ABSTRACT
This study aimed to evaluate the erosive potential of powdered juice drinks on dental enamel in 2 stages: physiochemical characterization and erosive challenge testing. In stage 1, the pH and titratable acidity of 5 commercially available powdered juices in 10 different flavors were analyzed. Five treatment groups were then established based on the pH values, titratable acidity, and presence of citric acid in the juices, and their energy-dispersive X-ray (EDX) spectroscopy profiles were studied. In stage 2, the erosive effect of the juices was tested using a pH cycling model; polished bovine dental enamel blocks (n = 8) were treated 4 times daily on 5 consecutive days with 1% citric acid (positive control) or lemon, orange, pineapple, or cashew juice. The specimens were immersed in the erosive solutions, under agitation (100 rpm), for 1 minute at 25°C. Overnight and between treatments, the blocks were stored in artificial saliva without agitation. At the end of cycling, the enamel surfaces were evaluated by profilometry and scanning electron microscopy. The stage 2 results were submitted to 1-way analysis of variance followed by Tukey test (α = 0.05). The pH values of the juices ranged between 2.86 (lemon) and 3.84 (cashew), while the titratable acidity ranged from 14.5 (cashew) to 90.00 (lemon) mmol/L. Lemon juice showed the least calcium content (2.76%) and no (0.00%) phosphorus concentration. Orange, pineapple, and cashew juices showed the greatest concentrations of calcium and phosphorus and were therefore less erosive than lemon juice. The mean [SD] surface loss was higher in the lemon juice group (0.52 [0.16] µm), with no significant differences (P > 0.05) from the control (0.39 [0.09] µm) and orange juice (0.41 [0.12] µm). In groups exposed to pineapple juice (0.36 [0.04] µm) and cashew juice (0.16 [0.08] µm), the surface loss was significantly lower (P < 0.05) than that found in lemon juice. The results demonstrate that powdered juice drinks (especially lemon juice) present erosive potential and lead to surface loss of dental enamel.
