Immediate function in edentulous maxilla implant rehabilitation: a 1-year retrospective clinical study

Aim: To evaluate the survival rate of immediately loaded, acidetched implants (Osseotites) in the edentulous maxilla over a period of 12 months. Materials and methods: Sixteen patients (mean age 59 years) with residual compromised maxillary teeth were made edentulous and rehabilitated with a screw-retained fixed provisional prosthesis with a gold-alloy framework and composite teeth in 24 h after surgery supported by a minimum of four implants to a maximum of six ones. To obtain the highest primary stability in all post-extractive sockets tapered implants were used whereas in parental bone cylindrical implants were inserted. After a mean healing time of 18 weeks, a definitive prosthesis was carried out. A total of 89 implants were analyzed. All patients were maintained in a regular recall program. Radiological examinations were made at implant placement, at definitive prosthesis delivery and at 12 months. Results: At 12 months follow-up the implants survival rate was 92.2% whereas the prostheses survival rate was 100%. No statistical difference was found between the survival of implants placed in post-extractive sockets and those in parental bone and between cylindrical and tapered implants. Seven implants failed during the first 3 months. Seventy one percent of lost implants were in distal areas. The mean reduction in marginal bone was 1.3mm. Conclusions: According to a severe surgical and prosthetic protocol, four to six implants seem to be enough to support an edentulous maxilla implant fixed rehabilitation. Treatment planning has to carefully consider primary implant stability and its maintenance during the healing period.