Reports & Studies

Can probiotics be used in maintenance therapy?

PD Dr. Kristina Bertl, PhD MSc MBA

The article ‘Probiotics in periodontal treatment – an overview’ took a first look at the potential role of probiotics in periodontal therapy. The review presented in that article was from 2016. Since then, however, several new studies on this topic have been published, one of which had an interesting approach: Can probiotics be used in maintenance therapy?

In general, although adjuvants in non-surgical periodontal therapy often have a statistically significant effect, their clinical impact tends to be minimal. Among other reasons, this is why many studies are increasingly concentrating on a more targeted use of adjuvants in maintenance therapy, for the treatment of residual pocket probing depths. The aim of this is to hopefully spare patients from undergoing a surgical procedure.

This was the case in the study by Laleman et al. (2019), who tested the use of probiotics (Lactobacillus reuteri) as an adjunct to mechanical re-instrumentation of residual pockets after non-surgical periodontal therapy. The study involved 39 patients who had previously received standard periodontal treatment but were still exhibiting increased pocket probing depths (pocket probing depths ≥ 6 mm or 5 mm with bleeding). These sites were re-cleaned mechanically. Subsequently, half of the patients took probiotic lozenges for 12 weeks, whereas the other half took a placebo. The final evaluation took place after 24 weeks.

Overall, the probiotic group showed a statistically significant additional improvement in pocket probing depth, and the larger the pocket probing depth at the start of the study, the greater the difference. However, perhaps an even more important parameter – particularly from the patients’ point of view – is how many pocket probing depths still required surgical intervention after this treatment. Here, too, the probiotic group had an advantage: After treatment, almost 15% more sites in the probiotic group had pocket probing depths of ≤ 3 mm, and only 4% of sites required surgical intervention (compared with 8% in the control group). Furthermore, the number of teeth that subsequently required surgical intervention was almost 10% lower in the probiotic group (15 vs. 24%).

A slight limitation of this study is that, despite randomization, the control group had a worse periodontal baseline status in certain parameters. It will therefore be exciting to see what future studies on this topic will reveal.


  1. Laleman I, Pauwels M, Quirynen M, Teughels W. A dual‐strain Lactobacilli reuteri probiotic improves the treatment of residual pockets: A randomized controlled clinical trial. J Clin Periodontol. 2019;00:1–11.