evaluation of microleakage and biocompatibility of universal adhesive containing titanium dioxide nanoparticles: a comparative in vitro study

Background & objective: although dental composites have undergone a high level of development in recent years, there are still difficulties including microleakage. the incorporation of nanoparticles (nps) in dental materials can produce antibacterial effects, but the effect of tio_2 nps on microleakage has not yet been investigated. the present study aimed to determine the effect of tio_2 nps incorporation in the universal single bond and pretreatment with them on microleakage of clv cavities using both total-etch and self-etch approaches. materials & methods: standard clv cavities were prepared on the buccal surfaces of the sixty non- carious human molar teeth. the restoration of samples was carried out with 6 different methods and randomly divided into six groups of ten subjects. microleakage in both gingival and occlusal margins was determined after placement in 2% basic fuschin solution for 24h. biocompatibility of a universal single bond was evaluated by mtt assay. results: in both occlusal and gingival margins in all groups, the application of tio_2 nps was better than no application. we observed the relatively low cytotoxic effect of tio_2 nps incorporated in the universal adhesive on nih-3t3 cell viability. conclusion: regarding the limitations of the present investigation, using tio_2 nps with both total-etch and self-etch approaches to universal single bond may lead to a decrease in the microleakage of resin composite restorations.