Acidity and dental erosive potential of fermented dairy products in Saudi Arabia: an in vitro study

Dental erosion is mainly linked to consumption of acidic foods and drinks, potentially including fermented dairy products. The aims of this primary in vitro study were to determine the acidity of different fermented milk products commonly consumed in Saudi Arabia and to evaluate their potential erosive effects on dental enamel. Extracted bovine tooth crowns were embedded in resin with the enamel exposed and randomly divided into three groups (n = 3/group): laban (buttermilk), yogurt, and milk (control). Each specimen was immersed in the test product (60 min, 25 °C), then submitted to surface profile analysis using optical profilometry and confocal laser scanning microscopy. Further, pH and titratable acidity were evaluated for seven dairy products: laban, Activia laban, ayran laban, full-fat yogurt, fruited yogurt, plain Greek yogurt, and milk (control). All tested fermented dairy products were acidic and had significantly lower pH than the control (p < 0.0001), with ayran laban the lowest (pH 4.1 ± 0.02) and Greek yogurt the highest (pH 4.6 ± 0.01). Tested yogurt products exhibited significantly higher titratable acidity than laban products. The yogurt group had the highest enamel surface roughness, which was significantly different to the untreated surface on profilometric analysis (p < 0.0001). All characterized fermented dairy products were acidic with erosive potential. Yogurt and laban both increased enamel surface roughness, and the effect was more pronounced with yogurt. These findings underscore the need to moderate fermented milk product intake, to prevent dental erosion, and to include guidance on their consumption in oral health dietary recommendations.