Additional clinical benefits of probiotics as an adjunctive therapy to nonsurgical periodontal treatment of periodontitis: a systematic review and meta-analysis

Abstract Background: With more and more concerns concentrated on the novel therapy applying probiotics, we challenge its trustworthy clinical efficacy as an adjuvant to scaling and root planning (SRP) as compared with SRP alone or combined with placebo applied as the initial therapy of periodontitis. Methods: Electronic databases retrieval, a grey literature and a hand search were performed until February 2020 under certain screening condition. Clinical randomized controlled trials (RCTs) to assess the efficacy of SRP + probiotic versus SRP treating systemically healthy and nonsmoker individuals diagnosed with periodontitis were included. Primary outcome variables were PPD (pocket probing depth) reduction, CAL (clinical attachment level) gain and the percentage of BOP (bleeding on probing) reduction. Results: After screening, eleven publications were eligible for the systematic review and ten were evaluated in the meta-analysis. Results demonstrated statistically significant more overall PPD reduction at 1 month (0.48mm, p=0.005), overall CAL gain at 1 (0.35mm, p=0.004) and 3 months (0.13mm, p=0.04) and BOP percentage reduction (10.38, p=0.001) at short-term and 6 months (7.57, p< 0.00001) favoring SRP + probiotics treatment. Moreover, significant more reduction of PPD for moderate (0.19mm, p< 0.00001) and deep pockets (0.58mm, p< 0.00001) and gain of CAL for moderate pockets (0.20mm, p=0.0001) were observed at 3 months favoring adjunctive efficacy of probiotics. However, there were not a significant difference of overall PPD reduction at 3 (0.14mm, p=0.07) and 6 months (0.2mm, p=0.26) and overall CAL gain at 6 months (0.19mm, p=0.53) between two groups. Conclusions: Within the ranges of this study, the adjunctive use of probiotics seem to achieve short-term clinical benefits in the treatment of periodontitis. Conclusions must be treated with caution because of high heterogeneity among included studies and future long-term RCTs are needed to testify the clinical application value of probiotics.