The combined enamel remineralization potential of arginine and fluoride toothpaste

Abstract

Objective(s)This study examined the remineralization potential of arginine (Arg) in NaF toothpaste. MethodsFifty enamel specimens allocated to five groups (n = 10) were subjected to artificial caries formation. A 10-day pH-cycling was performed to treat specimens as per group – [1]: 2% Arg – NaF, [2]: 4% Arg – NaF, [3]: 8% Arg – NaF, [4]: NaF and [5]: deionized water. The test solutions were subjected to pH measurement, fluoride estimation, Na-Cl element analysis using ICP-EOS and FTIR analyses. Mineral density of the specimens were assessed using micro-CT; while Ca/P ratio and surface fluorine concentration were determined using energy dispersive x-ray spectroscopy (EDS) and enamel fluoride uptake (EFU) by acid-etch method. ResultspH, fluoride concentration and Na-Cl ratio exhibited significant difference amongst groups (p < 0.001). FTIR analysis showed presence of free amino acids in 2% and 4% Arg-NaF group. The mean mineral gain (0.40 ± 0.07 g/cm3) and percent remineralization (27.91 ± 4.66%) of 2% Arg-NaF group were significantly higher than the other 4 groups (p < 0.001). Conversely, the median Ca/P ratio for 2% Arg-NaF (1.60) was significantly higher than deionized water (1.53) (p = 0.029). The mean surface fluorine concentration of specimens treated with 2% Arg-NaF (1.51 ± 0.14%) was significantly higher than treatment with NaF (1.02 ± 0.28%) (p < 0.001). The EFU of 2% Arg-NaF group (6.84 ± 1.59 μg/cm2) was significantly higher than NaF group (5.22 ± 1.88 μg/cm2) (p < 0.001). ConclusionIncorporation of 2% arginine in NaF toothpaste significantly increased the remineralization of enamel caries-like lesion when compared to NaF toothpaste; while 4% and 8% arginine in NaF toothpastes were ineffective in improving enamel remineralization. Clinical SignificanceIn high-risk patients, daily use of 2% arginine in NaF toothpaste might provide a synergistic anti-caries effect given the proven prebiotic benefits of arginine in caries prevention and the demonstrated remineralization effect in the present study.