Oral hygiene can be challenging to maintain while undergoing orthodontic treatment. For instance, fixed orthodontic treatments may cause the tooth surface to trap food or certain unwanted microbes such as Streptococcus mutans (S. mutans). S. mutans is the primary microbe associated with dental caries. Gingival inflammation, enamel demineralization, and a higher risk of dental caries may also occur. Recent evidence suggests that certain probiotics may help support oral health and dental hygiene in the presence of orthodontic treatment.

A recently published systematic review and meta-analysis by Chen and colleagues explored the potential association between probiotic supplementation and orthodontic health. This study included data from 15 randomized controlled trials involving fixed orthodontic appliances. Sample sizes of each study were between 24 and 85, involving participants between 8 and 35 years of age. The study durations were between 2 weeks and 6 months. The probiotics used in each study varied; however, Lactobacillus strains were most used. 

This meta-analysis and systematic review included studies with varied delivery methods for probiotics. A study by Jose and colleagues evaluated the efficacy of a probiotic toothpaste on S. mutans populations around orthodontic brackets. Significant decreases in S. mutans plaque levels were reported at the end of this 30-day treatment period. Another study using a probiotic mouthwash reported significant decreases in Porphyromonas gingivalis levels after 6 months when compared with placebo. The probiotic mouthwash included L. reuteri, L. rhamnosus, Bifidobacterium longum, and B. bifidum. 

One study by Shah and colleagues included in this review concluded that the probiotic treatment group experienced significant decreases in gingival inflammation and plaque build-up. Other conclusions from individual studies were less definitive. Overall results from the meta-analysis indicate that certain subgroup participants experienced significant reductions of S. mutans populations in the presence of probiotic supplementation when compared with placebo. In addition, probiotic administration was reported to help significantly reduce the likelihood of increasing S. mutans populations during the treatment periods. The authors report that, overall, there is insufficient evidence to make clinical conclusions, and the clinical implication of reductions in S. mutans populations is currently unknown. 

Drawbacks to the meta-analysis include small sample sizes and relatively short study durations. In addition, because varying delivery methods, probiotic strains, and treatment amounts were used in the RCTs evaluated, comparisons may not be truly achievable. Still, the conclusions from this study suggest that further research is merited. 

Probiotics have the potential to influence many aspects of oral and human health. Recent evidence suggests that certain probiotics may also help support oral hygiene, the inflammatory response, and orthodontic health. 

By Dr. C. Ambrose, ND, MAT