ЕXPERIMENTAL ASSESSMENT OF THE REPRODUCIBILITY AND DEGREE OF OVERLAP OF OCCLUSAL CONTACTS UNDER VARIOUS METHODS OF DIGITAL RECORDING OF INTEROCCLUSAL RELATIONS IN CONDITIONS OF PARTIAL EDENTULISM

Abstract

In modern dentistry, digital technologies play a leading role in diagnosing and planning prosthetic treatment. Intraoral scanning enables the acquisition of highly accurate three-dimensional models of the dentition and detailed analysis of occlusal interactions Despite numerous studies, the accuracy of digital registration of interocclusal relations remains controversial. Most studies focus on evaluating the accuracy of digital registrations in patients without significant dental abnormalities, while their application in complex clinical cases has not been sufficiently addressed. This is particularly true for complex conditions, such as partial edentulism and the presence of prepared teeth, where the number of stabilizing occlusal contacts is reduced, necessitating studies aimed at analyzing the reproducibility of occlusal contacts using different approaches to digital bite registration in patients with partial edentulism. Objective. To conduct a comparative assessment of the reproducibility of occlusal contact areas during frontal and bilateral digital bite registration on plaster models with partial edentulism and a prepared tooth for an orthopedic restoration. Materials and methods. The study was conducted at the Department of Restorative Dentistry of Uzhhorod National University and was aimed at analyzing the distribution of occlusal contact areas depending on the location of digital bite registration during intraoral scanning. The study subjects were plaster models of the upper and lower jaws that replicated a clinical situation of partial edentulism with a prepared tooth for a prosthetic restoration. Inclusion criteria were the presence of dental arches within the ranges 17–11/21–27 and 37–31/41–47 with a dental arch defect and a prepared tooth. To assess the reproducibility of digital results, the plaster model was scanned 25 times using an identical scanning protocol, minimizing the impact of random errors and ensuring the statistical reliability of the data. Results and Discussion. The study revealed that the location of digital registration of interocclusal relations significantly affects the reproducibility of occlusal contacts and the accuracy of digital model alignment. When using bilateral bite registration, the overlapping values ranged from 0.018 to 0.033 mm, which corresponds to physiological values and indicates high accuracy in reproducing intermaxillary relations. In contrast, with frontal bite registration, a significant increase in the overlap value to 0.082–0.176 mm was observed, indicating the presence of hypercontacts and potential occlusal overloads, while the distribution of contacts was markedly asymmetrical, localized predominantly in the lateral regions, which is a sign of an imbalance in occlusal forces. Furthermore, visualization of the occlusal charts revealed the presence of zones of intense contact and areas of collision, indicating a reduction in the accuracy of digital registration. Conclusions. The research demonstrated that the positioning of the digital registration of interocclusal relations is a significant factor influencing the accuracy and reproducibility of occlusal contacts in patients with partial edentulism and a prepared tooth for a prosthetic restoration. It was determined that bilateral bite registration ensures more accurate alignment of digital models, as evidenced by low overlap values (0.018–0.033 mm), uniform distribution of occlusal contacts, and the absence of significant occlusal interferences