A systematic review of single-tooth restorations supported by implants.

OBJECTIVES To make an inventory of clinical studies on single-tooth restorations supported by implants using a systematic review procedure and to aggregate overall survival results. DATA SOURCES Papers referring to single-tooth implants were located by a MEDLINE search 1990 to April 1998. Three hundred and twenty references were found, and they were subjected to a systematic review procedure. STUDY SELECTION A three-step inclusion/exclusion procedure was applied to identify papers that represented: good scientific practice (GSP), reported results of all patients, implants and crowns for more than 2years, and had sufficient data to generate life-table analyses. The outcomes were 'implant failure' and 'crown completion'. Nine studies survived. These data showed an overall mean GSP of 0.37 with a predicted 4year implant survival of 97% (n=459), and an uncomplicated crown maintenance of 83% (n=240). CONCLUSION Single-tooth implants show an acceptable short-term survival of 4years, but crown complications are common.