Efficacy of systemic bisphosphonate delivery on osseointegration of implants under osteoporotic conditions: Lessons from animal studies

Background The aim was to systematically review the role of systemic bisphosphonate (BP) delivery on osseointegration of implants under osteoporotic conditions. Methods The addressed focused question was "Does systemic BP delivery enhance osseointegration of implants under osteoporotic conditions?" PubMed/MEDLINE and Google-Scholar databases were searched from 1994 up to and including December 2013 using different combinations of the following keywords: "bone to implant contact", "implant", "bisphosphonate", "osseointegration" and "osteoporosis". Review articles, case-reports, commentaries, letters to the Editor, unpublished articles and articles published in languages other than English were excluded. Results Fifteen animal studies fulfilled our eligibility criteria. Osteoporotic conditions were induced via bilateral ovariectomy (OVX). BPs used in the studies were ibandronate, zoledronic acid and alendronate. Results from 12 studies showed that systemic BP delivery significantly increased bone volume and bone-to-implant contact under osteoporotic conditions. Two studies reported no significant difference in osseointegration among OVX animals with and without systemic BP delivery. In one study, systemic BP delivery negatively influenced implant osseointegration. Rough-surfaced and polished implants were used in 11 and one study respectively. In 3 studies implant surface characteristics remained unclear. Conclusion Within the limits of the present study, it is concluded that systemic BP delivery enhances implant osseointegration in animals with induced osteoporotic conditions. However, in a clinical scenario, the potential risk of BP related ONJ in osteoporotic patients undergoing dental implant therapy cannot be disregarded.