Microbiota of exposed root surfaces after fluoride, chlorhexidine, and periodontal maintenance therapy: A 3-year evaluation

Background: Fluoride and chlorhexidine (CHX) are state-of-the-art preventive measures for remineralizing teeth and for preventing plaque accumulation. The aim of this study was to examine the effects of fluoride and CHX varnishes on root caries and microbiota located on root surfaces. Methods: Thirty-three patients from a periodontal maintenance program, having at least one tooth with gingival recession in each quadrant, participated in this study. One tooth per quadrant was assigned randomly to the control group or to one of the test groups that were treated with fluoride varnish, 1% CHX, or 40% CHX. The varnish treatment and the tooth cleaning were repeated every 3 months. Clinical examinations were performed at baseline and once a year for 3 years. Caries status and oral hygiene indices were evaluated clinically. The total cultivable microbiota and percentage of Mutans streptococci (MS), Actinomyces (ACC), and lactobacilli (LB) were analyzed. Results: Oral hygiene was improved greatly during the course of the study. The percentage of MS, ACC, and LB of the total cultivable microbiota revealed a statistically significant reduction between baseline and final examination for each of the four groups. Conclusion: Professional tooth cleaning alone at 3-month intervals might be as effective in reducing MS, ACC, and LB as adjunctive treatment with fluoride or chlorhexidine.