The Effect of 8% Arginine Toothpaste on Primary Caries Lesion In Vitro

Abstract

Objective: This study aimed to evaluate the anticaries potential of 8% arginine toothpaste compared to a standard 1100 ppm sodium fluoride toothpaste. The primary hypothesis was that 8% arginine would reduce lesion depth and volume % mineral loss more effectively than the fluoride toothpaste in an in vitro multi-species biofilm caries model. Materials and Methods: Sixty-four extracted anterior human teeth were sectioned into 3 mm × 3 mm specimens. The specimens were divided into four groups: 8% arginine toothpaste, 1100 ppm sodium fluoride toothpaste (positive control), arginine- and fluoride-free toothpaste (placebo), and deionized water (negative control). A microbial caries model was used, with enamel specimens inoculated with pooled saliva and incubated with Tryptic Soy Broth (TSB) and mineral wash solutions. Treatment involved applying toothpaste slurries twice daily for eight days. Lesion depth and mineral loss were measured using cross-sectional microhardness (CSMH) and confocal laser scanning microscopy. Results: The group treated with 1100 ppm fluoride toothpaste showed the least mineral loss and higher enamel hardness compared to the other groups. No statistically significant difference was found in lesion depth between the 8% arginine group and the fluoride group. The fluoride group had significantly better performance in preserving mineral content compared to the deionized water group (p < 0.05). Conclusion: Toothpaste containing 8% arginine did not significantly prevent caries lesion formation or reduce lesion depth when compared to 1100 ppm fluoride toothpaste. These findings suggest that arginine alone, while influencing pH, may not be sufficient to offer comparable anticaries effects to fluoride, emphasizing the continued role of fluoride in effective caries prevention.