Clinical, microbiological and immunological short, medium and long-term effects of different strains of probiotics as an adjunct to non-surgical periodontal therapy in patients with periodontitis. Systematic review with meta-analysis

INTRODUCTION/OBJECTIVES: Probiotics have been proposed as adjuncts to non-surgical periodontal therapy (NSPT), however, the effect of their use remains unclear. The aim of this systematic review and meta-analysis was to analyze the evidence regarding the use of probiotics as an adjunct to NSPT in patients with periodontitis at a clinical, microbiological and immunological level. DATA/SOURCES: A comprehensive search to identify clinical studies investigating the use of probiotics as an adjunct to NSPT in patients treated for periodontitis was performed. The data were grouped according to probiotic strain, frequency, form and duration of the probiotic intake. STUDY SELECTION: A total of 25 articles were included, all articles analysed clinical parameters, 10 included also microbiological findings and only 4 had immunological findings. The difference in probing depth (PD) between the test and the control group was statistically significant in favour of the test group when the probiotics were in the form of lozenges, administered twice a day and when the strain was L. reuteri. In terms of Clinical Attachment Level (CAL) gain the difference was statistically significant in the short and in the medium term but not in the long term. Due to the heterogeneity of the data, it was not possible to compare trough a meta analysis the immunological and the microbiological findings that were therefore analysed only descriptively. CONCLUSIONS: The use of probiotics as an adjunct to NSPT in patients with periodontitis appears to provide additional clinical benefits that depend on the duration, the frequency, the form and the strain of probiotic used. CLINICAL SIGNIFICANCE: This review not only shows data on the efficacy of probiotics in non-surgical periodontal therapy, but provides important information on their effects over time and which forms of probiotic administration might be most clinically useful.