Hardness of enamel exposed to Coca-Cola® and artificial saliva

The purpose of this study was to determine the rate of change in indentation hardness of enamel in permanent teeth exposed to Coca-Cola (R). In a further experiment, the ability of a commercially available artificial saliva to remineralize enamel treated with Coca-Cola (R) was tested. Ten enamel specimens were randomly chosen to be treated with Coca-Cola (R) (experimental groups) and seven with water (control group). The fluids were applied for 1, 2, 3 h and overnight (15 h), washed off with a few drops of water and the moist enamel indentation hardness tested after each interval. With Coca-Cola (R) treatment, the mean enamel hardness was 92.6% (s.d. = 7.9) of the original baseline hardness after 1 h, 93.25% (s.d. = 10.15) after 2 h, 85.7% (s.d. = 12.03) after 3 h and 80.3% after 15 h. The mean indentation hardness of control specimens treated with water was 108.7% (s.d. = 16.09) of the original hardness after 1 h, 99.09% (s.d. = 18.98) after 2 h, 98.97% (s.d. =11.24) after 3 h and 98.42% (s.d. = 22.78) after 15 h. In a separate experiment, the hardness of 9 enamel specimens was tested, as previously described, before and after treatment with Coca-Cola (R) overnight and again after application of artificial saliva for 3 min. Coca-Cola (R) reduced the mean indentation hardness of enamel in the teeth, but the hardness was partially restored with artificial saliva (Salivart (R)) and increased by 18% from the demineralized enamel hardness.