11 COMPARATIVE EVALUATION

Aims And Objectives: To compare calcium ion, hydroxyl ion release and pH levels between nano calcium hydroxide and other calcium hydroxide based intracanal medicaments in vitro. Materials And Methods: Calcium hydroxide based substances were divided into six groups (n=5): Group A (Calcium hydroxide powder with distilled water), Group B (Nano calcium hydroxide powder with distilled water), Group C (Vitapex), Group D (RC Cal), Group E (Dentocal) & Group F (Calcium hydroxide points). For determining the particle morphology of different calcium hydroxide products, TEM technique was used. 30 polyethylene cylindrical tubes were taken, one end of which was sealed with temporary material and filled with the materials of each group. Tubes were then immersed in separate calibrated beakers, each with 10 ml of distilled water. For each group, 5 samples were analyzed after 0, 10, and 20 minutes; and after 1, 2, 24 and 48 hours, 1 week and 1 month. The pH value was measured by calibrated pH meter. Ion liberation was measured by an ICP-atomic emission spectrometry. Statistical analysis was done by ANOVA and Tukey's post hoc tests. Results: Group B had the lowest particle size. According to calcium ion and hydroxyl ion liberation, RC Cal was better and according to pH value, Dentocal was better than other groups. Conclusion: Aqueous based preparations of calcium hydroxide should be chosen over points or oil-based calcium hydroxide preparations. 1 2 3 4 5 Sonali, Garg Amit Kumar, Paul Rohit, Hans Manoj, Nagpal Ajay Department of Conservative Dentistry and Endodontics K. D. Dental College and Hospital, Mathura INTRODUCTION: Calcium hydroxide, widely used in endodontics is a strong alkaline substance having pH nearly 12.5. It dissociates into calcium and hydroxyl ions in aqueous medium. Antimicrobial activity, inhibition of tooth resorption and induction of repair by hard tissue formation are its biological properties. (1-3) That's why it has been recommended for use in several clinical situations. (4) Release of hydroxyl ions as highly oxidant free radicals show extreme reactivity with several biomolecules. (5) The microorganisms penetrate into infected dentin tubules from 50 to 100 ìm depth. (6) The application of calcium hydroxide into instrumented and irrigated root canals eliminates microorganisms effectively is known. (7) Due to buffering capacity of hydroxyapatite selective permeability of the hydroxide ions in the dentin tubules is there. (8) Because of a high local pH particles inserted into the open dentin tubules may act as a direct source of dissociated calcium hydroxide which dissolve continuously in aqueous form, enhancing antimicrobial effectiveness. (9) Nano-particles are microscopic particles of less than 100 nm which are different in properties such as active surface area, chemical and biological reactivity. (10) They are getting popular in dentistry and medicine as antibacterial agents. The higher surface to volume ratio and charge density results in their greater interaction with the environment and thus causes a higher antibacterial activity. (11) So this study was done to find out the effect of nano-particles & other calcium hydroxide based intracanal medicaments on the release of calcium & hydroxyl ions and on pH levels. COMPARATIVE EVALUATION OF CALCIUM ION, HYDROXYL ION RELEASE AND PH LEVELS BETWEEN NANO CALCIUM HYDROXIDE AND OTHER CALCIUM HYDROXIDE BASED INTRACANAL MEDICAMENTS : AN IN VITRO STUDY