Effects of Different Root Canal Preparation on Microleakage with Self-adhesive System

Abstract：Objective:By comparing the root canal preparation methods to study the microleakage between the root cannal wall and self-adhesive cement, providing the basis for the clinical application.Method:A total of 40 second premolars in mandibular which had simple root canal with similar shape and size were selected.The teeth were randomly divided into experimental group A(K file group) and B(Ni-Ti group),15 pieces in each group.The control group(positive control) C and D(negative group) had five pieces in each group.Root canal filling after different root canal preparations,and then used RelyX Unicem cement to bond the fiber to the root canal.After Hot and cold cycle in India ink stained in 1 week,observing the depth of dye penetration under the stereoscopic microscope.Result:The depth of dye penetration of two groups compared,there was statistically significant between the two groups(P<0.05).The depths of dying penetration in group A was longer than group B.The microleakage of group C was obviously.Group D had no microleakage happen.Conclusion:Under the condition of Hot and Cold cycle,the microleakage between root and cement after root canal preparation with K file was obviously worse than with Ni-Ti group.