Outcomes of one-stage versus two-stage implant placement.

Dr. Byrne is an associate professor, Department of Adult Restorative Dentistry, College of Dentistry, University of Nebraska, 40th and Holdrege, Room 128, Box 830740, Lincoln, Neb. 68583-0740, e-mail “[email protected]”. He also is an evidence reviewer for the American Dental Association. Address reprint requests to Dr. Byrne. Clinical question. Are there any differences in outcomes between onestage (nonsubmerged) and two-stage (submerged) surgical implant placement protocols in adults? Review methods. The authors searched four electronic databases for studies in which researchers compared one-stage versus two-stage implant placement through Jan. 21, 2009; they used no language restrictions. They also completed a hand search of printed journals. Their review included randomized controlled trials (RCTs) of adults that involved a minimum follow-up period of six months after prosthesis placement. They assessed the following outcomes: prosthesis failure, implant failure, radiographic marginal bone level, patient preference, esthetics and complications. Two independent reviewers screened the full reports, extracted data and independently assessed each report’s validity and risk of bias. Main results. The investigators selected five studies involving 239 patients and a total of 761 implants (four brands). Three trials involved parallel group designs, one a splitmouth design and one a hybrid design. All but one trial had a high risk of bias. Trials involved different oral locations and restorative scenarios. The 761 implants were divided nearly evenly in terms of placement protocol: 375 were placed by means of a one-stage procedure and 386 by means of a two-stage procedure. Twenty-three implants failed in 11 patients in the one-stage group, and nine implants failed in eight patients in the two-stage group. Meta-analysis showed no statistically significant differences (P < .05) between the two procedures in terms of prosthesis failure in three trials (relative risk [RR], 1.87 [95 percent confidence interval (CI), 0.33-10.40]) and implant failure in four trials (RR, 1.39 [95 percent CI, 0.59-3.27]). The one trial in which investigators accurately compared bone levels showed no significant dif-