The dissertation is devoted to increasing the efficiency of restoring endodontically treated lateral teeth by optimizing approaches to the preparation of cavities on their occlusal and contact surfaces by creating additional macroretention conditions and objectifying the choice of restoration method. According to the results of retrospective analysis of the clinical condition of direct tooth restorations after endodontic treatment, it was found that most of them, in particular, 81,1% of restorations are made of photocomposite materials, much less, namely, 10,9% and 8,0% – with chemical curing composites and glass ionomer cements, respectively, with 85,6% of restorations located in the lateral teeth, including 70,2% localized on their occlusal and contact surfaces. Among the most common violations were color mismatch (57,5%), marginal color (52,9%), increased surface roughness (40,2%), defects in the marginal fit of the material (31,2%) and anatomical shape (31,0 %). Contact point violations were detected in 34,6% of restorations that covered the contact surfaces. During the laboratory study, significantly (p<0,05) the lowest micropermeability, which was 1,5±0,21 points, was determined in endodontically treated teeth with indirect restorations made of ceramic material by CAD/CAM technology in cavities with additional macroretention element in the form of a groove on the gingival and vertical walls, the highest micropermeability, which was 3,2±0,27 points, was registered in teeth with direct photocomposite restorations in cavities with a flat bottom without an additional macroretention element; images were 12,9±2,3% and 57,3±4,8% (p<0,05). The destructive load in endodontically treated lateral teeth with indirect ceramic restorations, made by CAD/CAM technology in cavities with an additional macroretention element, was 1512,0±16,6 Н, which is significantly (p<0,05) higher than 1296,0±20,4 Н, in the absence of a macro-retention element. A method of preparation of carious cavities on the contact surfaces of lateral teeth has been developed, which provides for the formation of additional macro-retention element on the gingival and vertical walls, and a software product that is an information system for decision support, which allows to objectify approaches to choosing direct or indirect teeth by determining the volume of lost hard tissue. The clinical efficiency of indirect restoration of endodontically treated lateral teeth in the case of restorations of ceramic material by CAD/CAM technology in cavities on the occlusal and one of the contact surfaces with an additional macroretention element at 18 and 24 months was 94,9% and 91,1%, respectively, at that time, in the absence of a macro-retention element, the efficiency of indirect recovery in the respective terms was 90,1% and 79,0%. In the case of direct reduction carried out from photocomposite material in cavities with a macro-retention element, the efficiency in the same terms was equal to 75,6% and 60,2%, in its absence – 62,5% and 42,7%, respectively.
