A straightforward attempt to use one habit—chewing gum—to undo the unwelcome effects of a different habit—drinking coffee:
“Whitening Efficacy of Chewing Gum Containing Sodium Metaphosphate on Coffee Stain: Placebo-controlled, Double-blind In Situ Examination,” S. Makino, C. Kawamoto, T. Ikeda, T. Doi, A. Narise, T Tanaka, C. Almas, M. Hannig, R. Carvalho, and H. Sano, Operative Dentistry, in press 2019. The authors report:
This study aimed to evaluate the ability of chewing gum containing sodium metaphosphate (SMP) to remove coffee stains from enamel in situ. This was a double-blind (subjects, evaluators), parallel-group, crossover, randomized clinical trial with 30 healthy adult volunteers. Each participant held an appliance with a hydroxyapatite (HA) pellet on the lower lingual side of his or her mouth for two hours to allow pellicle formation. The appliances were subsequently immersed in coffee solution at 37°C for 48 hours. The color of the HA pellet before and after coffee immersion was measured using a spectrophotometer. The participant set the appliance and chewed two pieces of test gum, which contained 7.5 mg of SMP per piece, or control gum without SMP.
BONUS FACT (not necessarily related): The theme of this year’s Ig Nobel Prize ceremony will be HABITS.
BONUS (not necessarily worth even reading): At least one web site claims that chewing chewing gum “can help you lose facial weight.”