Biological and mechanical complications of implant-retained and implant-supported overdentures.

Objectives: In 2002 The 'McGill Consensus stated that the first treatment of choice for edentulous patients in the lower jaw, should be an implant-retained over denture. The aim of this study was to evaluate patients treated with implant supported dentures in the undergraduate clinic at The Hebrew University – Hadassah, School of Dental Medicine, in the 6^th year student complete denture course.
Methods: 35 patients treated by undergraduate students according to the McGill treatment protocol were invited to the clinical exam. All patients received implant-supported overdentures on 2 implants in the lower jaw .Clinical examination included (i) implant assessment (probing depth, BOP, mobility, plaque score); (ii) prosthetic parts assessment (screw loosening, wear); (iii) radiological assessment (peri apical) and (iv) assessment of retention, support and stability of the denture.
Results: 19 patients agreed to participate in the research. The survival rate of implants was 100%. The mean follow-up was 3 years. Low rates of BOP and an average PD of 3.75 mm was depicted. Radiographically, some implants showed an exposure of up to the first thread. Up to 50% of the dentures showed diminished retention, and reduced stability. 16% of the locator attachments were loose, 30% of the locator attachments were worn. 40% of the rubber bands weren't retentive at all.
Conclusions: Implant supported overdenture is a predictable treatment with high survival rates of the implants. Long term maintenance is crucial for the longevity of this kind of restoration.