Five Veterans Administration Medical Centers participated in a study to determine the comparative influence of fixed partial dentures (FDPs) supported by endosteal blade implants and removable partial dentures (RPDs) on masticatory performance. The study design, methodology, and success rates have been described in Parts I and II. A total of 232 patients received comprehensive dental care, including RPDs for 118 patients and FPDs for 114. Three standardized masticatory tests were made with peanuts and carrots before treatment. These tests were repeated at 16 weeks following RPD or implant insertion and thereafter at 6, 18, 36, and 60 months. At entry, there were no significant differences in performance scores and chewing time and strokes taken to reach the swallowing threshold between the RPD and FPD groups (p greater than 0.05). After treatment completion, FPDs and RPDs significantly improved the masticatory ability of patients with Kennedy class I or class II edentulous conditions (p less than 0.001). The improvements in performance scores for both test foods were slightly better in the RPD group than in the FPD group, although none of the 30 mean differences was significant (p greater than 0.05). After the baseline period to 60 months, only slight changes in performance scores were observed for both groups. RPDs and FPDs were comparable in improving the chewing efficiency of patients with Kennedy class I and class II partially edentulous conditions.