Kenneth N. May

Three-year clinical study of UV-cured composite resins in posterior teeth

Four proprietary composite resins cured with ultraviolet light were inserted into Class I and II cavity preparations. The restorations were evaluated over a 3-year period for color match, interfacial staining, secondary caries, loss of anatomic form, marginal adaptation, and surface texture. The percent of restorations exhibiting no generalized loss of anatomic form ranged from 47% to 93%.

Five-year clinical study of u.v.-polymerized posterior composites

Four u.v.-polymerized composites (Estilux, Nuva-Fil, Nuva-Fil P.A. and Uvio-Fil) were clinically evaluated in Class I and II cavity preparations in permanent teeth. The restorations were evaluated at baseline, 1, 2, 3, 4 and 5 years using USPHS criteria for direct evaluation and at 3, 4 and 5 years using the Leinfelder method for indirect evaluation of wear. The wear measured by the USPHS method showed increasing wear rates in earlier reports, apparently due to the limited sensitivity of the scale to early wear. The wear by the Leinfelder method showed gradually decreasing wear rates. There were no statistically significant differences among the wear values for the four u.v.-cured materials or between these materials and the self-cured and visible light-cured controls.

Burnished amalgam restorations: A two-year clinical evaluation

Bu rnishing amalgam restorations has been a subject of discussion for more than 30 years. Generally, burnishing has been considered detrimental to an amalgam restoration due to a possible mercury enrichment of the surface.‘-” It was speculated that restorations treated in this manner would be more susceptible to corrosion and tarnish and thus exhibit a higher rate of marginal fracture than those finished in a conventional manner. Recently, however, a number of laboratory studies have demonstrated that postcarved burnishing of conventional amalgams does not produce the adverse effects predicted by a number of investigators.4-7 In fact, such a procedure was shown to be responsible for improving a number of physical properties. including increasing surface hardness, reducing porosity and residual mercury, and slowing the rate of corrosion. These findings have been substantiated by at least one clinical study.’ In addition to postcarved burnishing, Kanai5 and Jfirgensen and Saito” have suggested that precarved burnishing enhances the clinical longevity of conventional amalgam restorations. The technique, which consists of overfilling the cavity preparation and burnishing with heavy pressure prior to carving, supposedly causes a reduction in porosity as well as mercury content. It is the purpose of this study to evaluate the clinical performance of conventional amalgam restorations subjected to this technique.