ABSTRACT
Context: Smear layer is a negative factor which prevents adhesion of the filling material to the dentinal walls. Chelating agents are used during cleaning and shaping of the root canals so as to remove the smear layer. Aims: To evaluate the effect of 17%EDTA, 17%EGTA, and 19% CITRIC ACID solutions on microhardness of root canal dentin using Vicker’s Hardness Tester and surface roughness using Computerized Roughness Tester. Settings and Design: Methods and Material: Sixty non carious specimens were divided into four groups and subjected to varied treatments as follows: 1) Group I – 17%EDTA + 5% NaOCl for 150 sec 2) Group II – 17%EGTA + 5% NaOCl for 150 sec 3) Group III – 19% Citric Acid + 5% NaOCl for 150 sec 4)Group IV – Distilled water. Each group was divided into subgroup ‘a’ and ‘b’. ‘a’ group were subjected to microhardness testing and ‘b’ group were subjected to surface roughness. Statistical Analysis Used: Results were subjected to Anova and Tukeys test. Results: Difference in microhardness values was significant between Ia and IIa (p<0.05, 0.029) and groups IIa and IIIa (p-0.001). Citric acid decreased the overall microhardness of the root canal dentin more than other irrigants. EGTA caused minimum reduction in microhardness. Maximum increase in surface roughness was seen in citric acid group and minimum increase in EGTA group. Conclusions: EDTA, EGTA and citric acid drastically reduce the microhardness and increase the surface roughness of radicular dentin. EGTA caused minimum reduction in microhardness and citric acid caused maximum increase in surface roughness.