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Veneering teeth withceramic has becomea major part ofesthetic dentistry,and many general

dentists provide this service.1-3

Dental laboratories have becomeproficient at making both firedand pressed versions of ceramicveneers. Each month, articlesare published in dental journalsand magazines on yet anotherway to prepare teeth forveneers, the best methods tofabricate them in the laboratoryand the best cementation pro-cedures. Although these restora-tions have been a part of dentalpractice for more than 20 years,it is interesting to note that onlya few articles have addressedtheir long-term service charac-teristics. What have practi-tioners learned from observingthese restorations in service?

What are the problems thathave been encountered during aperiod of service in the mouththat relate to tooth prepara-tions, cements, occlusion, peri-odontal health and other factors?

This article expresses myobservations on the relativelylong-term service characteris-tics of ceramic veneers. The con-clusions come from havingplaced thousands of veneersmyself, from research accom-plished by Clinical ResearchAssociates, from clinical studyclubs for which I am mentor,from hands-on courses that Iteach routinely and from dis-cussing the subject with den-tists around the world.

BULKY APPEARANCE

When the size and anatomicalappearance of the natural teeth

are acceptable before the place-ment of veneers, and the patientlikes the teeth’s preoperativeappearance, effort should bemade to reproduce the sameanatomy and shape for the fin-ished veneers. Maintaining theoriginal tooth shape oftenrequires the clinician to removea slight-to-moderate amount ofenamel when making the toothpreparations. I suggest that thetooth preparations be made inenamel whenever possible toavoid problems I will discusslater. Bulky veneers are to beavoided, because they appearfalse to observers.

COLOR OF VENEERS

If veneers are thin (approxi-mately 0.3 millimeters at thethinnest area), the color of theresultant veneer restoration is acombination of three colors:those of the remaining toothstructure, the cement and theceramic. Thin veneers can beone of the most conservative and

JADA, Vol. 137 http://jada.ada.org May 2006 661

Facing the challenges of ceramic veneers

P E R S P E C T I V E S O B S E R V AT I O N S

Gordon J. Christensen, DDS, MSD, PhD

Copyright ©2005 American Dental Association. All rights reserved.

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662 JADA, Vol. 137 http://jada.ada.org May 2006

beautiful of all restorations ifthe teeth are relatively normalin color and dentists use try-ongels before cementation to deter-mine the potential final color ofthe restoration. Some of the popular brands of resin-veneercement have excellent try-ongels that match the color of thecements well, while otherbrands of try-on gels do notmatch the color of the setcement.1,2 I suggest comparingthe try-on gel color with thecolor of the set cement to ensurethat the desired veneer color isobtained. Although thin, opaqueveneers used with opaquecements will lighten the color ofdarkly colored teeth, the finalesthetic result can be disagree-ably opaque. Usually, the colorof darkly discolored teeth is notcovered well with thin veneers,and thicker veneers or crownsprovide more esthetic restorations.

Color matching of veneers tothe adjacent teeth is easier withdeeper veneer preparations;however, I avoid deeply cutveneer preparations becausethey often result in other signifi-cant problems to be discussedlater. Practitioners must decidewhether tooth anatomy andcolor allow for thin or moder-ately thick veneers to be seatedon enamel, or if crowns wouldprovide stronger restorationswith optimum color. The mostconservative treatment shouldbe accomplished, whether it isbleaching only, minor orthodon-tics, no-preparation veneers orslightly or moderately preparedenamel surfaces.

LONG-TERM COLOR STABILITY

Fired-ceramic veneers can haveinternal colors fired into theceramic. If color variation is

desired in different locations onthe veneers, such as darker cer-vical color and more translucentincisal color, fired-ceramicveneers can provide those char-acteristics over a long serviceperiod without color change.Pressed-ceramic veneers startout as monotone in color untilsuperficial stains are fired onthe external surfaces. Techni-cians and dentists are dividedwith regard to which type ofveneer provides the best long-term service for patients.

Practitioners must decidewhich type of ceramic veneercan be fabricated best by thelaboratories they are using.Either fired or pressed veneers,properly constructed, can pro-vide excellent color stability overmany years.

POSTOPERATIVE TOOTH SENSITIVITY AND PULPAL DEATH

It has been my observation thatveneer tooth preparations cutdeeply into dentin often producepostoperative tooth sensitivityand even pulpal death. How-ever, some technicians preferdeep tooth preparations andencourage dentists to prepareteeth in that manner, becauseany desired tooth color andanatomy can be produced by thetechnician. Which tooth prepa-ration technique is the best forveneers: no tooth preparation atall, a shallow or moderate toothpreparation in enamel only, or atooth preparation extending intodentin? In my opinion, veneersare meant to be conservativerestorations. When they areplaced on deeply cut dentin sur-faces, and a total-etch procedureis accomplished before placingthe bonding agent and resincement, I have found throughclinical experience and research

that there is a significant chancethat some dentinal canals willnot be plugged adequately topreclude pulp irritation andpostoperative tooth sensitivity.3-8

If a significant amount of toothstructure must be removed toachieve proper anatomy andcolor, crowns would be a betterchoice than veneers for the fol-lowing reason. All-ceramic orporcelain-fused-to-metal (PFM)crowns can be seated with resin-modified glass ionomer cementor resin cement that contains aself-etch primer. In either case,the cements do not cause pulpaldamage, tooth sensitivity orpulpal death, while resincements placed over total-etchedand bonded surfaces have beenshown to cause unpredictableproblems.3

OVERHANGING CERAMIC OR RESIN CEMENT

I see many veneers placed inpractices all over the UnitedStates that have significantoverhangs. Roughness in theinterproximal areas of someveneers will not allow floss toslide between them withoutobjectionable catching. Suchinadequate finishing does notallow or encourage proper oralhygiene, and soon, gingivaltissue becomes red and swollen.Ceramic veneers should be fin-ished carefully with finishingstrips so that when a piece offloss is placed as far apically ascan be done without pain, thefloss exits without catching. Fin-ishing to this level cannot avoidstimulating some blood flow andcausing minor gingival irrita-tion. However, it is better tohave a little irritation at theseating appointment—irritationthat will go away in a fewdays—than to have chronicroughness, gingival bleeding

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and difficult cleaning for theservice life of the veneers.

STAINS ON THE GINGIVALMARGINS

Regardless of whether theveneers were placed slightlysubgingivally or supragingi-vally, I have seen many comingfrom practices across thecountry with staining aroundthe gingival margins. The stainsmay have been caused by atleast two situations. Contamina-tion of the gingival margin areasat the impression appointmentresults in an inaccurate die andoften will not provide a well-fitting veneer. Also, moisturecontamination at the time ofseating interferes with thecement polymerization. Placingnonchemical–impregnated gin-gival packing cords at the timeof impressions and on seatingprecludes moisture from leakinginto the marginal areas and pre-vents the objectionable gingivalstaining. Based on observingthousands of veneers accom-plished in this manner, I haverarely seen postoperative gin-gival staining when using thistechnique.

DISCOLORATION UNDERVENEERS

Some practitioners use ferricsulfate to control bleeding whenmaking veneer impressions orseating veneers. Ferric salts canbe used without difficulty forrestorations that are opaque,such as PFM or all-metalcrowns, or for any type ofopaque all-ceramic crown. How-ever, the iron salts impregnatethe dentin, and the gray discol-orations appear within weeksafter the veneers have beenseated.

I suggest that when stypticagents are needed for teeth



being veneered, aluminum chlo-ride should be used for tissuemanagement. This chemistrydoes not cause postoperative dis-coloration under the veneers. Apreventive technique that allowsthe clinician to make impres-sions and seat veneers withoutusing styptics or vasoconstric-tors is the patient’s use of 0.12percent chlorhexidine gluconateas a rinse twice daily for twoweeks preoperatively. After therinse is used as described, thesoft tissues are pink and firmand allow impressions to bemade without bleeding occur-ring. To encourage optimaltissue adaptation, the patientshould continue to use the rinsewhile the veneers are being fab-ricated and also for two weeksafter the procedure.

DEBONDING OF VENEERS

If the internal surfaces ofceramic veneers have beenetched properly with hydro-fluoric acid and silanated, and ifthey are seated over enamel sur-faces that have been etchedproperly with phosphoric acid,experienced clinicians know thatthey are extremely difficult toremove. However, if the veneersare seated over dentin surfaces,some come off during service.The dentist should avoidpreparing teeth deeply intodentin for veneers. If the depthis needed to remove caries or toreplace defective restorations, acrown would be a stronger andmore appropriate restoration.

CHIPPING ON INCISALEDGES

Veneers placed with marginsexactly on the chewing surfaceof the incisal edge may developchips on the incisal edge after afew years of service, and repairis difficult or impossible. Incisal

margins placed slightly lingualto the incisal edge but not intothe centric stop of the opposingarch of teeth, and configured asa “butt” joint, do not exhibitsuch chipping.

OPEN LINGUAL MARGINS

After several years of service,resin cement on the incisal/lingual edges of ceramic veneerswill wear more than the ceramicor the tooth, and some patientsmay complain that they can feela juncture line as their tonguemoves back and forth from theveneer to the tooth. Margins onthe lingual incisal surfaceshould be made as tight as pos-sible by laboratory techniciansto avoid this disagreeable situa-tion. This is the only location onan anterior tooth veneer wherethe tooth/veneer interface canfeel objectionable to patients. Inextreme cases, the open margincan be further opened with apointed diamond and the surfaceetched and repaired with resin.However, the clinician shouldnot expect long-lasting servicefrom this repair.

GINGIVAL RECESSION

Avoiding gingival recession isimpossible, but avoidingunsightly display of supragin-gival veneer margins is possible.Some clinicians recommend thatveneer gingival margins shouldbe placed supragingivally. In myopinion, such placement isacceptable occasionally if tooth-color change is not one of thereasons for the veneers.

I prefer to place veneer gin-gival margins at the gingivalcrest or slightly subgingivally ifthe tooth color is different fromthe color of the veneer. Suchplacement of margins allowsveneers to serve esthetically formany years. I have patients in


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my practice who have hadceramic veneers for 20 yearsthat still are acceptable estheti-cally. Seldom do PFM crownsserve esthetically for this long,because as the gingiva recedes,there is display of metal and achalky color of ceramic at thegingival margins, as well as dis-play of the margin/tooth interface.

DENTAL CARIES

After placing thousands ofveneers, I rarely have seen teethdevelop subsequent caries onthe veneer margins. Becausemany dentists place the inter-proximal margins of veneers inthe contact area, carious lesionsmust be relatively large to beobserved. I do not object to mar-gins in the interproximal areas,because the tooth/cement/ceramic interface can be fin-

ished easily. However, whenmargins are placed interproxi-mally, less radiopaque cementshould be used to allow observa-tion of caries on a radiograph.

SUMMARY

Ceramic veneers are extremelypopular and have been used formany years. In spite of theirphenomenal success, they offernumerous challenges duringservice. In this column, I haveidentified and discussed severaldegenerative situations com-monly observed, and I havedescribed methods of preventingor reducing the problems. Whenproperly placed, ceramic veneersare among the most beautifuland long-lasting of all dentalrestorations. ■

Dr. Christensen is co-founder and seniorconsultant, Clinical Research Associates, 3707N. Canyon Road, Suite 3D, Provo, Utah 84604.Address reprint requests to Dr. Christensen.

The views expressed are those of the authorand do not necessarily reflect the opinions orofficial policies of the American Dental Association.

1. Clinical Research Associates. Upper ante-rior veneers: state of the art (part 1). CRANewsletter 2006;30(1):1-3.

2. Clinical Research Associates. Upper ante-rior veneers: state of the art (part 2). CRANewsletter 2006;30(3):1-3.

3. Clinical Research Associates. Filledpolymer crowns:1 and 2 year status reports.CRA Newsletter 1998;22(10):1.

4. Clinical Research Associates. Self-etchprimer (SEP) adhesives update. CRANewsletter 2003;27(11/12):1-5.

5. Casselli DS, Martins LR. Postoperativesensitivity in Class I composite resin restora-tions in vivo. J Adhes Dent 2006;8:53-8.

6. Baghdadi ZD. The clinical evaluation ofsingle-bottle adhesive system with threerestorative materials in children: six-monthresults. Gen Dent 2005;53:357-65.

7. Unemori M, Matsuya Y, Akashi A, Goto Y,Akamine A. Self-etching adhesives and postop-erative sensitivity. Am J Dent 2004;17:191-5.

8. Perdigão J, Geraldeli S, Hodges JS. Total-etch versus self-etch adhesive: effect on post-operative sensitivity. JADA 2003;134:1621-9.


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