Effect of fluoride toothpaste containing calcium phosphate and toothpaste containing 1,000 ppm fluoride on surface microhardness of enamel caries

Abstract

This laboratory study aimed to compare the effect of fluoride toothpaste containing calcium phosphate and toothpaste containing 1,000 ppm fluoride on surface microhardness of enamel caries. Human premolar specimens (n=30) were randomly assigned to 3 groups (n=10): control (group 1), toothpaste containing 1,000 ppm fluoride (group 2), and toothpaste containing calcium phosphate (group 3). Artificial enamel caries specimens were immersed in dentifrice slurry twice a day for 2 minutes during a 10-day pH-cycling in treatment groups, except for the control group. Vicker’s microhardness measurements were obtained at baseline followed by after artificial caries formation and after pH-cycling. The surface hardness recovery was calculated. The median of surface hardness recovery of 3 groups were analyzed by Kruskal-Wallis at significant level 0.05 (α= 0.05), results showed statistical differences in surface hardness recovery were found among 3 groups (p < 0.001). The surface hardness recovery of each pair was compared by Mann-Whitney U test at significant level 0.0167 (α=0.0167) and it was found that there were significant differences for all pairs (p < 0.001). In conclusion, toothpaste containing 1,000 ppm fluoride had higher surface hardness recovery than toothpaste containing calcium phosphate.