Retrospective Study of Standard-Diameter Implants Inserted Into Allografts

Abstract

In the last decade, several investigators reported that standard-diameter implants (SDIs) achieved excellent results. However, no report is available regarding SDIs inserted into fresh-frozen bone (FFB). We conducted a retrospective study on a series of SDIs (diameter, 3.75 mm) inserted into homologous FFB to evaluate their clinical outcome. The SDIs inserted with FFB were analyzed. Several variables were investigated regarding patients, anatomic sites, implants, and prosthetic restoration. Implant failure and peri-implant bone resorption were considered predictors of clinical outcome. A Kaplan-Meier algorithm and Cox regression were performed to detect those variables statistically associated with clinical outcomes. One hundred thirty-three SDIs were inserted in 41 patients. Implant length ranged from 10 to 15 mm. Implants were inserted to replace 6 incisors, 13 cuspids, 60 premolars, and 54 molars. The mean follow-up was 23 months. Only 1 of 133 implants was lost (ie, survival rate=99.2%), and no differences were detected among study variables. On the contrary, crestal bone resorption correlates with type of prosthetic restoration, with a better outcome for removable dentures. The SDIs had high survival and success rates, similar to those reported in previous studies of 2-stage procedures in nongrafted bone. The SDIs inserted into FFB are reliable, although a greater marginal bone loss is to be expected if fixed prosthetic restorations are used.