Objectives
Effective oral hygiene products are essential for maintaining dental and gingival health. This study evaluated the antimicrobial activity of two probiotic toothpastes, one xylitol-containing toothpaste, and one fluoride-containing toothpaste against common oral pathogens such as Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis, and Candida albicans.

Materials & Methods
A double-blinded design was employed. Each toothpaste was coded and anonymized prior to testing. Toothpaste suspensions were evaluated through agar well diffusion, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and inhibition zone tests. Data were examined using SPSS version 28.0 and the Kruskal-Wallis test to assess group differences, where p < 0.05 was considered statistically significant.

Results
Fluoride toothpaste exhibited the strongest antimicrobial activity across all tested microorganisms, with consistently low MIC and MBC values and the largest inhibition zones. Xylitol toothpaste demonstrated moderate activity, particularly against S. mutans and E. faecalis. Probiotic formulations showed limited overall efficacy but displayed measurable inhibition against S. mutans.

Conclusions
Within the limitations of this in vitro study, fluoride toothpaste was the most effective, followed by xylitol and probiotic formulations. Although probiotics exhibited minimal direct antimicrobial action, their observed activity against S. mutans suggests potential adjunctive benefits. Further in vivo and clinical studies are warranted to validate these findings.