Method: Sixty human third molar dentin surfaces were exposed and the teeth were randomly divided into four groups. Each group has different irrigation protocols; Group 1, 5.25% NaOCl + 17% EDTA; Group 2, 5.25% NaOCl + 0.02% Chitosan; Group 3, 5.25% NaOCl + 17% EDTA+ 2% CHX; Group 4, 5.25% NaOCl + 0.02% Chitosan + 2% CHX (3 minutes for each solution). All groups were performed with SE Bond (Kuraray). Followed by the bonding procedure, 2 mm height and 4 mm in diameter composite resin block with Clearfil Majesty ( Kuraray) was built on the substrate. After 24 hours, shear bond strength was tested with micro-shear ( Bisco) test machine with a crosshead speed of 0,5 mm/min. Data were analyzed using Kruskal-Wallis and Dunnet tests (P=0.05).
Result: Combination of EDTA and CHX group showed significantly higher shear bond strength values than the other groups (P<0.05). No significant difference in shear bond strength was found in EDTA used alone or Chitosan groups when used with or without CHX.
Conclusion: This study concludes that using of CHX with EDTA increases the shear bond strength whereas groups irrigated with combination of CHX and Chitosan can not alter the bond strength of a self-etch system to dentin.