CHOICE OF MATERIAL FOR PROVISIONAL RESTORATIONS AND ITS FIXATION AS AN INTERMEDIATE STAGE IN THE TREATMENT OF TMJ DYSFUNCTION

The modern treatment protocol for temporomandibular joint (TMJ) dysfunction includes a mandatory stage of provisional occlusal rehabilitation after completion of splint therapy. The accuracy of transferring the established therapeutic mandibular position, as well as the stability of occlusal contacts throughout the preparation period for definitive prosthetics, directly depends on the quality of fabrication and the reliability of fixation of temporary overlays. Objective. To conduct a comparative evaluation of the clinical efficacy of two methods for fabricating and fixing provisional occlusal overlays. Materials and Methods. The study included 20 patients (12 women, 8 men) aged 25 to 55 years with a verified diagnosis of TMJ dysfunction. At the stage of transitioning from splint therapy to definitive restorations, patients were randomly assigned to two equal groups of 10 individuals each. In the first group, overlays were fabricated using the additive transfer (mock-up) method. In the second group, CAD/CAM milling of plastic blocks was used. Clinical efficacy was assessed based on the incidence of chipping, debonding, wear indicators, and the API index over a follow-up period of up to 6 months. Results. In the first group (mock-up), 3 patients (30 %) experienced chipping of supporting cusps within 2–3 weeks; after wearing for more than 4 weeks, all patients showed pronounced wear of the restorations with loss of occlusal accuracy. The API index after 4 weeks was 42.3 ±5.7 %. In the second group (CAD/CAM), no chipping was observed, occlusal wear was minimal, and the API index was 24.8 ±4.2 %. However, 2 patients (20 %) experienced debonding of the overlays due to insufficient adhesive compatibility of the PMMA material with hard tooth tissues. Conclusion. CAD/CAM milling of PMMA blocks provides higher mechanical strength and wear resistance compared to the mock-up method, but requires the mandatory creation of additional retentive elements to prevent debonding. The choice of technique should be determined by the clinical situation and the technical capabilities of the clinic.