Comparative evaluation of the biocompatibility and antibacterial efficacy of various toothpaste formulations

This study aims to evaluate the biocompatibility of twelve toothpaste formulations using human gingival fibroblast (hGF) cell cultures, and to compare their antibacterial efficacy. In accordance with ethical guidelines, healthy hGF were obtained from individuals. The toothpaste formulations tested included Colgate Total 12 (TP1), Colgate Maximum Cavity Protection (TP2), Curaprox Enzycal (TP3), Elmex Kinder (TP4), Klorhex (TP5), ROCS Baby (TP6), ROCS Kids (TP7), Meridol (TP8), Oral-B Pro Expert Stages (TP9), Sensodyne Pronamel for Kids (TP10), Sensodyne Multi Protection (TP11), and Aquafresh Little Teeth (TP12). The cytotoxic effects of these formulations were evaluated in real-time using the xCELLigence system, which monitored cellular activity at 5-minute intervals over a 72-hour period. The apoptotic effects of the toothpastes at their IC₅₀ concentrations on hGF were assessed through Annexin V and Caspase-3 assays. Genotoxicity was investigated using the Alexa Fluor^® 488 Mouse anti-H2AX assay. Antibacterial efficacy against Lactobacillus rhamnosus and Streptococcus mutans was determined using a modified microdilution method. Based on IC₅₀ values, TP8 was found to be the most cytotoxic toothpaste, while TP5 exhibited the least cytotoxicity. The cytotoxicity ranking of the formulations is as follows: TP8 (0.062)> TP2 (0.266) > TP3 (0.296) > TP10 (0.359) > TP11 (0.385) > TP6 (0.467) > TP7 (0.525) > TP4 (0.745) > TP12 (0.811) > TP9 (1.016) > TP1 (1.176) > TP5 (2.646) (p < 0.05). At the IC₅₀ concentrations, the Annexin V assay revealed no significant apoptotic effects on the hGF cells, except for TP2. Similarly, the Caspase-3 assay showed no significant impact on apoptosis, and the H2AX assay did not reveal any genotoxic effects (p > 0.05). TP8 and TP4 demonstrated the highest antibacterial efficacy against L.rhamnosus,whereas TP1, TP2, TP5, TP7, and TP10 exhibited superior activity against S.mutans. The tested toothpaste formulations exhibited marked variability in cytotoxicity and antibacterial performance in human gingival fibroblast cultures. While several formulations demonstrated strong antibacterial effects, these were frequently accompanied by increased cytotoxicity, particularly in products containing aggressive surfactant systems. Among the twelve formulations evaluated, Klorhex (TP5) showed the most favorable biological profile, characterized by the highest IC₅₀ value (lowest cytotoxicity), absence of significant apoptotic or genotoxic effects, and effective antibacterial activity against S. mutans. Based on the combined assessment of biocompatibility and antimicrobial efficacy, TP5 appears to be the most suitable option for clinical use, particularly for individuals with increased mucosal sensitivity or long-term dentifrice exposure. Clinicians should consider both the biocompatibility and antibacterial efficacy of dentifrices when making personalized recommendations for caries prevention.