Esthetic Dentistry

Single-tooth home bleachingGerald E. Denehy*/Edward J. Swift. Jr**

This article describes a simple btil effective method of bleaching single vital discoloredteeth. The patient applies a viscous 10% carbatnide peroxide gel in a plastic mouth-guard designed lo confine the gel otüy to the discolored tooth. This method has beeneffective for lightening vital teeth with calcified palpal spaces.(Quintessence Int 1992:23:595-598.)

Introduction

Effective internal bleaching of discolored endodonti-cally treated teeth cati be achieved with a mixiure ofsodium perborate and 30% to 35% hydrogenperoxide.' Tn some cases, however, individual teeth suf-fer impact tTauma and become discolored but remainvital- Discoloration is caused by deposition of dentinon the walls of the pulpal space." Radiographically, thepulp chamber may appear partially or completely ob-literated-

Elective endodontic therapy and internal bleachingare possible, but difficult, and perforations can occur.A common technique for treatment of single discol-ored teeth is external bleachitig with 30% to 35% hy-drogen peroxide and heat.' Commercial instrumentsare available to provide localized application of heat.Unfortunately, cUnical experience shows that thistechnique is frequently unsuccessful.

Albers"' recommended a modified internal bleachingtechnique for treating such vital discolored teeth. Al-bers' technique involves preparation of a lingual accesscavity, in effect re-creating the pulp chamber. With thistechnique, perforations to the external surface are pos-sibie- Furthermore, some pulpal tissue may be pres-ent, even if it is not apparent on the radiograph.

Professor- Department of Operative Dentistry, University ofIowa- School of Dentistry, Iowa City, Iowa 52242.Associate Professor, Department of Operative Dentistry, Uni-versity of Iowa-

Simpler, more predictable methods of bleachingsingle discolored teeth are desirable. Recently, ahome-use bleaching technique has been introducedfor treatment of multiple discolored teeth. The patientapplies a bleaching gel (most commonly 10% car-bamide peroxide) in a custom-fitted plastic tray for sev-eral hours daily. A typical treatment regimen is com-pleted after 3 to 4 weeks. This technique has beenhighly effective for treatment of some discolorations,particularly those in the yellow range.''"'' Althoughhome bleaching is usually used to treat six to eightteeth, Haywood*' has described a technique for bleach-ing single teeth with 10% carbamide peroxide (Prox-igel. Reed & Carnrick). This paper describes a mod-ification of this technique, using a more viscousbleaching gel and mouthguard-type tray to selectivelybleach individual discolored teeth-

Materials

For the single-tooth bleaching technique, the bleach-ing gel must have sufficient viscosity so that it is re-tained in the tray without significant dilution. Somecarbamide peroxide gels are thickened with a highmolecular weight resin polymer called Carbopol (BFGoodrich), Carbopol increases the viscosity and pro-longs the activity of carbamide peroxide gcls.*'̂Opalescence (Ultradent Products) has a high concen-tration of Carbopol and is the one of most viscousbleaching gels available.

For selective bleaching of individual discoloredteeth with Opalescence, the tray must maintain itsadaptation to the tooth surface without support from

Quintessence International Volume 23, Number 9/1992 595

Esthetic Dentistry

the adjacent tray material. A 2-mtTi soft muulliguardmaterial (Groat Lakes Orthodontics) provides suf-ficient support for a selective-bleaching tray. This mate-rial is easily trimmed atid its thickness assures not onlyproper support and adaptation, hut also patient com-fort.

The tray must be scalloped at the gingival marginsof the tcctli to prevent tissue irritation by the viscous,sustained-action bleaching gel. A portion of the traymaterial covering the teeth immediately aiijaeent tothe discolored teeth is removed to prevent contact ofthe bleaching gel with those teeth. Only the facial areaof the tray material is removed. The entire lingual as-pect of the adjacent tray material must be left in placeto ensure stabihty of the tray. In addition, a thin dm oftray material may be retained at the cervical aspect ofthe adjacent facial surfaees if the operator desires.

For the Opalescence system, application of die re-lief on the facial surface of the cast is recommended toprovide a small reservoir in the tray for the bleachinggel. However, die relief should be of minimal thick-ness and away from the gingival margin to maximizeadaptation of the seleetive-bleaching tray.

Opalescence bleaching gel is placed in a thin layeronly on the facial portion of the tray covering the dis-colored tooth or teeth. The patient must remove anyexess gel from the adjacent teeth and ¡issue wifh a cot-ton swab or toothbrush. Although bleaching gel maycome in contact with the lingual surfaces of the adja-cent teeth, the authors have not found this to be aproblem if the patient does not appiy an excessiveamount of bleaching gel.

Case reports

Case 1

A 33-year-old woman presented with discoloration ofboth maxillary central incisors (Fig 1), The pafientstated thaf the teeth had been discolored for approx-imately 10 years, but that the discoloration had worsenedover the last 5 years. A periapical radiographshowed calcified pulpal spaces, with no coronal orradicular pulpal tissue evident. There was no evidenceof periapical pathosis, and the patient responded to anelectronic pulp tester (EPT) at a low intensity level.

A home bleaching tray in 2-mm soft plastic mouth-guard material was constructed for the patient. The fa-cial aspects of the tray were trimmed away at themaxillary lateral ineisors (Fig 2). The patient appliedOpalescence to the central incisors and used the trayfor nighttime wear (approximately 8 hours per night).

After 2 weeks, the central incisors matched the shadeof the other anterior teeth (Fig 3).The palit-m ..^presseda desire to have all of the maxillary aniuviors light-ened, so a new complete-eoverage tray was fabricatedand the patient completed an additional 2 weeks ofbleaching.

At the completion of the bleaching regimen, thecentral ineisors were cosmetically contoured withabrasive disks. The mesial surfaces of the lateral incisorswere built up with a microfilled composite resin to pro-vide a more esthetic alignment (Fig 4).

Case 2

A 34-year-old woman presented with discolorationof several maxillary teeth: the right canine and lateralincisor and left central incisor. The discoloration wasparticularly evident in the right lateral and left centralincisors; the other incisors had a normal shade (Fig 5),The patient eould not recall any trauma to these teethand stated that they had been discolored for as long asshe could remember. All of the teeth appeared normalradiographically and responded to an EPT. A bleachingtray was constructed and the facial aspeets of the traywere removed at the right central and left lateralincisors so that the bleaching gel would not contactthose teeth. The diseolored teeth were bleached withOpalescence, placed in the tray in overnight wear for3 weeks. The mesioincisal angle of the right centralincisor was restored with composite resin to completethe treatment (Fig 6).

Discussion

The authors have found this selective-bleachingtechnique to be effective in many, but not all, cases.Final shades have ranged from minor lightening tocomplete color matehing. in general, the resuits havebeen superior to those of traditional oftice bleachingtechniques involving application of heat and hydrogenperoxide.

The selective-bleaching technique can be used onany discolored vital teeth, particularly those with cal-cified pulpal spaces. Another indication for selectivebleaching is treatment of canines that have beenmoved orthodontically to replace missing lateral in-cisors. Canines usually have a more yellow hue thando the incisors and can be lightened with this method.

Successful home bleaching of single or multipleteeth depends on patient compliance. However, mostpatients cooperate fully, wearing the appliance untilthe desired result is achieved. The patient is instructed

596 Quintessence International Volume 23. Number 9/1992

Esthetic Dentistry

Fig 1 Case 1. Discolored maxillary central incisors. Fig 2 Case 1. Piastic mouthguard constructed to bleacinthe discolored centrai incisors. The tray coverage ot ttie ad-jacent teetin tias been tnmmed oft to prevent their contactwith the bleaching gel.

Fig 3 Case 1. The maxillary central incisors have beenbleached and now match ttie shade of the other anteriorteeth.

Fig 4 Case 1. Completion of treatment. All maxillary an-terior teeth have been bleached. In addition, the incisaiedges ot the central incisors have been cosmetically con-toured and the lateral incisors brought into a more regularaiignment through ttie use of composite resin.

Fig 5 Case 2. Discolored right canine and Iaterai incisorand left iaterai incisor. Note the normal shade ot the rightcentral and left lateral incisors.

Fig 6 Case 2. Teeth after seiective bleaching of discoloredteeth and restoration of the incisai edge of the right centralincisor with composite resin.

Quintessence International Volume 23, Number 9/1992 597

Esthetic Dentistry

to tlisL-ontinuc bleaching and contact the dentist if anyadverse tissue reaction or looth sensitivity occui's.Also, if bleaching has not been effective after 3 or 4weeks, alternative treatments should be consiciered.

The lime necessary to aehieve lightening of diseol-ored individual teeth varies witli the severity of thestain. The patient should monitor the bleaching pro-cess carefully, and discontinue use of the bleaching gelwhen the tooth matches the shade of the normal adja-cent teeth.

Some patients tiiay wish to have only the individualdiseolored tooth lightened to match the resi of the den-tition. Others wish to have all of their teeth lightened,in addition to the obviously discolored one. The au-thors usually treat tbe single discolored tootb first andthen construct a new. eoniplete-eoveragc tray to bleachthe entire arch if the patient desires.

The rationale for this treatment sequence is basedon tbe oecasional nonresponse of a discolored toothto bleaching. As the otber teetb becotne lighter, thecolor disparity may become even more apparent. Incontrast, if the itidividual tooth can first be bleached

to a comparable sbade, subsequent bleuLlim.!; witb acomplete-arcb tray may produce a more uiufor'Ti Itght-ening result.

Initial results witb tbis single-tootli liorne bleachingtechnique have been good. However, long-term clin-ical evaluation will be needed to determine tbe ul-timate success of the procedure.

References1. Ho S, Goerig AC: An in vitro comparison of diffeient bleach-

ing agents in the discolored tooth. 7 Endnd iy!í9;I.S:lü6-ll1.

2. Joicobsen 1, Kcrekcs K: Long-term prognosis of traumatizedpermanent anterior teeth showing calcifying processes in thepulpeavity. Scoiid ] Dem Res l977;85:588-598.

3. Cohen S. Parkins FM: Bleaching tetiacyeline-stained vitalteeth. O.;il Siir^ Oral Met! Oral Falhni t970;2a:4fi5^71.

4. Albers HF: LightCEiing natural teeth. ADEPT Repon

5. Hayu'ood VB, Heymann HO: Nightguard vital bleaching.Qiiimessence fin ¡989^20:t73-Í76.

fi. Haywood VB: Nightguard vital bleaching: eurrent informationand research. Eslliel Dem Updme iy<)n:1:20-2.';. D

Moving Soon?

Please notify us promptly of any change of address to assure an uninterrupted subscription.

Complete the form below and send to: 0/ Subscription Department, Quintessence Publishing Co.Inc., 551 North Kimberly Drive, Carol Stream, IL 60188

NAME.

NEW ADDRESS.

MOVING FROM:

(OLD ADDRESS).

CITY, STATE, ZIP. (CITY, STATE, ZIP)

NOTE: To expedite delivery, send tbe change of address as soon as you know it, and allow 6 weeks for processing.

598 Quintessence International Volume 23, Number 9/1992