In vitro Investigation of Enamel Abrasion by Calcium Carbonate Chewing Gum

Methods: Plugs of sound human teeth, 3 mm in diameter, were mounted in blocks of dental acrylic with the enamel surface exposed. The specimens were ground flat and parallel to the acrylic base with a surface grinder. Then the enamel was polished to a mirror finish with 0.3 µm alpha alumina using a horizontal polishing wheel. A profilometer was used to trace the enamel surface both before and after treatment with the chewing gums. The enamel specimens were treated with the test chewing gum for a total of 1000 minutes using a mastication device to simulate human chewing (JDR 60:109, 1981). Fresh chewing gum and saliva were used after every 20 minutes of treatment in order to represent typical human usage. Total treatment was equivalent to daily usage of the gum for 20 minutes over 50 days. A total of 4 specimens were tested for each chewing gum.

Results: Comparisons of the before-treatment and after-treatment surface profiles found that no measurable changes (i.e. <0.1 µm) occurred to the enamel surface of specimens treated with the baking soda chewing gums containing either 0 or 4% calcium carbonate.

Conclusions: Addition of 4% calcium carbonate to a baking soda chewing gum caused no increase in enamel abrasion under the conditions of this experiment. In addition, the baking soda chewing gum without calcium carbonate also caused no measurable abrasion to the enamel surface of human teeth.

[Supported by Chew Tech I/S]