Microleakage of contemporary composite systems in dentin cavities

This study evaluated microleakage in vitro of self-etch and multi-step, total-etch adhesive systems. Ninety extracted non-carious human molars were randomly assigned to nine groups (n=10) and restored with nine different composite systems: Gluma CPS/Charisma, Syntac Sprint/Tetric Ceram, 3M Single Bond/Silux, Admira Bond/Admira, Optibond Solo Plus/Herculite, Trendy Bond/Saremco, Excite/Tetric Ceram, Syntac Sprint/Compoglass and Promt-L-Pop/Silux. Cavities (2 mm diameter/2 mm deep) were prepared on the facial and lingual surfaces of each tooth previously abraded with a silicon-carbide abrasion discs to produce two level dentin surfaces with whole margins in dentin. Each group of composite systems was treated following the manufacturer's instructions. After they were finished and polished, the specimens were subjected to 100 thermal cycles in baths of 4 degrees +/- 2 degrees C and 58 degrees +/- 2 degrees C with 60 seconds of dwell time for each bath. After the thermocycling, the specimens were sealed with acid-resistant varnish, leaving a 1-mm window around the cervical margin interface, and immersed in 1% methylene blue buffered solution for 4 hours. Then the specimens were sectioned longitudinally in half and evaluated under stereomicroscopy at 30 times magnification, using inserted millimeter measurer. Each specimen was measured for dye penetration, thickness of composite filling and distance from the bottom ofcavity to the pulp chamber. The data were analyzed using Kruskal-Wallis Analysis of Variance (ANOVA) and Pearson t- test. Syntac Sprint/Tetric Ceram, 3M Single Bond/Silux, Admira Bond/Admira, Optibond Solo Plus/Herculite and Gluma CPS/Charisma showed the least microleakage at the occlusal part of the cavity. There was no significant difference of microleakage at gingival part of cavity for all tested composite systems and the best sealing ability showed 3M Single Bond/Silux. Self-etch and multi-step, total-etch adhesive systems showed more or less similar microleakage "in vitro" conditions and marginal sealing ability of all tested composite systems was significantly lower at gingival margins of cavities.