B. O. Olorunfemi, BDS, M Med Sci
College of Dentistry, King Saud University, Riyadh, K.S.A

Ceramic inlays and veneers made on platinum foil produce a smooth fitting surface finish while those made on refractory investment die give a rough fitting surface finish. These ceramic restorations are then bonded to teeth with composite resin cement. This study examined i) the influence of the fitting surface finish on the ceramic/composite resin interfacial bond; and ii) the effect on the bond strength achieved following various ceramic surface treatment methods such as gritblasting, hydrofluoric acid etching and silane priming either as single treatment or in various combinations. Shear bond strength test was used to assess the ceramic/composite interfacial resin bond. The refractory investment die [rough] surface group had higher bond strength than the smooth [polished] surface group although the difference was not statistically significant. The control for the smooth-fitting surface surface group had a mean bond strength of 0.23 megapascals which was lower than that of the control for the rough-fitting surface group which had a mean of 5.23 megapascals. When the polished fitting surface was treated with a combination of gritblasting, hydrofluoric acid etching and silane priming, the mean bond strength was 10.72 megapascals whereas the mean bond strength for the refractory investment die surfaces with a similar treatment was 15,96 megapascals. The bond strength achieved by the above combination was significantly higher than the respective control at p<0.0001. The following bond failures were found: a) adhesive at the ceramic/composite resin interface, b) cohesive within the ceramic and c)a combination of both. Cohesive bond failure within the ceramic made it difficult to differentiate the effect of the different types of surface treatment on the interfacial bond strength.

Saudi Dental Journal 1998;10(1):9-17.