Clinical s h o w c a s e Comparison of Porcelain Veneers and Crowns for Resolving Esthetic Problems: Two Case Reports

Wafa El-Badrawy, BDS, MSc; Omar El-Mowafy, BDS, PhD, FADM

hen dentists are considering res- were discoloured, spaced and malaligned toration of maxillary anterior (Figs. 1a and 1b). Although these prob- Wteeth to improve esthetics, they lems had been present for several years, must often choose between porcelain ven- there had been recent deterioration, and eers and full-coverage crowns. Porcelain the patient had decided to seek treatment veneers are considered much more con- to avoid further deterioration. The maxil- servative in terms of the requirements for lary anterior teeth were darkened, with preparation, and they provide satisfactory, a between the central incisors; long-lasting esthetic results. Typically in addition, the right central incisor ap- “Clinical Showcase” is a only the facial surface is involved in peared rotated and out of alignment. series of pictorial essays that veneer preparation, with the minimal Vertical crack lines were visible at the focus on the technical art of preparation depth ranging from 0.3 to centre of the facial surface of the 2 central clinical . The section 0.5 mm to maintain the all-enamel surface incisors (Figs. 1a and 1b), but these marks features step-by-step case that is necessary for optimum bonding were only superficial. At the time of the demonstrations of clinical to the veneers.1 However, if the teeth are initial photographs, bleaching of the lower problems encountered in already compromised by the presence of anterior teeth was in progress. Lingual dental practice. If you would extensive carious lesions, wear, old restor- examination showed some evidence of like to contribute to ations or endodontic treatment, placement extrinsic staining, but the teeth were this section, contact editor- of a is the more prudent choice. otherwise free of caries and restorations in-chief Dr. John O’Keefe This article presents 2 selected cases, one (Fig. 1c). Incisal wear was minimal and at [email protected]. illustrating an ideal situation for veneer did not pose a serious concern. restorations and the other illustrating an The patient was offered several treat- ideal situation for crowns. ment options. The first would involve - at tempting to whiten the maxillary teeth Case 1 by a combination of in-office and at-home A 60-year-old woman presented with bleaching regimens. Although this option the chief complaint of anterior teeth that was likely to improve the colour of the

Figure 1a: Frontal view of the maxillary Figure 1b: Left lateral view. Rotation and anterior teeth in case 1. The teeth are protrusion of the maxillary right central dark, there is a diastema between the incisor are clearly visible. 2 central incisors, and the right central incisor appears rotated and out of alignment.

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Figure 1c: Lingual aspect of the maxillary Figure 1d: Appearance of the maxillary Figure 1e: Six porcelain veneers were teeth. Although there is evidence of some anterior teeth after preparation for restora- fabricated in a laboratory to restore extrinsic staining, the teeth are otherwise tion with porcelain veneers. More reduction the maxillary anterior teeth. free of caries and restorations. was required on the distal aspect of the facial surface of the maxillary right central incisor to create room for proper alignment of the veneer restorations.

Figure 1f: Postoperative appearance of Figure 1g: Lingual view of the maxillary the maxillary anterior teeth. The diastema anterior teeth after cementation of the between the 2 central incisors has been veneer restorations. This view shows how closed, the maxillary right central incisor is the porcelain had to be extended inter- now in proper alignment, and the shade of proximally between the 2 central incisors to the teeth is much lighter than the original. close the diastema.

teeth, it would not change the diastema or the the expected treatment outcome with the patient. position of the right maxillary central incisor. The The patient agreed to this treatment plan. patient was not interested in orthodontic treat- Figure 1d shows the appearance of the teeth ment because of the estimated length of the course after preparation. After the impression was taken, of treatment and the fact that she would need fixed 6 feldspathic porcelain veneers were made at a appliances. Because all of the maxillary anterior local dental laboratory (Fig. 1e). At the next visit, teeth were caries- and restoration-free, the rela- the prepared teeth were cleaned with a slurry of flour of pumice applied by means of a rubber cup. tively aggressive option of full-coverage crowns The prepared teeth surfaces were then etched with was not considered. The only remaining option a phosphoric acid etchant, and a resin cement was to prescribe porcelain veneers for all 6 max- was used for cementation of the porcelain ven- illary anterior teeth. It was acknowledged that eers. The diastema between the 2 central incisors this would involve more complex preparation for was closed, the maxillary right central incisor had the maxillary right central incisor, including suf- proper alignment, and the shade of the teeth was ficient reduction to allow the veneer restoration much lighter than the original (Figs. 1f and 1g). to bring this tooth into alignment. A waxed-up The lingual view shows that the porcelain had to model demonstrating the corrected positions and be extended interproximally between the 2 central anatomic features of the teeth was used to discuss incisors to close the diastema (Fig. 1g).

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Figure 2a: Facial view of the maxillary Figure 2b: Lingual appearance of the Figure 2c: The waxed-up model was used anterior teeth in case 2. The middle 6 maxillary anterior teeth. The maxillary to fabricate a silicon reduction guide. third of both maxillary central incisors left lateral has a porcelain-fused-to-metal shows evidence of loss of enamel. crown, and the remaining 5 teeth show The maxillary right lateral incisor has evidence of severe enamel wear and the a cervical abrasion lesion, and the presence of extensive restorations. right canine has excessive incisal wear, along with cervical abrasion and mesial restoration.

Figure 2d: A soft clear matrix was Figure 2e: Appearance of the anterior Figure 2f: The interior surfaces of the used to fabricate the provisional teeth after cementation of the temporary 6 ceramic crowns, which consisted of a zir- crowns. crowns. There has been a dramatic improve- conium oxide core veneered with porcelain. ment in esthetic appearance.

Case 2 models, a duplicate stone model was waxed up ac- A 52-year-old woman expressed a desire to cording to the “most agreeable smile” guidelines.2 improve the appearance of her anterior teeth More specifically, the maxillary central incisors (Fig. 2a). The 2 maxillary central incisors were and canines were waxed up to appear longer than discoloured and had areas of eroded enamel in the the maxillary laterals.2 The waxed-up model was middle third. The maxillary right lateral incisor used to discuss expected treatment outcomes with had a cervical abrasion lesion, and the right ca- the patient. It was also used for fabrication of a nine had excessive incisal wear, along with cervical silicon reduction guide (Fig. 2c). In addition, the abrasion and an old restoration at the mesial level. waxed-up model was used for making a duplicate The maxillary left lateral incisor had been restored stone model that was subsequently used for fabri- previously with a porcelain-fused-to-metal crown, cation of a soft clear matrix in a vacuum-forming which appeared too opaque. Examination of the machine. This was used in fabrication of the pro- lingual aspects of the maxillary anterior teeth re- visional crowns. vealed that the maxillary left lateral crown had After careful assessment of the case, it was a metal backing. The remaining 5 teeth showed decided that the most appropriate treatment for evidence of severe wear and erosion of the en- this patient would be to provide full-coverage amel and extensive resin composite restorations crowns for all of the maxillary anterior teeth. All (Fig. 2b). Following further analysis of study of the teeth had sustained extensive damage from

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Figure 2g: Facial view of the 6 crowns Figure 2h: Lingual view of the maxillary 2 weeks postoperatively. The gingival tissues anterior teeth 2 weeks postoperatively. This have rebounded to their original position view also shows rebounding of the gingival and appear healthy, representing a positive tissues to their original position. response to the ceramic crowns.

previous carious lesions, wear and erosion, and to veneers. Veneer restorations do not typically full-coverage crowns would provide the support provide coverage or protection for the lingual (bracing) necessary to maintain the structural in- tooth structure, but they definitely improve labial tegrity of the teeth under the forces of mastica- esthetics. The first case presented in this article tion. To optimize esthetics, nonmetallic crowns represents a classic situation in which veneers are were selected. The maxillary left lateral incisor the most appropriate treatment option. The second had previously undergone endodontic treatment, case illustrates the situation in which crowns including restoration with a metallic post, and the would be the most appropriate treatment option. a nonmetallic crown had to be capable of concealing the metallic shade of the post. Therefore, crowns THE AUTHORS made of zirconium oxide cores and porcelain veneer were chosen. The literature contains good Dr. El-Badrawy is associate professor in restora- evidence of the reliability and survival of non- tive dentistry, department of clinical dental sciences, metallic crowns when used on anterior teeth.3-5 faculty of dentistry, University of Toronto, Toronto, The 6 anterior teeth were prepared accordingly, Ontario. with guidance from the silicon reduction guide. Provisional crowns were fabricated using the soft Dr. El-Mowafy is professor in , clear matrix (Fig. 2d) and were then cemented in department of clinical dental sciences, faculty of dentistry, University of Toronto, Toronto, Ontario. place with temporary cement (Fig. 2e). Email: [email protected] Impressions were taken in a silicon material, and 6 ceramic crowns with zirconium oxide cores Correspondence to: Dr. Omar El-Mowafy, Department of clin- ical dental sciences, Faculty of dentistry, University of Toronto, were fabricated (Fig. 2f). These were cemented Toronto, ON M5G 1G6. with self-adhesive resin cement. By 2 weeks after cementation, the gingival tissues had recovered The authors have no declared financial interests. completely, and there was a dramatic improvement References in esthetics (Figs. 2g and 2h). 1. Calamia JR. Etched porcelain veneers: the current state of the art. Quintessence Int. 1985;16(1):5-12. Conclusions 2. De Castro MV, Santos NC, Ricardo LH. Assessment of the “golden proportion” in agreeable smiles. Quintessence Int. When considering treatment of the maxillary 2006;37(8):597-604. anterior teeth for esthetic purposes, the dentist 3. Odén A, Andersson M, Krystek-Ondracek I, Magnusson D. Five- must consider each case on its own merits. The year clinical evaluation of Procera AllCeram crowns. J Prosthet Dent. 1998;80(4):450-6. choice between porcelain veneers and crowns will 4. Fradeani M, D’Amelio M, Redemagni M, Corrado M. Five-year depend on the condition of the teeth. If the use of follow-up with Procera all-ceramic crowns. Quintessence Int. crowns would be beneficial in terms of providing 2005;36(2):105-13. 5. Zitzmann N, Galindo ML, Hagmann E, Marinello CP. Clinical support (bracing) to the lingual tooth structure, to evaluation of Procera AllCeram crowns in the anterior and posterior prevent future failure, then crowns are preferable regions. Int J Prosthodont. 2007;20(3):239-41.

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