Retention of zirconia ceramic copings bonded to titanium abutments

PURPOSE: The aim of this study was to evaluate the effect of 2 surface conditioning methods and 2 luting-gap sizes on the retention and durability of zirconia ceramic copings bonded to titanium abutments. MATERIALS AND METHODS: Zirconia ceramic copings (Camlog Biotechnologies, Winsheim, Germany) with a luting-gap size of either 30 microm or 60 microm were bonded to titanium abutments (Camlog Biotechnologies) using the composite resin cement Panavia F (Kuraray, Osaka, Japan). The bonding surfaces of the zirconia ceramic copings were either (a) pretreated with airborne particle abrasion and cleaned with alcohol or (b) just cleaned with alcohol, whereas the bonding surfaces of all titanium abutments had been abraded and cleaned. After the specimens had been stressed for either 1, 30, 60, or 150 days by water and thermal cycling, retention was measured. RESULTS: The surface conditioning method, luting-gap size, and storage time significantly (P = .001; 3-way analysis of variance ANOVA]) influenced retention. Air abrasion increased the retention significantly. Failure modes were predominantly adhesive. Air-abraded copings bonded with 30-microm luting gap achieved significantly greater retention than those bonded with a 60-microm luting gap. CONCLUSION: Surface conditioning methods and the size of the luting gap have a significant influence on the retention of Camlog zirconia ceramic copings bonded to Camlog titanium abutments.