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 to remove the smear layer.
Aims: To evaluate the effect of 17% EDTA, 19 % citric acid and 7 % malic acid solutions on microhardness and surface roughness of root canal dentin.
Materials and Methods: Eighty root halves of single-rooted teeth were divided into four groups (20 specimen for each) and subjected to different chemical treatments as follows: Group I – 17 % EDTA, Group II – 19 % citric acid, Group III – 7 % malic acid and Group IV - Saline as a control group. Each group was divided into two subgroup ‘a' and ‘b' (10 specimen for each). ‘a' group were subjected to microhardness testing and ‘b' group were subjected to surface roughness testing.
Statistical Analysis Used: Results were subjected to One-way ANOVA and Tukey's test.
Results: Difference in microhardness values was significant among all investigated groups. Malic acid decreased the overall microhardness of the root canal dentin more than other irrigants. Citric acid caused minimum reduction in microhardness. Maximum increase in surface roughness was seen in malic acid group and minimum increase in EDTA group.
Conclusions: Malic acid, EDTA and citric acid drastically reduce the microhardness and increase the surface roughness of radicular dentin. Citric acid caused minimum reduction in microhardness and malic acid caused maximum increase in surface roughness.