CBD against periodontitis: New study shows promising effect on oral biofilms

New Study Investigates CBD Against Periodontitis Bacteria

Periodontitis is one of the most common chronic inflammatory diseases worldwide. It arises from an imbalance in the oral flora, where pathogenic bacteria gain the upper hand and promote inflammation of the gums as well as the breakdown of the tooth-supporting apparatus. While mechanical cleaning of tooth surfaces and root areas remains the gold standard, scientists are searching for complementary agents that can specifically reduce disease-promoting bacteria. A recent study, published at the end of 2025 in the Journal of Oral Microbiology, therefore investigated the antimicrobial effect of cannabidiol (CBD) on a complex subgingival biofilm. The research group analyzed the effect of CBD against periodontitis on a total of 33 different bacterial species typically found in periodontal biofilms.

Why Are Biofilms So Problematic in Periodontitis?

A dental biofilm is much more than just dental plaque. It is a highly organized community of microorganisms embedded in a protective matrix. This structure offers numerous advantages to the bacteria:

• Protection from immune defense mechanisms
• Higher resistance to antimicrobial agents
• Improved communication between microorganisms
• Increased survival capability under unfavorable conditions

Particularly critical are the so-called "Red-Complex" bacteria. This group includes, among others:

Porphyromonas gingivalis

This germ is considered one of the most important triggers of chronic periodontitis. It influences the body's immune response and promotes tissue destruction.

Tannerella forsythia

This pathogen is also closely associated with advanced periodontal diseases. The stronger the presence of these bacteria in the biofilm, the higher the risk usually is for gum inflammation, bone loss, and tooth loss. These germs are crucial for the assessment of CBD oral health in the context of the study.

Study Design: How Was the Effect of CBD Tested?

The researchers developed a complex laboratory model with 33 different bacterial species. Two different application scenarios were examined:

Protocol A: Early Application During Biofilm Formation

CBD was applied during the formation of the biofilm. Concentrations tested were:

• 125 µg/ml
• 250 µg/ml
• 500 µg/ml

Chlorhexidine (CHX 0.12%) served as a comparison, currently regarded as the gold standard of chemical plaque control.

Protocol B: Application on Already Mature Biofilm

Here, an already established biofilm was treated twice daily for one minute. Tested were:

• CBD against periodontitis 500 µg/ml
• CBD against periodontitis 1000 µg/ml
• Chlorhexidine 0.12%

Subsequently, the researchers analyzed the total bacterial count as well as changes in individual bacterial groups.

Results: CBD Reduces Disease-Promoting Bacteria

The results were remarkable. Even at a concentration of 500 µg/ml, CBD was able to significantly reduce the total number of bacteria. Even more interesting was the change in microbial composition.

Fewer Red-Complex Bacteria

CBD significantly decreased the proportion of particularly aggressive Red-Complex bacteria. Especially affected were:

1. Porphyromonas gingivalis
2. Tannerella forsythia

Both are considered key pathogens of periodontitis. This confirms the relevance of CBD antibacterial effect in the oral biofilm.

Promotion of Health-Associated Bacteria

In the second experiment, CBD at 1000 µg/ml additionally showed an increase in the so-called Green Complex. This bacterial group is rather associated with a healthy periodontal condition. The authors see this as a possible indication of a so-called "rebiosis effect" – that is, a restoration of the microbial balance in the mouth.

CBD versus Chlorhexidine

Chlorhexidine still showed the strongest overall antibacterial effect. It reduced more bacterial species and lowered the total germ count more than CBD. Nevertheless, CBD achieved comparable effects in several areas. Particularly interesting for the researchers: CBD appears to act more selectively than chlorhexidine and could therefore possibly preserve beneficial bacteria to a greater extent.

What Advantages Could CBD Offer in Periodontology?

In addition to its antibacterial effect, cannabidiol possesses other properties that could be relevant for dentistry.

Anti-Inflammatory Effects

Earlier studies have already shown that CBD can reduce pro-inflammatory cytokines. This could help to alleviate swelling, tissue breakdown, and chronic inflammatory processes.

Lower Risk of Side Effects

Chlorhexidine can cause undesirable effects with long-term use:

• Tooth discoloration
• Taste disturbances
• Mucosal irritations
• Changes in the oral flora

CBD could potentially represent a more tolerable alternative in the future.

Potential for New Therapies

Possible examples include:

• CBD mouthwashes
• CBD products for sucking
• Individual carrier trays with CBD
• Combinations of CBD and conventional periodontitis therapies

Limitations of the Study

Despite the promising results, the authors urge caution. The investigation was conducted exclusively in the laboratory. The main limitations include:

• No application in humans
• Limited number of bacterial species tested
• Small sample size
• No investigation of clinical healing processes

Therefore, the results cannot yet be directly transferred to patients. Only clinical studies with larger participant numbers can show whether the observed effects also occur in the human mouth.

Conclusion: CBD Could Complement the Future of Periodontitis Therapy

The current study provides the first convincing evidence that cannabidiol can positively influence the composition of a complex subgingival biofilm. Particularly relevant is the inhibition of key periodontitis pathogens such as Porphyromonas gingivalis and Tannerella forsythia. At the same time, CBD seems to affect health-promoting bacteria less than classic antiseptics. Whether CBD can be used in the future as a mouthwash, lozenges, or complementary periodontitis therapy must be shown by further clinical studies. However, the available data suggest that cannabidiol belongs to the most interesting new research approaches in the field of oral microbiome modulation.

FAQ: Frequently Asked Questions About CBD Against Periodontitis

Is CBD Against Periodontitis Scientifically Proven?

Currently, there are initial in-vitro studies showing that CBD has antibacterial effects against typical periodontitis pathogens such as Porphyromonas gingivalis and Tannerella forsythia. However, clinical studies in humans are still lacking.

Can CBD Really Improve Oral Health?

The data suggest that CBD could support oral health by reducing inflammatory processes and inhibiting certain pathogenic bacteria in the biofilm. However, a medical application is not yet officially established.

How Does CBD’s Antibacterial Effect Work in the Mouth?

CBD seems to influence the composition of biofilms. In particular, problematic “Red-Complex” bacteria are reduced, while potentially beneficial bacteria are less affected.

Is CBD Better Than Chlorhexidine?

Chlorhexidine currently shows a stronger overall effect in reducing germs. However, CBD against periodontitis could offer long-term advantages through more selective action and better tolerability.

Can CBD Already Be Used as a Mouthwash?

There are already initial products, such as CBD-containing mouthwashes or CBD-containing xylitol lozenges. However, these are not yet approved as standard therapy for CBD oral health or periodontitis.

Are There Side Effects of CBD in the Oral Cavity?

CBD is generally considered well tolerated. Unlike chlorhexidine, no typical side effects such as discoloration or taste disturbances are known so far. However, long-term data are still missing.

When Could CBD Against Periodontitis Be Used in Practice?

Currently, research is still in an early stage. Before CBD antibacterial effect can be used clinically, larger human studies are necessary to confirm safety and efficacy.

Source of the study:
Tolentino PHMP et al. (2025): "Evaluation of the antimicrobial effect of cannabidiol (CBD) in a multispecies subgingival biofilm model". Journal of Oral Microbiology. DOI: 10.1080/20002297.2025.2603706

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