Comparative Evaluation of the Effect of Two Chelating Agents on Dentin-root Microhardness: An In-vitro Pilot Study

To compare the chelation effect on dentin-root microhardness and surface topography between 17% Ethylenediaminetetraacetic acid (EDTA), a commonly used chelating agent, and a potential chelating agent 25% copolymer of acrylic acid and maleic acid (Poly (AA-co-MA). Eleven extracted, well-preserved maxillary incisors were used. After the routine procedure of endodontic instrumentation, the roots were longitudinally split, dividing them into two halves. The samples were randomly divided into three groups of seven each (n=7). Group one was subjected to 17% EDTA. Group two was subjected to 25% Poly (AA-co-MA). Group 3 was used as a control group and treated only with saline. The chelating agents and saline were applied in a standardized method. The microhardness was evaluated using the Vickers Hardness test which was applied in three different spots on every half tooth. The surface topography was evaluated under Scanning Electronic Microscope. Paired t-test and Post Hoc tests with analysis of variance (ANOVA) were used to estimate the impact of the chelating agents on the dentin-root microhardness and to compare the two agents. A significant difference in the microhardness was observed within Group 1 and Group 2 (before/after) (p<0.05), but no significant difference was seen between Groups 1 and 2 (p>0.05). A scanning electron microscope revealed the clear impact of EDTA and Poly (AA-co-MA) in the removal of the smear layer compared with saline. Within the limitations of this study, it is concluded that 25% Poly (AA-co-MA) can be used as a chelating agent. It has an equal effect to 17% Ethylenediaminetetraacetic acid (EDTA) in reducing the dentin-root microhardness.