Effect of Treatment on Roughness and Bond Strength of Ceramics

Objectives:The aim of this study was to evaluate the influence of different surface treatments ( Air abraded, Acid etching, Lased) on the surface roughness and bond strength of a low fusing ceramic. Methods:Thirty six discs of low fusing ceramic (Finesse, Ceramco) were prepared (10 mm in diameter and 2 mm in thickness) according to the manifacturer's instructions. Specimens were divided into 3 groups (n =12), and the following treatments were performed: airborne-particle abraded with alumina particles (50 ìm), acid etched with 5% HCl and Nd:YAG laser irradiation (distance: 1mm, 100mJ, 20Hz, 2W, and 141.54J/cm2). Following surface roughness (Ra) determination by profilometry, specimens were examined by scanning electron microscopy. Within groups specimens were bonded in to pairs with composite luting cement (Clearfil Esthetic Cement). After 48 h of water storage, shear bond strength test was performed using a universal testing machine at a crosshead speed of 1 mm/min. The data were analyzed with 2 way analysis of variance (ANOVA) and Tukey HSD tests (á = 0.05). Results:Two-way ANOVA indicated that surface roughness was significantly affected by surface treatments (P<.001). Tukey honestly significant difference (HSD) indicated that the air abraded group had a significantly higher mean (P<.05) than the other groups. Shear bond strength was significantly affected by surface treatments (P<.001). Tukey HSD indicated that the air abraded group had a significantly higher mean (P<.05) than the other groups. No statistically significant differences were found between the acid etching and lased groups (P>.05). Conclusions:Airborne-particle-abrasion of low-fusing porcelain surfaces was effective in improving the bond strength, as compared to the laser etching and acid-etching method.