Global Health Nexus, Millennium Issue

Clinical Research in Aesthetic Restoration of Teeth
at New York University College of Dentistry

John R. Calamia, D.M.D.
Professor of Restorative and Prosthodontic Sciences (Operative Dentistry); Director of Research and Aesthetic Restoration (Division of Restorative and Prosthodontic Sciences)

Etched Porcelain Restorations

The etched porcelain veneer restoration has proven to be an exceptionally durable and highly aesthetic treatment modality. The original research, which began in June 1982 at New York University College of Dentistry NYU Dentistry, provided a simple, barely invasive technique using a glazed porcelain final restoration that not only could change the facial appearance of worn or broken teeth but also had a surrounding tissue response that proved to be exquisite both initially and over the long term. This is exhibited in Figures 1 through 4. Figure 1 shows a case of Amelogenesis imperfecta that was treated in October 1983. Figure 2 shows the six-month recall. Figures 3 and 4 show incisal and facial views of the 14-year recall.

Research at New York University continued to focus on the strength of porcelain bonded to composite as well as bond strengths attained with different concentrations of hydrofluoric acid (the acid used to etch the porcelain). The types of porcelains, and the use of silane couplers to aid the bond between porcelain and composite, were also studied. Thousands of restorations have been placed at NYU Dentistry, with indications running the gamut from diastema closure (Figures 5 and 6) to replacement of missing tooth structure and masking of stains of fluorosis (Figures 7 and 8). It has became abundantly clear over the past 17 years that, because of an almost negligible fracture rate and more than acceptable periodontal response, the etched porcelain laminate veneer is a conservative, predictable, and extremely successful treatment modality. The use of porcelain veneer restorations to restore worn and discolored enamel, shallow, extensive hypocalcifications, and even single discolored teeth is now the rule rather than the exception. During the initial phase of this research and development, predoctoral students assisted the faculty on many cases. Ultimately, the body of knowledge that evolved was incorporated into lectures and finally into our laboratory and clinical curriculum. By allowing students to see firsthand the marriage between research and clinical practice, this process has helped to enrich the dental education program at NYU.

Today, because of the combination of new adhesive technology allowing for strong bonds to dentin as well as enamel and the development of high-strength ceramics, it is not unusual to provide a patient with maximum functional and aesthetic results with minimal invasive preparation using all ceramic restorations. This is demonstrated in Figures 9 through 12. Figure 9 is a preoperative photo of a patient with a chief complaint of poorly shaped canines, a fractured lingual surface of tooth #8, short lateral incisor #7, and multicolored front teeth. A poorly designed, acid-etch-retained bridge had been removed and is replaced with an all-ceramic bridge of #s 6, 7, and 8 and porcelain veneers #s 9, 10, and 11, as shown in Figure 10. A final incisal and facial view of all the ceramic restorations is shown in Figures 11 and 12.

The College's Division of Restorative and Prosthodontic Sciences takes pride in being on the cutting edge of restorative technology. Currently the division is conducting clinical trials within the areas of computer-aided design and computer-aided manufactured (CAD/CAM) restorations (Figure 13). This has required the training of some full-time and part-time faculty who are offering this treatment modality to selected patients. This core group of faculty, including Dr. Steven David, Dr. Denise Estafan, and the author, has been allocated time to place these restorations and to demonstrate technique to small groups of students with the help of intraoral cameras (Figure 14). Once again, our students have been encouraged to assist with this project, and they are offered lectures and seminars on the results of these clinical cases.

New York University is one of only a handful of schools in the United States that uses this technology in the predoctoral program. Based on its clinical success to date and the future availability of budgetary resources, it is predictable that the use of this technology will expand at NYU and that it will play an expanded role in the predoctoral curriculum. In addition NYU dental students currently are being exposed to the FDA-approved, hard-tissue laser and its possible applications to restorative dentistry (Figure 15).

NYU Dentistry is proud of its clinical research history in the area of aesthetic restoration of teeth and looks forward to continuing to provide our predoctoral students with the most up-to-date technology available.