A prospective randomized study of 1-and 2-stage sinus inlay bone grafts: 1-year follow-up

The purpose of the present study was to compare the success of and surgical differences between 1- and 2-stage sinus inlay bone grafts and implants af ter 1 year in function. The individual risk for implant failure in grafted areas among 1-stage patients was about twice the risk in 2-stage patients ( odds ratio 2.3, CI 0.6; 8.5). The risk for implant failure in non-grafted a reas was significantly lower (P<.05) than in grafted areas, regardless of t he technique used. Forty edentulous patients, selected according to strict inclusion criteria from consecutive referrals, were allocated to one or oth er of the 2 sinus-inlay procedures. Twenty patients received bone blocks fi xed by implants to the residual alveolar crest in a 1-stage procedure (grou p 1). In another 20 patients, particulated bone was condensed against the a ntral floor and left to heal for 6 months before implants were placed (grou p 2). An almost equal number of implants was placed in the patients of each group, 76 in the 1-stage procedure and 74 in the 2-stage procedure. Additi onally, 72 and 66 implants were placed in the anterior non-grafted regions of group 1 and group 2 patients, respectively After 1 year in function, a t otal of 20 implants failed in 1-stage patients, versus 11 in 2-stage patien ts. Sixteen and 8 implants, respectively, of these were placed in grafted b one. All but one 1-stage patient received the planned fixed prosthetic rest orations, but 1 restoration was redesigned after the first year in function because of a functionally unacceptable prosthetic design. At the 1-year fo llow-up, one 2-stage patient lost her prosthesis as the result of multiple implant failures. Bruxism and postoperative infections were the only parame ters that could be related to implant failure, however, depending on the st atistical method used.