A Case Study: Esthetic & Biologic Management of a Diastema...

72 THE JOURNAL OF COSMETIC DENTISTRY • FALL 2002 VOLUME 18 • NUMBER 3

A Case Study: Esthetic & BiologicManagement of a Diastema Closure Using Porcelain Bonded Restorations for Excellent & Predictable Results

Dr. Lynn Jones received herDDS from the University ofWashington and is now recog-nized for both her excellent cos-metic dentistry and innovativemanagement practices. She is anaccredited member of theAmerican Academy of CosmeticDentistry, has served on theboard of directors and is current-ly an accreditation examiner.Dr. Jones has spoken on Microdentistry at the AACD, WSDAand other meetings. She is thedirector of "AestheticsContinuums" for the Universityof Washington CDE focusing oncosmetic and reconstructive den-tistry. Dr. Jones maintains a pri-vate practice in Bellevue,Washington.

DD O C T O RO C T O R ’’ SS PP E R S P E C T I V EE R S P E C T I V E

IN T R O D U C T I O N

One of the clearest indications for porcelain-bondedrestorations is diastema closures. Veneers can make a dra-matic improvement to the appearance in the smile withundersized teeth in an oversized arch (Figs 1 & 2). Beforewe had the ability to bond porcelain veneers to the teeth,these types of cases were practically untreatable.Although the occlusion often is ideal in diastema cases,the teeth are too small for the size of the jaw.Orthodontics can only rearrange the spaces. Compositesmight work but would be less predictable in large can-tilevered spaces between worn teeth, and composite ismore difficult to control where deep subgingival marginsare necessary for esthetic emergence profiles between theteeth. The other option, porcelain crowns, would haverequired excessive reduction of otherwise healthy teeth,and with dubious esthetic results.

Well-controlled bonded porcelain restorations can pro-duce beautiful results while preserving the strength of theoriginal tooth. If the guidelines for good smile design andtooth preparation are combined with occlusal manage-ment, veneers can look, feel, and function like healthynatural teeth.

A smile with a high lip line and large spaces poses somespecial challenges. Careful attention to the details ofinterproximal emergence profiles, biologic width, andpapillary height is necessary to get excellent results. If theteeth are worn or if the spaces are wide, the teeth willappear to be disproportionately short and wide after the

C L I N I C A L S C I E N C E

by Lynn A. Jones, D.D.S.

Michelle Robinson specializes inesthetic and reconstructive casesfabricated from a full range ofrestorative materials. An activemember of the AmericanAcademy of Cosmetic Dentistry,her goal is to help develop newmaterials to solve esthetic andreconstructive needs. As a clini-cal instructor for Team AestheticSeminars, she has gained a greatdeal of experience teaching clini-cal programs with Dr. DavidHornbrook and Dr. ThomasTrinkner. Her desire is to shareher knowledge with students andhelp propel them forward in theirquest for excellence.

by Michelle Y. Robinson

VOLUME 18 • NUMBER 3 FALL 2002 • THE JOURNAL OF COSMETIC DENTISTRY 73

diastemas have been closed withrestorations. The apparent height towidth ratios can be managed to somedegree by artistically controllingreflective and defective surfaces. It alsois possible to increase the actual lengthof the tooth a limited degree byextending it gingivally when com-bined with a crown-lengthening pro-cedure, and incisally until it interfereswith the envelope of function. Inextreme cases the entire verticaldimension of occlusion may need to bealtered to achieve the desired length.

The mesiodistal tooth positionitself is another consideration, espe-cially in a case where there is a high lipline. If the spaces are not symmetrical

or the apex of the gingival scallop isout of alignment because a tooth is outof position, it can make it impossibleto achieve the correct gingival archi-tecture. In an esthetically sensitivepatient, even a slightly asymmetricalpapilla can be a concern. With properplanning and understanding of thebiologic and esthetic rules of soft tissuemanagement, these issues can be pre-dicted and controlled. The purpose ofthis article is to use a case study toshow how to overcome these obstacleswith careful planning, soft tissue man-agement, attention to occlusion,preparation design, laboratory commu-nications, and excellent porcelainwork.

PAT I E N T ’ S CO N C E R N S

The patient wanted to close thespaces between his teeth (Fig 3); hewanted very white teeth with nounsightly amalgam restorations; andhe did not like his flat, worn canines(Figs 4 & 5). He is an esthetically sen-sitive patient with a high lip line. Thespaces on the lower left were almost asmuch of a concern to him as the spacesin the upper anterior (Fig 6). He alsowas somewhat concerned about theworn incisal edges. He had consultedwith an orthodontist, who had advisedhim that his teeth were too small tocompletely close the spaces with toothmovement.

Figure 1: Pretreatment diastema undersizedteeth relative to the size of the arch.

Figure 2: Veneers can make a dramaticimprovement to the appearance.

Figure 3: Pretreatment smile. Figure 4: Pretreatment maxillary leftlateral.


D I AG N O S I S A N DTR E AT M E N T PL A N

The patient’s medical history wasnoncontributory. He is 42 years oldand has a healthy dentition with nocaries and good periodontal health;there are preexisting amalgam restora-tions on ## 2, 3, 4, 18, 29, and 31; andpreexisting composite on ## 14 and15. Teeth 13 and 19 have preexistingendodontic treatment and crowns. Allfour wisdom teeth are missing.Moderate wear was noted on the ante-rior teeth. Diastemas ranging from 0.5to 2.5 mm are located between almostevery tooth anterior to the first bicus-pids. There are no signs of temporo-mandibular disorder (TMD) and theocclusion is Class I normal with largediastemas

To achieve the desired results, theteeth would be whitened first with anin-office whitening system. All of theconservative Class I amalgam fillingswould be replaced with direct compos-ite. Teeth 4–13 and 21–28 would berestored with reverse 3/4 porcelain-bonded restorations.

There are various methods fordeveloping the smile design, includingfull intraoral mock-ups done directlyon the teeth, or mocking-up the max-illary central incisors only and thendoing the diagnostic wax-up. To designthe smile for this case I chose to usecomputer imaging and laboratory-made wax-ups.

The original smile design was devel-oped with computer imaging using theImage/FX program from Sci-Can

(Pitsburgh, PA). Three differentdesigns of varying lengths were pre-sented to the patient to gauge hisexpectations and clarify his estheticdesires. It helped to determinewhether we should design a flat smileor one with more contours; and howlong he wanted his teeth. From theimaging, the patient immediatelyrejected longer teeth and expressed adesire for pointed canines. He alsoagreed that wider incisal embrasureslooked better.

Once a smile design is selected fromthe image, the necessary records aremade for a preliminary wax-up. Thelaboratory will need specific informa-tion to give the best result. If theocclusion is going to be equilibrated,this is the easiest time to do it. In this

Figure 7: A level stick-bite. Figure 8: Pretreatment retracted anteriors.

Figure 5: Pretreatment maxillary rightlateral.

Figure 6: Pretreatment mandibular leftlateral.


case the equilibration was not indicat-ed, so the bite registration was made incentric occlusion. A level earbow wasmade for the Artex articulator(Girrbach Dental; Pforzheim,Germany) a level stick-bite was made,and both recordings were confirmedwith a photograph (Fig 7). A “before”smiling photograph and the selectedimage were included with writteninstructions for the desired overbiteand overjet and desired tooth length(computer photos are not 1:1).

DE T E R M I N I N G T H EDE S I R E D PO S I T I O N O FT H E IN T E R P R OX I M A LCO N TAC T

On the preparation day after thepatient has been anesthetized, theinterproximal depths are sounded todetermine this specific patient’s bio-logic width of tissue and how deep themargin can be placed to establish theproper emergence profile. This alsohelps determine the point where theproximal contact should meet. A bio-logic width of 2.5 mm or more is nec-essary to prevent a violation that caus-es chronically red and inflamed gingi-va. To create the desired emergence,the margin must be placed as far belowthe tissue as possible. In most cases, 1to 1.5 mm is ideal for controlling the

black holes and avoiding the peri-odontal biologic width. Note that theinterradicular distance can influencethe distance between the interproxi-mal contact and the alveolar crest. Adepth of 5 mm or less is necessary toguarantee that the papilla will fullyoccupy the gingival embrasure space1

based on roots that are 2.5 mm apart.In this case, the sounding depthbetween teeth 8 and 9 was 4mm andthe interradicular distance was 3.5mm. That meant the contact pointshould be no more than 4 mm from thealveolar crest.

For example, if the sounding depthwere 3 mm, space closure would bemore difficult because this patient hasa naturally narrow biologic width.That means the contact point wouldbe moved to within 3 mm of theosseous crest; if it were placed 4 mmabove the alveolar crest it would resultin a black triangle. A sounding depthof 5 mm may mean that there is a longepithelial attachment. Placing a deepmargin may result in recession and lossof papilla. If the contact point is madeat 5 mm, in this example, it is likely toleave a black hole. So it is still a goodidea to make the contact 4 mm fromthe alveolus.2

Very wide diastemas over 4 mmrequire an extreme alteration of emer-gence profile approaching 90°. This

causes an unnatural gingival contourand a very boxy looking tooth. If thegumline recedes to reveal the marginof the veneer with its obvious over-hang, the esthetics will be ruined. Ifthat is the case, it would preferable torearrange the spaces with orthodonticsso that they are distributed evenlybetween all of the anterior teeth priorto veneering. Evaluate the shape of theteeth and the size of the spaces. If thecoronal portion of the tooth is notmuch wider than the root (as we see inthis case) and the spaces between theteeth are under 3 mm, the contours ofthe crown should appear to be normal.

GI N G I VA L AP E X

Gingival contours are distortedwhen the tooth is made wider to closea space. The apex of the gingival mar-gin will not move even if you performa crown-lengthening procedure.3 Theapex will always be over the rootprominence. If this is not acceptablethen the tooth will have to be movedby orthodontics.

In this particular case, #8 is tilted tothe distal but the gingival apex of thecrown is very close to the proper posi-tion (Fig 8). This made it possible toveneer the tooth without orthodonti-cally repositioning it. Had #8 been inthe same position with the root verti-

Figure 9: Midline placement. Figure 10: Facebow.


cally above it, the apex of the gingivalscallop would have been in the wrongplace and the midline papilla wouldhave been asymmetrical. In that case,minor tooth movement or reposition-ing the dental midline with porcelainto compensate for the asymmetrywould be required.

GU M LI F T S

Another way to control the emer-gence profile and create a more desir-able height-to-width ratio is to do agum lift. A “gum lift” by either a gin-givectomy alone or combined withosseous recontouring of the facial sur-face has become an essential adjunct

to many cosmetic-veneering proce-dures. About 80% of the populationhave some gingival display. The transi-tion from the tooth to the gingivaposes one of the most challenging cos-metic problems when closingdiastemas. A gum lift serves a dual pur-pose: it improves the height-to-widthratio of a short, wide tooth; and ithelps to lengthen the taper of the gin-gival scallop around the necks ofsquare looking-teeth.

A gingivectomy gives a longer runat the interproximal emergence profileso the gingival contours look smootherand more tapered rather than comingout at a right angle to the proximalwall of the tooth. The goal is to

increase the scallop, where the osseousand gingival architecture around wide-ly spaced teeth tend to be flat.

MI D L I N E A N D GO L D E NPR O P O RT I O N

MI D L I N E

A line connecting the lowest pointof the V in the upper lip with the mid-line of the lower incisors defines themidline (Fig 9).4 Locating the midlinevaries from one case to the next andsometimes, for various reasons, wechoose to ignore it. More importantthan the location of the midline is thedegree of cant. Variance in themesiodistal position of the midline is

Figure 13: Placement of the interproximalcontact.

Figure 14: Closing black holes/emergenceprofile.

Figure 11: The teeth can be made to looknarrower by decreasing the area of the

reflective surface.

Figure 12: The teeth can be made to looksmaller and narrower by tapering the incisalangles towards the tooth and the opening the

embrasure.


not generally noticeable. A midlinecant, however, generally is the mostvisible distraction from the esthetics ofan otherwise normal healthy smile.4

To obtain a record of the verticalmidline, a facebow for an Artex artic-ulator was made over the prototyperestorations (Fig 10). Before the face-bow recording was set the patient wasasked to stand straight. The ear-bowhas a little play inside the ear and theuniversal joint, which connects it tothe bite-fork, moves freely. The ear-bow is attached to the bite-fork, whichis securely positioned on the teethwith a maxillary bite registration sothat it remains stationary. While thepatient was standing with his headlevel, the front of the earbow wasmaneuvered into a line parallel withthe floor. This position was confirmed

with a level on the earbow and a pho-tograph to confirm the relationship ofthe earbow to the face. Several refer-ence points have been suggested todetermine the true vertical in thepatient’s face. Different elements comeinto play depending upon the patient.The interpupillary line is perhaps themost frequently used reference but ithas drawbacks because the eyes oftenare not level. It also has been suggest-ed that a line connecting the exactcenter of the bridge of the nose andthe center of the labial filtrum repre-sents the best vertical line; anothersuggestion is to use the horizon or alevel to determine true vertical in thesmile. Like many artistic decisions,judgment will guide which of theseguidelines is most useful in an individ-ual case. In this particular case the

patient’s face was very symmetrical andall of these guidelines indicated thesame vertical line. A stick-bite with aphotograph is used to confirm the face-bow recording and give the laboratoryanother point of reference for ensuringa vertical midline. With these twopieces of information, the laboratory isable to mount the case on an articula-tor with the occlusal plane and smileline oriented in the right plane. Thestick-bite is made over the final proto-type restorations to give the horizontalorientation of the smile line and alsoto indicate the incisal edge position ofthe provisional restorations. The stick-bite is made by spinning a stick (a dis-posable paintbrush works) into the softregistration material at the incisal edgeof the upper centrals while the patientbites in centric occlusion.

Figure 15: Closing black holes/marginplacement.

Figure 16: Post treatment retracted rightlateral.

Figure 17: Post treatment retracted leftlateral.

Figure 18: Post treatment retractedanteriors.


GO L D E N PR O P O RT I O N

The ratio of the centrals to the lat-erals in this case is 1:6.9, or very closeto Golden Proportion. The ratio of thelaterals to the canines is 1:0.88—a lit-tle further from Golden Proportion butnot enough to be a distraction fromthe harmony of the smile design. Theratio of the canines to the first premo-lar is 1:0.75, once again close toGolden Proportion. The importance ofGolden Proportion has been muchdebated and has been demonstrated tobe the exception more often than therule.5 It is helpful to use as a guide ifsomething doesn’t look right, but veryfew anterior teeth are arranged exactlyin Golden Proportion.

More important than GoldenProportion is the symmetry of theteeth and harmony with the face andsmile. The facial of 6 and the distal of8 and 10 were out of alignment (Fig 3).To achieve symmetry, those surfaceswere contoured to be parallel with thedistal contours of the remaining teethprior to preparing the teeth for porce-lain.

CO N T R O L L I N G IL L U S I O N S

Are these rectangles the same size? Theyillustrate the next principle in illusions forcreating esthetic space closures (Fig 11).

The apparent size of the tooth isidentified primarily by the reflectivesurface, that is, the surface that reflectslight back into the eye of the viewer. Itdoes this because that surface is per-pendicular to the line of sight anddirects the light straight back to theviewer and appears brighter. Thedeflective surfaces direct the lightaway from the viewer’s eye and causethat part of the surface area to recede.In this case the actual height-to-widthratio is 1.0:0.9 on the centrals, but thereflective surfaces are 1.0:0.7.Controlling the light this way makesthese central incisors appear narrowerthan they actually are, just like therectangle on the right in the previousillustration. Yet both rectangles areexactly the same size.

Another way to make the rectanglelook narrower is to physically takeparts away. Rounded incisal angles cre-ate an optical illusion that causes thetooth to appear narrower by drawingthey eye toward the center of thetooth. Also, the tooth is actually nar-rower in the incisal region, whichhelps to reduce excessive bulkiness. Tomake the tooth look narrower, theincisal edge has been tapered in to aratio of 0.7:1.0, similar to the rectanglein the illustration (Fig 12).

PR E PA R I N G T H E TE E T H

To esthetically close a diastema theinterproximal contact is placed moreto the lingual (Fig 13). By moving itlingually it creates a larger embrasure.This is how the greater deflective sur-face areas are created, thus making thereflective surfaces appear narrower.This technique is also useful in givingthe teeth more relief if the estheticsappear flat and lifeless.

Another problem with diastemas isthat the papillae are usually flat. Thisleads to the dual challenge of creatinga pointed papilla and completely clos-ing the little black holes in the gingi-val embrasure (Fig 14). If the contactis extended gingivally and toward thelingual it can be used to create volumewith the porcelain, which will thenpush the papilla forward and incisallyinto the gingival embrasure on thefacial of the contact. This will help toprevent little black holes in the gingi-val embrasure and make the papillaelook longer and more pointed.

If the sounding depth is only 3 mmthe margin cannot be placed morethan a half millimeter below the tissue.A deeper margin could potentially vio-late the biologic width of the peri-odontium. In a case like this the emer-gence profile would have to be almostperpendicular to the interproximal

Figure 19: Post treatment lower left. Figure 20: Post treatment smile.


Figure 21: Post treatment right lateral view. Figure 22: Post treatment retractedanteriors.

wall of the tooth and the contactwould have to be very long. This is eas-ier to do with circumferential veneerbut a reverse 3/4-veneer design worksif the margins are placed well to thelingual of the contact area (Fig 15).

The margin of the veneer must be placedapical and lingual to the papilla, as shownin the two images on the left (Fig 13).

The apparent contact area shouldbe about 50 percent of the full lengthof the central incisor. The preparationdesign for d-SIGN® (Ivoclar/Vivadent;Amherst, NY) porcelain should allowa thickness of 0.5 mm at the gingivalmargin, 0.7 mm in the mid-body andat least 1 mm in the incisal third toprevent dentin shine-through and toconceal the silhouette of the prepara-tion under the porcelain.

If the margin is placed too far to thelabial several problems occur. First, thelaboratory technician will not haveenough room to create a deep labialembrasure and large deflective surfacesto visually narrow the tooth. Second,the margin of the porcelain will pro-trude from the gingival-axial wall, cre-ating a plaque trap. The emergenceprofile from the gingival margin mustbe almost 90° and near the labial sur-face, causing an unnatural gingivalcontour—and the technician still

might not be able to completely closethe little black hole.

Combining all of the elements ofplanning the diastema closure smiledesign, correct preparation design,proper margin placement, adequatetooth reduction, beautiful porcelaincontours, color, and surface texture, wewere able to achieve the excellentresults illustrated in this article (Figs16-22).

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References1. D Tarnow, AW Magner, P Fletcher. The effect of

distance from the contact point to the crest ofbone on the presence or absence of the inter-proximal dental papilla. J Periodontol 63(12):995-996, 1992.

2. JC Kois, RT Vakay. Relationship of the peri-odontium to impression procedures.Compendium, 21(8):684-692, 2000.

3. C Townsend, Resective surgery: An estheticapplication. Quintessence Int 24(8):535-542,1993.

4. VO Kokich Jr., HA Kiyak, PA. Shapiro.Comparing the perception of dentists and laypeople to altered dental esthetics. J Esthet Dent11(6):311-324, 1999.

5. JD Preston, The Golden Proportion Revisted. J Esthet Dent 5(6):247-251, 1993.

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LL A BA B TT E C H N I C I A NE C H N I C I A N ’’ SSPP E R S P E C T I V EE R S P E C T I V E

IN T R O D U C T I O N

Diastema cases present manyesthetic challenges. One of the chal-lenges for the ceramist in this situationcomes when the restorations appeartoo wide or out of proportion (ideal is75 percent width-to-length ratio oncentrals). We are able to control whatappears to be the width of the tooth byexaggerating the deflective areas andminimizing the reflective area (facial)of the tooth/teeth. To do this, the con-tacts must be moved to the lingual ofthe interproximal surface and theembrasures must be opened to allowfor light illumination. If the embra-sures are not opened enough thetooth/teeth will look “square” or“boxy” and the food will trap near thepapilla, resulting inevitably inunhealthy tissue. After moving thecontacts lingually and filling the“black triangle” spaces with porcelain,we sometimes are left with small can-tilever pontics that appear to be part ofthe tooth. These ledges are easilymaintained if constructed properly.

Upon laboratory receipt of the case,the communication letter is read and


the case is logged in, while ensuringthat all items needed to complete thecase as requested are included. Allitems that need to be disinfected areprocessed according to OSHA require-ments. The case is then sent to themodel department for the impressionsto be worked-up. Before the stonemodels are trimmed the accuracy ofthe stick-bite is verified with theincluded photos. The maxillary modelis trimmed with the stick-bite on theanterior teeth ensuring that the base ofthe model will be parallel to the max-illary plane. The maxillary model istrimmed to the mandibular. All othermodels are trimmed in a similar fash-ion, resulting in parallel bases on allmodels. One prepped model is pinnedand all models are based using the

split-cast system. The pinned modelsare sectioned into individual dies, butbefore the dies are replaced in the basethe adjacent pinned teeth and all basesare polished. All models are mounted,cross-mounted, and polished again.The ceramist reviews the case and thedoctor’s requests. Refractory work isthen done. The success of any refractorycase depends heavily upon the level ofrefractory work your lab team is capableof creating. Refractory die position isverified by an incisal matrix made froma solid model. Rotation or misplace-ment of any die will be detected and/orcorrected at this time.

PO R C E L A I N WO R K BU I LTI N d.SIGN PO R C E L A I N

When reviewing a diastema casebefore starting porcelain applicationthere are several things that need to beaddressed:

• Where have the contacts beenplaced in the provisionals?

• Are there “Black Triangles”present?

• Has the doctor. prepped slightlysubgingival to allow for triangleclosure?

• How wide are the teeth to bebuilt?

• What is the final desired length?

• Are the Golden Proportionspleasing to the eye?

Figure 23: Incisal matrix made from puttyfor incisal edge position.

Figure 24: Soaking of refractory dies prior to porcelain application.

Figure 25 Application of undiluted dentin inlobe formation to create base structure.

Figure 26: Fired refractory dies.


This is where the provisionalrestorations come into play. Models ofprovisional restorations (as well asphotos of them) are necessary whenbuilding a diastema case. They answerall of the above questions and providea 3D visual to work from.

By placing the maxillary provision-al model on the articulator with themandibular model, it is possible tomake an incisal edge matrix of themaxillary against the mandibularmodel (Fig 23), thus providing theincisal edge position, tooth width, andfinal veneer length. Again, theceramist’s artistry can enhance whathas already been established.Provisionals take the guesswork out of

almost any case. What color(s) are theprepared teeth (i.e., Is there any mask-ing that needs to be done to achievethe final desired color of a B-1)?Luckily, the prep shades in this case areideal, which leaves many options.Should the upper or the lower be builtfirst? Should they be built simultane-ously, as the preps are opposing eachother? It is best to try to choose thesimpler way to avoid problems. Thechoice here is to build the lowerrestorations to full contour (pre-glaze)before starting the upper units. I buildin several layers and fire many times tohave the most control over the finalresult. By carefully planning the build-ing strategy it is easier to avoid makinginternal mistakes.

The refractory dies are soaked inwater prior to any porcelain applica-tion (Fig 24). Neutral or clear porce-lain is applied in a small crescentmoon area at the margin. This willallow the restorations to blend wellwith the natural dentition when seat-ed. Undiluted dentin shade is placedover the rest of the prepped areas, withlobe formations extending over theedges of the preps (Fig 25). The diesare then fired (Fig 26). The dies arecooled, soaked again in water, andplaced back into the water reservoirmatrix. A dentin/neutral mix isapplied as a full contour in the gingivalhalf and as full contour lobing (usingthe upper provisional model as aguide) on the incisal half. The dies are

Figure 29: Layering of different internaleffects.

Figure 30: Verification of the horizontalplane of the restorations.

Figure 27: Full contour build-up. Figure 28: Creation of internal lobes usingthe incisal edge matrix for correct

placement.


fired again. Satisfied that the develop-mental lobe placements are correct, itis now time to build in internal effects.Effects are not created from surfacestaining. E3/E4 mix (Ivoclar/Vivadent;Amherst, NY) is placed on the mesial,distal, and middle lobes, extendingslightly beyond the fired dentin in afinger-type effect. A yellow-gray fingeris placed slightly off-center on themiddle lobe for additional characteri-zation. An E3 high-value band isadded horizontally between the gingi-val and middle thirds and a khaki isapplied sparingly (because the desiredfinal shade is so light) on the cervicalneck area. Before firing, the final inter-nal touch is added in an almost “water-color” fashion using a watery variega-

tion of salmon and light mammelonporcelains. These are difficult to applybut add greatly to the final beauty. Avery wet liner brush with a heavilydiluted mammelon effect is draggeddown the incisal surface of wet porce-lain. The dies are then fired again.Shade is constantly monitoredbetween each firing. It is important tonote that up to this point the contactsbetween each tooth are either open orloose. It is easy to overbuild, resultingin mispositioning a die if the contactsare binding. When these are placedback into the reservoir matrix theeffects are evaluated; these can besharpened with a mini-diamond disk ifany of them appear to run together.Next, teeth are built to full contour

with diluted dentin in deficient areason gingival half and a variegated E1,E2, and TS1 across the incisal edge(Fig 27). The dies are fired again. Afterchecking contacts and occlusion, thecontours are finalized. Surface mor-phology is emphasized. If any add-onsare needed, they are applied witheither an E2 or neutral, dependingupon the area.

Moving onto the maxillary arch,the units are built in a similar fashion.Contacts are built to the lingual, andthe deflective angles of the teeth arebroader to make each tooth look nar-rower. The key here is to keep thetransition between the reflective anddeflective angle smooth to avoid harshlight reflection that results in an

Figure 31: Restorations prior to final polishand devesting.

Figure 32: Porcelain added to embrasurearea to correct a potential “black triangle”.

Figure 33: Final polish with a soft brushand porcelain polishing paste.

Figure 34: Completed restorations on solidmodel.


unnatural look The incisal matrixmade from the provisional restorationsis used as a guide to determine whereto build the lobes and (of course) toothwidth and length (Fig 28). Whenbuilding the maxillary units the samesteps are followed, with the exceptionof heavier internal effects with moreincisal porcelains to create moreincisal characteristics (Fig 29). Thestick-bite is clipped onto the lowermodel to be used as a guide for a cor-rect horizontal plane as well as a per-pendicular midline (Fig 30).Periodically during the incisal porce-lain application all excursive move-ments are checked against the lowerunits to ensure that proper functionand occlusion have been established.Once all of the restoration contourshave been finalized all units are glazed.Contacts are checked again using aMylar strip for consistency. Black tri-angles have been monitored through-out the building process and changesare made prior to final polish (Figs 31& 32).

Final polish is an important step. Abeautiful, natural luster is achieved byfirst rubber-wheeling the restoration

until slightly dull, with particularemphasis on the high areas of the lobesor the areas of the lobes that the lipscontinuously rub on. Next, using aRobinson™ bristle brush (BuffaloDental Mfg. Co.; Syosset, NY) withDia-Shine Fine grit (VH Techno-logies; Bellevue, WA), polish is repeat-edly worked over the restorations untilthe polish has disappeared (Fig 33).The veneers are steamed and ready tobe devested. Devesting is a simpleprocess using glass beads at 60 to 80 psito blow the refractory material awayfrom the veneer. Any overhangs orover-extensions on the margins arecarefully removed using a diamond-impregnated wheel. Restorations areready to be fit to the master dies. If therefractory work was done well, thenfitting time should be minor. If there isa bit of hesitation to a restoration seat-ing, then fit-checker spray is a handytool. Unfortunately, refractory veneersin comparison to pressed ceramicveneers are more fragile to fit; greatcare must be taken not to chip or frac-ture the restorations at this point. Alldies are placed back into the base andthe veneers are tried-in, first in small

groups, adjusting any contacts neces-sary; and then all together to ensurethat orthodontic placement is correct.A tacking material under the veneerskeeps them in place during final checkof occlusion and excursive move-ments. Veneers are transferred to thesolid models to note any corrections(Fig 34). If any corrections need to bemade then the d-sign km is appliedand the units to be fired are placed onthe firing tray with an instant refracto-ry material such as Vest-It (Green-KelInnovations Inc.; Cranberry, PA) Ifthe program temperature is not too hotthen there is very little chance of anywarping. Finally, the all-on is refinedwith a rubber wheel and diamond-pol-ished as before. The case is completeand the quality check is done before itis sent back to the doctor.

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A Case Study: Esthetic & Biologic Management of a Diastema...

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