In Vitro Evaluation of Push-out Bond Strength of Mineral Trioxide Aggregate at Middle third of the Root after One Week and 1and 2 Months

Several materials are used for retrograde treatment and perforations repair. Mineral trioxide aggregate has been widely used as a promising biomaterial to repair root perforations because of its excellent biocompatibility, high sealing abilities, ability to set in the presence of blood and induction of dentin, bone and cement. The aim of this study was to evaluate the push-out strength of MTA-dentin in the middle third of the root. Subjects and This in vitro study was performed on 60 human single-rooted teeth. After preparation, the specimens were randomly divided into 3 groups (n=20, for each period of assessment) and soaked in synthetic tissue fluid (STF) (pH= 7.4). The push-out bond strengths were then measured by using a universal testing machine after one week and 1and 2 months of use. Data were analyzed by SPSS software (version 13) and ANOVA and Tukey statistical tests. Average push-out bond strength at the first week specimens was 2.3157 Megapascal which was more than the average after the first month (0.125) and two months (0.12). There were significant differences between the average push-out bond strength after one week,one month and two month (P<0.001). With passage of time from one week to two months the push-out bond strength of MTA is decreased.