title: Dynamic shear modulus in torsion of human dentin and enamel.
abstract: The dynamic shear moduli of human dentin and enamel were measured using a torsion pendulum over a temperature range from 23 to 150 degrees C. For dentin, the shear modulus slightly increased for temperatures near 50 to 100 degrees C, which was caused by a loss of free water. The peak in the loss tangent was observed near 75 degrees C. The shear moduli at 37 degrees C for sixty coronal dentin specimens ranged from 5.77 X 10(10) to 1.16 X 10(11) dyn/cm2. For enamel, the shear modulus and the loss tangent were markedly stable and independent of the temperature. The shear moduli at 37 degrees C for forty specimens ranged from 2.35 X 10(11) to 4.48 X 10(11) dyn/cm2. Enamel had a modulus which was approximately three to five times higher, and a lower loss tangent than those of dentin. For both dentin and enamel, there were no significant correlations between the values of the shear modulus and sex, age or tooth type.
authors.forename: H
authors.initials: H
authors.lastname: Arikawa
mesh_terms: D003743:Dental Enamel; D003799:Dental Stress Analysis; D003804:Dentin; D006801:Humans; D014070:Tooth