Seven oral care products and orange juice as a positive control were tested for the erosive potential by immersing each enamel specimen (10 per group) into solutions of the various products for 10 and 20 min. Before and after the experiment Knoop surface hardness (SMH) was measured. The enamel microstructure before and after immersion was assessed by scanning electron microscopy and confocal laser scanning microscopy. Orange juice produced the most marked losses of hardness after 10 and 20 min. Among the dental hygiene products only the fluoride-free toothpaste produced a significant reduction of hardness after 10 as well as after 20 min. With the exception of Elmex gel, all tested oral care products led to a significant (p < 0.05) increase of enamel hardness. The results of the hardness measurements corresponded with the microstructure findings. It may, therefore, be concluded that the tested fluoride-containing oral care products do not exhibit any erosive potential, which could be picked up with the methodologies under study.
Copyright 2001 S. Karger AG, Basel.