Purpose: To analyze implant and prosthetic survival rates, complications, patient satisfaction, and biological parameters of patients rehabilitated with implant overdentures (IOV) on splinted and nonsplinted implants and different attachment systems, in function for one to 17 years. Methods: This retrospective study evaluated data collected from patients rehabilitated with implant overdentures between January 2001 and December 2016 in nine different centers. Outcome measures were implant and prosthetic success rates, mechanical complications, marginal bone loss (MBL), oral health impact profile (OHIP), bleeding on probing, and plaque index. Results: A total of 581 implants were installed in 194 patients. Patients were followed for a mean period of 60.6 months (range 6–206). Eighty-nine patients received 296 low profile attachment (OT Equator), 62 patients received 124 ball attachments, and 43 patients received 107 Locator attachments. In eighty-three patients the implants were splinted with computer aided design/computer aided manufacturing (CAD/CAM) or casted bar. At the last follow-up, 10 implants failed in eight patients. Statistical significance was found for failed prostheses (P = 0.0723) and complications (P = 0.0165), with better values for splinted implants. No statistically significant differences were found in proportion of implant and prosthetic failure (P > 0.05). At a five-year follow-up, proportion of complications (P = 0.0289) and failed prostheses (P = 0.0069) were statistically higher for IOV on Locator attachments. No difference was founded in MBL at one- and two-year follow-up between different attachment systems (P > 0.05). Statistically significant improvement in all the OHIP categories was reported in all the patients, after one year of function. Conclusions: Implant overdenture showed high implant and prosthetic survival rates, low complications, high patient satisfaction, and good biological parameters in the long-term follow-up. Splinting the implants may reduce number of mechanical complications. Locator attachments showed higher number of complications. Further studies are needed to confirm these preliminary results.

Purpose: To evaluate implant and prosthetic survival rates, complications, patient satisfaction, and biological outcomes of patients rehabilitated with a ball attachment system for implant retained- and supported-overdentures (IOV), which was in function for 3 to 5 years. Methods: This retrospective study evaluated data collected from patients treated between April 2001 and May 2018 with IOV on splinted and non-splinted implants and a ball attachment system. Patients were followed for 36 to 206 months (mean follow-up was 128.1 ± 51.9 months). Data were collected at the 3- and 5-year follow-up examination. Outcome measures were implant and prosthetic survival rates, technical complications, marginal bone loss (MBL), oral health impact profile (OHIP), and periodontal parameters (bleeding on probing and plaque index). Results: A total of 46 patients (16 males and 30 females) with 124 implants were included in this study. Twenty-five implant-retained overdentures were delivered on 53 unsplinted implants, while the other 21 patients received an implant-supported overdentures and the implants were splinted. At the five-year follow-up examination, one implant and one prosthesis failed in the unsplinted group, resulting in a cumulative survival rate of 97.8% at the patient level. Two minor technical complications were experienced. Conclusions: Implant overdenture retained or supported by ball attachment systems showed high implant and prosthetic survival and success rates. A low number of complications, high patient satisfaction, and successful biological parameters were experienced in the mid-term follow-up. Data need to be confirmed by further randomized trials.

Background. Prosthetic rehabilitation of patients with atrophic arches can be very challenging. Purpose. The aim of the present prospective multicenter study was to report the two-year preliminary data on clinical and radiographic performance of implant-supported overdentures with a metal bar and low-profile attachments. Material and Methods. A computer-aided design/computer-aided manufacturing (CAD/CAM) titanium bar or a conventional cast metal bar was fabricated according to the anatomy of the ridge, prosthetic contours (teeth setup), and implant position. Three to six threadable OT Equator attachments (Rhein 83, Bologna, Italy) were placed along the implant bar. A cobalt-chromium alloy metal framework was fabricated and fitted onto the metal bar as a counterpart. Prosthetic survival rate, biologic and technical complications, peri-implant bone loss, changes in oral health impact profile index, bleeding on probing, and plaque index were reported. Results. Overall, 177 implants were placed (range three to six) to support 43 metal bars with 170 OT Equators (Rhein 83, range three to six). Eleven metal bars were fabricated using CAD/CAM technology, while the other 32 were conventionally produced using cast technique. All the participants were followed up for at least two years (mean 42.2 months, range 24–88 months) after prosthesis delivery. Two maxillary implants failed in one nonsmoking patient (1.1%). The 2-year prosthesis survival rate was 97.7%. Only three minor technical complications were reported. Two years after loading, the mean marginal bone loss was 0.22 ± 0.09 mm (95% CI: 0.16 to 0.26). Two years after loading, OHIP was 22.3 ± 7.1 (95% CI from 17.4 to 24.6). Compared to the baseline, the difference was statistically significant ( $P\le 0.001$ ). At the two-year follow-up session, successful periodontal parameters were experienced. Conclusions. Implant overdenture supported by a CAD/CAM titanium bar may be a reliable option for the treatment of the edentulous arch over a 2-year period. Oral health-related quality of life significantly improved in all treated participants.