CLINICAL AND INSTRUMENTAL STUDY RESULTS OF COMPARING DIGITAL OCCLUSION INDICES AT REGISTRATION OF INTERCUSPAL POSITION IN PATIENTS WITH EDENTULOUS SPACES BEFORE AND AFTER PROSTHETIC REHABILITATION
Authors: Hlushko Тaras , Vovk Yuriy , Vovk Volodymyr , Kryukov Petro , Lohash Мaksym 
Published: November 2022

Aim. The research aims at carrying out a comparative clinical and instrumental analysis related to registering occlusal relations of intercuspal contact position in patients with edentulous spaces before and after prosthetic rehabilitation using various registration materials.
Material and Methods. Examination of 5 patients of both genders aged 28 to 51 years was performed at clinical bases of the department of surgical and prosthetic dentistry of the Faculty of Postgraduate Education at Danylo Halytskyi Lviv National Medical University. Clinically, all patients were provided with a standard diagnostic dental examination including the control of a temporomandibular joint condition, examination of masticatory muscles, as well as the static and dynamic occlusion with the help of articulating wax and paper according to the two-stage Bausch method. The examination also involved impressions of dental arches of both jaws. Their cast models were produced for laboratory study. The received register, involving the use of materials, namely Futar D, metalized wax, and Consiflex, were reexamined for compliance with the intercuspal contact position in all patients. Location of the occlusal contact areas of antagonistic teeth was determined using Bausch Progress 100® 0.1 mm thick articulating paper (Bausch, Germany). Simultaneously, instrumental registration of digital occlusion indices was performed using the T-scan III device (Boston, USA).
Results and Discussion. While comparing mean values of the percentage distribution between the left and right halves, the greatest asymmetry was recorded with the use of Futar D material in the D mode both before and after treatment. According to the results of performed instrumental study concerning occlusal relations with the help of the T-Scan III device, it was found that in case of applying Futar D registration material in patients before prosthetic rehabilitation, mean values of occlusal forces at MAX on the left were (50.72 ± 13.86)%, on the right they were (49.28±13.86)%, after prosthetic rehabilitation they made up (50.12±8.75)% on the left, and (49.88±8.75)% on the right. In case of Consiflex registration material application in patients before prosthetic rehabilitation, it was found that COF mean values at MAX on the left accounted (41.28±16.97) %, while on the right they accounted (58,72±16,97) %. After prosthetic rehabilitation - (54.72±13.39) % on the left, and (45.28±13.39) % on the right, respectively. The conducted instrumental studies demonstrate challenging opportunities for revealing personalized features of static and dynamic occlusal balance at clinical registration of intermaxillary position of intercuspation by various registration materials and methods.
Conclusions.
1. A uniform contact of dental arches with synchronous contact of all tooth groups is an important feature of physiologically coordinate dentofacial system functioning.

Frequent sliding contacts are observed in ending intercuspal contact position at static and dynamic occlusion. Area of the contact surfaces of the teeth expands with the increase of occlusal pressure in the direction of the maximum intercuspal contact position (maximum intercuspation). At the same time, occlusal pressure occurs in this area, causing the redistribution of functional load of the patients' dentofacial system components.
Occlusal space in the intercuspal contact position and the maximum intercuspation or the D index, which can be established using the "Tekscan III" digital technology, manifests the spatiotemporal indices of inter-maxillary relations redistribution. The values of these indices in patients with partial anodontia provoke a special interest.
The use of Futar D registration material at performing clinical and instrumental analysis of digital indices of the transition from intercuspal contact position to maximum intercuspation, allowed establishing the extension of occlusal joining of teeth duration after dental prosthetics by 1.02 times, reduction of the length of joining trajectory by 1.37 times. The use of Consiflex resulted in the identical length of joining trajectory and extension of the duration of occlusal joining of teeth after dental prosthetics by 1.04 times. The application of metalized wax was characterized by the identical length of joining trajectory and prolonged occlusion time after dental prosthetics by 1.61 times.