Methods: Thirty-six extracted premolars were sectioned buccolingually and 72 root halves were randomly divided into two groups according to the sealer (experimental sealer MSR-M200-2 and AH Plus). The cut surfaces were ground with 800 grit emery paper. Three-mm high build-ups with a constant surface area of 3.45 mm2 were created using the sealers and allowed to set (37ºC, 100% humid, 72 hrs). The samples were tested to failure for shear bond strength (1 mm/minute). The cut surfaces were re-ground and subjected to %5,25 NaOCl for 5 minute. Three subgroups were created according to the final irrigation protocol as follows (n=12): 10% Boric acid, 17% EDTA and 10% Citric acid for one minute. Shear bond strength study protocol was repeated. The data was calculated (MPa) and analyzed using paired samples t-test.
Results: AH Plus showed higher bond strength than MSR-M200-2 before or after irrigation regimen. 10% Boric acid, 17% EDTA and 10% Citric acid use as final irrigation increased shear bond strength of MSR-M200-2 (p<0.05). The failure analysis showed that experimental sealer MSR-M200-2 showed mostly cohesive failure within the sealer.
Conclusions: Chelating agents have an effect on shear bond strength of the tested sealers. MSR-M200-2 showed lower shear-bond strength than AH Plus and the percentage of the cohesive failures were higher than AH Plus.