In vitro Study of Canal Microleakage in Relation to Remained Space between Post

The success rate of endodontic treatment is dependent upon many factors among which is fitness of residual apical gutta-percha and post. The purpose of this in vitro study was to determine the effect of the distance between the post and the residual gutta-percha on canal microleakage. In this experimental study, a total of 72 human central maxillary teeth with same size roots were selected. The process of root canal obturation, post space preparation and post cementation was the same for all the teeth.The teeth were divided randomly into three groups of 1-no gap between the gutta-percha and the post, 2-gap of>0 to 2 mm and 3-gap of>2 mm. Posts were cemented by Glass Ionomer and the leakage was determined by dye method. Samples were cut longitudinally and were then observed under the microscope. The results were analyzed by Chi-square tests. There was a significant difference in microleakage between the studied groups. The highest leakage of total surfaces was seen in group with space more than 2 mm between the residual gutta-percha and the post, and the least microleakage was seen in group without any space. The results were singnificant (P<0.001). When the space between post and gutta-percha increases or decreases, the leakage will increase or decrease as well. However, by decreasing this space to zero, the leakage will never be none.