Silane application is not mandatory for repairing silorane-based resin composite, which can be successfully repaired even with different repair adhesive/materials. However, early signs of nanoleakage can be detected.
SUMMARYObjectives: To investigate the effect of silane primer application, intermediate adhesive agent/repair composite, and storage period on the interfacial microtensile bond strength (lTBS) of repaired silorane-based resin composite compared with unrepaired composites and on the nanoleakage.Methods: Forty-eight 1-month-old substrate specimens from Filtek P90 were roughened, etched, and distributed over two groups (n=24) based on receiving silane (Clearfil Ceramic Primer) or not. Then, half of the specimens (n=12) were repaired with P90 System Adhesive/Filtek P90 and the other half with Adper Scotchbond Multipurpose adhesive/Filtek Z250 resin composite. Within each repair category, repaired specimens were stored in artificial saliva at 378C for either 24 hours (n=6) or two years before being serially sectioned into sticks (0.6 6 0.01 mm 2 ). From each specimen, two sticks were prepared for nanoleakage determination and four sticks were used for lTBS testing. Additional unrepaired specimens from each composite (n=12) were made to determine the cohesive strength at 24 hours and two years. Mean lTBS were calculated and statistically analyzed. Modes of failure were also determined.Results: General linear model analysis revealed no significant effect for the silane priming, intermediate adhesive agent/repair composite, and storage period or for their interactions on the lTBS values of the repaired specimens. There was no significant difference between the cohesive strength of Filtek P90 and Filtek Z250; both were significantly higher