shear bond strength of composite-resin to porcelain: effect of thermocycling

objective: different ceramic repair systems have been reported for fractured ceramics. however, limited information is available concerning the bond strength of these systems especially after thermocycling. the aim of this in-vitro study was to determine the effect of thermocycling on the shear bond strength of composite-resin to feldspathic porcelain with and without silane pretreatment. materials and methods: in this experimental study, forty porcelain blocks were prepared and randomly divided into four groups (n=10). all porcelain surfaces were etched with 9.6% hydrofluoric acid, rinsed and air dried. in groups 1 and 3, silane pretreatment was applied using adper scotchbond multipurpose plus (asmp). small-particle composite-resin was subsequently added on the ceramic surfaces, and light-cured. specimens of groups 3 and 4 then subjected to 1000 thermal cycles. shear bond strength was determined on a universal testing machine at a crosshead speed of 1mm/min. two-way anova test (a=0.05) was used to analyze the bond strength. results: there were statistically significant differences between study groups (p<0.05). thermocycling caused a decrease in the shear bond strength for both silanized and non-silanized groups. conclusion: according to the results of this study, shear bond strength after thermocy-cling reduced considerably in asmp system. in addition, silane treatment of porcelain was critical for achieving durable bond strength between composite-resin and porcelain.