In situ evaluation of 200 ppm fluoride toothpaste content trimetaphosphate, xylitol and erythritol on enamel demineralization and dental biofilm

Objective: To evaluate the effect of low-fluoride (F−) toothpaste and sodium trimetaphosphate (TMP) associated with xylitol and erythritol (XE) on enamel demineralization and biofilm composition. Methods: This crossover double-blind in situ study consisted of five phases (seven days each), in which 14 volunteers wore oral appliances containing four enamel bovine blocks. The cariogenic challenge was performed by exposure to a 30% sucrose solution (6x/day). The toothpaste treatments (3x/day) were as follows: placebo (no F−/TMP/XE); 200 ppm F− (NaF) (200F); 1,100 ppm F− (1100F); 16% Xylitol and 4% Erythritol (XE); and 200 ppm F−, 0.2% TMP, 16% xylitol, and 4% erythritol (200F-TMP-XE). Percentage of surface hardness loss (%SH) and integrated loss of subsurface hardness (ΔKHN), and calcium (Ca2+), phosphate (PO43−), and F− on enamel and biofilm were determined; as well as insoluble extracellular polysaccharide (EPS). Results: XE and 1100F groups showed no significant difference for %SH and ΔKHN values (p = 0.220 and p = 0.886), and the 200F-TMP-XE group had the lowest mineral loss (p < 0.001). Ca2+ and PO43− in the enamel showed the highest values (p < 0.001) for the 200F-TMP-XE group. Higher values of F− in the enamel and biofilm were observed for the 1100F group (p < 0.001). There was no difference for Ca2+ (p = 1.00) and EPS (p =0.918) values between XE and 200-TMP-XE groups in the biofilm, but their values were higher and lower than the 1100F (p = 0.002 and p = 0.029), respectively. Conclusions: 200F-TMP-XE promoted a greater protective effect against enamel demineralization and significantly affected the composition of biofilm formed in situ compared to 1100F toothpaste. Clinical Significance: Low-F− toothpaste containing TMP and polyols can be considered an effective and safe measure to improve the oral health of individuals, especially patients with high caries activity.