PERI-IMPLANT MUCOSAL ASPECTS OF ITI IMPLANTS SUPPORTING OVERDENTURES - A 5-YEAR LONGITUDINAL-STUDY

Sixty-six ITI implants placed in the mandible of 33 edentulous elderly patients (mean age: 69 years) were observed longitudinally for 5 year s. The implants served as overdenture anchorage either by means of a c onnecting bar or single spherical attachments. During the study period , 2 implants failed (one because of a peri-implant lesion and one beca use of a fracture) and had to be removed. At the beginning of the stud y, all implants were osseointegrated and had successfully been in func tion for 3-5 months. Oral hygiene practices and the peri-implant mucos al status were assessed according to the criteria of conventional peri odontal parameters. Approximately 50% of the implants had been install ed into lining mucosa and hence were to surrounded by keratinized muco sa. The peri-implant mucosal tissue was maintained healthy during the whole observation period, and no or only minimal loss of attachment wa s observed. The probing depths averaged approximately 3 mm. At the end of the study, orthopantomographic radiographs were obtained from all patients to assess the peri-implant bony structures. Small local angul ar bony defects were detected on 16 implants (22%) in 12 patients. Sli ghtly increased probing depths were observed when angular bony defects were present. Loss of attachment was significantly less frequent when the implants had been placed following a prolonged period of edentulo usness (> 5 years). This study demonstrated that advanced age, reduced dexterity of elderly patients and environmental conditions of overden tures do not represent a higher risk for the development of peri-impla nt lesions.