Method: Extracted 120 human central insicors were separated 1 mm under cemento-enamel junction. Teeth were grouped 10 different groups randomly. All of these groups prepared until F3 file (Protaper Rotary System). At the groups 5 and 10 were irrigated with distile water, other groups were irrigated with 2 cc EDTA, 2 cc NaOCl, 2 cc distile water and 2 cc chlorohexidine respectively. After irrigation procedures, no temporary root sealers were applied at the groups 4,5,9 and 10. % 45 CaOH were applied at the groups 1 and 6 (Metapex), % 95 CaOH were applied at the groups 2 and 7 (Kalsin), % 30 CaOH were applied at the groups 3 and 8 (Calcicur). All access cavities were sealed with glass ionomer cement.Groups 1 to 5 were stored at 72 hours 37°C and Groups 6 to 10 were stored at 2 weeks 37°C. 50 µ, 100 µ and 250 µ measurement made with universal microVickers testing machine. Data was analyzed with ANOVA Tukey’s LSD and Duncan tests.
Result: No significant differences were observed between Group 1 and 2 at the 50 µ. On the other hand, group 3 showed significant differences with Group 1 and 2 at the same. At the groups 6 to 10, all of these groups have shown significant differences at all distances. Negative control groups showed higher values than other groups.
Conclusion: Endodontic treatments have negative effects on root canal dentin microhardness. This study has shown that irrigation canal sealers and temporary root sealers and its impact on dentin microhardness is limited in a little area.