Method: A total of 108 bovine enamel samples (Ø=3 mm)were embedded in acrylic resin and allocated to 6 groups (n=18). Orange juice and soft drinks (Coca-Cola, Sprite) were used both in their regular forms and at a kinetic viscositiy of 5 mm2/s, which was adjusted by adding hydroxypropyl cellulose (HPC). All solutions were pumped over the enamel surface from a reservoir with a drop rate of 3ml/min. Each specimen was eroded for 10 min at 20°C. Erosion of enamel surfaces was measured using profilometry. Data were analyzed using independent t-tests and one-way ANOVAs (p<0.05).
Result: Enamel loss was significantly higher for the regular (Coca-Cola: 5.6 ± 1.0 μm, Sprite: 5.5 ± 0.9 μm, orange juice: 1.4 ± 0.4 μm) than for the viscosity-modified drinks (Coca-Cola: 4.9 ± 0.3 μm, Sprite: 4.5 ± 0.4 μm, orange juice: 1.1 ± 0.2 μm). For both regular and viscosity-modified forms, the soft drinks caused higher enamel loss than orange juice.
Conclusion: Increasing the viscosity of orange juice and soft drinks to 5 mm2/s reduced enamel erosion by 12.6 - 18.7%.