بررسي تغييرات PH و انتشار يون كلسيم در عاج ريشه دندان در موارد استفاده از هيدروكسيد كلسيم بعنوان داروي پانسمان داخل كانال

PH Changes and Calcium Ion Diffusion from Calcium Hydroxide Intracanal Medication through Root Dentin

Aim: Considering that the use of intracanal medicaments in teeth with necrotic pulp, periapical lesion, or exudating canals is evident, this study was performed to evaluate the ca ++ and OH- diffusion through root dentin using calcium hydroxide paste as intracanal dressing. Method & Materials: 52 single - rooted teeth were selected. The canals were enlarged to size 60 master apical file and flared to size 110. External defects were created on the corona) one- third of the root surface. 17%EDTA and 5% sodium hypochlorite were used to eliminate the smear layer. Ali surfaces except the external defects were sealed and the teeth were placed in normal saline. Ten teeth were selected as the control group and after three days, ca+2 concentrations and the pH in the saline were determined. 42 remaining teeth were divided to three groups with 14 teeth in each one (A, B, C groups). Calcium hydroxide powder and distilled water were mixed to make calcium hydro>ide paste. This paste was placed in root. canal of 42 teeth. Ca++ concentration and pH of normal saline were determined after 24 hours in group A, after 48 hours in group B and after one week in group C. Results: The ca++ concentration and pH in all three groups (A, B and C) were significantly different from control group. The most ca++ release and pH was seen in group C that was significantly different from groups A and B. Conclusion: In order to gain the maximum effect of calcium hydroxide as an intracanal dressing it is recommended to be used for 1 week.