Survey on the prevalence of occlusal interferences in central relation in posterior crowns

Survey on the prevalence of occlusal interferences in central relation in posterior crowns Dr. V. Karimi * - Dr. Z. Mahdavi Izadi ** - Dr. F. Karimi *** - Dr. H. Soori**** * - Dentist ** - Assistant Professor of Fixed Prosthodontics Dept. - Faculty of Dentistry – Tehran Islamic Azad University. *** - Assistant Professor of Medical Sciences Research National Center. **** - Associate Professor of Medical Sciences Research National Center. Background and Aim: Centric interference is a premature contact that happens during mandible closing, while condyles are in good position, causing mandible deviation to back, forward and lateral. Centric interference results in destructive effects on periodontal and pulpal tissues, temporomandibular joint, occlusion, jaws and masticatory system. The aim of this study was to evaluate the prevalence of occlusal disturbances in CR in posterior crowns. Materials and Methods: In a descriptive and cross-sectional study on 42 patients referring to Faculty of Dentistry, Tehran Islamic Azad University, 105 posterior crowns were evaluated for existing occlusion interference condition in CR. Results: Out of 105 crowns, 68 of them (64.7%) had contact in CR and 37 of them (35.2%) had no contact in Cr. Out of 68 posterior crowns with contact in CR, 19 of them (18.1%) had interference. There was no significant difference between posterior crowns regarding occlusal interferences (P<0.05). Conclusion: Considering the fact that occlusal interferences in crowns and metallic restorations are more destructive that those exist in natural dentition, it is recommended to pay more attention in the establishment of a correct occlusion in crowns and metallic restorations. Key words: Crown - Posterior crown – Interference - Occlusal interference - Centric relation.