Eligible studies were prospective studies with at least five patients in each study arm that had five rough surface dental implants (<10mm) as well as at least five rough surface (≥10mm). Eligible studies needed to report (or include data that allowed calculation of) the total number of implants placed and the number that survived. Studies needed to have follow-up of 12 months or more.
Studies with an unclear or mixed design were excluded from the review. Also excluded were studies with patients who smoked more than 10 cigarettes a day and studies that included patients with medical or systemic diseases that could potentially affect implant survival (such as malignant tumours, HIV). Studies were excluded if the dental implant was placed in a periodontally compromised patient without previous periodontal therapy.
An implant was defined as surviving if it was not lost. Totally edentulous was defined as having no natural teeth in either jaw. Data were presented separately for totally edentulous and partially edentulous patients. Implants of 8mm or less and 10mm or less were defined as short implants. Implants of 10mm or more were defined as conventional length.
The primary outcome of interest was the percentage of implants that survived out of the total number placed. There were no secondary outcomes of interest.
Types of restorations included: implant-retained overdentures with bar or ball attachments, implant-supported fixed partial restorations (dentures), implant-supported single tooth restorations (crowns), implant-supported fixed partial restoration dentures (short span), implant/tooth supported fixed partial restorations/dentures (long-span) and implant-supported fixed partial restorations/dentures with a mesial or a distal cantilever. Single tooth implants were either splinted or non-splinted.
Two reviewers independently selected studies for inclusion in the review. Any disagreements were resolved by discussion.