One-stage versus two-stage implant placement. A Cochrane systematic review of randomised controlled clinical trials

To evaluate if a one-stage implant placement procedure is as effective as a two-stage procedure.

The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE, were searched and several journals were hand-searched with no language restriction up to January 2009.

All randomised controlled trials (RCTs) of osseointegrated dental implants comparing the same dental implants placed according to one- versus two-stage procedures with a minimum follow up of 6 months after loading were eligible. Screening of studies, quality assessment and data extraction were conducted in duplicate. Outcome measures were: prosthesis failure, implant failures, radiographic marginal bone level changes, patient preference including aesthetics, aesthetics evaluated by clinicians and complications.

Five RCTs were identified and included reporting data on 239 patients in total. On a patient basis, rather than a per implant basis, the meta-analyses showed no statistically significant differences for prosthesis and implant failures, though trends, especially in fully edentulous patients, favoured two-stage (submerged) implants.

The number of patients included in the trials was too small to draw definitive conclusions. The one-stage approach might be preferable in partially edentulous patients since it avoids one surgical intervention and shortens treatment times, while a two-stage submerged approach could be indicated when an implant has not obtained an optimal primary stability, when barriers are used for guided tissue regeneration or when it is expected that removable temporary prostheses could transmit excessive forces on the penetrating abutments, especially in fully edentulous patients.