Data sources: Medline, the Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews, Database of Abstracts of Review of Effect, Science Direct, and SCOPUS databases were searched. A manual search was performed of issues of the last 15 years of the Journal of Periodontology, International Journal of Periodontics and Restorative Dentistry, Journal of Clinical Periodontology, Journal of Dental Research, Journal of Periodontal Research, Journal of Dentistry, Clinical Oral Investigations, Clinical Oral Implant Research and Clinical Implant Dentistry and Related Research.
Study selection: Prospective cohort studies that compared patients with periodontal disease (PD) to periodontally healthy patients and that reported data on implant loss, peri-implant bone changes or incidence of peri-implantitis were included. Case series, reviews, case reports and retrospective studies were not included.
Data extraction and synthesis: Study selection and risk of bias assessment using the Newcastle-Ottawa Scale was undertaken independently by two reviewers. Dichotomous data were expressed as risk ratios (RRs) and 95% confidence intervals (CIs). Continuous data were expressed as standardised mean differences (SMDs) and random-effects meta-analysis conducted.
Results: Fourteen studies were included with sample sizes ranging from 10-717. Meta-analysis (11 studies) showed a higher and significant risk for implant loss in patients affected by PD (RR: 1.89, 95% CI: 1.35-2.66, P = 0.0002) with no evidence of heterogeneity (v2 = 4.31, P = 0.93; I2 = 0%). Significant implant bone loss was present in patients with PD compared with periodontally healthy patients (SMD: 0.44, 95% CI: 0.19-0.69, P = 0.0006) (three studies), with no evidence of heterogeneity (v2 = 2.463, P = 0.27; I2 = 24%). Periodontally compromised patients also showed an increased risk of peri-implantitis compared with patients without PD (RR: 2.21, 95% CI: 1.42-3.43, P = 0.0004), with moderate but not significant heterogeneity (v2 = 7.35, P = 0.12; I2 = 46%). Meta-analysis (seven studies) found that patients with both aggressive and chronic periodontitis had an increased risk of implant loss. The risk was greater for patients with aggressive periodontitis (RR: 4.04, 95% CI: 1.81-8.98, P = 0.0006) compared with patients with chronic periodontitis (RR: 1.59, 95% CI: 1.10-2.32, P = 0.01).When stratifying only those patients with chronic periodontitis, those with severe periodontitis had increased risks of implant loss (RR: 1.89, 95% CI: 1.16-3.07, P = 0.01). Higher risks were also seen for patients with moderate (RR: 2.54, 95% CI: 0.65-9.93, P = 0.18) and severe periodontitis (RR: 3.12, 95% CI: 0.92-10.57, P = 0.07).
Conclusions: Strong evidence suggests that periodontitis is a risk factor for implant loss; moderate evidence revealed that periodontitis is a risk factor for peri-implantitis and that patients with periodontitis have higher implant-bone loss.