Reparability of two different CAD/CAM polymer materials using a light-cured composite and universal adhesives

Abstract Objective To evaluate the reparability of CAD/CAM polymer materials with universal adhesive systems. Methods Eighty blocks of polymethyl methacrylate (PMMA) and eighty blocks of polyoxymethylene (POM) were milled by the manufacturer (7 mm of diameter and 4 mm height). The top surface of all specimens was abraded with 50 μm Al 2 O 3 . The 80 specimens of each material were randomly allocated to four experimental groups ( n  = 20) according to the adhesive system used: OptiBond XTR, Futurabond M+, Scotchbond Universal or OptiBond Solo Plus. Each adhesive and the repairing composite resin (GrandioSO) were applied according the manufacturer's instructions. Specimens were stored in distilled water at 37 °C for 48 h and submitted to shear bond strength (SBS) tests. Fracture surfaces were observed and classified as: adhesive, cohesive or mixed type. SBS data were analysed with 2-way ANOVA and Kruskal–Wallis and Mann–Whitney tests were used to failure mode data ( α  = 0.05). Results The mean SBS yielded with PMMA specimens was significantly ( p p  = 0.062) differences between adhesive systems. Statistically significant ( p p  = 0.925) differences in failure mode were identified between adhesives. Conclusion It is possible to achieve an adequate adhesion bond to POM and PMMA. SBS values were higher in PMMA specimens than to POM but no differences were found between adhesive systems.