Implant-retained mandibular overdentures: A comparative pilot study of immediate loading versus delayed loading after two years

Statement of problem. Treatment options for an increasing number of completely edentulous patients using fixed restorations may be limited due to anatomical or financial constraints. Purpose. The purpose of this pilot study was to compare immediate loading versus conventional delayed loading of implants placed for the retention of mandibular overdentures. Material and methods. Twenty-six subjects each received 3 implants placed in the symphysis area which were connected with a gold bar. In the experimental group (n=17), the 3 splinted implants were loaded 2 days after surgery; in the control group (n=9), the 3 implants were loaded 3 months after surgery using a conventional 2-stage approach. Recall appointments were scheduled every 3 months during the 2-year follow-up. The following clinical parameters were included and assessed: health of periimplant soft tissues using the bleeding index (BI), plaque index (PI), periimplant probing depth (PIPD), periimplant bone resorption as measured on panoramic radiographs, and implant stability using resonance frequency analysis (RFA). The Mann-Whitney test (alpha=.05) was used to compare each parameter in the 2 groups. Results. After 2 years, no implant failure was recorded in either group. No significant difference was found between the 2 groups after 2 years with regard to BI (P=.33), PI (P=.81), PIPD (P=.61), periimplant bone resorption (P=.32), or RFA (P=.06). After 1 year, periimplant bone loss (P=.05) and PIPD (P=.005) were increased in the control group. Conclusions. Immediate loading of 3 splinted implants retaining a mandibular overdenture shortens treatment time for prosthesis insertion and shows, after 2 years, results comparable with the delayed approach.