126

DENTISTRYTODAY.COM • APRIL 2012

INTRODUCTION The importance of the creation of an idealemergence profile to enhance aesthetics inthe high lip-line case in either conventionalor implant-supported short-span fixed par-tial dentures (FPDs) cannot be overstated.The success of the case shown in Figures 1 to3 is almost entirely due to the appearance cre-ated by the ovate pontic form of the 2 centralincisors and the supporting implant abut-ment teeth, which appear to emerge “natu-rally” from the gingival tissues.

The limitations of the use of pink porce-lain, as opposed to maximizing the use ofnatural tissues, are seen in the same casewhere the posterior segments required theaddition of a pink material to disguise theadvanced tissue loss in these areas (Figure 4).

Inevitably, there are situations in which

the use of a pink material makes sense, graft-ing is not always appropriate, and some pa -tients may prefer a simpler graft-free option.However, in the high lip-line case, aestheticswill be compromised by a visible junction be -tween the gingiva and any pink material.

BackgroundThe many difficulties associated withshort-span implant-supported FPDs arewell demonstrated in the case shown inFigure 5. The prosthesis provided is pooraesthetically for a number of reasons:

lThe tooth form does not conform to therequirements of the “Golden Proportion.”

l There has been no attempt to provideany form of emergence profile as can beseen from the gingival tissues on removalof the prosthesis (Figure 6).

l The implants appear to be too mesial-ly placed—there has been little or noattempt to disguise this.

l The improvement in aesthetics of thefinal prosthesis shown in Figure 7 was

achieved by the initial placement of a provi-sional screw-retained FPD fabricated in com-posite to help reposition the soft tissues. Thecreation of an emergence profile with ovatepontics (Figure 8) has addressed most of theproblematic issues. Tooth form is more har-monious, and the papillae and tissue con-tour have enhanced the appearance. In addi-tion, alteration of the emergence profilearound the implants has apparently “reposi-tioned” the lateral incisors distally and im -proved their apparent position.

Producing an ideal emergence profilewith provisional restorations is criticallyimportant, but this is only really purposefulif the created emergence profile can be accu-rately reproduced and transferred to theworking model in the laboratory. This isbecause the tissue form created is only stableas long as it is passively supported by the pro-visional restoration. Figures 9 and 10 showthe surprisingly swift collapse and distortionof the soft tissues that occurs in minutes once

Tom Bereznicki,BDS (Edin)

AndrewDawood, MRD,RCS, MSc, BDS

The Creation of an Emergence Profile, Part 1

continued on page 128

Figure 2. The created emergence pro-file following implant placement anduse of a provisional screw-retained compos-ite partial denture.

Figure 1. The case on presentationwith severe periodontal involvementand poor aesthetics.

Figure 3. The final aesthetic result, following fit of the definitive fixedpartial dentures (FPDs).

Figure 4. The aesthetic difficultiesassociated with pink porcelain.

AESTHETICS

This, and all future articles that are presentedin multiple parts, are available to our readersat our Web site, dentistrytoday.com.

Using an Interim Restoration as an Aid to Implant Positioning

Figure 5. Poorly designed definitiveimplant-supported FPD showing com-promised aesthetics.

Figure 6. The edentulous ridge uponremoval of the FPD and screw-retained abutments.

Figure 7. Redesigned cement-retainedFPD.

Figure 8. The created emergence pro-file prior to FPD cementation.

AESTHETICS128

the temporary restoration is removed.Reproduction of this distorted gingivalshape in the final impression wouldnegate the great deal of the time andeffort spent on the creation of the emer-gence profile—a definitive restorationfabricated on such a model would bedeficient in its support of the tissuesand be subject to arbitrary, time-con-suming additions to the porcelain in anattempt to restore the correct contours.

ObjectivesThree concerns associated with short-span implant-supported FPDs in theaesthetic zone are implant positioning,the creation of an emergence profile toenhance aesthetics, and the reproduc-tion of the created emergence profile inthe final working models.

SolutionsThe problem generally encountered bythe implantologist is not only to placethe implants within the best boneavailable, but also to judge exactlywhere the ideal position should be,commensurate with the aesthetic de -mands of the case. When the patient

presents to the implantologist with anedentulous ridge as shown in Figure11, the only aid to implant positioningmay be the provisional restoration.

One answer to the problem may liein the restorative phase of preimplanttreatment; refining the aesthetics of acase with a well-designed provisionalrestoration will not only prepare theemergence profile prior to implantplacement, but will also assist the sur-geon in optimizing implant positioning.

Finally, a technique was devel-oped which would accurately repro-duce the created emergence profile inthe impression phase of treatment.

CASE REPORTDiagnosis and Treatment Planning

A patient presented with failing inci-sors is shown in Figure 12. Intraoralradiographs showed varying degreesof bone loss around the teeth, whichexhibited grade 1 to 2 mobility.

In view of the poor prognosis of theincisor teeth, the high lip-line, and thepatient’s desire for improved aesthet-ics, a decision was made to remove theteeth. However, the patient was reluc-tant to undergo grafting procedures.

A decision was made to extract all 4incisor teeth and, in the first instance,replace them with an immediately pro-vided adhesive-retained FPD. The in -tention was to use this FPD to guidethe soft tissues during the healingphase. The created profile would thenin turn aid implant positioning, further

promoting tissue maintenance withthe final restoration.

Impressions and a face-bow record-ing were taken and the resultant studymodels mounted on a fully adjustablearticulator. During trial wax-ups onduplicated study models, it becameapparent that if the slightly over-erupt-ed lower incisors were shortened byabout 1.5 mm, the tooth position of theupper incisors could be retracted togive a more pleasing aesthetic result inthe interim healing phase with theMaryland bridge and with the finaldefinitive restoration. The patient wasaware that the prognosis of the loweranterior teeth was guarded and gavepermission for the relevant adjust-

ments to be made to them at the timeof fitting the upper Maryland FPD.

Clinical ProtocolImpressions were taken with a poly-ether impression material (ImpregumPenta-6 Minute Soft [3M ESPE]). Then,the working model was fabricated bysilver plating to ensure maximumaccuracy. The teeth scheduled for ex -traction were sectioned from the work-ing model and the anticipated ridgeshape post-extraction cut into themodel to allow the technician to fabri-cate an ovate pontic form in the finalMaryland FPD. The Maryland patternwas made in resin (Pi-Ku-Plast HP 36[Bredent]), then invested and cast in anonprecious metal alloy (Niadur DFS[Picodent LTDA]). The completed FPDframework was covered with compos-ite (Gradia [GC America]).

The author prefers the use of a glassionomer for cementation rather thancomposite. The use of this material al -lows straightforward removal of theFPD, minimizing the potential for dam-age to the tooth or distortion of the metalframework. The material used here wasGC Fuji TRIAGE Pink (GC America). Thepink color of this material allows foreasy identification and removal of the

DENTISTRYTODAY.COM • APRIL 2012

The Creation of an Emergence...continued from page 126

Figure 9. The emergence profile onremoval of a screw-retained provisionalcomposite FPD.

Figure 14a. The soft-tissue profile on extraction.

Figure 14b. The soft-tissue profile 4weeks after extraction.

Figure 14c. The healing emergence pro-file developing at 7 weeks.

Figure 14d. The finalized emergence pro-file at 10 weeks.

Figure 10. The collapsed emergence pro-file some 30 minutes following removal.

Figure 11. A typical edentulous ridge onpresentation for implant placement.

Figure 12. Preoperative photo of an aes-thetically displeasing case.

Figure 13. The Maryland FPD at initialcementation.

One answer...may lie in the restorative phase ofpreimplant treatments....

a

b

c

d

Figure 17. The created emergence profileupon removal of the provisional FPD.

Figure 15. Preoperative retracted anteriorphoto.

Figure 16. The clinical appearance after a10-week healing period.

AESTHETICS

cement with conventional instrumenta-tion or by blasting with 50 µaluminiumoxide powder using a chairside air abra-sion unit (EtchMaster Micro Air Abra -sive Tip [Groman Dental]).

Following the administration of lo - cal anaesthetic, the 4 incisors were ex -tracted with an atraumatic techniqueand the FPD immediately cemented as

shown in Figure 13. Discreet metalspurs between the canine and premo-lar teeth on the framework help to lo -cate the framework as it is cementedinto place and aid in retention andstability.

It is not in within the scope of thisarticle to describe in detail the clinicaltechnique used to influence the heal-ing tissues to form the final emergenceprofile, but essentially the MarylandFPD was removed at regular intervalsand composite added to the fit surfacesof the pontics to guide tissue healing inthe desired direction. The 10-weekprogress of the maturing tissues isshown in Figures 14a to 14c, with thefinal emergence profile achieved seenin Figure 14d. This profile now acts as aguide to implant placement; in this casein the lateral incisor pontic sites. Thechange in the clinical appearanceachieved is seen in Figures 15 and 16.

Implant PlacementThe emergence profile prior to im -plant placement is seen in Figure 17.When faced with an appearance suchas this, it is immediately evident thatthe ideal position for each fixture willbe at the base of the “depression”developed in the tissues by the bridgepontics. In this case, 2 implants arerequired, although the profile createdgives 4 options for placement. At thisstage, what is required is to cross ref-erence the clinical picture with theradiographic evidence, to confirmthat there is sufficient bone availablein each site to allow the fixture to beoptimally position.

Three-dimensional imaging withcone beam computed tomography(CBCT) in conjunction with the use ofplanning software hugely facilitatesplanning and helps to achieve a pre-dictable aesthetic result. In this case,the patient was scanned using anAccuitomo F170 scanner (J. MoritaUSA), and a 6-cm program was selectedfor the exposure. The DICOM data wasexported to NobelClinician planningsoftware (Nobel Biocare). NobelClin -ician provides an intuitive frameworkfor viewing CBCT data and for plan-ning implant treatment.

Using the software, it was possibleto visualize reformatted cross sectionsthrough the ridge in each prospectiveimplant site. It was possible to clearlyvisualize each pontic site, and to posi-tion a virtual fixture in each of thesesites, confirming that there was suffi-cient bone available for 13-mm activefixtures (Replace Select [Nobel Bio -care]). The software offers various visu-alizations modes which allow the vir-

tual fixtures to be viewed in situ, andthe position in relation to the bone andthe adjacent teeth to be modeled.

Although the software has thecapacity to produce a surgical guide, inthis case, it was felt that the FPD pon-tics visualized on screen and the creat-ed emergence profile gave a sufficient-ly distinct indication of exactly wherethe point of insertion for each fixtureshould be, and the cross-sectionalimaging clearly indicated that therewas sufficient bone in each site. Theauthors think of this as “pontic-guidedsurgery.”

Implant surgery took place using aflapless approach. A 4-mm biopsypunch was used prior to site prepara-tion. A 2.8/3.2-mm step drill was used tothe full depth of the site, and then a3.2/3.6-mm step drill was used to a depthof about 7 mm. This allowed for thedevelopment of a high insertion torque,a small amount of ridge ex pansion at thebase of the site, and avoided excessivestress at the fixture head, which mighthave led to crack development.

The NobelActive fixtures werecarefully placed using a hand insertiontool. The generally tapered form of thefixture, the aggressive thread design,and the clever reverse tap all contri -bute to a high, controlled level of pri-mary stability (Figures 18a and 18b).

The clinical appearance of the softtissues is seen prior to and immediatelyfollowing implant placement (Figures19 and 20). An impression of the im -plants was taken at the time of place-ment and sent to the dental laboratoryteam for the fabrication of the immedi-ate-loaded screw-retained compositeFPD to be fitted later the same day.

The completed fixed partial pros-thesis was fabricated in composite(Gradia) with reinforcement fibersincorporated (everStick C&B fibre[Stick Tech Ltd]). The palatal position-ing of the screw access cavities isideal—facilitating the provision of ascrew-retained design for both the pro-visional and definitive prostheses. Theprovisional restoration is shown at thereview 4 days later (Figure 21).

The provisional immediate res -toration was left in place for 4 months.The soft-tissue emergence profile re -sulting from further maturation isshown following removal of the provi-sional restoration in Figure 22 andwhen compared with the clinical pic-ture on the day of implant placement(Figure 23). This created profile willnow provide an excellent startingpoint for the definitive prosthesis.

The second article in this serieswill demonstrate the clinical impres-sion technique evolved to duplicatethis created emergence profile in thedefinitive working models.�

AcknowledgementThe authors would like to thank Ms.Lola Welch, London, UK, for the labo-ratory work in this case.

Dr. Bereznicki graduated from EdinburghDen tal Hospital and School in 1976. Hemoved to London and entered generalpractice and started his own private prac-tice in Queens gate, London, in 1982.Recently, he has joined the Dawood &Tanner Dental Prac tice in London as amember of the res torative team. His areaof special interest is aesthetic dentistry,and in particular the creation and dupli-cation of the created emergence profile inconventional and implant-re tained crownand bridgework. He can be reached via e-mail at tbereznicki@googlemail.com.

Dr. Dawood is a registered specialist inperiodontology and prosthodontics andhas honorary attachments to the depart-ment of maxillofacial surgery at St.BartholomewÕs and The Royal LondonHospital Trust and University CollegeHospital, London. He joined a long-established restorative dental practice in1987, which he later took over with hispartner Dr. Susan Tanner. His time hasbeen de-voted almost entirely to dentalimplants, imaging, and surgical planning.He is also the founder and clinical direc-tor of Cavendish Imaging(cavendishimaging.com), which providesimaging, computer-planned surgicalsolutions, and rapid prototype models,guides, and craniofacial implants forimplant and maxillofacial surgeons andhospital departments around the UnitedKingdom. He operates a center for post-graduate education and hosts regularmeetings and seminars from the Cav-endish Imaging premises in London,Oxford, and Birmingham, UK. He lecturesextensively abroad on topics related toimaging, dental implants, and restorativedentistry. He can be reached atinfo@dawoodandtanner.co.uk.

129

APRIL 2012 • DENTISTRYTODAY.COM

Figure 18a. The radiographic appearancewith the Maryland FPD in place, prior toimplant placement.

Figure 18b. The implant position, simu-lated in NobelClinician (Nobel Biocare)software.

Figure 19. The emergence profile prior toimplant placement.

Figure 20. The clinical picture immedi-ately following implant placement.

Figure 22. Clinical view upon removal ofthe immediate load FPD; 4 months afterimplant placement.

Figure 23. Clinical photo on the day ofimplant placement.

Figure 21. Clinical view; 4 days postim-plant placement and provision of theimmediate-loaded, screw-retained FPD.

a

b