Methods: One hundred and five extracted mandibular incisor teeth were used. The crowns of the teeth were removed and the roots were seperated longitudinally in a mesiodistal direction to produce a total of 210 specimens. The specimens were embedded in auto polymerizing acrylic resin and were grounded flat with silicon carbide abrasive papers (to #2000-grit). The specimens were randomly divided into seven groups of 30 teeth each according to the irrigation solutions used: pomegranate vinegar, apple vinegar, grape vinegar, octenidine-hydrochloride, 2.5% sodium hypochlorite, 2% chlorhexidine gluconate and control group (distilled water). All groups were then divided into two subgroups of 15 specimens each. The specimens in first subgroup were treated with each irrigation solution for 15 minutes whereas the second subgroup for 30 minutes. Each specimen was first subjected to surface roughness and then Vicker’s microhardness testing. The data were analysed using two-way ANOVA and Tukey tests.
Results: Significant differences were observed in roughness among the test groups. Pomegranate vinegar, apple vinegar and grape vinegar were similar to each other (P>0.05) and presented higher results. There was no statististically significant difference between irrigant groups when microhardness values evaluated (P>0.05). Application time had an effect on microhardness and decrease when exposure time increase from 15 min to 30 min (P<0.05).
Conclusions: The use of vinegar for endodontic irrigation may have softening effect on root canal dentin with time and may increase dentin roughness.