The challenge of endosseous implants placed in the posterior partially edentulous maxilla: A clinical report

The survival rate of implants placed in the maxillary molar area in a 2-sta ge procedure was evaluated. Between 1990 and 1997, 60 consecutive patients (32 females and 28 males, mean age 51 years) received 87 implants to replac e missing maxillary molar teeth. Radiographs were evaluated preoperatively for bone quantity (mesiodistal width, potential implant length not compromi sing the integrity of adjacent vital structures). Second-stage surgery was performed in a mean of 7.9 months postimplantation. The 5-year cumulative i mplant survival rate and the influence of implant characteristics (type, le ngth, diameter, and coating) on implant failure and complication rates (bet ween the 2 stages of surgery) were evaluated. The total 5-year cumulative s urvival rate was 95.4% (4 implants were lost). There were a total of 17 "co mplications" (premature spontaneous implant exposure) in non-failing implan ts, 11 with high and 6 with flat cover screws, respectively. Implantation i n the edentulous maxillary molar area is a predictable procedure with a con siderably high survival rate. The type of implant cover screw used can affe ct the complication rate.