Is osteoporosis a risk factor for implant survival or failure?

Data sourcesAn electronic search was performed in PubMed, Web of Science and the Cochrane Library and SciELO databases up to September 2016. References of included studies were also searched. English language restriction was applied.Study selectionClinical monitoring studies with at least six months of follow-up, including retrospective studies, prospective studies, and controlled and randomised clinical trials. Clinical case studies were excluded from the sample and only studies with a minimum of five patients were considered. Adults with osseointegrated implants were considered for these studies. Exclusion criteria encompassed studies performed in vitro, animal studies, non-controlled clinical cases, studies with incomplete data or those unsuitable for data collection.Data extraction and synthesisFour reviewers were involved in the research and screening process and disagreements were resolved by discussion. The quality of the studies was analysed using the bias scale from the Australian National Health and Medical Research Council (NHMRC). Data extracted from the studies included, when available: author, year of publication, study country of origin, number of patients, number of implants and sites, implant type, implant length and diameter, oral rehabilitation installation time, peri-implant bone loss rate, survival rate of implants in each situation analysed, follow-up time of each study, study type and drugs administered for the treatment of osteoporosis. For binary outcomes (implant failure) the estimate of the intervention effect was expressed in the form of a relative risk (RR) with the confidence interval (CI) of 95%. For continuous outcomes (marginal bone loss) the average and standard deviation (SD) were used to calculate the standardised mean difference with a 95% CI. A statistical test was used to express the heterogeneity among the studies. Publication bias was explored as well.ResultsA total of 15 observational studies were included in the review. The total number of patients involved was 8859 (29,798 implants) and the average age was 63.03 years.The follow-up period ranged from 0.75 to 22 years with a mean of 5.85 years. The smallest diameter used was 3.3 mm and the shortest implant length was 7 mm.The relative risk (RR) of implant failure and mean marginal bone loss were analysed within a 95% confidence interval (CI). The main outcome of the meta-analysis indicated that there was no difference in implant survival rate between patients with and without osteoporosis, either at the implant level (RR 1.39, 95% CI 0.93-2.08; P = 0.11) or at the patient level (RR 0.98, 95% CI 0.50-1.89; P = 0.94). However, the meta-analysis for the secondary outcome revealed a significant difference in marginal bone loss around implants between patients with and without osteoporosis (0.18 mm, 95% CI 0.05-0.30, P = 0.005). Data heterogeneity was low. An increase in peri-implant bone loss was observed in the osteoporosis group.ConclusionsThe implant survival rate in bone tissue with osteoporosis was similar to that of the control group at the implant level (P = 0.11) and at the patient level (P = 0.94). In conclusion, implants placed in patients with systemic osteoporosis did not present higher failure rates than those placed in patients without osteoporosis.