Objectives: To determine if periodontitis patients benefit from treatment with Lactobacillus brevis and Lactobacillus plantarum strains, applied into periodontal pockets as gel and thereafter taken as lozenges, as an adjunct to scaling and root planing (SRP).
Materials and methods: In a double-blind, randomized, placebo-controlled trial, 40 patients received scaling and root planing (SRP) in two sessions within 7 days. Patients then received either probiotic gel and lozenges (n = 20) or placebo (n = 20). The primary outcome variable was the number of diseased sites (DS: PD > 4 mm + BOP) at the 3-month re-evaluation. The effects of gender, age, probiotic therapy, presence of Porphyromonas gingivalis or Aggregatibacter actinomycetemcomitans, smoking, tooth being a molar and interdental location were evaluated using a multivariate multilevel logistic regression model.
Results: The number of DS after 3 months was similar in the test (Me = 8, IQR = 5-11) and control (Me = 5, IQR = 1-10) groups. Both groups showed substantial but equivalent improvements in periodontal parameters. The logistic regression showed higher odds for the healing of gingival bleeding (OR = 2.12, p = 0.048) and lower odds for the healing of DS (OR = 0.51; p < 0.001) in the probiotic group.
Conclusions: Patients with periodontitis benefit from adjunctive use of probiotics containing L. brevis and L. plantarum in terms of reduction of gingival bleeding. However, adjunctive probiotics increase the number of persisting diseased sites with PD > 4 mm and BOP.
Clinical relevance: The adjunctive use of probiotics containing L. brevis and L. plantarum strains in treating chronic periodontitis results in a higher number of residual diseased sites when compared with SRP + placebo; its use is therefore unfounded.
Keywords: Lactobacillus brevis; Lactobacillus plantarum; Periodontitis; Probiotic; Scaling and root planing.