Efficacy of strontium supplementation on implant osseointegration under osteoporotic conditions: A systematic review

Strontium has been validated for potent bone-seeking and antiosteoporotic properties and elicits a potentially beneficial impact on implant osseointegration in patients with osteoporosis. However, the efficacy of strontium supplementation on improving new bone formation and implant osseointegration in the presence of osteoporotic bone is still unclear.The purpose of this systematic review was to comprehensively assess the efficacy of strontium supplementation, encompassing oral intake and local delivery of strontium, on implant osseointegration in patients with osteoporosis.Searches on electronic databases (MEDLINE or PubMed, Web of Science, EBSCO, Embase, and Clinicaltrials.gov) and manual searches were conducted to identify relevant preclinical animal trials up to June 2020. The primary outcomes were the percentage of bone-implant contact and bone area; the secondary outcomes were quantitative parameters of biomechanical tests and microcomputed tomography (μCT).Fourteen preclinical trials (1 rabbit, 1 sheep, and 12 rat), with a total of 404 ovariectomized animals and 798 implants, were eligible for analysis. The results revealed a significant 17.1% increase in bone-implant contact and 13.5% increase in bone area, favoring strontium supplementation despite considerable heterogeneity. Subgroup analyses of both bone-implant contact and bone area exhibited similar outcomes with low to moderate heterogeneity. Results of biomechanical and μCT tests showed that strontium-enriched implantation tended to optimize the mechanical strength and microarchitecture of newly formed bone despite moderate to generally high heterogeneity.Based on the available preclinical evidence, strontium supplementation, including local and systemic delivery, showed promising results for enhancing implant osseointegration in the presence of osteoporosis during 4 to 12 weeks of healing. Future well-designed standardized studies are necessary to validate the efficacy and safety of strontium supplementation and to establish a standard methodology for incorporating Sr into implant surfaces in a clinical setting.