Rejuvenating Previously Restored and Endodontically Treated Anterior Teeth

It is my experience that many dental professionals who provide state-of-the-art aesthetic treatments may not always feel that their own “less-than-perfect” smile is important when attempting to persuade patients to accept proposed treatment plans. However, as dental professionals, it is imperative that we take a serious look at our own, and our staff’s, dental condition and remember that the patient may judge the dentist’s clinical skills based on what types of smiles are seen in the reception and treatment areas.

There is no greater encouragement for proposed aesthetic dental treatment than the recommendations of professionals who have undergone such procedures themselves, and who can visibly demonstrate the benefits of one approach or material over another. With this is mind, integrating sound, clinically proven materials and techniques can foster greater confidence in dental professionals who are about to undergo restorative treatment, and in their ability to successfully perform aesthetic restorative treatments for their patients.

This article demonstrates the manner in which the symbiosis of dental artistry and science can enable dental professionals to create lifelike replacements for what has been lost due to trauma, and how a dental professional’s own treatment can provide skeptical patients bona fide reasons to accept proposed treatments and refer others for aesthetic and predictable long-term dentistry.

CASE PRESENTATION

A female patient—a dental hygienist who is also  my wife—presented requesting replacement of restorations on the central incisors (Figures 1 through 3). The patient’s pre-existing PFM crown on tooth No. 8 and large mesial, palatal, and incisal composite on tooth No. 9 had been previously placed to restore tooth structure that had been lost in an accident. Although the restorations were acceptable clinically, the concern was to replace them with a more aesthetic material.

The PFM on tooth No. 8 had been placed in 1979, and served the patient functionally until the gingival tissue began to recede, thereby exposing the underlying metal margin. In addition, there was a significant darkening of the underlying root and remaining tooth structure due to previous endodontic treatment and the placement of a metal post, which retained the original core. The challenge in this case was not strictly matching the adjacent teeth as much as it was masking the darkened tooth No. 8 to the natural color of the underlying structure on tooth No. 9.

TREATMENT PLAN

After the patient lightened her other maxillary teeth using a dentist-dispensed at-home tooth-whitening kit with a custom tray, the old PFM was sectioned and removed, as was the composite on the adjacent tooth. The original intent was to prepare tooth No. 9 for a wraparound porcelain veneer.

Figure 4. After removal of the previously placed PFM crown, shade taking was completed.

Shade matching was completed (Figure 4) to match the adjacent dentition. However, without adequate blockout of the metal in tooth No. 8, the desired shade would have only been useful for a PFM crown1; the original intent was to construct the crown with a metal-free, full-porcelain technique and opaque out the unwanted discoloration.

Figure 5. The composite provisional restorations adequately masked the underlying tooth structure.

Following proper shade selection utilizing a properly color-corrected lighting environment (Colortone 50, Philips Lighting Company), the newer Chromoscope shade guide (Ivoclar Vivadent), and a Stumpf shade guide (Ivoclar Vivadent), the patient was provisionalized using a preoperative impression of the original restorations, which satisfied the desired ideal contours and occlusal parameters. The composite and bis-GMA provisional material more adequately masked discoloration (Figure 5), which may sometimes fool the operator into assuming that the final porcelain restorations will do the same. However, because of the inherent nature of porcelain to be more translucent than composite material, the ability of porcelain to equally cover discoloration is unlikely.2,3

Material Selection and Preparation

The material selected was a metal-free restorative porcelain (IPS Empress, Ivoclar Vivadent) with the opaque ingot for tooth No. 8, in order to properly mask the darkened root.4 The IPS Empress material was selected based on its wear characteristics and aesthetics, biocompatibility, and conservative preparation requirements. The traditional cutback technique was employed to add incisal translucency and the “halo” effect to mimic the adjacent natural, yet whitened, dentition.5

Evaluating Aesthetic Success

Figure 6. Two initial, yet unsuccessful, attempts were made to adequately cover the metal post in tooth No. 8, as revealed by transillumination.	Figure 7. The patient visited the laboratory to help establish a perfect shade. However, the resulting “re-do” did not match.

After two unsuccessful attempts to adequately cover the metal post in tooth No. 8 and its associated darkened core, and after repeated attempts to match the central incisors to each other and the adjacent dentition, a new treatment plan was considered. Transilluminating the centrals with a light source demonstrated the difference in light refraction and reflection between the two central incisors, and the inability for initial porcelain crowns to mask the discolored tooth No. 8 (Figure 6). Even having the patient visit the laboratory to establish a perfect shade was not sufficient to achieve the desired result without first trying in the restorations to realize the desired outcome (Figure 7).

Figure 10.	Figure 11.
Figure 12.	Figure 13.
Figure 14.	Figure 15.
Figure 16.	Figure 17.

In order to procure the luminescence and translucency necessary to mimic the adjacent natural teeth, it was determined that the metal post would be retrieved from tooth No. 8 (Figures 8 and 9). This was accomplished using an ultrasonic scaler to provide oscillatory movement to help break the cement seal, and then the post was carefully loosened with Howe pliers. Following the successful removal of the post, there was sufficient missing tooth structure to warrant the placement of a customized post and core (Ribbond, Ribbond, Inc) using the modified Hornbrook technique1,6 (Figures 10 through 17).

After recoring tooth No. 8 (Figure 18), it was determined that in order to obtain the same amount of light transmission through both central incisors, a full-coverage crown restoration would have to be placed on tooth No. 9 to achieve the ideal aesthetic result. Although this meant losing tooth structure in tooth No. 9, it was necessary not only to allow the amount of light to penetrate equally, but also to control its direction. While it is essential to adopt a conservative treatment approach whenever possible, there are times when placing full-coverage crown restorations, as in this case, is necessary for achieving the most satisfactory aesthetic result.

COMMUNICATING WITH THE LABORATORY

The varied amounts and locations of opacity and translucency inherent with natural teeth were referenced with the “milk” effect, which refers to having “regular milk” at the gingival area, “2% milk” in the mid-portion of the crown, and “skim milk” at the incisal edge. Although somewhat crude, this analogy was invaluable when discussing the desired look that natural, unrestored teeth possess.

Since the desired shade for the provisional restorations was lighter than the B1 Luxatemp (Zenith) that was used, a cut-back of the provisional was performed, and an overlay of bleach shade composite (Heliomolar, Ivoclar Vivadent) was blended in using a camel hair brush to match the natural teeth. The provisional was luted in place (Provilink, Ivoclar Vivadent), and the case was again sent to the laboratory. Accompanying the case were slide photographs of the preoperative restorations, the prepared teeth, the previously constructed crowns, and the temporaries to help the laboratory technician construct properly shaded and contoured crowns. Several slides were also included that had the actual shade tabs selected, placed adjacent to the teeth, to help standardize the relationship of the tabs to the preparations and desired final shade(s).

FINAL PLACEMENT AND CEMENTATION

After the case was returned from the laboratory, the crowns were found slightly lower in value and of a slightly different hue when compared with the natural adjacent teeth. Therefore, additional slides were taken and sent to help the laboratory correct the shade. At the second try-in, a natural shaded try-in paste (Varliolink, Ivoclar Vivadent) was used, and it was determined that the match was exact and sufficiently covered the darker shade of tooth No. 8.7 Masking the darkened tooth No. 8 was also effectively achieved following the laboratory’s expert advice to use the more opaque ingot for the IPS Empress crown on this tooth.

For final placement, the area was isolated with a rubber dam, and the crowns and preparations were etched with 35% phosphoric acid. Priming and bonding was done with a fifth generation bonding agent (Prime & Bond NT, DENTSPLY Caulk). Variolink II (Ivoclar Vivadent) was the material of choice for luting the crowns. Following the manufacturer’s directions, the crowns were luted and cured using the natural shade and, after removal of the excess cement, the margins were polished using Astropol polishers (Ivoclar Vivadent). Lastly, glycerin was placed on all margins, and a final light cure was accomplished to seal the oxygen-inhibited layer and inhibit stain formation along the margins.

CONCLUSION

Figure 18. The recored tooth No. 8.	Figure 19. Postoperative view of the patient’s new anterior teeth.

The final results of this case (Figure 19) have been used several times to help promote this type of dentistry to other patients. Comparing the before smile (Figure 1) with the after (Figure 19) illustrates why metal-free dentistry should be the primary objective for optimum aesthetics and predictability. The value of such treatments are best demonstrated “in person” to patients who must consider the procedures and become comfortable with paying for them. As in the case presented here, no greater encouragement exists than the recommendations of friends, family, and staff who are satisfied with their own experiences. Further, when dental professionals have undergone the proposed treatments themselves, their testimony can visibly demonstrate the benefits and superiority of one approach over another.

References

1. Hornbrook DS, Hasting JH. Use of bondable reinforcement fiber for post and core build-up in an endondontically treated tooth: maximizing strength and aesthetics. Pract Periodontics Aesthet Dent. 1995;7:33-42.

2. Nathanson D. Current developments in esthetic dentistry. Curr Opin Dent. 1991;1:206-211.

3. Moscone R. Aesthetic restorations through conservative dentistry: composite or ceramics? Pract Periodontics Aesthet Dent. 1994; 6:11-12.

4. Trinkner TF, Rosenthal L. Esthetic restoration of anterior dentition with metal-free restorative material. Compend Contin Educ Dent. 1998;19:1248-1255.

5. Manufacturer information. Ivoclar Vivadent. Amherst, New York.

6. Bertolotti R. “Fifth Quarter Seminars” (Lecture). Pittsburgh, Pa; November 7 and 8, 1997.

7. Vichi A, Ferrari M, Davidson CL. Influence of ceramic and cement thickness on the masking of various types of opaque posts. J Prosthet Dent. 2000;83:412-417.

Dr. Voller maintains a private practice emphasizing aesthetic, restorative, and reconstructive dentistry and orthodontics in Kittanning, Pa. He is a guest lecturer at the University of Pittsburgh and West Virginia Schools of Dental Medicine, and constituent dental societies. He has presented his “Occluso-Bondodontics” lecture series to several audiences. He is also a guest lecturer at the Greater Lakes Institute of Technology in Erie, Pa. He can be reached at (724) 543-4948 or voller@penn.com.