Development Of Resin-Porcelain MixturesOne of the technological benefits of the "space race" in the 1960's was the development of light weight but highly durable composite (resin-porcelain mixtures) materials. These composites rapidly expanded into different uses and found their way into all industries, including dental materials. Hence, tooth-colored composite "bonding" materials became highly popular. These resin based materials had some drawbacks--tendency to wear, chip and stain, and better techniques were sought.
Introduction of VeneersIn 1982, my in-house porcelain technician and I developed a technique for fabricating veneers for teeth out of porcelain, instead of composite, made on porcelain foil. The interior of the porcelain veneer could be acid-etched and then bonded to a tooth. I described the technique in presentations to the Pacific Coast Society of Prosthodontics in 1983 and to the California Dental Association Annual Meeting yearly from 1983 to 1987. In 1999, I presented a 15-year retrospective on porcelain veneers to the CDA meeting, and reported an overall 15 year success rate of 97%.
Combining Veneers With CrownsAs with any technique, success leads the procedure to be used in more demanding situations. One of these often advertised is the use of veneers in combination with crown lengthening, to create longer teeth and eliminate a "gummy smile." These veneers inevitably have margins (edges of the veneers) on root surfaces or dentin, instead of enamel. A recent report in the JADA Specialty Scan quotes a scientific study which shows failure rates of veneers bonded to dentin to be 10.3 times higher than those bonded to enamel, and also a high increased risk of failure associated with crown lengthening, with the most frequent failure type being fracture.
Robert G. Tupac, DDS, FACP, Inc., Diplomate, American Board of Prosthodontics (661) 325-1275 | www.drtupac.com 5060 California Ave., #170, Bakersfield, CA 93309