Supplementation with iron reduces the erosive potential of cola drink

Iron has been suggested to reduce the erosive potential of cola drinks in vitro. Objective: The aim of this study was to evaluate in situ the effect of iron supplementation on the inhibition of the erosion caused by a cola drink. Methods: Ten adult volunteers participated in a crossover protocol conducted in two phases of 5 days, separated by a washout period of 7 days. In each phase, they wore palatal devices containing two human enamel and two human dentin blocks. The volunteers immersed the devices for 5 minutes in 150 mL of cola drink (Coke^®, pH 2.6), containing iron (10 mmol/L) or not (control), 4 times per day. The effect of iron on the inhibition of erosion was evaluated by profilometry (wear). Data were analyzed by unpaired t tests with Welch correction (p<0.05). Results: The mean wear (±se) was significantly reduced in the presence of iron, both for enamel (control: 5.8±1.0 µm; iron: 2.8±2.5 µm) and dentin (control: 4.8±0.8 µm; iron: 1.7±0.7 µm). Conclusions: The supplementation of cola drinks with iron can be a good alternative for the reduction of their erosive potential. Additional studies should be done to test if lower iron concentrations can also have a protective effect, as well as the combination of iron with other ions. Financial support: FAPESP (Grant n. 04/12632-2).