Microleakage of endodontic access cavities restored with composites

A proper seal of restorative composites in endodontic access cavities is mandatory to prevent ingress of microorganisms and debris into the tooth-restoration interface. Chemically cured composites tend to have less polymerization shrinkage than photopolymerization composites. This study compared in vitro sealing performance of a chemically cured and a photopolymerization composite for access cavity restorations in endodontically treated teeth. In addition, the effects of four dentin pretreatments on the seal were evaluated. One hundred twenty-eight roots of extracted human incisors were cleansed, shaped and obturated with gutta percha and Grossman's sealer. The endodontic access cavities were later treated by Scotchbond Multipurpose, All-Bond 2, Vitrebond and Ketac-Bond. Half the access cavities within each group were filled by Coltene Microhybrid H.P., a chemically cured microhybrid composite. The other half were filled with Aelitfil, a photopolymerized composite. The filled teeth were thermocycled, submerged in silver nitrate solution, sectioned longitudinally, and their dye penetration measured and statistically analyzed by two-way ANOVA at 95 percent confidence level. The results show that the chemically cured composite allowed less dye penetration than the photopolymerized composite. As for the dentin pretreatments, the Scotchbond Multipurpose and All-Bond 2 exhibited less microleakage than Vitrebond and Ketac-Bond for both chemical and photopolymerized composite. Ketac-Bond allowed the highest amount of dye penetration, followed by Vitrebond, Scotchbond Multipurpose, then All-Bond, which had the least depth of microleakage. Chemically cured composites bonded with All-Bond 2 and Scotchbond Multipurpose may exhibit less microleakage than photopolymerized composites in endodontic access cavity restoration.