Retention of implant retained maxillary overdenture with single bar versus separate two bars. (an in vitro study)

fully edentulous patients have been frequently rehabilitated with complete dentures; however, due to progressive maxillary bone loss, these patients often experience a lack of prosthetic retention, stability, and chewing efficiency, which negatively affects their oral health-related quality of life. Aim of the study: this in-vitro study aimed to evaluate the retention of maxillary overdenture by four implants using a single bar versus two separate bars and clip attachments. Material and methods: Ten maxillary models were prepared from clear acrylic resin; implants were placed in the anterior area according to the anteroposterior spread concept. Samples were grouped into two groups: Group I(SG)(n5): implants retained maxillary overdenture with singlet bar. Group II (TG)(n5): implants retained maxillary overdenture with two separate bars. Retention was measured for each group using a universal testing machine. Result: The result revealed that the mean value of the retentive test with Group I (SG) was higher than Group II and the difference was statistically significant. conclusion: within the limitation of this study it is recommended to use a single bar rather than two separate bars and clip attachments when it is planned to use four implants to retain maxillary overdenture.