Clinical and microbiological effects of a propolis toothpaste in patients with periodontitis under supportive periodontal therapy: a randomized double-blind clinical trial

Objectives Propolis possesses antibacterial, anti-inflammatory, and antioxidant properties. While its application in oral care has garnered significant attention, evidence supporting its effectiveness against periodontal bacteria is limited. This study used a randomized double-blind protocol to assess the safety and efficacy of toothpaste containing propolis compared to a placebo in patients undergoing supportive periodontal therapy (SPT).
Materials and methods Thirty-two participants in SPT were randomized into two groups: toothpaste containing 2.5% ethanol-extracted propolis (EEP) and a placebo without EEP. Participants brushed twice daily for four weeks, and clinical parameters, bacterial counts, and salivary characteristics were assessed before and after the intervention.
Results The propolis group showed a significant reduction in periodontal pocket depth (P = 0.006), with a mean depth of 3.80 mm compared to 4.35 mm in the placebo group. Bleeding on probing was significantly reduced in both groups (P = 0.032 in the propolis group and 0.0498 in the placebo group), but did not differ between groups. Total bacterial and Porphyromonas gingivalis (P. gingivalis) counts did not differ significantly between the groups; however, the number of patients with decreased P. gingivalis was slightly larger than those in the placebo group (not significant). Additionally, saliva acidity decreased significantly in the propolis group (P = 0.041), suggesting a shift toward a less pathogenic oral environment. No adverse events were observed.
Conclusion These findings suggest that propolis may contribute to stabilizing periodontal disease during supportive periodontal therapy by modulating salivary acidity.
Clinical relevance Periodontal pocket depth and the rate of bleeding on probing are reduced, along with decreased saliva acidity. Meanwhile, the levels of P. gingivalis in the periodontal pockets remain low. Propolis-dentifrice may help alleviate gingival inflammation during SPT.
Clinical trial registration Registered in the University Hospital Medical Information Network Clinical Trial Registry (ID: UMIN000029554).

The version of record of this article, first published in Clinical Oral Investigations, is available online at Publisher’s website: http://dx.doi.org/10.1007/s00784-025-06456-5