Role of alcohol in the fracture resistance of teeth.

Healthy dentin, the mineralized tissue that makes up the bulk of the tooth, is naturally hydrated in vivo; however, it is known that various chemical reagents, including acetone and ethanol, can induce dehydration and thereby affect its properties. Here, we sought to investigate this in light of the effect of alcohol on the mechanical properties of dentin, specifically by measuring the stiffness, strength, and toughness of dentin in simulated body fluid and Scotch whisky. Results indicated that chemical dehydration induced by the whisky had a significant beneficial effect on the elastic modulus, strength, and fracture toughness of dentin. Although this made teeth more resistant to fracture, the change in properties was fully reversible upon rehydration. This effect is considered to be associated with increased cross-linking of the collagen molecules from intermolecular hydrogen-bonding, where water is replaced with weaker hydrogen-bond-forming solvents such as alcohol.