Abstract: Objective: To study the incidence of loss of interproximal contact between implant fixed denture and adjacent teeth, and to investigate its possible related factors. Methods: From September 2012 to September 2017, 105 patients were followed up, and at the end of September 2017, a total of 164 implant fixed dentures were studied. After crown/bridge restorations, different thickness of adjacent contact was used to analylze the interproximal contact. If the interproximal contact was over 50μm, it was considered as the interproximal contact loss. Furthermore, the incidence of the loss of interproximal contact and its possible influencing factors were evaluated. Results: Totally, there were 210 interproximal contacts, of which 107 were the loss of interproximal contact (50.9%). The interproximal contact position, the level of alveolar bone in the adjacent teeth, and the jaw position could affect the loss of interproximal contact. According to statistical analysis, those results had statistical significance (P<0.05). Conclusion: The loss of interproximal contact is one of the complications of implant denture with a higher incidence. The results showed that the incidence of interproximal contact loss of maxillary is higher than that of mandible. The mesial contact is easily loss than the distal contact. In addition, the number of adjacent dental root and the alveolar bone absorption of adjacent teeth are also associated with the loss of interproximal contact.

Key words: Clinical research, Implant-fixed prostheses, Interproximal contact loss