Erosive potential of soy-based beverages on dental enamel.

BACKGROUND: This study aimed to investigate the erosive potential of soy-based beverages in comparison to fruit juices of the same flavor.

METHODS: Human enamel blocks were randomly divided into 9 groups (n = 8), according to the beverage category (soy or non-soy juices). The initial pH, TA and β at the original pH value were measured in triplicate. The composition of calcium, phosphate and total protein was analyzed using the specific colorimetric method. The fluoride analysis was performed using a selective electrode. The degree of saturation (DS) and the critical pH (CpH) of each beverage with respect to hydroxyapatite (HAp) and fluorapatite (FAp) were calculated using the computational software. Enamel samples were immersed into 67.5 mL of each drink for 120 minutes. Enamel surface loss (ESL) and differences in surface roughness (ΔRaE-S ) were analyzed by a 3D non-contact profilometer.

RESULTS: Non-soy beverages exhibited the lowest pH values (2.93 to 3.40). The highest values of calcium concentration were founded in soy-based formulations. Juices with soy in their composition tend to have high DS when compared with non-soy based beverages (p = .0571). Soy beverages produced less ESL than non-soy beverages (p < .05). ΔRaE-S was not significantly different between the categories. The ESL and ΔRaE-S were positively correlated with initial pH and buffering capacity in soy-based beverages. On the other hand, in non-soy beverages, the ESL was negatively correlated with the TA to 7.0 and the fluoride composition whereas the ΔRaE-S was negatively correlated with the TA to 5.5.

CONCLUSIONS: The erosive potential of soy beverages was lower than non-soy based beverages.