Is oral lichen planus a risk factor for peri-implant diseases? A systematic review and meta-analysis

Abstract Background : To evaluate whether oral lichen planus (OLP) is a risk factor for peri-implant diseases (PIDs) with a systematic review and meta-analysis. Methods : Six electronic databases including Medline, Web of Science, etc. were searched. Included studies are observational human studies written in English. Population of interest were those with/without OLP who received dental implant treatment. Follow-up time after implantation is from one month to 20 years. The quality of the included literature regarding risk of bias and methodology was assessed with Newcastle-Ottawa Scale or the Agency for Healthcare Research and Quality. The data involving exposure (OLP), primary outcomes (implants having PIDs) and secondary outcomes (probing depth/PD, bleeding on probing/BOP and bone loss/BL) and potential confounders were extracted. Heterogeneity was assessed by I² tests. Dichotomous data were expressed as risk ratio (RR) and 95% confidence interval (CI) which were calculated with a fixed effect model. Results : Of 139 literatures, two studies were enrolled and evaluated as high quality, which totally contained 68 participants receiving 222 (OLP vs. non-OLP, 112 vs. 110) implants with 12 to 120-month follow-up time. Proportions of implants with PIDs between OLP and non-OLP groups were as follows: 19.6% (22/112) vs. 22.7% (25/110) for PIM; 17.0% (19/112) vs. 10.9% (12/110) for PI. Meta-analysis found no recognizable difference in number of implants with PIDs (PI: RR = 1.49, 95% CI 0.77-2.90, P = 0.24; PIM:RR = 0.88, 95% CI 0.53 -1.46, P = 0.61; PIDs: RR = 1.08, 95% CI 0.75 -1.55, P = 0.68) or BOP (RR = 0.90, 95% CI: 0.70-1.15, P = 0.40) between OLP and non-OLP groups. Conclusions : Available literature regarding the effects of OLP on PIDs remains very limited. Existing evidence seems not support OLP as a suspected risk factor for PIDs. Large-scale prospective trials are required to test the findings. Keywords : dental implants; peri-implant diseases; oral lichen planus; systematic review; meta-analysis.