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