Systematic review of bone- versus tissue-level dental implants

Objective: The aim of the present systematic review was to address the focused question: “In patients treated with dental implants placed in pristine bone, what are the clinical outcomes of bone-level implants placed in a single or 2-staged procedure versus tissue-level, 1-stage implants, following prosthesis placement?” Methods: The search strategy incorporated scanning of online databases supplemented by hand searching of major related journals. An electronic search on MEDLINE, EMBASE, and CENTRAL (Cochran Central Register of Controlled Trials) was conducted through July 2009 to identify prospective randomized controlled trials, controlled clinical trials, and cohort studies using a combination of MeSH terms and text words, without language restrictions. A three-stage screening process was performed independently and in duplicate. Any disagreement was resolved by discussion between the two reviewers, and when necessary, a third internal reviewer was consulted. Results: The search strategy revealed in total 3,956 articles. The first stage of screening resulted in 498 papers while the second screening at the abstract level yielded 63 publications. Full text reading identified 11 articles that fulfilled the inclusion criteria and they were finally included in the systematic review. The survival rates of both implant types were very high for a follow-up period of up to 3 years (range 93-100%). The marginal bone loss and the incidence of peri-implantitis were small for bone- and tissue-level dental implants. Primary data revealed no differences between the two implant systems for additional clinical parameters including peri-implant sulcus depth, bleeding on probing, and plaque accumulation. Conclusions: No differences in clinical outcomes were detected between bone- and tissue-level dental implants. Both implant systems meet the requirements for dental treatment of mandibular/maxillary, partial/full edentulism.