EFFECT OF IRRIGATION SOLUTIONS ON FRACTURE RESISTANCE OF ENDODONTICALLY TREATED MOLARS

Purpose: to evaluate the effect of sodium hypochlorite (naocl) and ethylenediamine tetraacidic acid (edta) irrigation on fracture resistance of endodontically treated. materials and methods: extracted fifty human third molar were selected for this study mod cavities were prepared. after removing of pulpal floor endodontic accesses were done and the teeth were randomly divided into five groups according to the irrigations (n=10) as follows: g1: irrigation with only distilled water, g2: irrigation with 1 min 5 ml 17% edta followed by 1 min 5 ml 5,25% naocl, g3: irrigation with 1 min 5 ml 17% edta followed by 10 min 5 ml 5,25% naocl, g4: irrigation with 10 min 5 ml 17% edta followed by 1 min 5 ml 5,25% naocl, g5: irrigation with 10 min 5 ml 17% edta followed by 10 min 5 ml 5,25% naocl. the teeth were restorated with a microhybrid composite resin and specimens subjected to a compressive fracture test in a universal testing machine. the failure modes were analyzed and sem photograph were taken for each groups. results: the fracture strengths values were range between 132,76 and 149, 57 newtons. the highest fracture strength values were shown in g1, also the lower values were obtained in g5; whilst there was not any statistically difference in working groups. the failure mode analyses showed that there were unrestorable cracks in g4 and g5. conclusion: the naocl and edta combinations in short exposure times did not effect the fracture resistance strength, although, fracture modes were unrestorable.