Influence of endodontic materials on the bonding of composite resin to dentin

We assessed the bond strength of a composite resin to dentin that had been in contact with different materials. Flat dentin surfaces in freshly extracted human teeth were covered for 15 min or 48 h with a 1-mm layer of a variety of materials. The products were mechanically removed and a composite resin cylindrical specimen bonded to the dentin surface using the Prisma universal bond system. After 7 days immersion at 37 degrees C in water, the tensile bond strength was tested. The results were compared with those on dentin surfaces not in contact with any endodontic material. Statistical analysis showed that some materials (Grossmans Cement, IRM, Maisto's slowly resorbable paste) reduced the strength of the bond or even precluded bonding. It is necessary to develop techniques that will eliminate this when restoring endodontically treated teeth.