The Combined Remineralization Potential of Arginine and Fluoride

Abstract

Objectives: Incorporation of arginine might enhance the anti-caries effect of NaF. Thus, the objective of the study was to examine the remineralization potential of arginine (Arg) in NaF toothpaste. Methods: Fifty 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 analysis. The specimen mineral density was assessed using Micro-CT, Ca/P ratio and surface fluorine concentration was determined using energy dispersive x-ray spectroscopy (EDS) and enamel fluoride uptake (EFU) by acid-etch method. Statistical analysis was performed using parametric/non-parametric tests with pairwise/multiple comparisons at p-value < 0.05. Results: pH, fluoride concentration and Na-Cl ratio exhibited significant difference amongst groups (p < 0.001). FTIR analysis showed presence of free amino acids with 2% Arg-NaF. The mean mineral gain (0.40 ± 0.07g/cm3) and percent remineralization (27.91 ± 4.66%) for 2% Arg-NaF was significantly higher than other groups (p < 0.001). The median Ca/P ratio for 2% Arg-NaF (1.60) was significantly higher than DI water (1.53) (p = 0.029). The mean surface fluorine concentration for 2% Arg-NaF (1.51 ± 0.14%) was significantly higher than NaF (1.02 ± 0.28%) (p < 0.001). The EFU for 2% Arg-NaF (6.84 ± 1.59 µg/cm2) was significantly higher from NaF (5.22 ± 1.88µg/cm2) (p < 0.001). Conclusions: Incorporation of 2% arginine into NaF toothpaste significantly increased the remineralization of artificial incipient enamel carious lesion when compared to NaF toothpaste. Incorporation of 2% arginine in NaF toothpaste might provide synergistic anti-caries effect given the proven prebiotic benefits of arginine in caries prevention and the demonstrated remineralization effect in the present in vitro study.