Aim. The aim of the study is to evaluate the difference in MB2 prevalence with different slice thicknesses in maxillary first molars. Materials and Methods. Two hundred nonfilled MB2 canals in maxillary first molars of 156 people (75 females and 81 males) aged from 20 to 73 years old were evaluated with CBCT with different slice thicknesses: 0.5 mm, 1 mm, 3 mm, and 10 mm. A general analysis was performed out, as well as in the age groups and on gender groups. Results. Visualization with 0.5 mm and 1 mm slice thicknesses was 100% and generally equal, in both the male and the female group. General MB2 visualization with 3 mm slice thickness was 42% and 29% for the male group and 27% for the female group. No canals were visualized with 10 mm slice thickness. The study did not demonstrate a statistical difference in the MB2 prevalence between gender and age groups with the 3 mm slice thickness. Conclusion. The most valuable way to evaluate the root canal system in first maxillary molars with CBCT is using 1 mm slice thickness for both genders and every age group.

Deep margin elevation (DME) is a nonsurgical, alternative technique of dental crown lengthening. Portion of direct restoration placed only at the deep apical part of the cavity to elevate the margin to a more coronal and more adequate position for final cementation of indirect restoration.Materials and methods. In this systematic review, we were looking for in vitro studies in which deep margin elevation (DME) technique were used. The electronic databases PubMed and EMBASE were used for the search. The search began on July 29, 2021 and ended on August 10, 2021. We have analyzed the materials and methods of each research and entered them in the appropriate tables to give a clearer assessment of the obtained results.Results. Analysis of marginal quality showed the best results when indirect restorations luted to dentin directly and with DME technique with three consecutive layers of resin composite. In groups without DME there were fewer microleakage. DME did not statistically significantly influence the fracture strength.Conclusions. We conducted a systematic review that included 12 in vitro studies. Even though samples without DME showed better results in in vitro studies, the difference between samples with and without DME was not statistically significant. However, in clinical practice, DME facilitates the insertion of indirect restorations. Therefore, further studies and clinical observations are necessary.

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urpose. To determine the orthodontic treatment relevance on the base of metaanalysis of the prevalence of dentoalveolar anomalies, and to compare the accuracy of 2D and 3D cephalometry to detect them. Materials and methods. Comprehensive literature search on the prevalence of dentoalveolar anomalies and comparison of 2D-and 3D-cephalometry results was carried out using two databases. After the selection of the selected criteria, 46 articles on prevalence and 20 articles containing studies on the comparison of teleroentgenogram and CBCT were taken for the analysis. The prevalence was estimated in two groups: analysis of the situation in different regions of the Russian Federation (RF) and prevalence in the world. Results. The analysis of statistical data showed a high prevalence of dentoalveolar anomalies, the highest figures were recorded in Colombia (88%) and Nigeria (88.2%), the lowest figure was recorded in Iran (29%). Among the RF subjects the highest value was found in Tyumen (89%), the lowest-in the Republic of North Ossetia-Alania (42.25%). The analysis of comparison of accuracy of teleroentgenogram and CBCT showed discrepancy in results of the carried-out works at different authors. Conclusion. Need for orthodontic treatment is quite high due to the high prevalence of dentoalveolar anomalies among the population. The advantages and disadvantages of 2D and 3D cephalometry are analyzed. For the final result in comparison to the accuracy requires further clinical and morphological studies..