Clinical, Microbiological and Immunological Evaluation of the Effects of Systemic Probiotics in the Periodontal Treatment

Brief Summary

Detailed Description

The association of scaling and root planing (SRP) with systemic metronidazole (MTZ) and amoxicillin (AMX) has been advocated as one of the most promising therapeutic protocol for the treatment of advanced periodontitis, since the early 2000's. More recently, probiotics has also been suggested as a promising adjunctive treatment for periodontitis due to their antimicrobial and anti-inflammatory properties. Therefore, the aim of this study is to evaluate the clinical, microbiological and immunological effects of probiotics as an adjunct to SRP alone or in combination with MTZ and AMX in the treatment of periodontitis. In this randomized, double-blind, placebo-controlled trial, subjects with periodontitis will be randomly assigned to receive (i) SRP alone, or combined with: (ii) two probiotics lozenges a day for 90 days (Prob), (iii) 400 of MTZ, plus AMX (500 mg) thrice a day (TID) for 14 days (MTZ+AMX), or (iv) Prob and MTZ+AMX. Subjects will be monitored up to 1 year post-therapy. Nine subgingival plaque samples will be collected at baseline and at 3, 6 and 12 months post-therapy; three samples in each of the following pockets categories: shallow (probing depth \[PD\]≤3 mm), moderate (PD=4-6 mm) and deep (PD≥7 mm). The microbiological samples will be analyzed by checkerboard DNA-DNA hybridization for 40 bacterial species. Two non-contiguous diseased sites (i.e PD and CAL ≥ 5mm, bleeding and probing \[BOP\] and no furcation involvement) and two non-contiguous healthy sites (i.e. PD and clinical attachment level \[CAL\] ≤ 4 mm without BoP and/or marginal bleeding) will be randomly chosen per patient for gingival crevicular fluid (GCF) sampling, from the same sites selected for the microbiological monitoring. Peripheral blood samples will also be collected one week after clinical examination. The GCF and blood samples will be analyzed using a multi-analyte method by means of a 17-multiplex fluorescent bead-based immunoassay for 17 cyto/chemokines. The significance of differences over the course of the study will be sought using repeated measures ANOVA and Tukey multiple comparison tests, and at each time point (among groups) using either ANOVA and Tukey multiple comparison tests or ANCOVA with adjustments for the baseline values. The Chi-square test will be used to compare the differences in the frequency of gender, and to compare the differences in the frequency of subjects achieving the clinical endpoint at 1 year and of self-perceived adverse effects. A stepwise forward logistic regression analysis will be performed in order to investigate the impact of predictor variables on the clinical endpoint for treatment, i.e., "presence of ≤4 sites with PD≥5 mm at 12 months post-therapy (yes/no)". The Number Needed to Treat (NNT) with adjunctive antibiotic in order to obtain treatment success (≤4 sites with PD ≥5 mm) will be calculated. The level of significance will be set at 5%.

Primary Outcomes

Secondary Outcomes

• Mean CAL changes in sites with initial CAL between 4-6 mm(Baseline - 12 months)
• Mean CAL changes in sites with initial CAL ≥ 7 mm.(Baseline - 12 months)
• Number of sites with PD ≥ 7 mm.(Baseline, 3, 6 and 12 months)
• Change in the number of sites with PD ≥ 6 mm(Baseline, 3, 6 and 12 months)
• Mean PD changes in sites with initial PD between 4-6 mm(Baseline - 12 months)
• Mean PD changes in sites with initial PD ≥ 7 mm.(Baseline - 12 months)
• Change in the number of sites with PD ≥ 5 mm.(Baseline, 3, 6 and 12 months)
• Number of sites with PD ≥ 6 mm.(Baseline, 3, 6 and 12 months)
• Percentage of sites with bleeding on probing(Baseline, 3, 6 and 12 months)
• Percentage of sites with plaque accumulation(Baseline, 3, 6 and 12 months)
• Occurrence of vomiting obtained through a questionnaire of adverse effects(90 days after taking probiotic)
• Occurrence of diarrhea obtained through a questionnaire of adverse effects.(90 days after taking probiotic)
• Number of sites with PD ≥ 5 mm.(Baseline, 3, 6 and 12 months)
• Change in the number of sites with PD ≥ 7 mm(Baseline, 3, 6 and 12 months)
• Percentage of sites with marginal bleeding(Baseline, 3, 6 and 12 months)
• Proportions of periodontal pathogenic bacterial species.(Baseline, 3, 6 and 12 months)
• Counts of chemokines in the peripheral blood samples(Baseline and 12 months)
• Full-mouth Probing Depth (mm).(Baseline, 3, 6 and 12 months)
• Full-mouth Clinical Attachment Level (mm)(Baseline, 3, 6 and 12 months)
• Occurrence of headache obtained through a questionnaire of adverse effects(90 days after taking probiotic)
• Counts of periodontal pathogenic bacterial species.(Baseline, 3, 6 and 12 months)
• Occurrence of nausea obtained through a questionnaire of adverse effects.(90 days after taking probiotic)
• Counts of chemokines in the crevicular gingival fluid.(Baseline and 12 months)