ABSTRACT
There has always bee a concern about the easiness, durability and costs of filling in teeth which are extremely decayed. Different restorative methods such as use of Pre Fubricated Post with Amalgam Core, composite and FRC Post have been considered but the most common one is use of melted post core. Retention of the post is influenced by different factors such as length, width, shape of post and the type of cement. Another important retentive factor is the procedure of the post cementing. The aim of this study was to compare cast post retention of three different cementing methods. In this invitro experimental study, 40 central incisors were selected. After preparing and making the posts, the teeth were randomly divided into three groups of ten as A, B and C. The cement which was used was glass lonomer [GC Fuji I] mixed according to the manufacturer's instructions and was used in three ways: Group A; cement was placed in the canal with lentulo. Group B: cement was injected into the canal. Group C: first it was injected followed by use of lentulo. In order to keep the cemented teeth out of humidity, vaseline was applied. Finally, after 72 hours, the tensile stress at the speed of 1mm per minute was applied. Tukey test, Kruskal Wallis test and one way ANOVA were used for data analysis. The maximum strength was observed in group C [in jection+lentulo] in which 90% of the samples had more than 50kg tensile strength. The minimum strength was observed in group A [Lentulo placed cement] in which 10% of the samples had more than 50kg tensile strength [P<0.05]. 1] The procedure and method of cementation of the post had greeted role in retention of it. 2] The best way of cementing post was injection followed by lentulo use