Material and method: Sixty freshly extracted human single-rooted mandibular premolar teeth were selected for the study. Teeth with fractured root, cracks, anddilacerations were rejected. All teeth were cleaned with ultrasonic scalers. Standard access opening was done and root canal treatment was performed with rotary files followed by obturation. After storing in saline for a week apical 3 mm of the root was resected at 900 angles to the long axis of the root. Retro cavity preparation was done with ultrasonic tips. The teeth were divided into four groups of 15 specimens each. Group I - Biodentin, GroupII-Bioaggregate, Group III - MTA Plus, and Group IV - MTA. After the restoration of retro cavities of all the teeth as per manufacture instructions, two coats of nail varnish were applied to leave apical 3 mm. All teeth were stored in 2% methylene blue for 72 h followed by emersion in 65% nitric acid for the next 72 h for Dye extraction. The obtained supernatant solution was then centrifuged and optical density or absorbance was measured with a UV spectrophotometer.
Result: Microleakage was found to be increasing in this order: Biodentin 0.01).
Conclusion: All materials exhibit some amount of microleakage. Biodentin shows the least microleakage among all the bioceramic material groups. Hence, Biodentin and bioaggregate are better material of choice for the retrograde filling to prevent microleakage.
Aim: This study investigated the prevalence and location of second mesiobuccal (MB2) canal in mesiobuccal root of maxillary first molar using cone beam computed tomography (CBCT) images in an Indian population.
Materials and methods: CBCT images of 598 three rooted maxillary first molars were studied. In each CBCT image, the floor of pulp chamber was located and advanced by 2 mm to standardize the observation for MB2 canal. Its location was determined in relation to mesiobuccal (MB1) and palatal (P) canal.
Statistical analysis: The data was analysed using descriptive statistics. The presence of MB2 canal was correlated with age, gender and tooth position using Chi square test.
Results: The prevalence of MB2 canal in three rooted maxillary first molar was 61.9%. It was seen that the prevalence of MB2 was highest in 20-40years age group (67.4%) followed by > 40 years (57.5%) and lowest in <20 years (50.6%) and the difference was statistically significant (p = 0.005). It is located mesiopalatally; 2.5 mm ± 0.6 mm palatally and 1.0 ± 0.4mmmesially to the MB1 canal or present directly on the line joining the MB1 and palatal canal.
Conclusion: There is a high probability of finding MB2 canal in Indian patients. The access cavity must be modified from a triangular shape to rhomboid shape. Troughingmesiopaltally (about 2.5 mm palatally and 1 mm mesially) from MB1 to a depth of about 2 mm from the floor of pulp chamber may be necessary for locating MB2 canal.