Effect of exposure time of an acidic beverage on the microhardness, mineral weight, and rate of calcium and phosphate ion release of human enamel

Aims and Objectives: The aim of this study was to investigate the effect of exposure times of Coca Cola on enamel's microhardness, mineral weight, and rate of calcium and phosphate ions discharging from it. Materials and Methods: Thirty-two enamel blocks were randomly divided into four groups and exposed to 10mL of their respective solution daily for 7 days, with each group containing eight specimens: Group 1 (enamel blocks exposed to artificial saliva, control group), group 2 (enamel blocks exposed to Coca Cola for 5 minutes), group 3 (enamel blocks exposed to Coca Cola for 10 minutes), and group 4 (enamel blocks exposed to Coca Cola for 30 minutes). Microhardness data (Vickers hardness number [VHN]) and mineral weight were calculated at baseline (sound enamel) and postexposure to Coca Cola. Inductively coupled plasma-optical emission spectrometry (ICP-OES) was utilized to study calcium and phosphate ion percolation from enamel surfaces. Results: Decrease in VHN was directly proportional to exposure time for all experimental groups. Comparison of baseline and postexposure values between control and experimental groups was statistically significant (P < 0.05). Mineral weight of enamel blocks decreased as the exposure time increased for all experimental groups. ICP-OES analysis revealed linear relationship between release of calcium and phosphate ions at 5 and 10 minutes, but at 30 minutes, a decrease in concentration of both ions was observed. Conclusion: The microhardness and mineral weight of enamel decreased linearly with exposure time. The release of calcium and phosphate ions from enamel increased initially but gradually decreased as the exposure time increased.