Role of local alendronate delivery on the osseointegration of implants: a systematic review and meta-analysis

There is controversy regarding whether locally delivered alendronate enhances osseointegration. The aim of this systematic review was to assess the role of local alendronate delivery (topical, or as a coating on implant surfaces) in the osseointegration of implants. The focused question was, "Does the local delivery of alendronate affect osseointegration around implants?". To address this question, indexed databases were searched, without time or language restriction, up to and including January 2017. Various combinations of the following key words were used: "alendronate", "bisphosphonates", "osseointegration", and "topical administration". letters to the editor, historic reviews, commentaries, case series, and case reports were excluded. In total, 18 experimental studies were included: alendronate-coated implants were used in 13 of these studies and local delivery in five studies. The results of 11 of the studies showed that alendronate coating increased new bone formation, the bone volume fraction, or bone-to-implant contact (BIC) and biomechanical properties. Results from two studies in which alendronate was administered topically indicated impaired BIC and/or biomechanical fixation around implants. On experimental grounds, local alendronate delivery seems to promote osseointegration. From a clinical perspective, the results in animal models support phase 1 studies in healthy humans (without co-morbidities other than edentulism).