No abstract

SUMMARYThis study evaluated the bond strength of resin composite to dentin, mediated by a self-etching adhesive, following the application of various dentin desensitizing treatments and artificial saliva storage.The buccal cervical areas of 24 extracted human third molars were ground flat to expose cervical dentin. The dentin surfaces were polished with 1200-grit SiC paper, then the teeth were randomly assigned to six groups, five desensitizing treatments and one control: Group I-VivaSens; Group II-Fluor Protector; Group III-Isodan; Group IV-Futura Bond NR; Group V-Nd:YAG laser and Group VI-Control (without application of a desensitizing agent). After applying the desensitizing treatments and storing the molars in artificial saliva for 14 days at 37°C, Futura Bond NR was used to bond resin composite to dentin. TPH composite build-ups were constructed incrementally to a height of 5 mm. The teeth were sectioned to obtain bonded slices of 0.7 mm thick specimens containing the resincomposite joint. The specimens were then trimmed into an hourglass shape and sub- Clinical RelevanceDesensitizing treatments, except for self-etching adhesives, might have an adverse effect on the bond strength of a resin composite to dentin mediated by a self-etching primer. Therefore, it might be important for clinicians to evaluate previous desensitizing treatments.sequently subjected to microtensile testing at a crosshead speed of 1 mm/minute. The data were analyzed using the Kruskal-Wallis analysis and multiple comparisons test.The control (Group VI) and Futura Bond NR self-etching treatment (Group IV) group yielded statistically significant higher bond strength values than the other desensitizing treatment groups tested (p<0.005). While pretreatment of dentin surfaces with desensitizing agents (Fluor Protector, VivaSens and Isodan) and laser (Nd:YAG) reduced the bond strength values of the resin composite, higher bond strengths were achieved using a self-etching adhesive (Futura Bond NR) as a desensitizing agent.

The purpose of this study was to examine the effect of thermal cycling on microleakage of a fissure sealant after it was bonded with different bonding agents and polymerized with different light curing units. To this end, two bonding agents Xeno III, iBond , three light curing units Astralis 3, Elipar free-light, Elipar free-light 2 , and a fissure sealant Fissurit FX were used. Microleakage was then evaluated using a dye penetration method after thermal cycling. When the fissure sealant was polymerized with Elipar free-light and Elipar free-light 2, microleakage at 10,000 cycles was significantly increased compared with that at 5,000 cycles. In terms of comparison among the curing units, the best microleakage score was observed with Astralis 3 p 0.05 . In terms of comparison between the two bonding agents, no significant differences in microleakage score were observed p 0.05 . Further, it was concluded that in order to evaluate microleakage scores appropriately, it was necessary for specimens to be subjected to thermocycling of 10,000 times or more.