr. Roland Hille, whichworks hard to support the interests of dentists working in the field of implantolgy and implan-tology as a whole.

DGZI is aware of its responsibility for the further development of this special field and intendsto face the coming years with momentum and a healthy self-confidence. We will draw on triedand tested methods to reach our potential and are especially dedicated to enhancing the workof junior staff as well as students. Apart from providing opportunities for expert colleagues toexchange thoughts and for universities to cooperate freely, DGZI’s approved training curricula,regional study groups, congresses and many other training programs are an important basis forthe future activities of our specialist implantology association.

Yours,

Dr Friedhelm Heinemann

Making history

04 I implants4_2010

I content _ implants

I editorial

03 Making history| Dr Friedhelm Heinemann

I research

06 Single molar restoration| Prof Dr Amr Abdel Azim, Dr Amani Zaki,

Dr Mohamed el Anwar

12 Implant fracture:A look at the physical mechanisms for failure| Dr Dov M. Almog, Dr Odalys Hector, Dr Samuel Melcer,

Dr Kenneth Cheng

14 In vitro wear of human enamel opposing YTZP zirconia| T. R. Tambra, M. E. Razzoog, B. R. Lang, R. F. Wang,

B. E. Lang

I user report

24 Sinus lift without scalpel| Dr Philip Jesch, Dr Klaus Eder

28 3-D alveolar ridge reconstruction in a case with severe bone loss| Prof Dr Marcel Arthur Wainwright

32 The use of polylactide-coated �-TCP| Dr Stefan Neumeyer, Dr Stefanie Neumeyer-Wühr

II meetings

37 International events 2011

38 After 40 years, DGZI is in its prime| Dr Christian Ehrensberger

42 The Anatomy Weekend is also in great international demand | Dr Christian Ehrensberger

I news

44 Manufacturer News

48 Congratulations and Happy Birthdayto all DGZI-members around the world

I about the publisher

49 | submission guidelines

50 | imprint

research 14 user report 24 user report 28

Cover image courtesy: Friadent GmbH; XiVE S (subgingival) implant with two

TempBase abutments (3.8 and 4.5 diameter) and TempBase Cap.

user report 32 meetings 38 meetings 42

TiUnite® surface and Groovy™to enhance osseointegration.

Implant design that replicates the shape of natural tooth roots.

Internal tri-channel connection for accurate and secure prosthetic restorations.

Color-coded system for accu rate and fast component

identification and ease of use.

Color-coding: step-by-step drilling protocol for predictable

surgical procedures.

NobelReplaceTM

The world’s most used implant system.*

* Source: Millennium Research Group

Disclaimer: Some products may not be regulatory cleared/released for sale in all markets. Please contact the local Nobel Biocare sales office for current product assortment and availability.

Versatility, ease-of-use and predict-ability have made NobelReplace Tapered the most widely used implant design in the world.*NobelReplace Tapered is a general use, two-piece implant system that performs both in soft and hard bone, one- and two-stage surgical proce-dures, while consistently delivering

optimal initial stability. NobelReplace Tapered is a system that grows to meet the surgical and restorative needs of clinicians and their patients – from single-tooth restorations to more advanced multi-unit solutions. Whether clinicians are just starting or are experienced implant users, they will benefit from a system that

is unique in flexibility and breadth of application. Nobel Biocare is the world leader in innovative and evidence-based dental solutions. For more information, or visit our website.

www.nobelbiocare.com

TiUnite® surface and Groovy™to enhance osseointegration.

Implant design that replicates the shape of natural tooth roots.

connection for accurate and secure prosthetic

* Source: Millennium Research Group© N

ob

el B

ioca

re S

ervi

ces

AG

, 2

01

0.

All

rig

hts

res

erve

d.

No

bel

Bio

care

, th

e N

ob

el B

ioca

re lo

go

typ

e an

d a

ll o

ther

tra

dem

arks

are

, if

no

thin

g e

lse

is s

tate

d o

r is

evi

den

t fr

om

th

e co

nte

xt in

a c

erta

in c

ase,

tra

dem

arks

of

No

bel

Bio

care

.

Now also available in 11.5 mm lengthN

EW

NobelReplace A4 11,5 Implants.indd 1 10-10-14 16.09.28

I research _ restoration

Fig. 1_Load distribution during mas-

tication shows marked increase in

the molar and premolar area.23

Fig. 2_Occlusal view showing a

missing first molar. The mesio-distal

width is very wide and restoration

couldn't compensate it leaving a

space distally.

Fig. 3_Proximal cantilever shown

radiographic view of maxillary right

first molar on standard Brå nemark

implant with standard abutment

(Nobel Biocare).1

_The single-tooth restoration has become one ofthe most widely used procedures in implant dentistry.1

In the posterior region of the oral cavity, bone volumeand density are often compromised. Occlusal forces aregreater in this region and, with or without parafunc-tional habits, can easily compromise the stability of therestorations (Fig. 1). 2, 3

The single-molar implant-supported restorationhas historically presented a challenge in terms of formand function. The mesiodistal dimensions of a molar ex-ceed that of most standard implants (3.75 to 4.0 mm),creating the possibility of functional overload resultingin the failure of the retaining components or the failureof the implant (Figs. 2 & 3).4 Wider-diameter implantshave a genuine use in smaller molar spaces (8.0 to 11.0 mm) with a crestal width greater than or equal to 8 mm (Fig. 4 a).5 Clinical parameters governing the pro-posed restoration should be carefully assessed in lightof the availability of implants and components that pro-vide a myriad of options in diameter, platform configu-rations and prosthetic connections. Many of the newersystems for these restorations are showing promisingresults in recent clinical trials.6-8 It has further been sug-gested by Davarpanah and others,9 Balshi and others,2

English and others10 and Bahat and Handelsman11 that

the use of multiple implants may be the ideal solutionfor single-molar implant restorations (Figs. 4 b & c).Most standard implants and their associated prostheticcomponents, when used to support a double implantmolar restoration, will not fit in the space occupied by amolar unless the space has been enlarged (12 mm orlarger).4 Moscovitch suggests that the concept of using2 implants requires the availability of a strong and sta-ble implant having a minimum diameter of 3.5 mm. Additionally, the associated prosthetic componentsshould ideally not exceed this dimension.2

Finite element analysis (FEA) is an engineeringmethod that allows investigators to assess stresses andstrains within a solid body.10-13 FEA provides calculationofstressesand deformationsof each element alone andthe net of all elements. A finite element model is con-structed by breaking a solid object into a number of dis-crete elements that are connected at common nodalpoints. Each element is assigned appropriate materialproperties that correspond to the properties of thestructure to be modeled. Boundary conditions are ap-plied to the model to stimulate interactions with the en-vironment.14This model allows simulated force applica-tion to specific points in the system, and it provides theresultant forces in the surrounding structures. FEA is

Single molar restorationWide implant versus two conventional

Authors_Prof Dr Amr Abdel Azim, Dr Amani Zaki, Dr Mohamed el Anwar, Egypt

06 I implants4_2010

Fig. 2 Fig. 3Fig. 1

PERFECT FIT BY DESIGN

In combining Soft Tissue and Bone Level implants with a comprehensive prosthetic portfolio,

Straumann has devised one system for all indications. The Straumann® Dental Implant System –

excellent product quality designed for convincing, naturally esthetic outcomes.

Featuring the

SLActive® surface!

I research _ restoration

08 I implants4_2010

particularly useful in the evaluation of dental prosthe-ses supported by implants.13-16 Two models were sub-jected to FEA study to compare between a wide im-plant restoration versus the two implant restoration oflower first molar.

_Material and Methods

Three different parts were modeled to simulate thestudied cases; the jaw bones, implant/abutment as-sembly, and crown. Two of these parts (jaw bone andimplant/abutment) were drawn in three dimensionsby commercial general purpose CAD/CAM software“AutoDesk Inventor” version 8.0. These parts are regu-lar, symmetric, and its dimensions can be simply meas-ured with their full details.

On the other hand, crown is too complicated in itsgeometry therefore it was not possible to draw it inthree dimensions with sufficient accuracy. Crown wasmodeled by using three-dimensional scanner, RolandMDX-15, to produce cloud of points or triangulationsto be trimmed before using in any other application.

The second phase of difficulty might appear forsolving the engineering problem, is importing and ma-nipulating three parts one scanned and two modeledor drawn parts on a commercial FE package. Most ofCAD/CAM and graphics packages deal with parts asshells (outer surface only). On the other hand the stressanalysis required in this study is based on volume of dif-ferent materials.3 Therefore set of operations like cut-ting volumes by the imported set of surfaces in addi-tion to adding and subtracting volumes can ensure ob-taining three volumes representing the jaw bone, im-plant/abutment assembly, and crown.2 Bone wassimulated as cylinder that consists of two parts. The in-ner part represents the spongy bone (diameter 14 mmand height 22 mm) that filling the internal space of theother part (shell of 1 mm thickness) that represents cor-tical bone (diameter 16 mm and height 24 mm). Twoimplants were modeled one of 3.7 mm diameter andthe other of 6.0 mm. The implants/abutment designand geometry were taken from Zimmer dental cata-logue (Fig. 5).

Linear static analysis was performed. The solid mod-eling and finite element analysis were performed on apersonal computer Intel Pentium IV, processor 2.8 GHz,1.0 GB RAM. The meshing software was ANSYS version9.0 and the used element in meshing all three dimen-sional model is eight nodes Brick element (SOLID45),which has three degrees of freedom (translations in theglobal directions). Listing of the used materials in thisanalysis is found in Table 1. The two models were sub-jected to 120 N vertical load equally distributed (20 Non six points simulate the occlusion; one on each cuspand one in the central fossa). On the other hand, thebase of the cortical bone cylinder was fixed in all direc-tions as a boundary condition.17-21

Fig. 4a_Radiographic view of wide

implants used to restore missing

lower first molars.1, 24

Fig. 4b_Buccal view of 2 standard

20-degree abutments on 3.5 mm

Astra Tech implants for restoration of

mandibular right first molar.1, 24

Fig. 4c_Radiographic view of the

restoration.1, 24

Fig. 5_Crown, implants and bone

assembled in a model (FEA software).

Figs. 6a & b_Von Mises stress on

crown (a. wide implant;

b. two implants).

Tab. 1_Material Properties.

Material Poisson’s ratio Young’s modulus MPa

Coating (porcelain) 0.3 67,200

Restoration (gold) 0.3 96,000

Implants (titanium) 0.35 110,000

Spongy bone 0.3 150

Cortical bone 0.26 1,500

Fig. 6a Fig. 6b

Fig. 4b Fig. 4c

Fig. 5

Fig. 4a

research _ restoration I

I 09implants4_2010

Fig. 7a & b_Spongy bone deflection

in vertical direction (a. wide implant;

b. two implants).

Figs. 8a & b_Cortical bone deflection

in vertical direction (a. wide implant;

b. two implants).

Tab. 2_Results.

_Results and Discussion

Results of FEA showed a lot of details aboutstresses and deformations in all parts of the two mod-els under the scope of this study. Figures 6a & bshowed a graphical comparison between the crownsof the two models which are safe under this range ofstresses (porcelain coating, gold crown, and implantsshowed the same ranges of safety). No critical differ-ence can be noticed on these parts of the system. Alldifferences might be found are due to differences insupporting points and each part volume to absorbload energy (equation 2).** Generally a crown placedon two implants is weaker than the same crownplaced on one implant. This fact is directly reflected onporcelain coating and the two implants that havemore deflections. Comparing wide implant modelwith the two implants from the geometrical point ofview it is simply noted that cross sectional area wasreduced by 43.3 % while the side area increased by6.5 %. Using one implant results as a reference in a de-tailed comparison between the two models by usingequation (1) resulted in Table 2 for porcelain coating,gold crown, implant(s), spongy and cortical bones re-spectively.

Difference % = {One implant Result—Two implantsResult}*100 / One implant Result…(1)

Spongy bone deformation and stresses (Table 2)seems to be the same in the two cases. Simple and fastconclusion can be taken that using one wide implant isequivalent to using two conventional implants. On theother hand a very important conclusion can be exertedthat, under axial loading, about 10 % increase in implantside area can overcome reduction of implant cross sec-tion area by 50 %. In other words, effectiveness of in-creasing implant side area might be five times higherthan the increasing of implant cross section area onspongy bone stress level under axial loading. Startingfrom Figure 7 a & b, slight differences can be noticed onspongy bone between the two models results. Thestresses on the spongy bone are less by about 5 % in thetwo implants model than the one wide diameter im-plant. The exceptions are the relatively increase in max-imum compressive stresses and deformations of order12 % and 0.3 % respectively. The bone is known to re-

spond the best to compressive and the least to shearstresses22, so considering the difference in compressivestresses less significant, the two implants were found tohave a better effect on spongy bone. Contrarily, Figures8a & b, showed better performance with cortical bone incase of using one wide implant over using two implants,that, deformations in cortical bone are less by 20 %while the stresses are less by about 40 %. The stressesand displacements were significantly higher in the twoimplant model due to having two close holes, which re-sults in weak area in-between.

_Conclusions

This study showed various results between corticaland spongy bone. It was expected that the maximumstresses in the cortical bone was placed in the weak areabetween the two implants. In addition to be higher thanthe case of using one wide implant. Although the mid-dle part of spongy bone was stressed to the same levelin the two cases, using two implants resulted in morevolume of the spongy bone absorbed the load energy**which led to reduction of stress concentration and rateof stress deterioration by moving away from implants.That is considered better distribution of stresses fromthe mechanics point of view, which may result in longerlifetime. Porcelain coating showed less stress in case oftwo implants, longer life for the brittle coating material

Fig. 7b Fig. 8aFig. 7a

Differences%

Porcelaincoating(1mm)

Goldcrown

Implants Spongybone

Corticalbone

Usum -17.86 -16.70 -8.18 -0.28 -19.57

Uz -11.10 -11.10 -2.72 -0.03 -19.62

S1 31.59 -179.99 -6.72 5.96 -37.17

S3 0.71 -33.44 -310.74 -11.24 -70.43

Sint -1.26 -18.08 -166.39 4.75 -31.82

Seqv 0.25 -10.22 -196.86 4.00 -39.17

I research _ restoration

10 I implants4_2010

is expected. Contrarily more stresses were found on thegold crown placed on two implants due to its volume re-duction (less material under the same load). This isclearly seen in increasing stresses on the two implants,that more load effect was transferred through the weakcrown to the two implants. That showed maximumstresses in the area under the crown, while the wide im-plant showed maximum stresses at its tip. Looking toenergy** absorption and stress concentration on wholesystem starting from coating to cortical and spongybone, although the stress levels found was too low andfar from cracking danger, the following conclusions canbe pointed out; the total results favourise the two im-plants in spongy bone and the wide implant in the cor-tical layer, but the alveolar bone consists of spongy bonesurrounded by a layer of cortical bone. It’s also wellknown that according to the degree of bone density thealveolar bone is classified to D1,2,3,4

23 in a descending or-der. So, provided that the edentulous space after themolar extraction permits, it’s recommended in theharder bone quality (D1,2) to use one wide diameter im-plant and in the softer bone (D3,4) quality two averagesized implants. Therefore more detailed study to com-promise between the two implants size/design and in-termediate space can put this stress values in safe, ac-ceptable, and controllable region under higher levels ofloading.

** The area under the ��-�� curve up to a given value of strain is the to-tal mechanical energy per unit volume consumed by the material instraining it to that value (Fig. 9). This is easily shown as follows in equa-tion 2:

_Summary

Restoration of single molar using implants en-counters many problems; mesio-distal cantilever dueto very wide occlusal table is the most prominent. Anincreased occlusal force posteriorly worsens theproblem and increases failures. To overcome the over-load, the use of wide diameter implants or two regu-

lar sized implants were suggested. The aim of thisstudy was to verify the best solution that has the besteffect on alveolar bone under distributed verticalloading. Therefore, a virtual experiment using FiniteElement Analysis was done using ANSYS version 9. Asimplified simulation of spongy and cortical bones ofthe jaw as two co-axial cylinders was utilized. Full de-tailed with high accuracy simulation for implant,crown, and coating was implemented. The compari-son included different types of stresses and deforma-tions of both wide implant and two regular implantsunder the same boundary conditions and load appli-cation. The three main stresses compressive, tensile,shear and the equivalent stresses in addition to thevertical deformity and the total deformities were con-sidered in the comparison between the two models.The results were obtained as percentages using thewide implant as a reference. The spongy bone showedabout 5 % less stresses in the two implants modelthan the one wide diameter implant. The exceptionsare the relatively increase in maximum compressivestresses and deformations of order 12 % and 0.3 % re-spectively. The stresses and displacements on the cor-tical bone are higher in the two implant model due tohaving two close holes, which results in weak area in-between. The spongy bone response to the two im-plants was found to be better considering the stressdistribution (energy absorbed by spongy bone**).Therefore, it was concluded that, using the wide di-ameter implant or two average ones as a solution de-pends on the case primarily. Provided that the avail-able bone width is sufficient mesio-distally andbucco-lingualy, the choice will depend on the type ofbone. The harder D1,2 types having harder bone qual-ity and thicker cortical plates are more convenient tothe wide implant choice. The D3,4 types consist of morespongy and less cortical bone, are more suitable to thetwo implant solution.

Editorial note: The literature list can be requestedfrom the author.

Fig. 9_Strain energy = area under

stress strain curve.

Fig. 10_Equation 2 (stress energy).

Fig. 8b

Fig. 9

Amr A. AzimProfessor, Faculty of Dentistry, Cairo UniversityE-mail: drazim@link.net

Amani M. ZakiGBOI. 2009, EgyptE-mail: amani.m.zaki@gmail.com

Mohamed I. El-AnwarResearcher, Mechanical Engineering Department,National Research Center, EgyptE-mail: anwar_eg@yahoo.com

_contact implants

Fig. 10

For occlusally screw-retained crown and bridge restorations. Proven CAMLOG handling.Improves safety, saves time thanks to special aligning tool. CAMLOG offers more.Further information: www.camlog.com

VARIO SR SCREW-RETAINED COMPONENTS FOR

MORE POSSIBILITIES

I research _ implant fracture

Figs. 1a & b_Implants #6 and #7

(Lifecore Biomedical, 3.3 mm x

15 mm) before (A) and after

the fracture (B).

Figs. 2a & b_Retrospective analysis

of the site planned for the implants

#6 and #7 (A) revealed an extended

overbite, requiring long crowns (B) to

meet esthetic needs, and at the same

time, the opposing occlusion pre-

sented extensive occlusal wear.

_The etiology and physical mechanism of frac-tured dental implants phenomenon have been re-viewed and studied at length in recent years.1–8 For themost part, the studies concluded that the crown-to-root ratio guidelines associated with natural teethshould not be applied to a crown-to-implant restora-tions ratio. According to these studies, the crown-to-implant ratios of those implants that were consideredsuccessful at the time the reviews took place were sim-ilar to those implants that failed. Apparently, accordingto some of these studies, the guidelines that are used bysome clinicians to establish the future prognosis of im-plant supported restorations are usually empirical andlack scientific validation as far as the possible causes forimplant fractures. However, as oral implantology hasbeen the fastest growing segment in dentistry, the gain-ing of insight into these failure processes, including theaccurate understanding of critical anatomical, restora-tive and mechanical information, might stimulate theclinicians’ implementation of preventive action thatmay avoid the future fractures outcome with dental im-plants.

_Case report

A 72-year-old Caucasian male recently presented to

our clinic. Consistent with the patient’s chief complaint,a comprehensive oral and maxillofacial examination,including full-mouth X-rays, revealed, among otherthings, two fractured endosseous implants #6 and #7(Fig. 1).

These 3.3 mm x 15 mm implants (Lifecore Biomed-ical, Chaska, Minn.) were placed and restored in 2003.The implants were placed as per protocol, utilizing a sur-gical template consisting of two guiding sleeves (De-Plaque, Victor, N.Y.). The implants were allowed to inte-grate for six months. No surgical complications werenoted during this time. At the conclusion of the six-month waiting period, the implants were uncovered inthe normal manner and healing abutments placed.

The implants were subsequently restored with im-plant-supported crowns that were functional for ap-proximately six years until the implants fractured. Whilethis treatment option was developed with an apprecia-tion of the patient’s occlusal and mechanical circum-stances and habits, following the implants’ fracture, aretrospective analysis of the site planned for the im-plants revealed extended inter-occlusal space on the ar-ticulated models and widespread occlusal wear of theopposing dentition (Fig. 2).

Implant fracture: A look at the physical mechanisms for failureAuthors_Dr Dov M. Almog, Dr Odalys Hector, Dr Samuel Melcer, Dr Kenneth Cheng, USA

12 I implants4_2010

Fig. 2a Fig. 2bFig. 1a Fig. 1b

research _ implant fracture I

When the patient presented recently to our clinic,the only portion of the restoration that was still pres-ent in his mouth was abutment #6, which was stillconnected to one of the fractured implants, and wasremoved with a hex driver (Fig. 3). Proceeding withcareful assessment of all the available retrospectivediagnostic information and upon further discussionwith the patient, several diagnostic assumptions andone follow-up treatment option were establishedthat included replacement of the implant-supportedcrowns by a removable cast partial denture.

Considering the need for the removal of fracturedimplants must be balanced against the risk of in-creasing damage, a decision was made to remove theremaining abutment and the fractured piece of im-plant #6 allowing for primary closure of the soft tis-sue over the remaining implant bodies #6 and #7, i.e.,“put them to sleep” (Fig. 4). This was followed by in-sertion of an immediate acrylic removable partialdenture, and subsequently, a cast partial denture willbe fabricated. This report attempts to provide an ar-gument in favor of the consideration of physicalmechanisms as potential contributors to implantfractures.

While controversy continues to exist as to whethercrown-to-root ratio can serve as an independent aidin predicting the prognosis of teeth,9 the same cer-tainly applies to crown-to-implant ratio, unless mul-tiple other clinical indices such as opposing occlusion,presence of parafunctional habits and material elec-trochemical problems, just to name a few, are consid-ered. Implant fractures are considered one potentialproblem with dental implants, especially delayedfracture of titanium dental implants due to chemicalcorrosion and metal fatigue.2

Following careful review of the referenced articles,which are very enlightening, we realized that to agreat extent they support our theory that there aremultiple factors involved in implant fractures. Thesefactors include magnitude, location, frequency, di-rection and duration of compressive, tensile andshear stresses; gender; implant location in the jaw;type of bone surrounding the implant; pivot/fulcrum

point in relation to abutment connection; implant de-sign; internal structure of the implant; length of timein the oral environment as it relates to metallurgicchanges induced in titanium over time; gingivalhealth and crown-to-implant ratio. Considering themultiple factors involved in implant fractures, bothphysical and biological, we can only assume that it canhappen especially if the forces of the opposing occlu-sion and/or parafunctional habits are greater than thestrength of the implant, especially over time. There-fore, it is imperative that the clinician be knowledge-able about the diversity of factors before recom-mending dental implants. Errors in diagnosing poten-tial contributors to implant fractures are the mostcommon reason that dental implants fail.

_Conclusion

Although, according to the literature, the use ofthe crown-to-implant ratio in addition to other clin-ical indices does not offer the best clinical predictors,and even though no definitive recommendationscould be ascertained, considering that dental im-plants are becoming increasingly popular, an increasein the number of failures, especially due to late frac-tures, is to be expected.8 This report attempted to pro-vide an argument in favor of consideration of physi-cal mechanisms as potential predictors to implantfractures. Therefore, it is essential for us to familiarizeourselves with the understanding, and diagnosticcompetence of the multiple factors involved in im-plant fractures. Once observed, this predictor wouldcertainly lead to better diagnosis and treatment plan-ning._

Editorial note: The literature list can be requested fromthe editorial office.

Figs. 3a & b_By default, based on

physical principles, once an implant

has integrated in the bone, the weak-

est point is the fulcrum where the in-

ternal screw engages the implant (A).

Note the fracture level in implant #7

and fracture line in implant #6 (B).

Figs. 4a, b & c_The remaining abut-

ment and the fractured piece of im-

plant #6 were removed, allowing for

primary closure of the soft tissue over

the remaining implant bodies #6 and

#7 (A, B), followed by an insertion of

an immediate acrylic removable par-

tial denture (C). (Photos/Provided by

Dr Dov M. Almog)

I 13implants4_2010

Dr Dov M. Almog, DMDChief, Dental Service (160)VA New Jersey Health Care System (VANJHCS)385 Tremont Ave., East Orange, N.J. 07018E-mail: dov.almog@va.gov

_contact implants

Fig. 4b Fig. 4cFig. 3a Fig. 3b Fig. 4a

_Introduction

Porcelain fused to metalrestorations are the mostwidely used restorations indentistry today. However, insome clinical situations a lackof inter-occlusal space doesnot allow for the appropriatethickness of opaque and den-tine porcelains to be appliedto the metal substructure.

Consequently, the opaque layer may still be visibleand imparts a matt, lifeless appearance to the finalrestoration. The dentist should also consider the ef-fect the restorative surface will have on opposingenamel. The hardness of a ceramic material has beenviewed as a predictor of its potential to abrade hu-man enamel, and thus manufacturers have beenpushed to develop ceramics with equivalent hard-ness to enamel to try and solve the wear issue.1, 2

However, the microstructural elements of a ceramicas well as fracture toughness and hardness all influ-ence the wear characteristics of the material.3, 4, 5 Inan attempt to replicate the colour, texture, translu-cency and shape of the natural dentition a variety of

all ceramic systems have been developed. Many ofthese systems have a dense core material, replacingthe metal substructure, onto which dental porcelainis veneered to achieve the desired aesthetics. Zirco-nia has rapidly become the material of choice for useas the core of all ceramic (implant and tooth borne)restorations. The translucency and colour of thesecores allow the ceramist to produce a natural look-ing, aesthetic restoration. Yttrium-Stabilized-Zir-conia (YTZP) is one such material and several com-panies have recently introduced CAD/CAM basedsystems for milling such units. The physical proper-ties of zirconia have been widely documented: how-ever, the effect of these materials on the naturaldentition and on other restorative materials has notbeen fully investigated.

In normal masticatory function if the veneeringporcelain is lost due to modification of the occlusion(chairside adjustment by the dentist or attrition) thezirconia core may come into direct contact with theopposing dentition. Another situation where thismight occur is when there is insufficient interarchspace for the veneering porcelain resulting in oc-clusal stops directly on the zirconia core material.One must then consider if it is possible to place the

I research _ dental surfaces

In vitro wear of humanenamel opposing YTZPzirconiaAnd various polished dental porcelain surfaces

Authors_T. R. Tambra, M. E. Razzoog, B. R. Lang, R. F. Wang, B. E. Lang, UK

14 I implants4_2010

Fig. 3

Fig. 1a

Fig. 2

Fig. 1b

research _ dental surfaces I

forces of occlusion directly on the zirconia core ma-terial and the possible effects of direct contact withthe zirconia core on the opposing dentition. In bothsituations two—surface (body) wear will occur re-sulting in loss of both enamel and restorative mate-rial. The goal of restorative dentistry is to develop arestorative surface that has the same wear charac-teristics as human enamel.

The specific aim of this study was to compare thein vitro wear characteristics of human enamelagainst a zirconia based core material with two sur-face finishes and various zirconia and aluminiumoxide specific porcelains. The zirconia core materialwas studied in its as-manufactured state and afterundergoing polishing with a proprietary polishingkit and diamond polishing paste. The dental porce-lain surfaces underwent various surface treatmentsof which the polishing process was identical to thatapplied to the zirconia, allowing a direct comparisonof zirconia and porcelain surfaces. A polished typeIV gold surface acted as the control surface for thewear study. Laser videography (Mitutoyo / MTI corp.Aurora Ill™) was the method employed to assess thewear that occurred on the porcelain, gold and zirco-nia samples as a result of abrasion by humanenamel, however, only the enamel wear data will bepresented here.

_Materials and Methods

Discs of YTZP stabilised zirconia core material13.0 mm in diameter and 2.00 mm in thickness (Figs.1 & 2) were supplied by the manufacturer (Procera;

Nobel Biocare, Kloten, Zurich, Switzerland). For thepurposes of the article the term “zirconia” willequate to “YTZP stabilised zirconia core material”.Discs of type IV gold of the same dimensions werefabricated by the examiner to serve as a control sur-face—“G” in the results tables and graphs. The zirco-nia samples were divided into two groups:

_The as manufactured group—“Za” in the results ta-bles and graphs with the surface finish as deliveredfrom the manufacturer (Procera; Nobel Biocare,Kloten, Zurich, Switzerland).

_The polished group—“Z” in the results tables andgraphs—the test surface of the zirconia samplesunderwent polishing with a proprietary polishingsystem (Dialite ceramic polishing system, Bras-seler™) and diamond polishing paste (Ultradent™).

Discs of dental porcelains 20 mm in diameter and3–5 mm in thickness were supplied by the variousmanufacturers outlined below (Fig. 3). The dentalporcelains underwent three separate surface treat-ments, specifically:

_Application of an external glaze (powder glaze)._Autoglazing (self glaze procedure)._Mechanical polishing (same method used with the

zirconia core material).

The dental porcelains evaluated in the studywere:

_CZR Cerabien—Zirconia specific porcelain (Nori-take™)—“C” in results tables and graphs.

I 15implants4_2010

Fig. 4 Fig. 5 Fig. 6

Fig. 7 Fig. 8 Fig. 9

I research _ dental surfaces

_Cerabien—alumina framework specific porce-lain (Noritake™)—“C” in results tables andgraphs.

_Willi Geller Creation AV—for use with alu-minium oxide cores, InCeram Spinell and InCe-ram Zirconia core material (Jensen Industries™)—“J” in results tables and graphs.

_VITA Alpha 900 – alumina specific porcelain(VITA Zahnfabrik™)—“V” in results tables andgraphs.

The test porcelains in Groups 1 and 2 (CZRCerabien and Cerabien) are both designated “C”.Most porcelain systems have enamel porcelain asthe final layer when fabricating a crown. However,Noritake™ has designed the CZR Cerabien and Cer-abien systems to use a second distinct layer of su-per-fine particle sized enamel porcelain on top ofthe basic enamel porcelain in an attempt to im-prove the wear characteristics of the restoration.This layer is called the Luster porcelain. It is not anover-glaze. The rational behind the developmentof the Luster porcelain is that the glass particle sizeis more important than the hardness of the porce-lain in determining the wear characteristics of thematerial. The Luster layer utilized in both the CZRCerabien and Cerabien is the same material form-ing the final surface finish of the restoration. Forthis reason only one set of test samples was fabri-cated from the Luster porcelain. The results pro-duced by the wear study would apply to bothporcelains as the Luster layer undergoes any andall surface treatments. Therefore, the designation“C” is given to both the CZR Cerabien (zirconia spe-cific) and Cerabien (aluminous) porcelains. Thepolished surface treatment was the only surfacetreatment that the dental porcelains and the zir-conia core material experienced so only this datawill be presented here. The type IV gold controlsample was polished to high shine finish usinggold polishing compounds and a buffing wheel at-tached to a polishing lathe. A proprietary polishingsystem (Dialite®) was used to polish the porcelainand zirconia samples. The system consists of a se-ries of colour coded, diamond impregnated, abra-sive wheels of increasing fineness, blue—course,red—intermediate, grey—extra-fine. Once the Di-alite® polishing sequence was completed a finalpolish was carried out using 1 micron grit diamondpolishing paste (Ultradent™) and a flannel clothwheel (Brasseler™).

A motor driven wear machine was fabricated tosimulate the accelerated wear of human enamelagainst various surfaces (Fig. 4). The wear machineconsisted of a variable speed motor connected to arotating drum by a belt driven bearing assemblythrough which a series of abrader rods, on to which

the enamel samples were attached, could be fed.The test sample blocks were positioned beneaththe rotating drum within a water bath. The waterbath contained a solution consisting of 50 % Glyc-erine and 50 % Ethanol which was also the storagemedium used to preserve the enamel samples.

The abrader rods were held in position by a hold-ing sleeve that passed through the rotating drumparallel to the rotational axis of the drum but offcentre. This resulted in the abrader rods producinga circular path of motion with an inner diameter of7 mm and a maximum outer diameter of 12 mm.The variable speed motor allowed the wear ma-chine to run at a frequency of 0–100 rpm. All testsamples were run at a frequency of 65 rpm. A 500 gexternal load was applied to each enamel abradersample by means of a weight placed on the abraderrod and all samples were run for a total of 10,000cycles (Figs. 5 & 6). Newly extracted, caries free hu-man third molars were used to obtain adequateenamel specimens. All teeth were stored in a solu-tion consisting of 50 % Glycerine and 50 % Ethylalcohol to avoid desiccation and maintain enamelintegrity. A trephine bur (used to biopsy bone) wasused to score the enamel surface to aid cuttingsamples of similar dimensions. All cutting wascompleted with high-speed diamond burs with co-pious irrigation to prevent overheating the enameland desiccating the samples. The enamel was cutinto 3 mm diameter cylinders that extended atleast 5 mm into dentine and placed in the storagemedium. The enamel cylinder was then attached tothe reference end of an abrader rod with a smalldrop of cyanoacrylate resin and reinforced withpolymethyl methacrylate resin (Fig. 7).

The dentine side of the enamel sample waspressed against the flat end of the abrader rodleaving the enamel exposed to wear. All enamelmeasurements (Fig. 8) were made using a digitaltravelling micrometer (Mitutoyo™) accurate to0.001 mm as follows. At the reference end of eachabrader rod a fine line was scribed around the cir-cumference of, and 10 mm from the end of, theabrader rod. A second set of lines were then scribedparallel to the long axis of each abrader rod bisect-ing the initial scribe line at 90 intervals to producefour cross-hair marks. One of the cross hair markshad a further “dot-mark” placed and this was des-ignated “reference position 1” (Fig. 8). Measure-ments of enamel length were made from each ref-erence position to the edge of the enamel with thedigital travelling micrometer.

The arithmetic mean of these four readings persample was taken to be the overall sample length. Bysubtracting the post wear measurement from the

16 I implants4_2010

Fig. 10

Ems-swissqualitY.com

For more information > www.ems-swissquality.com

savE cEllsNEw Ems swiss iNstrumENts surgErY –saviNg tissuE with NEw iNNovatioNs iN implaNt dENtistrYThe inventor of the Original Piezon Method has won another battle against the destruction of tissue when dental implants are performed. The mag ic word is dual cooling –instrument cooling from the inside and outside together with simultane-ous debris evacuation and eff icientsurgical preparations in the maxilla.

cooliNg hEalsA unique spiral design and internal irrigation prevent the instrument’s temperature from rising during the surgical procedure. These features combine effectively to promote excel-lent regeneration of the bone tissue.

EMS Swiss Instruments Surgery MB4, MB5 and MB6 are diamond-coated cyl indr ica l instruments for secondary surgical preparation (MB4, MB5) and f inal osteotomy (MB6). A spiral design combined with innovative dual cooling makes these instruments unique in implant dentistry. coNtrol savEsEffective instrument control fosters atraumatic implant preparation and minimizes any potential damage to the bone tissue.

prEcisioN rEassurEsSelective cutting represents virtually no risk of damage to soft tissue

(membranes, nerves, blood vessels, etc.). An optimum view of the operative site and minimal bleeding thanks to cavitation (hemostatic effect!) further enhance efficacy.

The new EMS Swiss Instruments Surgery stand for unequaled Swiss precision and innovation for the

benefit of dental practitioners and patients alike – the very philosophy embraced by EMS.

> EMS Swiss Instrument Surgery MB6 with unique spiral design and internal instrument irr igation for ultralow temperature at the operative site

I research _ dental surfaces

18 I implants4_2010

initial baseline measurement the amount of enamelwear that occurred during the experiment (in mi-crons) was determined. A custom jig made from analuminium block with a locking set-screw ensuredthat the abrader rod (and enamel sample) could berepositioned in the same location on the table of thedigital micrometer (Fig. 9) when taking measure-ments. This meant all enamel measurements weremade with the cross-hair marks on the abrader rodin the same focal plane for both the baseline andpost-wear measurements. At each measurement“reference position 1” was lined up with the lockingset screw on the custom jig so all measurementswere completed in the same clockwise sequence. Allmeasurements were completed by the same ob-server to avoid inter-observer error and each meas-urement for each reference position was made fivetimes (arithmetic mean determined) to ensure allreadings were accurate.

Each enamel sample was held perpendicular tothe test substrate to ensure uniform wear. Enamelsamples were initially run in the wear machineagainst 600 micron grit silicon carbide paper in theartificial saliva medium to produce a smooth, uni-form flat surface with at least 0.5 mm thickness ofenamel remaining. The sample was then removedfrom the wear machine and baseline enamel lengthfigures were recorded as outlined above. The test

block was then placed in the water bath filled withsaliva substitute and positioned on the wear ma-chine. Enamel specimens were then passed throughthe rotating drum in the holding sleeve and lined upon the appropriate test sample. An unloaded test cy-cle (1 revolution) was carried out to ensure theenamel was abrading around the centre of the testspecimen. The test block was then secured to thewear machine by means of two C-clamps. The 500 gload was applied to the abrader rod and the wear ma-chine was activated at a speed of 65 rpm and run forexactly 10,000 cycles. The process was repeated foreach test sample in each test group (Figs. 10 & 11).

The amount of wear experienced by the test sur-face after being abraded by human enamel was alsodetermined. This was achieved by using a laservideography procedure that involved scanning thesample surface (pre and post enamel abrasion) to de-termine how much wear the test surface experiencedfrom abrasion by human enamel. Thus the totalamount of wear in microns that occurred within thistwo-body wear system—enamel plus substrate—was determined. This was equal to 100 % of the totalwear occurring in that sample group. By convertingthe micron loss figures to a ratio the percentageenamel wear figures were determined. The data ob-tained was analyzed using a 0ne-way ANOVA sta-tistical analysis with a significance level of P = 0.05.

Fig. 11_Enamel wear micron loss

zirconia vs gold.

Fig. 12_Enamel wear percentage

loss zirconia vs gold.

Fig. 13_Enamel wear wear micron

loss polished surface finish.

Fig. 14_Enamel wear percentage

loss polished surface finish.

Fig. 13 Fig. 14

Fig. 11 Fig. 12

research _ dental surfaces I

I 19implants4_2010

Tab. 1_ Mean values for enamel loss

in microns when opposing zirconia

core material as manufactured and

post-polishing.

Tab. 2_One-way ANOVA on surface

finish zirconia (Za, Z) gold control (G):

p = 0.05).

anova table for enamel wear mm

row exclusion: view data set.

Tab. 3_ANOVA Table for

enamel wear %

Row exclusion: view dataset.

Tab. 4_Means table for

enamel wear mm

Effect: surface finish

Row exclusion: view dataset

Tab. 5_Means table for

enamel wear %

Effect: surface finish

Row exclusion: view dataset

Tab. 6_Fisher’s PLSD for

enamel wear mm

Effect: surface finish

Significance level: 5%

Row exclusion: view dataset

Tab. 7_Fisher’s PLSD for

enamel wear %

Effect: surface finish

Significance level: 5%

Row exclusion: view dataset

_Results

Key for table headings: SS = Sum of Squares, MS = Mean Squares, SD = Standard Deviation, SE = Stan-dard Error, MD = Mean Difference, CD = Critical Difference.

Za Z G

Sample 1 0.030 mm 0.036 mm 0.023 mm

Sample 2 0.050 mm 0.055 mm 0.028 mm

Sample 3 0.051 mm 0.034 mm 0.021 mm

Sample 4 0.045 mm 0.036 mm 0.026 mm

DF SS MS F-Value P-Value Lambda Power

Surfacefinish

2 0.001 4.28E.04 6.384 0.0188 12.768 0.774

Residual 9 0.001 6.71E.05

DF SS MS F-Value P-Value Lambda Power

Surfacefinish

2 0.049 0.025 35.151 0.0005 70.303 1.000

Residual 6 0.004 0.001

Count Mean SD SE

Z 4 0.04 0.01 0.005

Za 4 0.044 0.01 0.005

G 4 0.025 0.003 0.002

Count Mean SD SE

Z 4 0.834 0.028 0.014

Za 4 0.847 0.025 0.012

G 1 0.605

MD CD P-Value

Z : Za -0.004 0.013 0.5335

Z : G -0.016 0.013 0.0236 S

Za : G -0.019 0.013 0.0083 S

MD CD P-Value

Z : Za -0.012 0.046 0.5427

Z : G -0.229 0.073 0.0002 S

Za : G -0.241 0.073 0.0002 S

Tab. 1

Tab. 2

Tab. 3

Tab. 4

Tab. 6

Tab. 5

Tab. 7

I research _ dental surfaces

20 I implants4_2010

Tab. 8_One-way ANOVA on material,

polished surface finish. P = 0.05

C (CZR, Cerabien), J (Willi Geller

Creation AV), V (VITA Alpha 900),

Z (zirconia), G (gold)

ANOVA table for enamel wear mm

Row exclusion: view dataset

Tab. 9_ANOVA table for

enamel wear %

Row exclusion: view dataset

Tab. 10_Means table for

enamel wear mm

Effect: material

Row exclusion: view dataset

Tab. 11_Means table for

enamel wear %

Effect: material

Row exclusion: view dataset

Tab. 12_Fisher’s PLSD for

enamel wear mm

Effect: material

Significance level: 5%

Row exclusion: view dataset

Tab. 13_Fisher’s PLSD for

enamel wear %

Effect: material

Significance level: 5%

Row exclusion: view dataset

TIP:Please have a look at Figs. 11 & 12 after the

Tabs. 6 & 7 and at Figs. 13 & 14after Tabs. 12 & 13.

DF SS MS F-Value P-Value Lambda Power

Material 4 0.063 0.016 6.384 0.0188 12.768 0.774

Residual 15 0.004 2.760E-4

DF SS MS F-Value P-Value Lambda Power

Material 4 0.094 0.024 35.727 < 0.0001 142.906 1.000

Residual 12 0.008 0.001

Count Mean SD SE

C 4 0.105 0.006 0.003

J 4 0.180 0.028 0.014

V 4 0.057 0.021 0.011

Z 4 0.040 0.010 0.005

G 4 0.025 0.003 0.002

Count Mean SD SE

C 4 0.882 0.010 0.005

J 4 0.919 0.013 0.006

V 4 0.797 0.040 0.020

Z 4 0.834 0.028 0.014

G 1 0.605

MD CD P-Value

C, J -0.075 0.025 < 0.0001 S

C, V -0.048 0.025 < 0.0010 S

C, Z -0.065 0.025 < 0.0001 S

C, G -0.081 0.025 < 0.0001 S

J, V -0.123 0.025 < 0.0001 S

J, Z -0.140 0.025 < 0.0001 S

J, G -0.155 0.025 < 0.0001 S

V, Z -0.017 0.025 < 0.1684

V, G -0.033 0.025 < 0.0138 S

Z, G -0.016 0.025 < 0.1999

MD CD P-Value

C, J -0.036 0.040 < 0.0686

C, V -0.085 0.040 < 0.0005 S

C, Z -0.048 0.040 < 0.0218 S

C, G -0.277 0.063 < 0.0001 S

J, V -0.122 0.040 < 0.0001 S

J, Z -0.084 0.040 < 0.0006 S

J, G -0.313 0.063 < 0.0001 S

V, Z -0.037 0.040 < 0.0619

V, G -0.192 0.063 <0.0001 S

Z, G -0.229 0.063 <0.0001 S

Tab. 8

Tab. 9

Tab. 10 Tab. 11

Tab. 12 Tab. 13

The new kit for success.

www.geistlich-pharma.com LEADING REGENERATION

Geistlich Combi-Kit Collagen – the best kit for successful and predictable results in ridge preservation and minor augmentations.

combined in Geistlich

Combi-Kit Collagen

Geistlich

Bio-Oss® Collagen and

Geistlich Bio-Gide®

From May 2010

I research _ dental surfaces

22 I implants4_2010

_Discussion

Wear of dental hard tissues is a naturally occur-ing and inevitable phenomenon. However, whenhuman enamel is opposed by ceramic (or otherrestorative material) the enamel experiences accel-erated wear. Developing a material of equivalenthardness to human enamel was seen as the solutionto the enamel wear problem.1, 2 However, it has nowbeen shown that microstructural differences andchanges in surface topography are much more im-portant than hardness.3 To account for these vari-ables the chemical make up of the veneering porce-lain was (and still is being) modified to produce theconventional aluminous porcelains e.g. VITADURALPHA, machinable ceramics e.g. VITA Mark II andthe hydrothermal porcelains e.g. Duceram-LFC.Studies on the wear characteristics of these porce-lains produced varying results13, 14, 15 with no signif-icant reduction in abrasiveness to human enamel.The pattern of enamel wear varies according to theceramic system used and its surface characteristics. 4,

6, 7, 8, 9, 13, 16 The amount of wear that will occur on boththe restored surface and opposing enamel is an im-portant consideration in dentistry as this will affecttooth movement and the vertical dimension of oc-clusion. Restorative dentistry must therefore pro-vide restored occlusal surfaces that are wear resist-ant themselves and more importantly, do not pro-mote excessive wear of the opposing occlusion.4, 5

The major driving force in dentistry today is aes-thetics. Several all ceramic systems have been de-veloped. Most of these systems rely on a core mate-rial onto which a porcelain veneer is applied. Someof the most studied systems are Dicor™ (a castableglass ceramic), IPS Empress (leucite core, lithiumdisilicate core in Empress II and E-max) and In-Ce-ram (aluminium oxide core). The advent of improvedzirconia systems such as Procera™ and Etkon™shows a wide availability of systems on the markettoday. However, all these systems rely on veneeringporcelains and several studies have demonstratedthat these veneering porcelains are more abrasive tohuman enamel than the core material itself.4, 6, 7, 8, 9,

13, 16

Zirconia based core materials have recently beenintroduced. Several companies have introducedCAD/CAM systems to produce cores for naturaltooth restorations as well as abutments and bridgesfor implant based single and multiple unit restora-tions. This study examined the in vitro wear of hu-man enamel against a zirconia (YTZP) core materialwith two surface finishes and various dental porce-lains designed specifically for veneering zirconiaand alumina cores to produce all ceramic restora-tions. A polished type IV gold surface acted as a con-

trol surface. The porcelain surface was compared tothe zirconia surface to determine if the applicationof the veneering porcelain was beneficial or detri-mental to human enamel i.e. is it less harmful toenamel to have the zirconia core exposed or ve-neered? Studies have shown that a polished dentalporcelain surface is the least abrasive porcelain sur-face finish to human enamel.10, 11, 12 The entire studydid evaluate the autoglaze and powder glaze sur-face finishes as well but only the polished finish wasthe same for both zirconia and the test porcelains soit was the only data presented here.

Wear does not occur in isolation. It is not just theenamel that is abrading but also the opposingrestorative surface. The ideal situation is for theenamel and the opposing restorative material tohave the same physical and mechanical properties.This way the restorative: enamel interface shouldwear at the same rate as an enamel: enamel inter-face. To date, the least abrasive surface to humanenamel is a highly polished type IV gold surface.5 Thisis seen as the standard to which all other materialsare compared. Most, if not all, studies show thatdental porcelains (regardless of surface finish) andall the ceramic core materials are far more abrasiveto human enamel than a polished type IV gold sur-face.4, 6, 7, 9

Zirconia has greater strength and flexibility com-pared to aluminium oxide, allowing thinner cores ofequivalent strength to be fabricated. This allows theuse of zirconia in situations where inadequate oc-clusal clearance exists for an aluminium oxide core.The only alternative would then be a metal-ceramicrestoration with exposed metal occlusal contacts.Zirconia has now largely superseded aluminium ox-ide as the core material of choice for most all ce-ramic restorations. Initially the zirconia cores had abluish white colour; however, shaded versions arenow available to improve aesthetics.

The Power value for the one-way ANOVA data setfor the polished zirconia and porcelain surfaces ver-sus the type IV gold control is 1.00. The Power valuefor the one-way ANOVA data set for zirconia versustype IV gold is 0.774 for zirconia mm wear data setmaking the results statistically significant althoughthe sample size is small. Considering the polishedzirconia vs type IV gold results (Tab. 1) samples 1, 3and 4 produced virtually identical levels of enamelwear (mean 0.035 mm) where as sample 2 producedsignificantly more wear (0.055 mm). Thus sample 2had a significant negative impact on the data set.

The significance level for this study is P = 0.05.The results of this experiment show that the zirco-nia core material in its as-manufactured state and

research _ dental surfaces I

after a proprietary polishing procedure producesminimal wear of human enamel. When compareddirectly with a polished type IV gold surface, the zir-conia (both surface finishes) does produce statisti-cally significantly more enamel wear than the con-trol. When comparing the two zirconia surface fin-ishes to each other, the polished zirconia surfaceproduced less enamel wear than the as-deliveredsurface but the difference was not statistically sig-nificant.

Several all-ceramic veneering porcelains werealso evaluated in this study. The polished zirconiasurface underwent the same polishing procedureas the veneering porcelains allowing a direct com-parison between gold, zirconia and porcelain. Thiswas to determine whether the application of ve-neering porcelain would have a positive or negativeimpact with regards to the abrasiveness of therestorative surface. Firstly, when the polishedporcelain surfaces were compared to the type IVgold control surface all the polished porcelain sur-faces were statistically significantly more abrasiveto human enamel. This result corresponds with ear-lier studies.8, 9, 10, 11, 12 Secondly, there was no statis-tically significant difference between the polishedzirconia surface and the polishedtype IV gold con-trol surface (p > 0.05) indicating that the polishedzirconia surface was equivalent to a polished goldsurface in its level of abrasiveness to humanenamel.

In this study the application of veneering porce-lain to the zirconia core material statistically sig-nificantly increased the abrasiveness of the zirco-nia surface to human enamel. The polished zirconiasurface was statistically comparable to a polishedgold surface in its degree of abrasiveness to humanenamel indicating that it is beneficial to have pol-ished zirconia forming the occlusal contact sur-faces rather than applying a porcelain veneer.

Zirconia has far greater strength than alu-minium oxide when in similar dimension. The pos-sibility therefore exists to use zirconia as a core ma-terial in the posterior region of the mouth and inhigh occlusal load areas where the occlusion can beplaced directly on the core material (cingulum ofupper canines and occlusal surfaces of molars) ifthe restoration is opposing enamel. The porcelainveneer is then placed mainly for aesthetics. If therestoration is opposing another crown then the ap-plication of a porcelain veneer is optional.

The use of CAD/CAM technology allows fabrica-tion of customized zirconia cores, abutments andbridges to restore natural teeth and dental implantswith the appropriate reduction for veneering

porcelain. This is known as the “dual scan” tech-nique where the technician uses either casting waxor a composite resin to build up the proposedrestoration—crown or bridge—to full contour andin occlusion with the opposing arch. The wax orresin pattern is then “cut back” leaving all the cen-tric stops intact and supporting the opposing oc-clusion. This modified pattern is then scanned toproduce the customised zirconia framework withall the occlusal loads being borne directly on thecore material. The increased thickness of the zirco-nia in these areas improves both the physical andmechanical properties of the core. This does not im-ply that one can simply rely on the strength ofrestorative materials to withstand high occlusalloads and simply ignore the underlying causes,such as bruxism and parafunctional habits. Diag-nosis, treatment planning and prescribing the ap-propriate restorative surfaces are just as importanttoday as they have been in the past.

_Conclusions

Within the limitations of this study the follow-ing conclusions can be made:

_The type IV gold surface produced the leastamount of enamel wear.

_The polished zirconia surface produced lessenamel wear than the as-manufactured zirconiasurface but the result was not statistically signif-icant when compared directly to the type IV goldcontrol surface.

_The polished and as-manufactured surfaces pro-duced statistically significantly greater enamelwear than the type IV gold control surface.

_All the veneering porcelains produced statisticallysignificantly more enamel wear than the type IVgold control surface.

_When viewing all the polished surface data (zirco-nia, porcelains and type IV gold) the polished zir-conia surface was not statistically significantlymore abrasive than the type IV gold control sur-face p > 0,05). All the porcelains were significantlymore abrasive than the type IV gold control sur-face.

Editorial note: The literature list can be requestedfrom the author.

I 23implants4_2010

Dr Tussavir TambraWolverhampton, UKE-mail: dr.tambra@hotmail.co.uk

_contact implants

I user report _ sinus lift

Fig.1_The JEDER®-System.

Fig. 2_Pressure-, Frequency-, and

Volume-Monitor.

_Owing to the loss of vertical bone volumes inthe maxillary sinus area, an implantation with suffi-cient primary stability is often not possible. In manycases a therapeutical consequence is introduction of abone augmentation in the sinus area (sinus lift). Fearof this procedure and higher costs are often the causesof why patients resist having this operation done. Be-cause of these reasons, our development moved to thenext step. With the JEDER®-System it is possible toperform a sinus lift without the use of a scalpel. Incomparison to the conventional lateral fenestration ofthe buccal sinus bone, in our procedure all one needsis a small opening on the crestal alveolar ridge. Overthis opening it is possible to place the augmentationmaterial and the implant itself. The risk of a rupture inthe Schneiderian membrane can also be reducedthrough this innovative technique.

_Virtually bloodless procedure

In order to place implants, maxillary bone sub-stance with sufficient height and diameter is required.Owing to atrophic processes it becomes increasingly

difficult to place implants after tooth loss. Under suchatrophic conditions it is not possible to place implantswith sufficient primary stability, especially when themaxillary bone height falls below 4 mm. In these casesan augmentation is unavoidable. Hence it is necessaryto place augmentation material between the sinusfloor and the Schneiderian membrane: the sinus lift.

With this innovative surgical technique it is possi-ble to simply lift the Schneiderian membrane in a gen-tle and safe manner through a 3.5 mm opening in thecrestal bone with the use of the JEDER®-System (Fig. 1A-C) (Patent AT 507208 & Patent AT 504552). After themembrane has been lifted with the aid of a pressurized,oscillating saline solution depicted graphically on thedisplay (Fig. 2), the bone augmentation material can beinserted into the newly formed cavity above the holeof the initial drilling. A successive implantation imme-diately after augmentation poses no problem. Thissurgical technique drastically reduces postoperativepain and ensures the surgeon simultaneous feedback-control during the procedure itself. At the same time,the classical risks of swelling and membrane ruptureare reduced. The surgical procedure is explained in thefollowing three simple steps.

1.) A.T.P-Punch (Atraumatic Transginigival Perforation) After application of the local anaesthesia, the

A.T.P-Punch (Fig. 3), developed by Prof Dr WolfgangJesch (sales: DENTSPLY Friadent) is used to punchthrough the mucoperiosteum. Simultaneously thepunch makes a small incrementation in the crestalbone in which the primary drill for implantation cangain purchase. The advantages in perforating of thesoft tissue in this manner are: a clean access to thealveolar ridge and a minimal invasive procedure thatmakes a smaller wound, resulting in fewer traumasand less pain for the patient. After the A.T.P-Punch is

Sinus lift without scalpelAuthors_Dr Philip Jesch, Dr Klaus Eder, Austria

24 I implants4_2010

Fig. 1 Fig. 2

user report _ sinus lift I

used, the JEDER®-System is applied. This system iscomprised of two components: The Pressure Bone Drill(P.B.D) and the Sinus Vibration Pump (S.V.P).

2.) The Pressure Bone Drill (P.B.D)The drilling is continued until just below the sinus

floor (Fig. 4). If necessary a panoramic X-ray can bedone in order to examine the exact position of drilldepth. After fixing the tight fitting P.B.D (Fig. 1A) meas-urable pressure is created using saline solution. In theinside of the P.B.D a drill moves forward at a rate of onetenths of a millimetre in the direction of the sinus floor.A soon as the slightest perforation is made through theremaining bone, the saline solution (which is underpressure) forces the schneiderian membrane upwardand away from the pursuing drill that could damagethe membrane. Since a resulting loss in pressure canbe measured using the JEDER®-System, the forward-moving drill is abruptly stopped by the surgeon.

3.) Sinus Vibration Pump (S.V.P)After successful “penetration“ of the remaining

bone volume a panoramic X-ray can be made to ensurethat a bubble was made with the aid of the pressurized

saline solution. After this step, the saline solution isbrought into oscillation with the aid of the S.V.P (Fig.1B). At the same time the volume of the solution canbe increased precisely (Fig. 1C). Through this methodthe Schneiderian membrane can be lifted more easilyfrom the sinus floor (Fig. 5). After pumping the salinesolution out of the cavity, this newly formed cavity canbe filled with the bone augmentation material. Ac-cording to our protocol we place the implants imme-diately after augmentation (Fig. 6).

The surveillance of the operation is monitored in itsentirety through constant pressure and volume meas-urements. A simple technique to determine if a mem-brane rupture has taken place is the conventional val-salva test commonly practiced after wisdom tooth re-moval in the maxilla. An advanced way of checking arupture was with the aid of an endoscope, which weused in the preliminary examinations. Setting the im-plants always went according to the guidelines of theimplant manufacturer. The healing phase was set atthree months in each case. Similar technology uses aballoon to lift the membrane. The difference in theJeder®-System is the comparative reduction of fric-

Fig. 3_A.T.P-Punch fort he minimal

invasive approach.

Fig. 4_Drill until slightly below the

sinus floor.

Fig. 5_Schneiderian membrane

being lifted through the saline

solution.

Fig. 6_Implantat in place.

Fig. 7_Preoperative volume

tomography.

Fig. 8_Digital planning of the implant

positions.

Fig. 9_Virtual measurement of sinus

lift volume.

Fig.10_Maxilla before operation.

I 25implants4_2010

Fig. 3 Fig. 4 Fig. 5

Fig. 6 Fig. 7 Fig. 8

Fig. 9 Fig. 10

tion that is placed upon the membrane: since only wa-ter creates the pressure, the risk of a rupture is reducedconsiderably. At the same time, the amount of salinesolution volume is monitored, thus ensuring a veryprecise knowledge of how much bone augmentationmaterial should be applied (Fig. 2). In 2009 alone, 30patients with a total of 35 sinus lifts were successfullytreated with the JEDER®-System.

_Case report

A 64-year-old edentulous patient who was wear-ing a full denture for almost two years wished a fixedprosthetic solution. The bone volume assessmentshowed an inner-antral bone height of 14–18 mm. The

bone height in the sinus area was between 3–5 mm.Preoperative planning is essential for success. In orderto accommodate the high aesthetic demands of thepatient a detailed surgical and prosthetic plan wasprepared. It was determined that wax-up and navi-gated implantation were essential for a positive out-come of this case.

The surgical procedure was divided into two parts:the implantation and the sinus augmentation. In orderto assess the available bone volume a preoperativevolume tomography was made (Planmeca; ProMax®,Helsinki; Fig. 7). Digital planning of the implant posi-tions was made possible with the navigating softwareMaterialise® (DENTSPLY Friadent). A further importanttool in this software is the virtual measurement of theexpected volume of the sinuslift. In so doing, a volumeamount was calculated before the procedure itself,thus providing important knowledge of the saline so-lution volume and bone augmentation material re-quired and how much of both will be required duringthe operation itself. In this case 0.88 ml for the right si-nus, and 0.66 ml for the left sinus were calculated vir-tually (Fig. 8 and 9).

For the minimal invasive sinus lift the describedcomponents P.B.D and S.V.P (Fig. 1A and B) were ap-plied. Because of the small crestal opening (3.5 mm di-ameter x 5 mm in height) only a paste-like bone aug-mentation material could be used. In our cases we usedOstim® (Heraeus Kulzer). The intraoperative drill-splint from Materialise® made an exact positioning ofthe implants possible (Fig. 10 to 15). A postoperative

I user report _ sinus lift

Fig.11_Use of the A.T.P-Punch.

Fig.12_All eight implant positions.

Fig.13_Navigation splint in use.

Fig.14_P.B.D in use.

Fig.15_Placement of the implant

after sinuslift.

Fig.16_Postoperative volume

tomography.

Fig.17_Coronal view of the sinuslift.

Fig.18_Emergence profiles.

Fig.19_Individual zirkonia

abutments.

Fig. 20_Final restauration.

26 I implants4_2010

Fig. 15

Fig. 12 Fig. 13

Fig. 14

Fig. 11

Fig. 16 Fig. 17

Fig. 19Fig. 18

Fig. 20

volume tomography documents the implant positionsas well as the minimal invasive sinus lift (Figs. 16 &17).In order to mange the soft tissue for an optimal aes-thetic result, following aids were used:

_The use of the A.T.P-Punch to avoid a mucoperiostealflap and to reduce soft tissue trauma.

_The use of very large healing abutments (diam. 7 mm)to make space for the individual zirconium prostheticabutments (Fig. 18).

_An optimal provisional bridge that contours the softtissue as well.

_Using a fine burr to model the keratinized gingiva inthe papilla areas.

Owing to the high primary stability of the eight im-plants (incl. sinuslift) an immediate loading of all im-plants was decided upon. Full ceramic individual abut-ments, zirconium framework and a ceramic finish(Dental Design Koczy, Figs. 19 & 20) made this bridgeperfect in all aspects of the patient’s aesthetic de-mands. The manufacturing of the bridge took threeweeks and was cemented permanently using iCem®(Heraeus Kulzer).

_Conclusion

In summary and according to our concept, the fol-lowing is needed for an optimal management of softand hard tissue.

_Flapless implantation (A.T.P)_Flapless sinus lift (JEDER®-System)_Navigated implantation (Materialise®)_Individual abutments/Zirconium Framework_Individual provisional solution

Advantages using the JEDER®-System_Minimal invasive technique_No suture, no swelling_No discolouration (haematoma)_Short operation_Almost no pain or discomfort after operation_Large reduction of risk (membrane rupture)_Simplified surgical procedure

Dr Philip JeschZahnambulatorium Wienerberg CityHertha Firnbergstr. 10/2/11100, Vienna, AustriaE-mail: office@jesch.atWeb: www.jesch.at

Mag Andreas Bayerleabayerle@jedersystem.com

_contact implants

✂ ���������� �

I hereby agree to receive a free trail subscription of ����� ��������������������� ������������ (4 issues per year). I would like to subscribe to ����� for € 44 inclu-ding shipping and VAT for German customers, € 46 including shipping and VAT for cus-tomers outside Germany, unless a written cancellation is sent within 14 days of thereceipt of the trial subscription. The subscription will be renewed automatically every yearuntil a written cancellation is sent to OEMUS MEDIA AG, Holbeinstr. 29, 04229 Leipzig,Germany, six weeks prior to the renewal date.

Reply per Fax +49 341 48474-290 to OEMUS MEDIA AG or per E-mail to grasse@oemus-media.de

Last Name, First Name

Company

Street

ZIP/City/Country

E-mail Signature

Notice of revocation: I am able to revoke the subscription within 14 days after my order by sending a written cancellation to OEMUS MEDIA AG, Holbeinstr. 29, 04229 Leipzig, Germany.

OEMUS MEDIA AG Holbeinstraße 29, 04229 Leipzig, Germany

Tel.: +49 341 48474-0, Fax: +49 341 48474-290, E-Mail: grasse@oemus-media.de

Signature

IM 4

/10

YYou can also subscribe via www.oemus.com/abo

����������������

�������������������������� ������������

I user report _ alveolar ridge reconstruction

Fig. 1_Presurgical aspect revealing

massive Periodontitis and bone

resorption in region 32, 42, 44.

Fig. 2_The CB-Scan exposing

region 32—with partial loss of the

buccal and lingual wall region 32–44.

_Introduction

A high clinical evidence of grafting procedures fromextraoral autologeous donor sites like i.e. from the iliaccrest in difficult bone loss sites is still the practice in oralor oral-maxillofacial surgery. However, the invasivesurgery combined with a prevalence of patients mor-bidity and suffer is an issue to discuss the persisting le-gitimation of this procedure. Since the appearance ofreliable bone substitute materials with or without anyautologeous bone added, the positive results concern-ing longterm stability of regenerated bone even in dif-ficult cases have become very predictable.

This article will point out in a case report the relia-bility of alternative and less invasive techniques for 3-D bone reconstruction in the mandible and question

the necessarity of iliac hip grafts for intraoral bone aug-mentation.

_Materials and methods

A female patient aged 48 years old with a severe andadvanced periodontitis in the maxilla and the mandiblecame into our clinic with the desire of a complex treat-ment plan with an implant retained denture in bothjaws. This case report will pinpoint the treatment of themandible. A CBVT was revealing massive bone loss inheight and width in the mandible arch from canine tocanine and apical cyst at tooth 23, 26 and 28 (Figs.1& 2). According to our protocol we started with an ini-tial scaling and HELBO®-Laser decontamination priorto the surgery to decrease the number of pathologicgerms and post op infections. Tooth 18 and 19 in the

left mandible were intended tomaintain until the finalization of theprosthetics to give some comfortduring temporization with an im-mediate denture that was placedpost op. Preoperative the patient re-ceived 1,200 mg of Clindamycin. Thepatient desired the surgery of toothremoval and ridge augmentationpersued under general sedation.

After nasal intubation and localanesthesia the bridge in the lowerwas removed and the remainingteeth despite from 18 and 19 asmentioned before (Figs. 3 & 4). Afterfull flap preparation with crestal in-cision, releasing incisions and expo-sure of the mental nerve exit, thevolume of the severe bone loss wasrevealed as well as the minor soft

3-D alveolar ridge reconstruction in a casewith severe bone lossAuthor_Prof Dr Marcel Arthur Wainwright, Germany

28 I implants4_2010

Fig. 1 Fig. 2

user report _ alveolar ridge reconstruction I

tissue conditions due to inflammatory tissue prolifer-ation (Figs. 5 & 6). The success of 3-D bone augmenta-tion is bonded to primary wound closure and tension-less flap adaptation. Thus, the periosteum is dissectedwith a scissor from the epiperiostal connective tissuebefore augmentation procedures to reduce bleedingand guarantee a flap flexibility without compromisingsoft tissue and nutritive blood vessels.

For bone augmentation a bone block was harvestedvia ultrasonic surgery from the retromolar region dis-tal from 32 of the right mandible (Piezotome II, ActeonFrance).

This bone block was devided into two halfs. One wasused for two “bone shields” to create a mold for thegrafting material, one was particulated with a bone milland mixed with defect blood and a �-TCP (Nanobone®,Artoss GmbH, Rostock, Germany). The bone blocks werefixed with two osteosynthesis screws (Fig. 7) and themixture of autologenous bone plus �-TCP in mixing ra-tio 50:50 was used to fill the gaps and increase therigde width and height. To increase the bone augmen-tation material volume an allograft block (Puros®, Zim-mer Dental) was particulated and added to the mixture.Before placing the material a non resorbable titanium-

reinforced membrane (Cytoplast Ti-250, Sybron Im-plant Solutions) was adapted lingually and folded toshape the augmentation complex according to the newand desired crest volume (Fig. 8). Upon the non re-sorbable membranes three xenogenous resorbablemembranes (Tutodent®, Zimmer Dental) were placedaccording to the sandwich membrane layer techniqueto create a better adaptivity to the flaps (Fig. 9) and en-hance wound healing. Primary wound closure (Fig. 10)was achieved with a 4-0 metric suture (Gore-Tex®,Gore). The patient carried a clamb retained provisionaldenture that was rebased with a soft material and wasinstructed to have no solid food for 10 days. Postoper-ative the patient continued with 1,800 mg Clinda -mycin, Ibuprofen 600 mg and a decongestant enzymebased medicine (Bromelain-Pos®, Ursapharm, Ger-many). The next day the patient had an expected cheekswelling but was not suffering from pain, after 10 daysthe sutures were removed. However, 6 weeks later amembrane exposure of the non resorbable membranewas evident, but due to the fact that this is tollerablewhen the patient is instructed to maintain oral hygieneand re-called once a week, the success of the outcomewas not threatened (Fig. 11a). The titanium pins and thetitanium reinforced membranes were removed after 4months.

Fig. 3_ Site before bridge removal

and extraction.

Fig. 4_Surgical Site after bridge

removal and extraction

of teeth 33, 32, 42, 43, 44.

Fig. 5_After Cystektomy the dra-

matic severe horizontal and vertical

bone loss is visible.

Fig. 6_Frontal aspect of the

compromised bone situation.

Fig. 7_Fixation of the autologous

bone blocks which have been har-

vested ultrasonically from the retro-

molar region of the right mandible.

Fig. 8_3-D crest reconstruction with

the “mold-technique” with clearly

visible horizontal and vertical aug-

mentation. Fixation of a titanium

reinforced ePTFE- membrane

with pins.

I 29implants4_2010

Fig. 3 Fig. 4

Fig. 7 Fig. 8

Fig. 5 Fig. 6

Fig. 9_Resorbable collagenous

membranes are placed upon the non

resorbable membranes.

Fig. 10_Wound closure with 4-0

metric GoreTex sutures after

flap mobilasation.

Fig. 11a_Membrane exposure of the

non resorbable ePTFE membrane

after 4 weeks. Clearly visible ist the

enhanced soft tissue situation.

Fig. 11b_6 months post surgical the

fully reconstructed bone situation

is obvious.

Fig. 12a_CBS of the pre-op region 44

with entire loss of the buccal plate in

region tooth 44.

Fig. 12b_Region tooth 44 after

6 months of healing with fully recon-

structed bone prior to implant

surgery.

Fig. 13_Inserted implants in the fully

reconstructed bone.

Eight months after augmentation the 2-D aspect ofthe CBVT showed clear evidence for entire ridge recon-struction of the deficient sites (Fig. 11b) with osteosyn-thesis screws in position. To emphasize the efficiencyand predictability of this technique the pre-op scan ofregion 28 (Fig. 12a) and the reconstructed bone 8 months later (Fig. 12b) show clear an increasement ofbone height and width.

The well vascularized bone was used to insert 4dental implants (4 x 3.75 x 13 BEGO Semados®, BEGO,Germany) for a later bar-retained denture, the healingtime is estimated with 8 weeks (Fig. 13) and was notcompleted before publication, here my apologies tothat.

_Discussion

3-D bone augmentation in cases with severe boneloss can be accomplished also with a less invasive surgi-cal protocol than the iliac hip graft. The morbidity can bedramatically reduced with the use of ultrasonic devices.Regarding the donor site, which may be favorized withthe retromolar region patients have close to zero com-plains if a single incision procedure is performed. Allo-graft materials may enlarge the volume of the augmen-tation material and in addition to that the success of �-TCP is not to be questioned. Regarding the long termstability the regenerated bone is superior to pure autol-ogous bone from the iliac crest, which resorption rate ismuch higher compared to intraoral bone or �-TCP. Re-

duced pain and postoperative complainsshould be reduced and enlarges thenumber of patients willing to undergooral augmentative procedures. _

Fig. 11bFig. 11a

I user report _ alveolar ridge reconstruction

30 I implants4_2010

Prof Dr Marcel A. WainwrightDDS, PhDDentalspecialistsKaiserswerther Markt 25–2740474 Duesseldorf, GermanyE-mail: Weinrecht@aol.comwww.dentalspecialists.de

Universidad de SevillaFacultád de OdontologiaCalle Avicena s/n41009 Sevilla

_contact implants

Fig. 9 Fig. 10

Fig. 12a Fig. 12b

Fig. 13

Tollfree Infoline: 00800 4030 4030www.implantdirect.eu

Europe’s No. 1 Online Provider for Dental Implants

In times of financial constraints - look for innovation with the best value!

Implant Direct sets new standards with high-quality implants with low prices and value added All-in-One™ Packaging for only 115 Euro per implant, including the corresponding prosthetic components. Besides the unique Spectra System, we offer compatible implant systems to Nobel BiocareTM, Str aumann and Zimmer ©

Dental. Make a decision today and choose a path of smart solutions and considerably more profit.

*Registered trademarks of Straumann, Zimmer © Dental and Nobel BiocareTM

Spectra-SystemSix application-specific implants

All-in-One Package: € 115

It’s Time for a ReThink: High Quality at factory-direct Prices

Zimmer©Dental*

Implant: from €100

Hexagon Tri-Lobe Octagon

Nobel BiocareTM*RePlant LineRePlus Line

ReActive LineAll-in-One Package: from € 115

All-in-One Package: includes implant, abutment, cover screw, healing collar, comfort cap and transfer

Straumann*SX-Plant Line

All-in-One Package: € 145

Anzeige_210x297_2009-02-26_en_alleSysteme.indd 1 26.2.2009 18:21:24 UhrUnbenannt-3 1 10.11.2010 18:24:28 Uhr

I user report _ oroantral communications

Fig. 1_OAC in region 26.

Fig. 2_Closure of the perforation with

oxydized cellulose.

Fig. 3_The extruded bone graft sub-

stitute is flatted at its front.

_Abstract

Methods for the closure of oroantral communica-tions that occur occasionally after tooth extraction areinvasive and laborious. Here, we assessed a simple andefficient technique to close such perforations in ninepatients. The oroantral communication at the bottomof the extraction socket was covered with oxygenized,degradable cellulose and the coronal two thirds of thesocket were filled with in-situ hardening polylactide-coated �-tricalcium phosphate (�-TCP). An airtight,stable barrier could be established in all cases, andwound healing was uneventful. The novel procedurewas minimally invasive and patient-friendly. Soft tis-sue covered the material after two weeks, and the bio-logical width was reestablished after two months. Hardand soft tissue structures were preserved. The bonesubstitute has been partially replaced by alveolar boneat the end point of this case-cohort study. A completeregeneration of the alveolar bone can thus be expected.

_Background

Oroantral communications (OACs) may occur afterthe extraction of the upper first molars and—less fre-quently—after extraction of premolars or second and

third molars (Ehrl 1980; Amaratunga 1986). Left un-treated, this may result in the formation of oroantralfistulae and chronic infection of the sinus cavities(Amaratunga 1986). An immediate and complete clo-sure of the communication is thus indicated if the si-nus cavities are not already infected (Kraut and Smith2000; Greenstein et al. 2008).

Frequently, soft tissue flaps are used to close thecommunications, with good results (Lambrecht 2000).However, flap mobilization involves slitting of the mu-cosa and the periost and is rather invasive, post-oper-ative swelling and pain are thus common (Gacic et al.2009). Furthermore, the procedure leads to displace-ment of tissue and scarring. As a consequence, reloca-tion procedures become necessary in most cases.Oroantral communication closure with tissue trans-plants and membranes represent an alternative to theflap-based methods. These surgical methods can becombined with augmentative measures to preserve thedimensions of the alveolar ridge (Becker et al. 1987;Watzek 2008). Membrane-based techniques and softtissue transplantations are characterized by good alve-olar hard- und soft tissue preservation and thus are be-coming more popular (Schwarz et al. 2006; Cardaropoliand Cardaropoli 2008; Fickl et al. 2008). Nevertheless,

The use of polylactide- coated �-TCPClosure of oroantral communications

Authors_Dr Stefan Neumeyer, Dr Stefanie Neumeyer-Wühr, Germany

32 I implants4_2010

Fig. 2 Fig. 3Fig. 1

user report _ oroantral communications I

Fig. 4_Bone graft substitute in the

defect.

Fig. 5_The defect is filled up to the

ginigival level.

Fig. 6_Sligth expansion of the aug-

mentate one day after the operation.

Fig. 7_Superficial degradation of the

bone graft substitute in the height of

the biological with after two weeks.

Figs. 8a & b_Complete soft tissue

closure, occlusal view after 3 (left)

and 8 months (right).

Tab. 1_Localization of the OACs

after tooth extraction.

I 33implants4_2010

Fig. 4 Fig. 5 Fig. 6

Fig. 7 Fig. 8a Fig. 8b

these techniques are also intricate and invasive, andthere is always a risk for dislocation of graft materialinto the sinus cavity (Thoma et al. 2006).

Frequently, the occurrence of an oroantral commu-nication is not anticipated and therefore the interven-tion to close the perforation was not scheduled in ad-vance. An easy, efficient and minimally invasive methodwould represent a benefit for both patients and clini-cians alike. Communication closure by insertion of root analogs made chair-side from a porous �-tricalcium phosphate (�-TCP) composite fulfillsthese criteria (Thoma et al. 2006). The technique wasshown to be fast and easy. Furthermore, less pain andswelling were observed compared to the patients thatwere treated with a buccal flap (Gacic et al. 2009). How-ever, the fabrication of root analogs is only possible withunfractured roots as templates (Thoma et al. 2006).

Here, we present a template-independent tech-nique for oroantral communication closure that uses amoldable polylactide-coated �-TCP. The initially softbone substitute hardens in the defect and therebyforms a barrier between the oral and the nasal cavities.In this pilot study, we addressed the question whetherthe novel method is successful in closing the oroantralcommunications that have occurred in nine patientsafter tooth extraction. The safe establishment of a bar-rier, healing and regeneration of hard and soft tissuestructures were evaluated.

_Materials and methods

Subject population and clinical situationAll patients with an oroantral communication after

tooth extraction between June 18, 2007, and October17, 2008, in a private dental practice were treated withthe described method. The study included 5 female and4 male patients who were between 21 and 86 years old.The occurrence of oroantral communications was rou-tinely checked by asking the patient to pressurize his orher nasal cavity. Positive findings were verified visuallyand with a blunt probe. Subjects were excluded fromthe study if the anamnesis or mucous nasal dischargeindicated an acute infection of the maxillary sinus or ifthe residual height of the buccal plate was below 3 mm,which may interfere with stable fixation of the graftmaterial. Based on these criteria, no patient had to beexcluded. The dimensions of the extraction socketswere measured by probing, radiographically and onclinical pictures (Figs. 1 & 2). The extraction defectsmeasured 6 to 14 mm in the mesio-distal and 8 to 12 mm in the bucco-oral direction. The height of thebuccal plate in the socket was between 3 and 11 mm. Allextraction sockets were surrounded by intact gingiva.

Closure of the oroantral communicationIn a first step, the site of the perforation at the bot-

tom of the extraction socket was covered with of oxy-genized cellulose (Tabotamp, Johnson&Johnson Med-ical, Gargrave, United Kingdom) (Fig. 2) in order to pre-

Region 18 17 16 15 14 24 25 26 27 28

OAC 1 – 1 1 – 1 – 3 2 –

I user report _ oroantral communications

Figs. 9a & b_Complete soft tissue

closure, lateral view after 3 (left) and

8 months (right).

Fig. 10_Radiograph after

OAC-closure.

vent a displacement of the graft material into the nasalcavity. Only after the formation of a stabilized coagu-lum the socket was filled with a fully synthetic bonegraft substitute (easy-graft®, Degradable SolutionsAG, Schlieren, Switzerland) to the gingiva level. The ma-terial consists of porous �-TCP granules that are coatedwith a 10 µm thin film of a polylactide. By mixing thegranulate in the syringe with a liquid plasticizer, thepolymer layer is softened and the granulate is trans-formed into a moldable mass. Excess liquid has to bediscarded prior to graft application by pressing it care-fully into a sterile swab. The bone graft substitute wasapplied directly from the syringe into the defect. Incases of larger perforations, the putty-like mass wasflattened at its front end in order to prevent compres-sion or displacement of the cellulose-stabilized coag-ulum (Fig. 3). The bone substitute was pressed gentlyinto the defect and adapted to the socket walls with asharp spoon (Fig. 4). The putty-like material hardens incontact with blood and other aqueous liquids into aninherently stable, porous, defect-analog body withinminutes (Fig. 5). The soft tissue was not sutured. Com-plete closure of the communication was verified byasking the patients to pressurize his or her nasal cavity.Defect filling was assessed radiographically. In order tominimize pressure onto the implant material, the pa-tients were advised not to blow their nose at the day ofthe operation and to eat with care in order not to put amechanical strain on the defect site. Six patients took abroad-spectrum antibiotic during 3 to 8 days; the otherthree patients declined the use of antibiotics for antibi-otic prophylaxis (Table 2).

_Follow-up

Recall appointments were scheduled after one day,seven days, two weeks and five weeks. More appoint-ments were fixed if the medical situation demandedclose monitoring of the patient. One patient did not ap-pear for the one-week control, two patients were notavailable for the two- and the five-week controls. Allpatients were seen at least once between week one andweek two, and all but one patient were followed up forfour weeks or more. Oroantral communication closure,healing and clinical outcome were documented pho-tographically and radiographically. In one case, soft

and hard tissue samples taken during the placement ofa dental implant were subjected to histological analy-sis.

_Results

Occurrence of oroantral communicationsMostly, the oroantral communications have oc-

curred after extraction of the first molar (4/9), twooroantral communications were opened up due to ex-traction of the second molar, the remaining threeoroantral communications were observed after re-moval of a first and a second premolar and a wisdomtooth, respectively.

Surgery and healingThe graft material hardened within minutes to an

inherently stable body in the extraction socket. All sub-jects were able to pressurize the nasal cavities, whichindicated a complete closure of the perforation. The pa-tients reported weak pain on the first day after the op-eration and a weak sensation of warmth in the regionwhere the perforation has been closed. Swelling wasnot observed in the operated region in any of the pa-tients. Bloody nasal discharge, which would be a sign ofbleeding into the nasal cavity, was not observed. Thebone graft substitute material formed a stable blockthat was well adapted to the wound contours. The �-TCP composite swells slightly due to water uptake.The graft was thus tightly fixed in the extraction socketand protruded slightly above the gingiva level (Fig. 6).Within two weeks, the graft material was covered withsoft tissue. Single �-TCP granules have been integratedinto the covering tissue layer (Fig. 7). The vertical di-mension of the material decreased due to the ongoingdegradation procedure. However, the material alwaysremained at the height of the biological width. Afterfour to six weeks, a complete regeneration of the softtissue could be observed. A collapse of the alveolarridge could be prevented. After nine months, the ini-tially convex buccal plate has receded slightly and ap-peared straight in the occlusal view (Figs. 7 & 8), indi-cating a marginal reduction in the width of the alve olarridge. Nevertheless, the vertical and horizontal dimensions of the well-attached gingiva were main-tained nearly completely (Fig. 9).

34 I implants4_2010

Fig. 9b Fig. 10Fig. 9a

user report _ oroantral communications I

RadiographyAfter closure of the oroantral communication, the

bone graft substitute in the coronal two thirds of theextraction socket but not the oxygenized cellulose inthe bottom of the extraction socket could be detectedradiographically (Fig. 10). After three to four months,the outlines of the graft particles appeared blurred, theformation of a tissue radiologically identical to bonecould be observed in the periphery of the graft material(Fig. 11). The vertical dimensions of the marginal bonestructures were not altered (Figs. 10 & 12). Even after 18 months, variations in the radiopacy could be ob-served in the center of the former extraction socket(Figs. 12 &13). However, an implant could be inserted atthe former extraction site with sufficient primary sta-bility (Fig. 13).

Histological analysisIn the hard tissue sample taken after 18 months,

capillary structures in the central part and a rathercompact lamellar bone of various mineralization

grades were detected (Fig. 14). The histological analy-sis of the soft tissue sample showed a connective tissuethat is covered with an unkeratinized, stratified squa-mous epithelium Remnants of graft material were notobserved in either sample, which was expected giventhat the material was described to resorb completelywithin three to 14 months (Nair et al. 2006; Rothamelet al. 2007).

_Discussion

It has been shown that the incidence rate oforoantral communications after extraction of upperteeth ranges between 0.3 and 4.7% (Thoma et al. 2006).If the maxillary sinus is not already infected, immediateclosure of the perforation is indicated in order to pre-vent contamination of the sinus cavity and a subse-quent infection. The flap-based techniques accordingto Rehrmann-Wassermund or Axhausen are rather in-vasive and entail surgical tissue relocation proceduresdue to structural tissue changes. The results are often

Fig. 11_Blurring of the outlines of the

graft material after 3 moths.

Fig. 12_Central remodelling after

18 months.

Fig. 13_Sinus floor elevation and

insertion of an Aesthura® Classic

implant in region 26 after 19 months

with 25 Ncm.

Tab. 2_Patient overview.

I 35implants4_2010

Fig. 11 Fig. 12 Fig. 13

Patient 1 Patient 2 Patient 3 Patient 4 Patient 5 Patient 6 Patient 7 Patient 8 Patient 9

Age (y) 52 37 21 43 53 62 49 54 86

Sex f f f m m m f m f

Region 15 26 26 16 26 27 24 18 27

Amount of easy-graft

1 x 0.4 ml 2 x 0.4 ml1 x 0.15

ml

2 x 0.15ml

1 x 0.4 ml 2 x 0.4 ml 1 x 0.4 ml 1 x 0.15ml

1 x 0.4 ml 1 x 0.4 ml

Antibiotics–

Isocillin1.2 Mega

Isocillin1.2 Mega

Sobelin300 mg

Isocillin1.2 Mega – –

Isocillin1.2 Mega

Isocillin1.2 Mega

Antibiotic intake –

3 x 1 daily, 4 days

3 x 1 daily, 4 days

3 x 1 daily, 4 days

3 x 1 daily, 8 days – –

3 x 1 daily, 4 days

3 x 1 daily, 4 days

I user report _ oroantral communications

Figs. 14a & b_Histological analysis

of soft (left) and hard tissue (right).

Harvesting and preparation artifacts

are visible.

not satisfying from an esthetic point of view. Therefore,a membrane-based approach in combination with amethod to preserve the alveolar ridge after tooth ex-traction is favored. The perforation can be closed witha membrane and/or a tissue transplant and the extrac-tion wound is filled with a material suitable for socketpreservation (Becker et al. 1987; Watzek 2008). Finally,the wound is sealed towards the oral cavity with an-other membrane and/or soft tissue transplant. How-ever, this technique is laborious, costly and is masteredmainly by experienced oral surgeons. Membrane-inde-pendent, minimally invasive subantral augmentationmethods are simple and efficient one-step proceduresfor closure of oroantral communications (Thoma et al.2006). The method presented in this case-cohort studycritically depends on the unique features of the novelsynthetic graft material. Initially it is moldable, and canbe inserted into defects of any shape. In contact withblood, the material hardens and forms an inherentlystable but openly porous body. Most likely, coagulatedblood in the interconnected pores and the underlying,stabilized coagulum supports the formation of an air-tight barrier. During the first days, the polymer layer thatmediates the formation of a stable scaffold takes up wa-ter, which results in a slight volume increase and guar-antees a tight contact between the defect walls and thegraft material. The �-TCP composite is tissue-friendlyand the phase-pure �-TCP is degraded in parallel withbone formation (Nair et al. 2006; Rothamel et al. 2007;Gläser 2009). Unlike other methods, the described sub-antral augmentation procedure does not inflict furtherdamage to the soft- and hard tissue surrounding the de-fect site. Pain, swelling and increased risk of infectionthat results from soft tissue and periost slitting and theexposure of the underlying bone are avoided, whichrepresents a major patient benefit. It took two weeks forthe graft material to be covered with soft tissue whereasdefect closure is immediate with other techniques. Itcould be argued that the delayed coverage with soft tis-sue may increase the risk of infection. However, neitherin the present study nor in a larger study that used anidentical, thermally molded �-TCP composite fororoantral communication closure did such infectionsoccur (Gacic et al. 2009; Thoma et al. 2009). Furtherstudies will need to compare larger patient groups toaddress this issue in more detail. The clinical and radi-

ographic controls showed an almost complete preser-vation of soft and hard tissue structures similar to mem-brane-based surgical techniques. Expansion of the si-nus cavity towards the alveolar ridge was observed inone case 18 months after tooth extraction, making a si-nus lift for stable implant placement necessary (Fig. 12).The �-TCP composite is replaced by bone that is sub-jected to physiological bone remodeling. Expansion ofthe sinus cavity thus occurred like it would be the casein any non-augmented edentulous setting.

The described minimally invasive method fororoantral communication closure is well suited fororoantral communications that are located above un-problematic extraction sites. However, it should not beapplied if the size or the geometry of the defect does notallow stable anchorage of the material. Alternativemethods should be considered in patients with verylarge oroantral communications that may result fromthe extraction of two or more molars. In such cases, thegraft material may be lost or displaced into the sinuscavity by mastication forces. Also, safe anchorage of thematerial and efficient closure of the oroantral commu-nication may not be given in shallow extraction sockets,e.g. if the buccal lamella is missing. A perforation withonly 3 to 5 mm remaining vertical bone height could besuccessfully closed during this study. This patient wasmonitored more closely than described in the protocol.Defects shallower than this certainly should be treatedwith an alternative method.

In conclusion, the described minimally invasivemethod for closure of oroantral communications hasseveral obvious advantages over conventional tech-niques. It is fast and efficient and does not inflict dam-age to the surrounding tissue since no additional sur-gery is needed. Nevertheless, alternative methodsshould be considered if an unsuitable defect geometryjeopardizes stable graft anchorage. Soft and hard tis-sue structures were mostly preserved, and no compli-cations or failures to close the perforations wererecorded during this retrospective case cohort study._

Article scheduled for publication, based on the article “Der Einsatz von polylactid-beschichtetem �-Tricalciumphosphat zum MAV-Ver-schluss”, published in Quintessenz 08.

36 I implants4_2010

Fig. 14bFig. 14a

Dr Stefan NeumeyerDr Stefanie Neumeyer-WührLemminger Straße 1093458 Eschlkam, GermanyE-mail: praxis@dres-neumeyer.de

_contact implants

meetings _ events I

I 37implants4_2010

2011ITI Congress FranceWhere: Paris, FranceDate: 21–22 January 2011Website: www.iti.org

AEEDC DubaiWhere: Dubai, UAEDate: 1–3 February 2011Website: www.aeedc.com

26th Annual Meeting of AOWhere: Washington DC, USADate: 3–5 March 2011Website: www.oesseo.org

IADR General Session & ExhibitionWhere: San Diego, CA, USADate: 16–19 March 2011E-Mail: sherren@iadr.orgWebsite: www.iadr.org

34th International Dental ShowWhere: Cologne, GermanyDate: 22–26 March 2011E-Mail: ids@koelnmesse.deWebsite: www.ids-cologne.de

International Osteology SymposiumWhere: Cannes, FranceDate: 14–17 April 2011Website: www.osteology-cannes.org

5th CAD/CAM & Computerized Dentistry International ConferenceWhere: Dubai, UAEDate: 12–13 May 2011Website: www.cappmea.com

FDI Annual World Dental CongressWhere: Mexico City, MexicoDate: 14–17 September 2011Website: www.fdiworldental.org

7th Arab German Implantology MeetingWhere: Beirut, LebanonDate: 21–24 September 2011Contact: drtamimi@drtamimi.com

41th International Congress of DGZIWhere: Cologne, GermanyDate: 30 September–1 October 2011Website: www.dgzi-jahreskongress.de

AAID 60th Annual Meeting Where: Las Vegas, NV, USADate: 19–22 October 2011Website: www.aaid-implant.org

AOS 8th Biennial ConferenceWhere: Adelaide, South AustraliaDate: 9–11 November 2011Website: www.aosconference.com.au

International events

I meetings _ DGZI

_DGZI (German Association of Dental Im-plantology) celebrated its 40th Annual Interna-tional Congress on October 1st and 2nd in Berlin.With over 500 participants it attracted wide inter-est and met all ambitious expectations. Highlyqualified speakers from practice and science gavean insight into the status of and future opportuni-ties in this booming field of dentistry. Not only didwe celebrate the anniversary of our association, butDGZI’s efforts in promoting the standing implan-tology in dentistry were also celebrated, as the suc-cess of this field is due in great deal to the efforts ofDGZI.

In his opening speech DGZI President Dr Fried-helm Heinemann compared the associations devel-opment with human life: “In the beginning it wassmall with only seven founding members, thencame the age of “puberty” with times of dramaticdevelopment, but now we are in our prime. We areestablished, respected and well equipped, and wedeliberately assume the responsibility for our ex-pert field.” Many friendships with other associa-

tions have been established and developed over theyears. Among others, Dr Heinemann underscoredDGZI’s excellent cooperation with the GermanDental Medical Association (BZÄK), the Profes-sional Association of Oral Surgeons e.V. (BDO), theGerman Association of Prosthodontics and DentalMaterials (DGPro) and the German Association ofOral Implantology e.V. (DGI), which he calls “the lit-tle brother”. “It is crucial to show common ground”,said Dr Heinemann. “There have been many exam-ples in the past where politics have succeeded inpitting one group against another, true to themotto ‘divide et impera’ (divide and rule).”

_Together we are strong—globally interconnected

The Board of Directors was particularly proud ofDGZI’s international reach. For example the entireBoard of the Japanese Association AIAI was gath-ered in the auditorium. In his welcoming speech,BZÄK’s President Dr Peter Engel expressed it so:“Implantology has mutated from a supposed ugly

After 40 years,DGZI is in its primeDGZI celebrates its anniversary with a top class congress

Author_Dr Christian Ehrensberger, Germany

38 I implants4_2010

meetings _ DGZI I

duckling to a proud swan, and it is still gainingground.” DGZI has reached the proud number ofover 4,000 members. On its 40th Annual CongressDGZI offered a program to suit diverse interests aswell as its international participants. Science andpractice and numerous different professional as-sociations—this is the motivation which makes usreflect on how we can further develop implantol-ogy together. Just as Gauß once said, “It is not onlythe knowledge, but the learning, not the possess-ing, but the gaining, not the being, but the reach-ing, which gives the real enjoyment.”

“The past was identified by respectful aloof-ness”, characterized Prof Dr Dr Hendrik Terheyden,but he went on: “As a young DGI President I am inthe happy position to approach future coopera-tions in a much more unburdened way.” Now thatthe conflict of interest between practitioners andscientists is obsolete, the question of which im-plantology association may claim one of the twofields for itself has also fallen away. According toProf Terheyden, DGZI works together with qualified

university professors, and equally DGI has manypractitioners among their members. “Does a com-petition between implantological associationsmake any sense? I leave this to anyone s guess,” saidProf. Terheyden.

Dr Heineman thanked Prof Terheyden for hiswelcoming speech and “for the possibilities whichresult from it”. Dr Heineman then moved on to aspecial feature of this congress. Though the Asso-ciation generally agreed not to deliver tributes orpresent awards, an exception was made in celebra-tion of its anniversary. The coveted DGZI ImplantDentistry Award was given to Dr Sönke Harder, Kiel,(3rd place), Prof Dr Thomas Gredes, Greifswald (2nd

place), and Dr Stefanie Schwarz, Heidelberg (1st

place) by Dr Roland Hille, DGZI Vice President andscientific chairman of the congress. The subject ofthe winning work was the “Immediate Loading ofImplants”.

One of the congress highlights was the shortwelcoming speech of Prof Dr Hans Grafelmann.Among other distinctions, he is an honorary doctorof the University of Istanbul and an associate pro-fessor in New York. But more than anything, it washe and six colleagues who founded DGZI on Febru-ary 20th, 1970 in Bremen. “I still remember the Im-plantology Congress in 1969. There were 85 partic-ipants and two university professors who attendedthe congress. Today there are more than 500 par-ticipants and many university representatives.DGZI has a worldwide reputation for its reliabletraining programs”, said Prof Grafelmann, consid-ering the development of DGZI. In the name of hisProf Dr Grafelmann Foundation, Prof Grafelmannhanded over a check of ⇔20,000 to Dr Heinemann,which will serve as a basis for DGZI’s future devel-opment. In his speech it became clear how close tohis heart DGZI rests as he explained, “It was my life-work. I want to thank all of you.”

“40 years ago titanium was known as the materialof submarines”

Dr Hille had the opportunity to introduce one ofhis own academic mentors, Prof Dr Wilfried Schilli,Freiburg, who gave the first scientific speech of theconference. The subject of his speech was “Oral Im-plantology in 1970”. Prof Schilli said, “Back then, wethe dentists as well as the general population hadto worry about so many things, and carrying outimplantology was not a top priority. Titanium wasknown for being a material used in Soviet nuclear-powered submarines that rendered them invisibleto radar. However, the problem was obvious, asshown in the following statistic. One quarter of the40–50 year olds belonging to the Bosch companystaff were already edentulous. Those patients suf-

I 39implants4_2010

I meetings _ DGZI

fered significantly, and we often could not helpthem satisfactory on a long term basis. The scien-tific consensus was that a bone transplanted to thealveolar process would melt like butter in the sun.Augmentation seemed to be nonsensical. The possi-bility of an implantation was kept under wraps, evenin the specialist press. However, it was also the timewhen subperiostal leaf- and/or pin-shaped im-plants, and enossal bone screws smoothed the wayfor implantology’s subsequent success (for refer-ence see studies made by Prof Grafelmann).

In comparison, Prof Dr Dr Frank Palm, Konstanz,summarized today’s implantology status as follows:“Functional examination, possible augmentation,3-D planning, and connective tissue transplants areroutine implantological options used daily.” In pre-vious times the damaging of a nerve was not con-sidered to be a crucial mistake, but today we are ea-ger to avoid such damage. Simply dye it and make itvisible in a three-dimensional image! Tissue regen-eration has become much more certain, and long-term success really means long-term success, notjust two years plus X. We also find solutions for morecomplex cases according to the patient’s wishes. Westill cannot completely avoid bone resorption afterimplantation, but it does not exceed the extent ofcommon physiological resorption.

Prof Palm also spoke about a number of still-open questions: Immediate loading, periimplantitistherapy, unclear state of the art in case of reduceddiameter implants. On the second day of the con-gress Prof Palm chaired a special panel of short pre-sentations dedicated to “Minis, Shorties and otherson trial”. The speakers were Prof Dr ChristophBourauel, Prof Dr Joachim Hermann (a “grandee” ofimplantology), DGPro chairman Prof Dr MichaelWalter, Dr Dr Martin Bonsmann, and Prof Dr Dipl.-Ing. Ernst Jürgen Richter. Following this sessionthere was a lively and at times even controversialdiscussion among the experts on the podium in re-sponse to questions from the audience, and afriendly but also pointed exchange of pros and conswas set forth. It became clear that many current is-

sues are still not resolved. Implantology remains adynamic field, and there is still much left to be dis-covered, clinically examined and newly developed!

“We should offer implantology in a much more self-confident manner”

Overall, DGZI’s 40th International Annual Con-gress provided an excellent overview of all relevantimplantological topics under discussion today. Prof.Terheyden, Kassel, outlined aspects concerning theLe-Fort-I-osteotomy. In particular, he called on alldentists to show more self-confidence. Alveolarridge atrophy is a disease which requires treatmentand also essential financial support. If in doubt, evena three to four days hospital stay should also be in-corporated—such a stay would never be called intoquestion in the case of, for example, knee prosthe-sis, because it is common in other medical disci-plines to inform patients in a much more aggressivemanner.

Prof Dr Werner Götz, Bonn, explained the biolog-ical basics of osseointegration. “It is advantageousfor a dentist carrying out an implantation that bonecells in the jaw are highly osteogenous. This is some-times a reason to be envied by other medical disci-plines.” It is interesting that nowadays the olddogma of unloaded healing is of less importance.However, the implant-bone-interface, which en-ables deliberate healing, is not yet well understood.We know that osteoblasts prefer a medium roughimplant surface. Osseointegration can be improvedby blasting, etching or anodizing. In future, a com-pletely different concept might come to the fore: anew periodontal apparatus could be constructedusing a specially cultivated tissue.

Dr Stephen Wallace, USA, reported on the currentpossibilities of bone augmentation in the course ofa sinus floor elevation, which are already appliedoverseas. He presented in particular the mushroom-shaped diamond-coated dental grinding instru-ments that are used for forming round and oval win-dows in the lateral walls. He also introduced artifi-cially produced recombinant human growth factors

40 I implants4_2010

meetings _ DGZI I

(rh-PDGF), which bind to bone substitutes, andBMPs (bone morphogenetic proteins) that improvethe resorption of bone substitutes. However, atpresent, these materials are still very expensive(about ⇔5,000 per treatment). At the moment thesetechniques do not improve long-term success, butthey do help in achieving the desired result in lesstime.

_The future: Interdisciplinary cooperation

In his discussion of the “Closing the Interdiscipli-nary Gap”, Prof Dr Paul-Georg Jost-Brinkmann,Berlin, discussed the possibility of preparing ortho-dontic treatment before carrying out implantation.He also highlighted the alternative solution of atransplantation of one’s own teeth.

Prof Palm talked about the latest developments inthe GBR technique. He specifically addressed thequestion of whether future augmentations may besuperfluous, with a clear “no”. Guided bone regenera-tion instead of classic bone augmentation may workin some cases, but not in general. In his speech titled“Is the Implant s Length of any Importance?” DrAchim W. Schmidt, MSc, Munich, considered whethershort implants are an alternative to direct sinus lift-ing. His conclusion is that short implants functionsuccessfully with sintered surfaces, which feature thenecessary porousness. He proved this with the exam-ple of many cases from his own practice.

Prof Dr Matthias Kern, Kiel, began his discussionwith an almost heretical example. He integrated aMaryland bridge into the region of the anterior teethof a 15-year-old patient. After 19 years the bridge isstill in situ, and the patient does not require any im-plant! Afterwards he pointed out the pros and consof full ceramic abutments. Esthetics and bio com-patibility are clearly advantageous, but missinglong-term experience, higher costs, and the morecomplicated and thus critical treatment (adhesivefixation of the abutment on a titanium basis withPanavia 21) are of disadvantage.

Dr Peter Gehrke, Ludwigshafen, considers indi-vidually manufactured abutments to be very attrac-tive. They can be produced centrally and on an in-dustrial scale by applying new digital techniques.“For CAD/CAM generated zirconium oxide mount-ings there are no restrictions on how to shape themomentum to mesial and distal.”

In his speech on “Implants and General Medi-cine“, Prof Dr Thomas Weischer, Essen, indicatedthe limits of implantology in cases of severe orchronic disease, and he explained their current de-velopment. Today, even HIV patients can be treatedwith implants, provided that certain conditions areobserved. The conclusion is that in most cases adental implant restoration can be performed, evenin cases of existing general diseases like HIV, os-teoporosis, cancer or diabetes mellitus. It is highlyimportant to keep in contact with the patient spractitioner, oncologist or other expert physicians.

At the end of the congress Dr Heinemann andProf Palm took turns evaluating the various scien-tific contributions made, considering the aspectsthat are important to practice—information whichis of practical value to the user in optimizing hisown implantological work. The result of this analy-sis can be downloaded from DGZI s homepagewww.dgzi.de under “Scientific Review” along withadditional literature for private review.

The scheduled podium program was comple-mented by a number of other events, including apre-congress workshop on “Periodontology inPractice”, workshops led by corporate sponsors,seminars, a symposium on “Digital Dental Tech-nologies in Implant Prosthetics” for dental techni-cians, and a large dental exhibition housed directlyin the venue itself, the Maritim Hotel.

The congress’ participants could also enjoy avery special Friday evening event, which took placein the wonderful atmosphere of the Berlin Wasser-werk—after all, we had something very special tocelebrate: 40 years of DGZI!_

I 41implants4_2010

I meetings _ anatomy weekend

_Refreshing one’s knowledge and receiving up-dates at the same time—the clear structure of DGZI(German Association of Dental Implantology)“Anatomy” curriculum has made it a long-standingfavourite. Including an insightful theoretical intro-duction, an impressive demonstration including a livevideo broadcast from the dissection room, and pa-tient-side practice on human specimens, this weekendcourse (October 8 and 9 in Dresden) was once again asuccess. In addition, the number of international par-ticipants continues to rise—this year one quarter of the40 participants came from abroad. A special pre-course-program started already on Thursday. Prof DrMazen Tamimi reported about the advantages of amodern navigation system. A hands-on-course anddinner sponsored by Schütz Impla Dental completedthe program on Thursday.

A specially designed DGZI course module foranatomy has been a permanent feature of the Im-plantology curriculum for a decade. Following its suc-cess in recent years, colleagues for whom it has beensome time since they passed their state examinationor implantological exams, may have realised that theyare no longer able to recall the enormous amountknowledge required, and could benefit from this up-to-date weekend course—a two-day professional

training course to refresh their anatomical knowledge.Thus, many participants and “guest auditors“ took partin the Implantology curriculum in Dresden. The con-tributions of anatomist Dr med habil WolfgangSchwab of TU Dresden, oral biologist and anatomistProf Dr Werner Götz of the University of Bonn, dissec-tion assistant Ute Nimtschke, implantologists DrRainer Valentin and Dr Rolf Vollmer, and oral surgeonsDr Martina Vollmer and Dr Uta Voigt meant that thecourse was in competent hands, and ensured thatfrom the beginning the different perspectives of vari-ous disciplines were considered. The first day of thecourse was dedicated to a thorough introduction tothe anatomy of the skull, including an exact demon-stration of the supply for nerves and blood vessels andthe anatomy of bones, tongue, throat and larynx. In or-der to explain the particular surgical basics, the speak-ers demonstrated the procedures used for autologousand xenogenous augmentation as well as those forbone spreading. Various augmentation methods andtechniques, e.g. the extraction of bone from differentlocations, were explained in detail on the course. Thehighlight of the day was the application by Dr med ha-bil Schwab and Prof Dr Götz of theoretical knowledgeto an actual anatomical specimen. Courtesy of certainmodern technology, including a live video broadcastfrom the dissection room, the participants could ask

The Anatomy Weekendis also in great international demandAuthor_Dr Christian Ehrensberger, Germany

42 I implants4_2010

meetings _ anatomy weekend I

questions in real time during the presentation, includ-ing for example, what the route of the sural nerve is,which is used for nerve transplantations. After all gapsin knowledge had been addressed it was time to gatherand enjoy a nice group dinner.

The second day of the course again began with atheoretical introduction—this time Dr Rolf Vollmer in-troduced a number of different implant techniques tothe participants. Additionally, the sponsoring compa-nies (Geistlich Biomaterials, Mectron, Resorba, SchützDental, Helmut Zepf Medizintechnik) explained thefeatures of the instruments and working materialswhich they had provided, so that the participantscould practice their newly-acquired techniques with

those products. In this way all structures relevant fordental anatomy and implantology could be shown andprepared. Throughout the course Ute Nimtschke, ProfDr Götz and Dr med habil Schwab were prepared to an-swer all manner of questions. Towards the end, DrSchwab and Dr Valentin demonstrated an autologousbone removal from the iliac crest. During the coursethese proven experts made clear how good planningand early trouble shooting can significantly minimizeor even avoid the risk of later complications. Thishighly successful professional training weekend wasconcluded with an exam.

DGZI’s next Anatomy Weekend will take place onSeptember 15–17, 2011. _

I 43implants4_2010

I manufacturer _ news

44 I implants4_2010

Manufacturer NewsStraumann

New Straumann®

MembraGel™ for guided bone regeneration

Guided bone regeneration involves the use of a bar-rier membrane to help stabilize the bone graft andprevent unwanted growth of soft-tissue into the de-fect. Straumann MembraGel is designed to achieveundisturbed bone regeneration, which is a pre -requisite for optimal clinical and esthetic outcome.Based on advanced polyethylene glycol (PEG) hy-drogel technology, Straumann MembraGel is ap-plied in liquid form and molds to the defect precisely.Within 20–50 seconds after application, the liquidcomponents solidify, stabilizing the bone graft andproviding an effective barrier to tissue infiltration.

Straumann MembraGel has completed preclinicaland clinical trials including head-to-head compar-

isons with conventional materials. Further clin-ical data have been collected in an ongoing‘non-interventional’ study and a multicenterclinical trial. Data from the clinical program in-clude more than 40 centers in Europe and NorthAmerica.

Throughout development, Straumann hasworked closely with leading independent ex-perts. The company is combining the launchwith an education program that includeshands-on product training. Straumann Mem-braGel is being launched initially in key Euro-pean markets, North America and Australia,where it has received regulatory approvals/clearances.

Institut Straumann AG

Peter Merian-Weg 12

4052 Basel, Switzerland

E-mail: info@straumann.com

Web: www.straumann.com

Implant Direct

New European TrainingCenter

Implant Direct, Europe’s No. 1 Online Provider forDental Implants, continues its expansion with abrand-new European Head Office in Zurich,Switzerland. On the 1st of September the team ofImplant Direct Europe AG moved into the new Eu-ropean Headquarter at the Hardturmstrasse 161 inZurich.

The fast growth of Implant Direct’s sales requiredthe expansion of the customer service depart-ment, a centralized European logistics depart-ment, and foremost, a state-of-the-art trainingcenter for workshops and hands-on trainings withcustomers.

2011 will start with trainings and hands-on work-shops in which Implant Direct will welcome speak-ers and customers in their training rooms with aspectacular view over the Swiss mountains. Thenew training center offers modern presentation fa-cilities and is the ideal signboard for a young ex-

panding and innovative company in the implantol-ogy like Implant Direct. The tremendous growth isthe result of Implant Direct’s effort in constantlyimproving and developing new products. One ofthe most recent examples, is the new one-piece lo-cator implant “GoDirect” that has been patented.This world first product includes modern attributesand accomplishments of future implantology. Theimplant unifies all the advantages of a one-piececonstruction. “GoDirect” implant is available in

Ø 3.0, 3.7 and 4.7 mm and the prosthetic part of thelocator in 1.5 and 3.0 mm height. Furthermore it isprosthetical compatible with the system of ZestAnchorTM.

Implant Direct Europe AG

Hardturmstrasse 161

8005 Zurich, Switzerland

E-mail: info@implantdirect.eu

Web: www.implantdirect.eu

bio

nic

s

ticky

gra

nule

s

easy

-gra

ft®C

RY

STA

L

Degradable Solutions AGWagistrasse 23CH-8952 SchlierenPhone: +41 43 433 62 60www.degradable.chdental@degradable.ch

Ingenious: Simple handling and accelerated osteocon-duction for long-term volume preservation.

Order your free test sample over the internet!

AD

BEGO Implant Systems

Competitively pricedalternative for occlusal screw-retained crown andbridge solutions

The implant company BEGO Implant Systems,based in Bremen, Germany, offers its customers acompetitively priced alternative to tried and testedgold cast-on abutments. Expensive high-gold al-loys are not required and, instead, less costly non-precious alloys can be used. The patented Sub-TecUniversal abutment (available with and withoutanti-rotation protection) enablesthe practitioner to secure the su-perstructure, produced from allavailable dental alloys, intraorallywith either a primary or occlusalscrew fixation. The resulting oxidelayers which form on non-pre-cious alloys when casting or with ceramic firingand which have to be removed by machine do notaffect the subsequent fit between the implant andthe Sub-Tec Universal abutment. The dental tech-nician completes the work as usual and adheresthe Universal base produced from a titanium alloyto the custom-made structure. The seat of thescrew is found in the cast part. Another benefitworthy of mention is the fact that the challenging

removal of residual cement is no longer necessary.In contrast to cemented restorations where thesubgingival removal of residual cement is essen-tial, with these screw-retained designs this is notthe case and, as such, the periimplant soft tissueis protected. As with all other BEGO superstructurecomponents, these high-quality abutments comewith two screws. The slotted screw is for dentalprocessing in the laboratory, whilst the separatelypackaged hexagon socket screw is used for final

placement of the restoration in thepatient’s mouth. “This ensures that anew screw is used for every singlepatient and, in turn, that he or she iscompletely satisfied with the implantin the long term”, explained ChristophStaufenbiel, Product Manager at

BEGO Implant Systems.

BEGO Implant Systems GmbH &

Co. KG

Technologiepark Universität

Wilhelm-Herbst-Str. 1

28359 Bremen, Germany

E-mail: info@bego-implantology.com

Web: www.bego-implantology.com

EMS

Piezon Master Sur-gery with three newinstrument systems

Since it was introduced, Piezon Master Sur-gery—based on Piezon technology—has had aremarkable track record inmany practices. Today, EMS hasexpanded the clinical scope ofapplication of the Piezon MasterSurgery product range. With anenhanced product offering—and special instruments such asSinus System and Implant Sys-tem—practitioners haveaccess to technologiesallowing them to workeven more efficiently. With Piezon Master Sur-gery, additional applica-tion-specific instruments arenow available: a total of fourperio instruments especially

designed for resective and regenerative peri-odontal surgery, five advanced surgical instru-ments for gentle and uniform sinus lifts, as wellas six special fully diamondcoated instrumentsfor implant applications with dual cooling systemand extraefficient debris evacuation.

These instruments are seen as particularly suit-able for four clinical applications: implant sitepreparation following extraction, implant sitepreparation following splitting of the alveolarridge, implant site preparation in the posteriortooth area, and implant site preparation in com-promised areas, such as a narrow alveolar ridge.

In principle, instruments can be used at low OPtemperature of no more than 33 degrees centi-

grade. They provide drilling efficiency andprecision in the maxillary area.

EMS

Electro Medical Systems S.A.

Chemin de la Vuarpillière 31

1260 Nyon, Switzerland

E-mail: welcome@ems-ch.com

Web: www.ems-dent.com

I manufacturer _ news

46 I implants4_2010

Degradable Solutions

Moldable, in situ hardening bone graft substitutes

easy-graft™ CLASSIC and easy-graft™ CRYSTALare moldable, fully synthetic bone defect fillers forindications in oral surgery, implantology and peri-odontology. In contact with blood, the materialsharden within minutes into a porous, inherentlystable body. A membrane to contain the materialsis not necessary in most cases. The easy-graft™products are frequently used for ridge preserva-tion after tooth extraction. The socket must be freeof infected and inflamed tissue prior to graft inser-tion. The materials are applied directly from the sy-ringe into the defect where they harden and sealthe extraction wound. For most cases, a mem-brane or suturing of soft tissue are unnecessary.easy-graft™ CLASSIC and CRYSTAL are designed

to have different resorption characteristics. easy-graft™ CLASSIC is composed of phase-pure ß-tri-calcium phosphate (�-TCP). It degrades com-pletely and is replaced by bone. easy-graft™CRYSTAL contains 40% �-TCP and 60% hydrox-yapatite (HA). It is degraded only partially and re-mains integrated in the newly formed bone forlong-term volume preservation. In summary easy-graft™ combines established biomaterials for

bone regeneration with a unique handling advan-tage – moldable from the syringe, hardening in thedefect.

Degradable Solutions AG

Wagistrasse 23

8952 Schlieren, Switzerland

E-mail: info@degradable.ch

Web: www. degradable.ch

Nobel Biocare

Excellent initial stability and perfect aesthetic results

With its latest product NobelActive™ the Swiss company Nobel Bio-care has created a 3rd generation dental implant. This innovative im-plant was developed to efficiently meet the high demands of dental im-plant surgery and implant prosthetics. Its positive effect of high initialstability is of benefit to immediate loading after insertion, setting No-belActive clearly apart from conventional implant systems.

With its novel thread design, NobelActive™ condenses the bone duringinsertion. The innovative implant design allows gradual and efficientbone condensing with each rotation. This benefit clearly differentiates No-belActive™ from other conventional, self-tapping implants available on themarket. Further the expanding, tapered implant body of NobelActive™ featuresa double lead thread design, which also contributes to the high initial stability.

And the newly designed implant tip allows fine adjustments to implantorientation during insertion to optimise the final position of the implantin the bone, without jeopardising initial stability. The implant threadallows gradual atraumatic narrow ridge expansion and was devel-oped to attain high initial stability even in compromised bone situa-tions. Furthermore, NobelActive™ is provided with two reverse-cut-ting flutes. The coronal region of NobelActive™ is back-tapered anddesigned to maximize alveolar bone volume around implant collar forimproved soft tissue support. These new attributes are very importantadvantages for the subsequent prosthetic management, in additionto ultimately facilitating the co-operation between surgical and pros-thetic management.

Nobel Biocare Management AG

P.O. Box

8058 Zurich Airport, Switzerland

E-mail: info@nobelbiocare.com

Web: www.nobelbiocare.com

CAMLOG

Prosthetic components for occlusally screw-retained restorations

With the introduction of the new Vario SRprosthetic components, users are nowable to choose between cement-retainedor screw-retained crown and bridgerestorations on CAMLOG® implants. VarioSR abutments are available in straight andin 20° and 30° angled versions for implantdiameters 3.8/4.3/ 5.0/6.0 mm.

Prefabricated Vario SR prosthetic componentsBurn-out plastic copings can be used to fabricatecrown, bridge and bar constructions. The titaniumcaps have a retention surface on the outside and aredesigned for temporary or final bridge restorations

made of plastic. Titaniumbar caps are available forlaser-welded bar con-structions.

For bridge and bar con-structions, the impres-sion can be taken usingVario SR impression

caps, open or closed tray, directly over the Vario SRabutment already in its final position in the implant.The retention screw of the impression cap, open tray,can be shortened by 3 mm extra-orally if space limi-tations are encountered.

For crown restoration, the impression can be takendirectly over the implant shoulder using CAMLOG®

impression posts, open or closed tray.

CAMLOG Biotechnologies AG

Margarethenstrasse 38

4053 Basel, Switzerland

E-mail: info@camlog.com

Web: www.camlog.com

48 I

I DGZI _ social news

implants4_2010

Congratulations and Happy Birthday to all DGZI-members around the world

65th BirthdayDr Bernd Peter Wylutzki (01.10.)

ZA Hartmut Pickroth (20.10.)

60th BirthdayDr Uwe-Alexander Lück (25.10.)

55th BirthdayBricky Yosy (03.10.)

Dr Jamal Hajjar (14.10.)

Dr Holger Hanstein (18.10.)

Dr Joachim Malert (18.10.)

Dr Reinhold Waibel (30.10.)

50th BirthdayDr Ludger Dietze (01.10.)

ZÄ Cornelia Batzer (08.10.)

Dr Klaus Köhler (11.10.)

Dr Rainer Hubertus Kreuzkamp (15.10.)

Dr Petra Hille (24.10.)

Dr Elke Behle (27.10.)

Dr Frank Flügge (31.10.)

45th BirthdayDr Marcus Betz (06.10.)

Dr Haddad Tameem (07.10.)

Dr Holger Vicari (10.10.)

Dr Fernando Zurits (13.10.)

Dr Saad Mohammed Aboshagara (25.10.)

Dr Thomas Staudt (25.10.)

40th BirthdayNina Bronik (07.10.)

Marc Mainka (20.10.)

Dr Ralf Schlichting (27.10.)

Achim Schmidt (28.10.)

Dr Thomas Martin (28.10.)

ZA Marcel Liedtke (28.10.)

75th BirthdayDr Meluid Ganz (16.11.)

65th BirthdayDr Imamura Naoki (27.11.)

Dr Christian Damek (28.11.)

60th BirthdayDr Ulrich Glaß (30.11.)

55th BirthdayDr Waldemar Nitschke (07.11.)

Dr Alexander Axelrad (11.11.)

Dr Hideto Inoue (16.11.)

Dr Hajnalka Nagy (18.11.)

50th BirthdayDr Matthias Thümmler (19.11.)

ZA Ioannis Kiriazis (21.11.)

ZA Norbert Dreyer (30.11.)

45th BirthdayDr Christoph Halfmann (06.11.)

ZÄ Eva Fezler (14.11.)

Andrea Wenker (15.11.)

Dr Rasmus Pöggeler (15.11.)

Dr Dr. Frank Dwornik (16.11.)

Dirk Haase (19.11.)

Dr Nils Knüppel (29.11.)

40th BirthdayDr Andreas Kurrek (06.11.)

ZA Roman Paul Warwas (08.11.)

Dr Andreas Thonke (20.11.)

Dr Spyros Chryssikopoulos (23.11.)

Dr Jochen Heyen (30.11.)

OCTOBER 2010

70th BirthdayDr Johannes Merk (18.12.)

65th BirthdayDr Goran Skerlepp (16.12.)

60th BirthdayZA Harald Perrin (01.12.)

Dr Knut Damerau (01.12.)

Dr Marlies Glahe (04.12.)

Dr Klaus Mayer (09.12.)

Dr Günter Schneider (10.12.)

Dr Imre Laszlo Mohos (12.12.)

Dr Bodo Heckroth (24.12.)

Dr Slawomir Sodczyk (25.12.)

Dr Karl Fehlner (25.12.)

Dr Manfred Janssen (30.12.)

55th BirthdayDr Gerhard Kießler (06.12.)

Prof Dr Manfred Bender (10.12.)

Dr René Ecker (15.12.)

Dr Achim Frömel (16.12.)

Dr Suhail Lutfi (24.12.)

50th BirthdayDr Malek Serlani (01.12.)

Dr Wolfgang Standhartinger (05.12.)

Dr Petra Furth (05.12.)

ZA Christian Nordheim (09.12.)

Dr Christian Drägert (10.12.)

Dr Jürgen Süllwold (11.12.)

Dr Norbert Weißen (12.12.)

Ingo Potthoff (14.12.)

Dr Stephan Jurisch (19.12.)

Dr Jörg Kutscher (24.12.)

Dr Hans-Joachim Schäfer (27.12.)

Dr Sven Görrissen (27.12.)

Dr Walter Quack (27.12.)

Dr Ulrich Eichberger (29.12.)

45th BirthdayDr Antje Poblotzki (01.12.)

Dr Michael Sieper (17.12.)

Dr Raj Kumar (20.12.)

Dr Thomas Löffler (20.12.)

Dr Andreas Lindemann (22.12.)

Dr Detlef Granrath (30.12.)

40th BirthdayDr Thomas Sons (11.12.)

Dr Thomas Reinscher (15.12.)

Alhariri Hase (22.12.)

DECEMBER 2010

NOVEMBER 2010

I 49

about the publisher _ submission guidelines I

implants4_2010

submission guidelines:Please note that all the textual components of your submissionmust be combined into one MS Word document. Please do not submit multiple files for each of these items:

_the complete article;_all the image (tables, charts, photographs, etc.) captions;_the complete list of sources consulted; and_the author or contact information (biographical sketch, mailingaddress, e-mail address, etc.).

In addition, images must not be embedded into the MS Word document. All images must be submitted separately, and detailsabout such submission follow below under image requirements.

Text lengthArticle lengths can vary greatly—from 1,500 to 5,500 words— depending on the subject matter. Our approach is that if you need more or less words to do the topic justice, then please makethe article as long or as short as necessary.

We can run an unusually long article in multiple parts, but thisusually entails a topic for which each part can stand alone be-cause it contains so much information.

In short, we do not want to limit you in terms of article length, so please use the word count above as a general guideline and ifyou have specific questions, please do not hesitate to contact us.

Text formattingWe also ask that you forego any special formatting beyond theuse of italics and boldface. If you would like to emphasise certainwords within the text, please only use italics (do not use underli-ning or a larger font size). Boldface is reserved for article headers.Please do not use underlining.

Please use single spacing and make sure that the text is left jus -tified. Please do not centre text on the page. Do not indent para-graphs, rather place a blank line between paragraphs. Please donot add tab stops.

Should you require a special layout, please let the word processingprogramme you are using help you do this formatting automati-cally. Similarly, should you need to make a list, or add footnotes or endnotes, please let the word processing programme do it foryou automatically. There are menus in every programme that willenable you to do so. The fact is that no matter how carefully done,errors can creep in when you try to number footnotes yourself.

Any formatting contrary to stated above will require us to removesuch formatting before layout, which is very time-consuming.Please consider this when formatting your document.

Image requirementsPlease number images consecutively throughout the article by using a new number for each image. If it is imperative that certain images are grouped together, then use lowercase lettersto designate these in a group (for example, 2a, 2b, 2c).

Please place image references in your article wherever they are appropriate, whether in the middle or at the end of a sentence.If you do not directly refer to the image, place the reference at the end of the sentence to which it relates enclosed withinbrackets and before the period.

In addition, please note:

_We require images in TIF or JPEG format._These images must be no smaller than 6 x 6 cm in size at 300 DPI._These image files must be no smaller than 80 KB in size (or theywill print the size of a postage stamp!).

Larger image files are always better, and those approximately the size of 1 MB are best. Thus, do not size large image files downto meet our requirements but send us the largest files available.(The larger the starting image is in terms of bytes, the more lee-way the designer has for resizing the image in order to fill up morespace should there be room available).

Also, please remember that images must not be embedded intothe body of the article submitted. Images must be submitted separately to the textual submission.

You may submit images via e-mail, via our FTP server or post a CD containing your images directly to us (please contact us for the mailing address, as this will depend upon the country fromwhich you will be mailing).

Please also send us a head shot of yourself that is in accordancewith the requirements stated above so that it can be printed withyour article.

AbstractsAn abstract of your article is not required.

Author or contact informationThe author’s contact information and a head shot of the authorare included at the end of every article. Please note the exact information you would like to appear in this section and for-mat it according to the requirements stated above. A short biographical sketch may precede the contact information if you provide us with the necessary information (60 words or less).

Questions?Kristin Urban (Managing Editor)k.urban@oemus-media.de

50 I

I about the publisher _ imprint

implants4_2010

Copyright Regulations _implants international magazine of oral implantology is published by Oemus Media AG and will appear in 2010 with one issue every quarter. The

magazine and all articles and illustrations therein are protected by copyright. Any utilization without the prior consent of editor and publisher is inad-mi ssible and liable to prosecution. This applies in particular to duplicate copies, translations, microfilms, and storage and processing in electronic systems.

Reproductions, including extracts, may only be made with the permission of the publisher. Given no statement to the contrary, any submissions to theeditorial department are understood to be in agreement with a full or partial publishing of said submission. The editorial department reserves the right tocheck all submitted articles for formal errors and factual authority, and to make amendments if necessary. No responsibility shall be taken for unsolicitedbooks and manuscripts. Articles bearing symbols other than that of the editorial department, or which are distinguished by the name of the author, representthe opinion of the afore-mentioned, and do not have to comply with the views of Oemus Media AG. Responsibility for such articles shall be borne by the author.Responsibility for advertisements and other specially labeled items shall not be borne by the editorial department. Likewise, no responsibility shall be assumedfor information published about associations, companies and commercial markets. All cases of consequential liability arising from inaccurate or faulty representation are excluded. General terms and conditions apply, legal venue is Leipzig, Germany.

PublisherTorsten R. Oemus oemus@oemus-media.de

CEOIngolf Döbbeckedoebbecke@oemus-media.de

Members of the BoardJürgen Isbanerisbaner@oemus-media.de

Lutz V. Hillerhiller@oemus-media.de

Chief Editorial ManagerDr Torsten Hartmann (V. i. S. d. P.)hartmann@dentalnet.de

Editorial CouncilDr Friedhelm Heinemannfriedhelmheinemann@web.de

Dr Roland Hilledr-hille@t-online.de

Prof Dr Dr Kurt Vinzenzkurt.vinzenz@aon.at

Dr Torsten Hartmannhartmann@dentalnet.de

Dr Suheil BoutrosSMBoutros@aol.com

Editorial OfficeKristin Urbank.urban@oemus-media.de

Eva Kretzschmanne.kretzschmann@oemus-media.de

Executive ProducerGernot Meyermeyer@oemus-media.de

Designer Sarah Fuhrmanns.fuhrmann@oemus-media.de

Customer ServiceMarius Mezgerm.mezger@oemus-media.de

Published byOemus Media AGHolbeinstraße 2904229 Leipzig, GermanyTel.: +49 341 48474-0Fax: +49 341 48474-290kontakt@oemus-media.de

Printed byMessedruck Leipzig GmbHAn der Hebemärchte 604316 Leipzig, Germany

implantsinternational magazine of oral implantologyis published in cooperation with the GermanAssociation of Dental Implantology (DGZI).

DGZI PresidentDr Friedhelm HeinemannDGZI Central Office Feldstraße 80, 40479 Düsseldorf, GermanyTel.: +49 211 16970-77Fax: +49 211 16970-66office@dgzi-info.de

www.dgzi.dewww.oemus.com

implantsinternational magazine of oral implantology

implantsinternational magazine of oral implantology

I hereby agree to receive a free trial subscription of implantsinternational magazine of oral implantology (4 issuesper year).

I would like to subscribe to implants for € 44 includingshipping and VAT for German customers, € 46 including ship-ping and VAT for customers outside of Germany, unless a writ-ten cancellation is sent within 14 days of the receipt of the trialsubscription. The subscription will be renewed automaticallyevery year until a written cancellation is sent to OEMUS MEDIAAG, Holbeinstr. 29, 04229 Leipzig, Germany, six weeks prior tothe renewal date.

Last Name, First Name

Company

Street

ZIP/City/County

E-mail Signature

Signature

OEMUS MEDIA AGHolbeinstraße 29, 04229 Leipzig, Germany, Tel.: +49 341 48474-0, Fax: +49 341 48474-290, E-Mail: grasse@oemus-media.de

Reply via Fax +49 341 48474-290 to OEMUS MEDIA AG or per E-mail to grasse@oemus-media.de

Notice of revocation: I am able to revoke the subscription within 14 days after my order by sending a writtencancellation to OEMUS MEDIA AG, Holbeinstr. 29, 04229 Leipzig, Germany.

IM 4

/10

� Subscribe now!

You can also subscribe via www.oemus.com/abo

Implants_Abo_A4_Implants_Abo_A4 18.11.10 12:30 Seite 1

ww

w.a

dwor

k.de

BIONIC ENGINEERING DESIGNED IMPLANTS

BEGO Semados® patented Implants embody:

Indication-optimised contour design

Function-optimised implant-abutment-connection

High purity and ultra-homogenous-surface

Polished rim for an infl ammation-free gingiva-attachment

100 % German design – 100 % German manufacturing

Value for money

www.bego-implantology.com

GO FOR GOLD.

BEGO Semados® Mini-Implant

Bionic Engineering Design transfer of optimal living nature solutions

to technical productsBEGO Semados®

S-ImplantBEGO Semados®

RI-Implant

Official care provider to the German Olympic teams since 2002

Are YouInterested?

info@bego-implantology.com

BES-09049_Bionik_GB Teamwork Media 210x297.indd 1BES-09049_Bionik_GB Teamwork Media 210x297.indd 1 14.04.10 13:5014.04.10 13:50