دراسة مقارنة لفتح الحجرة اللبية في الارحاء الموقتة بالسنبلة المخروطية محمية الراس والسنابل الكروية

ackground & Objective: The endodontic access is an important process of any endodontic treatment in primary molars. There is no agreement about the best and fastest method of endodontic access in primary molars. This study aimed to compare between three ways and burs of preparing access cavity in primary molars for quality and working time. Methods & Materials: Sixty extracted primary molars (34 upper, 26 lower) with good pulp chamber floor were used in this study, divided randomly to three groups of 20 molars each. A round bur on low speed handpiece was used in first group, in second group a round diamond bur on high speed handpiece was used, and in third group a safe-end tapered diamond bur was used. Each prepared tooth was examined to check unroofing, over preparation, the pulp chamber floor, wall smoothness and working time. Pearson Chi-Square and Kruskal Wallis tests were used. Results: All methods were safe on pulp chamber floor and over preparation, but the safe-end tapered diamond bur was superior in unroofing and wall smoothness (Pearson Chi-Square P<0.05), and was the fastest. (Kruskal Wallis test P<0.05). Conclusion: The use of the safe-end tapered diamond bur is the best in access cavity preparation of primary molar