Ceramic veneers havehad an amazing effecton dentistry sincetheir introductionmore than 20 years

ago. Ceramic veneers are esti-mated to be responsible forabout one-third of the revenue ofthe entire U.S. dental laboratoryindustry (B. Napier, coexecutivedirector, National Association ofDental Laboratories, oral com-munication, Aug. 7, 2008). Therehas been controversy aboutwhether such widespread andfrequent use of veneers can bejustified or whether other, moreconservative modes of treatmentcould have been used instead inmany cases. Some of the alter-native procedures are orthodon-tics, vital tooth whitening,incisal recontouring, gingivalrecontouring and combinationsof these techniques.

In any event, ceramic

veneers are extremely popular.Patients are requesting them,dentists are promoting themand millions of ceramic veneersare being placed on a routinebasis.

Opinions differ as to whethertooth preparations for veneersshould be minimal, without sig-nificant enamel reduction; mod-erate, involving the removal ofas much as one-half of theenamel; or relatively deeply cut,usually extending into dentin.The preponderance of opinion,research and suggestions in theliterature support either min-imal or moderate enamelremoval, with the tooth prepara-tions remaining primarily inenamel.1-12 I strongly agree withthose conclusions, after havingplaced thousands of veneersmyself. A major remaining ques-tion relative to enamel removalfor veneers is how much enamel

should be removed, if any.In this column, I discuss the

advantages and disadvantagesof slight or no enamel removalfor so-called no-preparationveneers in relation to veneerswith tooth preparationsinvolving moderate enamelremoval.

NO-PREPARATIONVENEERS: ADVANTAGESAND DISADVANTAGES

The no-preparation ceramicveneer concept is not new. Morethan 20 years ago, the techniquewas promoted by Den-Mat(Santa Maria, Calif.). Althoughsome dentists adopted the no-preparation concept at thattime, most dentists started theirventure into ceramic veneers byusing tooth preparations that,while moderately cut, still leftenamel to which to bond theceramic veneers. The popularityof veneers continued to increase,and they now are included inthe clinical repertoire of most

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Thick or thin 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 © 2008 American Dental Association. All rights reserved. Reprinted by permission

1542 JADA, Vol. 139 http://jada.ada.org November 2008

general dentists and prosthodontists.

In the last few years, the no-preparation concept againreceived major emphasis, initi-ated by Den-Mat with the brandname Lumineers. As a result ofthe no-preparation concept,other dental laboratories havewelcomed the new veneer orien-tation by promoting their ownbrands of these thin veneers.The typical advertised thicknessof no-preparation veneers is 0.3 millimeters. This thicknessis a fraction of that of conven-tional veneers made for moder-ately prepared teeth, whichrange from about 0.3 mm insome tooth locations to about 1.0 mm on the incisal or occlusaledges.

What are the apparentadvantages and disadvantagesof no-preparation veneers? I willenumerate them below.

ADVANTAGES OF NO-PREPARATION CERAMIC VENEERS

No anesthesia required.Because only a small amount ofenamel or no enamel isremoved, these veneers can beplaced without anesthesia,although some dentists stilladminister anesthetic to ensurepatients’ comfort during the procedure.

Less patient fear. Patientsfear the procedure significantlyless when they learn that anes-thesia delivery and tooth cuttingare not mandatory for no-preparation veneers.

Patients’ appreciation ofconservative tooth prepara-tions. Thin veneers requireminimal or no enamel removal,which patients view as a strongpositive characteristic andwhich often leads to theiracceptance of the concept.

Possibility of reversal. No-preparation veneers arereversible, although it is seldomthat any patient wants to returnto the appearance of his or herpreoperative smile. This charac-teristic makes redoing theveneers relatively easy someyears in the future when theyhave to be replaced.

DISADVANTAGES OF NO-PREPARATION CERAMIC VENEERS

Overcontoured appearance.Because no-preparation veneersrequire minimal or no enamelremoval, the teeth treated withthese veneers are larger thanthey were in their natural state.The result is that the veneeredteeth often have a bucktoothedappearance. However, somepatients prefer to have teethlarger and longer than their nat-ural teeth, thus potentially nul-lifying this apparent disadvan-tage (at least for those patients).

Possible need for moreveneers. If the clinician is con-templating veneering only a fewteeth with no-preparationveneers, producing an appear-ance that is harmonious withthe patient’s smile may requireplacing veneers on more teeththan those actually needing theveneers. The numerous veneersdecrease what would have beena bucktoothed appearance ofonly a few treated teeth. As anexample, if two central incisorsrequire veneering, often the clin-ician will place four to 10veneers to provide a harmoniousappearance.

Opaque, monotoneappearance. Often, thinveneers cannot cover discoloredteeth without producing anopaque, monotone effect.Because of the minimal thick-ness of no-preparation veneers,

it is difficult to cover objection-ably dark teeth without the useof relatively opaque cements.

Limited translucence. Theminimal thickness of no-preparation veneers limits theclinician’s ability to producetranslucence in the veneers’incisal edges, as compared withthicker veneers requiring moderate-depth tooth preparations.

Margins not visible to thetechnician. If teeth are not pre-pared, the technician may havedifficulty determining where toend the veneers, unlike whenteeth are prepared for moder-ately thick veneers on which themargins are distinctly visible.

Possible overcontouring ofmargins. When margins of thetooth preparation are not visibleto the technician, the ceramicmust end on a nonprepared por-tion of the tooth. Becauseceramic cannot easily be fired orpressed to a thickness much lessthan 0.3 mm, there is a ten-dency to overcontour the junc-tion between the unpreparedtooth structure and the ceramic.The ridge thus formed requirespostseating finishing by the clinician.

Possible inadvertent alter-ation of occlusion. If theincisal or occlusal edges of theteeth are not prepared, there isa potential for extending theincisal or occlusal edges fartherthan the patient’s occlusion cantolerate. Fracture of the overex-tended ceramic then becomes apotential postoperative problem.

INDICATIONS FOR NO-PREPARATION VENEERS

Although no-preparationveneers do have disadvantages,when are they indicated?

Small teeth. When teethappear to be small for the

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

Copyright © 2008 American Dental Association. All rights reserved. Reprinted by permission

patient’s body size, and buildingthem up to a fuller appearanceappears to be logical, no-preparation veneers are indi-cated if the occlusion will permitthe anatomical change. Anobvious example of this condi-tion is “peg” lateral incisors, forwhich tooth preparation seldomis necessary before placement ofceramic veneers.

Anterior teeth withdiastemas. If teeth are not toofull in appearance and thepatient has numerousdiastemas, no-preparationveneers are a logical restorativechoice. The other popular andsuccessful conservative tech-nique for diastemas is the addi-tion of small interproximal res-torations. However, theseadd-on restorations may nothave the same homogeneoustooth color as do the no-preparation veneers.

Teeth in lingual version.Teeth sometimes are inclinedlingually, producing anunpleasant, unnatural appear-ance. It is simple to correct thisappearance by restoring theteeth with no-preparationveneers into a normal relation-ship. In these situations,occlusal interferences areseldom a challenge.

Combinations of theabove. If any or all of the pre-ceding conditions are present incombination, no-preparationveneers may be indicated.

Patient’s desire for achange in teeth’s appear-ance. Some patients desire tohave their teeth made fuller inappearance and also to have theanterior teeth made longer.

These changes pose an ethicaldilemma for a dentist. He or sheshould present the patient withall of the alternatives for treat-ment, including no treatment atall, and should state in clearterms the disadvantages ofplacing veneers. After this edu-cational session, the decisionabout placing veneers purely foresthetic reasons should be madeconjointly by the patient and thedentist.

A desire for color upgrade.Patients should be informed ofthe difficulty of covering thecolor of discolored teeth with no-preparation veneers withoutproducing an opaque appear-ance. However, no-preparationveneers often are successful inthese situations, especially if thepatient does not need significanttranslucence in the incisal orocclusal edges.

SUMMARY

There is no question that no-preparation veneers are pop-ular, that they satisfy patientsand that they serve their func-tion well. In some situations,other modes of treatment—suchas tooth whitening, orthodon-tics, incisal recontouring, gin-gival recontouring, a combina-tion of the preceding proceduresor placement of veneersrequiring conventional toothpreparation—may be moreacceptable than no-preparationveneers. All patients consideringany form of ceramic veneersshould undergo a completework-up for a diagnostic study,should be educated about all ofthe alternatives for veneers andshould be asked to sign an

informed consent form statingthat all treatment alternativeshave been presented to them.

In view of the stated advan-tages and disadvantages of no-preparation veneers, it isapparent that these veneers arenot for everybody. However,there are some patients in every practice for whom no-preparation veneers are indicated. ■

Dr. Christensen is the director, PracticalClinical Courses, and cofounder and seniorconsultant, CR Foundation, Provo, Utah. Healso is the dean, Scottsdale Center for Den-tistry, Scottsdale, Ariz. Address reprintrequests to Dr. Christensen at CR Foundation,3707 N. Canyon Road, Suite 3D, Provo, Utah84604.

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

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

Copyright © 2008 American Dental Association. All rights reserved. Reprinted by permission