Marginal Bone Loss Around Mandibular Implant-retaining Overdentures and Implant Supported Fixed Hybrid Prosthesis

Few if any studies have compared marginal bone loss (MBL) around implant-retaining overdentures (2 implants with locators) versus implant supported fixed hybrid prosthesis (over 4 implants) in the mandible.

Material and Methods: Patients of the saint Joseph university dental clinics, who have already in their records peri-apical radiographs of the implants post loading, will be divided in 2 groups depending on the prosthetic treatment that they have had for 5 years in mouth, and will be recalled for a check-up session during which the investigators will take new peri-apical X-rays by means of the parallel long-cone technique for the implants that are supporting/retaining the prosthesis. A total of minimum 50 implants placed in a minimum of 19 patients will be examined. The mean mesial and distal radiographic MBL and bone to implant contact (BIC) will be recorded by comparing the two X-rays for each implant. the investigators will also investigate the possibly related factors that may have contributed to this marginal bone loss such as the medical history, smoking habits, oral hygiene, compliance, presence of keratinized tissue and possibility of proper cleaning. Results: the investigators aim to find a statistically significant difference in the Marginal bone loss around implants assisting these two types of prosthesis and a possible correlation with some risk and modifying factors.