Evaluation of Shear Bond Strength of Compomer Repaired with Different Protocols

Objectives: This study aimed to comparatively assess the bond strengths of the repaired compomer samples using different repair protocols under in-vitro conditions. Materials and Methods: 60 compomer specimens were prepared with the dimensions of 10×2.5×2 mm3 using metal moulds. The prepared samples were thermocycled for 5000 cycles, between 5-55 °C with 30 seconds dwell time. Samples were then randomly assigned to 3 different repair protocol groups as universal adhesive (Group 1- Prime&Bond® Universal), 2 step total etch system (Group 2- 35% Scotchbond Universal OF Acid+Prime&- Bond® Universal) and silane coupling agent (Group 3- Monobond Plus+Prime&Bond® Universal). For each group, the specimens were re-placed in a 20×2.5×2 mm3 mould and repair surface was subjected to the relevant repair protocol. Compomer restorative was placed to the remaining area of the moulds, polymerised and finished. Shear bond strength testing was performed using a universal testing machine. Obtained data were analyzed with Anova and Tukey’s HSD tests. The statistical significance level was considered as 5%. Results: Samples in Group 3 presented higher repair bond strength values with a statistically significant difference compared to Group 1 and Group 2 (p=0.000 and p=0.005, respectively). However, no statistical significant difference was found between Group 1 and Group 2 (p=0.639). Conclusions: The use of silane in the repair of compomer restorations can be recommended as an alternative to traditional repair methods.