ABSTRACT
INTRODUCTION: Failures of root canal treatments are mainly attributed to missed canals and ignorance about the complex anatomy of the root canal system. One such example of anatomic variation is the middle mesial canal (MMC) in mandibular molars which is often missed, and literature on methods for identifying them is limited. AIM: This in vitro study aimed to assess the occurrence of MMCs with cone-beam computed tomography (CBCT) and then under magnification in the mandibular first and second molars. MATERIALS AND METHODOLOGY: A total of 120 extracted intact human permanent mandibular first and second molars were selected. These were subjected to CBCT imaging and magnification for the detection of MMCs. The percentage of incidence in the detection of MMC was compared between these two methods. RESULTS: The incidence of MMC detected in mandibular molars using CBCT was 13.33% (16 of 120 teeth), while using a dental operating microscope, the incidence was 18.33% (22 of 120 teeth) and the comparison between the two methods was statistically not significant. The MMCs were classified based on the Pomeranz Classification. The most prevalent canal configuration was a confluent type which was found to be in 72% cases (16 of 22), followed by fin type which was 22.7% (5 of 22) and independent type was only 4.54% (1 of 22). The incidence of the location of MMC orifice was studied. In 50% of the cases, orifice was located closer to the mesiolingual canal, whereas in 27% of the cases, it was closer to the mesiobuccal canal and in 4.95% of the cases, it was detected midway. CONCLUSIONS: Since the incidence of MMC was higher with the use of a microscope, it is preferred to use simpler, chairside aids like magnification and ultrasonic troughing. On the other hand, one should be judicious while subjecting a case to preoperative CBCT evaluation owing to its ionizing radiation.
ABSTRACT
BACKGROUND: The success in endodontic therapy is dependent largely on the absolute elimination of pulp tissue remnants and the maximum reduction of pathologic microbial load present within the root canal system. AIM: The aim of this in vitro study was to compare and evaluate the ability of pulp tissue dissolution with and without activation of 5.25% sodium hypochlorite (NaOCl). MATERIALS AND METHODS: Pulp tissue samples collected from intact, noncarious extracted third molars were standardized to 8 mg in each group. These samples were placed in conical Eppendorf tubes of 15 ml with 10 ml 5.25% NaOCl for 4 min and were activated suitably according to the group specifications. All the procedures in this study were carried out at room temperature. The preweighed pulp tissue samples were further weighed again after the dissolution phase, and residual weight loss in each group along with its percentage was obtained. The results were then statistically analyzed using one-way analysis of variance and Tukey post hoc test. RESULTS: The maximum amount of pulp tissue dissolution was found in the laser-assisted irrigation group, i.e., NaOCl with Er, Cr: YSGG (P < 0.05) and showed a statistically significant result in comparison with other groups. CONCLUSION: Within the limitations of the study, laser-assisted irrigation with a radial firing tip (NaOCl activated by Er, Cr: YSGG) was the most effective in dissolving the pulp tissue in comparison with other groups. The ultrasonic activation also showed a considerable amount of pulp tissue dissolution comparable to laser-activated irrigation in this study.
ABSTRACT
INTRODUCTION: An array of factors control the success of endodontic surgery. One of them is the technique used to prepare the root end cavities which is conventionally being done with burs. In past decades, ultrasonic instruments have been introduced for the same. Studies comparing these instruments on root surface integrity are scarce. Thus, an in-vitro Scanning Electron Microscopy study was designed to evaluate the surface integrity of root end cavities prepared using conventional and piezoelectric devices. METHODOLOGY: Twelve single-rooted human intact mandibular premolar teeth were endodontically treated and included in the study. They were divided into two groups. In the first group, 3 mm root-end cavities were prepared using conventional retro preparation burs and in the second group, 3 mm root-end cavities were prepared using piezoelectric retro-tips. The specimens were coded for blind evaluation and analysed under scanning electron microscope at 100x, 500x and 1000x magnification for smear layer and debris. Gutmann's scoring criteria was followed to score the specimens. Statistical analysis was carried out using Shapiro Wilk test and the independent sample t-test was used to check mean differences between variables. RESULTS: It was noted that significant statistical differences existed in mean debris and smear layer scores (p< 0.001) between the two groups. In the piezoelectric group, significantly lower debris layer and smear layer was found, compared to the conventional bur group. CONCLUSION: Root-end cavities prepared using piezo retrotips produced cleaner, well-centered and more conservative surface with minimal debris & smear layer, compared to root-end cavities prepared using conventional burs.
