Study: THC Shown to Disrupt Cavity-Causing Bacteria and Dental Biofilms

OG article by Anthony Martinelli

January 21, 2026

Research in the International Dental Journal demonstrates that THC inhibits Streptococcus mutans, the main cavity-causing bacterium, and disrupts dental biofilms. In vitro tests showed THC at 2 μg/ml inhibiting over 90% of bacterial growth and acid production, reducing pH drops that erode enamel. At 1-2 μg/ml, it prevented new biofilm formation by 88-90%+, decreasing viable bacteria and extracellular polysaccharides via imaging. THC did not eradicate existing biofilms but lowered their metabolic activity and growth for hours, indicating bacteriostatic effects through membrane hyperpolarization disrupting cellular processes. This reduces S. mutans' cariogenic potential by limiting adhesion, acid output, and biofilm development. While promising for anticavity applications, THC's psychoactivity limits direct dental use. Researchers suggest developing non-psychoactive cannabinoid derivatives for oral health therapies. The study highlights THC's antimicrobial properties against key oral pathogens, offering insights into potential natural alternatives to traditional fluoride or antiseptic approaches. Further research is needed to explore formulations, safety in vivo, and clinical efficacy for preventing dental caries.