Lactobacillus Reuteri in the Supportive Therapy of Periodontitis

Literature shows the potential effectiveness of L. reuteri as an adjunct to non-surgical periodontal therapy in initial treatment of periodontitis, but also underlines the limits of the conclusions, and the heterogeneity and limited sample size of the available studies. Therefore, there is a need for longer-term, randomized, controlled studies. Moreover, only one study addresses the use of this probiotic during the supportive therapy, in particular in patients with severe forms of periodontitis, and only few patients were included. Patients meeting the criteria of periodontitis stage III and IV, grade C are considered to be affected by severe and advanced forms of periodontitis with a rapid rate of progression. This group of patients could particularly benefit from supplements for the maintenance of periodontal health. The hypothesis of the present randomized controlled trial is that the adjunctive use of probiotic treatment can bring clinical and microbiological advantages during the supportive therapy of periodontal disease, and reduce the number of residual pockets. To test this hypothesis, the patients, upon initial evaluation, will be divided in 2 study groups and, after a session of professional oral hygiene, will be prescribed one of the therapies below: * PLACEBO: The patients of the control group will receive control lozenges without live bacteria; * TEST: The patients of the probiotic group will receive probiotic lozenges containing Lactobacillus reuteri DSM 17938 and Lactobacillus reuteri ATCC PTA 5289 (a minimum of 2 × 108 colony-forming units L. reuteri Prodentis/lozenge, BioGaia AB). The probiotic and control lozenges will be identical in taste, texture and appearance. The lozenges will be given to all patients to consume at home. The patients will be instructed to dissolve them on their tongue twice a day, preferably after brushing, for 3 weeks. Periodontal and microbiological parameters will be evaluated at 3 and 6 months after the initial ther