Results

Of the six studies selected, three evaluated surface-treated implants and three machined implants (Table 1). The included studies all used similar criteria for implant survival, which was defined as the absence of mobility, pain, and radiolucent lesions. The implant survival was based on the percentage of implants evaluated, and the implant lengths in the studies range from 6 to 16 mm (Tables 2 and 3). The number of patients receiving wide implants was not specified in three studies which also evaluated other diameter implants. Only data on the wide-diameter implants in those studies were included in the meta-analysis. Three studies evaluated only wide-diameter implants. The number of patients evaluated in these studies was as follows: Khayat et al. studied 71 patients, Polizzi et al. studied 34 patients, and Schincaglia et al. studied 15 patients. Schincaglia et al.’s study was a randomized controlled trial evaluating immediate-loading versus delay-loading of wide-diameter implants; only data of the control group that was not immediately loaded was included in the meta-analysis. The mean patient follow-up of the six studies ranged from 1 to 8 years. The location of the implants placed in the selected studies (Table 4) was as follows: two studies evaluated implants placed in the posterior mandible, one study in the edentulous mandible, and three studies in various areas of the maxilla and mandible.