Potential risk factors for implant failure in temporomandibular disorders patients

Aim: The aim of this study was to evaluate the effects of abnormal occlusal forces on dental implants in patients with temporomandibular disorders (TMD), and to focus on concepts and the clinical procedures to reduce the potential risk factors for implant failure. The heavy force of compression, clenching and grinding, as in bruxism, simultaneously applies strong pressures to the implants, crestal bone, restorations and temporomandibular joints. This is a potential risk factor for crestal bone loss, loss of integration before and after restoration, abutment screw loosening and fracture, implant fracture, decementation of restorations and fracture of the porcelain. Materials and methods: 28 TMD patients were compared to 28 no-TMD patients in which were inserted 267 implants with the same features as number, size, position, design. Besides, were considered type of restoration, cemented or screwed, malocclusion type, smoking, load timing. Results: The results show that increasing the number of implants and reducing cantilevers, the stress on each one decreases; using the longest and widest implant possible increases implant-bone surface area and reduces also strain on the restorations. Also implant design, occlusal table width, direction, duration and magnification of the forces influences the stress at the crestal bone-implant surface. Anterior guidance during excursive movements reduces forces and eliminate all lateral occlusal contact. Conclusion: Patients with temporomandibular disorders and bruxism can be eligible for implants, provide that treatment plans controlling the chronic bruxism through night-guards and modifying the occlusal forces on implants and their restorations are developed.