ABSTRACT
Background Mineral trioxide aggregate (MTA) is a biocompatible dental material used for root-end filling in endodontics. A wide variety of literature has been published on the assessment of fracture resistance of MTA. However, the results were conflicting in the reported studies, and the sample size used was insufficient to conclude the efficacy of materials such as MTA Plus and MTA Angelus. Therefore, this study was designed to compare and evaluate the effectiveness of two commercially available MTAs, namely, MTA Plus (Avalon Biomed Inc. by Prevest Denpro Ltd, Jammu, India) and MTA Angelus (Angelus Dental Solutions, Brazil) in terms of fracture resistance. Methodology To determine fracture resistance, 300 freshly extracted healthy human teeth with single roots and canals were collected by simple random sampling. Teeth were decoronated, the apical third was enlarged, and root canals were prepared to receive MTA as a 5 mm apical filling. The root segments were randomly categorized into two experimental groups of 100 samples each, namely, group A (MTA Plus) and group B (MTA Angelus), and the remaining 100 root segments were used as control (unfilled). Fracture resistance was determined using the Instron Universal testing machine. Results The results of our study showed statistically significant increased fracture resistance for MTA Plus (532.14 ± 5.19 N) than MTA Angelus (540.81 ± 3.56 N) and the control group (460.63 ± 7.91 N). Conclusions The control group showed the least fracture resistance. The composition and structure of MTA Angelus (group B) containing Portland cement, with a 4:1 addition of bismuth oxide, make it more fracture resistant than MTA Plus (group A).
ABSTRACT
AIM: The aim of the study was to evaluate the dimensional accuracy of three combinations of polyvinyl siloxane impression material by double-mix single-step impression technique. MATERIALS AND METHODS: Metal master model was made according to the ADA specification no. 19; ISO 4823:2000/AMD 2007. Impressions were made using perforated custom-made metallic trays of 2 mm and 4 mm spacing, the impression materials used were putty, heavy body, regular body and light body. A total of 30 impressions were made by single-step technique and poured in die stone to obtain resultant cast. Ten impressions were made of each combination of polyvinyl siloxane (PVS). Three dimensions (interabutment distance, height and diameter) on resultant cast were measured and compared with metal master model. The results were statistically analyzed and tabulated. RESULTS: Diameter of abutment, the height of abutment and interabutment distance in each group were larger in dimensions as compared with metal master model. The dimensional discrepancies of group I, group II and group III casts when compared with the master model were significantly different from each other. The least difference was found in group I. CONCLUSION: The one-step putty-light body combination (group I) produced the most accurate stone casts compared with one-step heavy body-light body and regular body-light body combinations. CLINICAL SIGNIFICANCE: In everyday dental practice, impression making is imperative. Hence, by doing this study, we tried to find out which material combination is suitable to give us predictable and accurate results.
