Evaluation of the Impact of Probiotic Supplementation on Gingival Inflammation in Subjects Undergoing Orthodontic Treatment with Fixed Appliances or Clear Aligners: A Randomized, Single-Blind Pilot Study

<b>Objectives:</b> Orthodontic patients are prone to developing gingivitis and require additional tools for maintaining oral hygiene and ensuring plaque control. The present study aimed to evaluate the effects of Bifidobacterium animalis subs. lactis HN019 on plaque accumulation and gingival bleeding in orthodontic patients. <b>Materials and Methods:</b> This study is a randomized, single-blind controlled trial. Orthodontic patients were grouped into two groups: subjects undergoing fixed orthodontic treatment and subjects undergoing treatment with a clear aligner. For each group, patients were divided into a test group (probiotic intake) and a control group (no probiotic intake). Patients took the probiotic for one month following a professional oral hygiene session, suspended its intake for 30 days, and then resumed it for another month. Full Mouth Plaque Score (FMPS) and Full Mouth Bleeding Score (FMBS) were collected at all timesteps. <b>Results:</b> In fixed orthodontics patients, the results show that the average FMPS improved at every timestep in both groups, especially for the test group, decreasing from 56.20 ± 27.7 to 36.47 ± 23.90. The data show a worsening FMBS during the period when patients do not take the probiotic, from 3.13 ± 3.50 to 6.53 ± 7.42. For the clear aligner patients, the comparison between groups suggests that the plaque index particularly improves for the test group during the period when patients are taking the probiotic, from 43.45 ± 19.52 to 25.93 ± 15.67 and from 26.60 ± 15.79 to 18.93 ± 17.99, respectively. For the bleeding index, data analysis shows a progressive improvement in FMBS at all timesteps in the test group, from 6.93 ± 7.00 to 2.60 ± 2.75. <b>Conclusions:</b> The intake of probiotics is useful in decreasing bacterial plaque accumulation and gingival bleeding in orthodontic patients.