Abstract
The aim of this study was to investigate the surface topography and to compare the calcium and phosphorus ions concentration in dentine and cement following their contact with five acidic drinks in the presence or absence of saliva. 25 caries free extracted teeth were used in this study. All the teeth were longitudinally sectioned in three slices. One slice has been stored in distilled water (control group). The second slice has been continuously immersed for 12 h in one of the tested beverages: Red Bull, Lipton Green Tea, a commercial apple juice, a natural carbonated mineral water and lemon juice. The third slice has been subject to 3 cycles of immersion in one of the tested beverages for 1 min, followed by storage in artificial saliva (AFNOR NF S90-701) for 4 h. The samples were analyzed using a scanning electron microscope and an EDX detector. The specimens continuously stored in acidic beverages showed enlarged dentinal tubules. The specimens successively stored in acidic beverages and saliva showed a slightly eroded surface of dentine and cement. The calcium and phosphorus ions concentration in dentine and cement significantly decreased following continuous storage in all the tested beverages (mean calcium ion concentration (wt%) in dentine (D)/cement (C): 28.17/23.93 control group, 16.45/11.07 apple juice, 22.84/11.48 Lipton Green Tea, 24.01/21.46 natural carbonated mineral water, 15.06/9.22 lemon juice, 18.09/10.52 Red Bull; mean phosphorus ion concentration (wt%) in D/C: 10.80/ 9.92 control group, 7.84/6.55 apple juice, 8.70/6.98 Lipton Green Tea, 9.39/9.21 natural carbonated mineral water, 7.45/6.28 lemon juice, 7.85/6.79 Red Bull). The decrease of mineral ions concentrations in dentine and cement was significantly lower when saliva has been used as a storage medium between immersions in acidic beverages (p < 0.05, ANOVA and Bonferroni test). Under the conditions of this study, saliva offered to dentine and cement a protective effect against the acidic challenge of tested beverages. Keywords: dentine, cement, acidic beverages, SEM, calcium ions, phosphorus ions