title: Morphology and fracture of enamel.
abstract: This study examines the inter-relation between enamel morphology and crack resistance by sectioning extracted human molars after loading to fracture. Cracks appear to initiate from tufts, hypocalcified defects at the enamel-dentin junction, and grow longitudinally around the enamel coat to produce failure. Microindentation corner cracks placed next to the tufts in the sections deflect along the tuft interfaces and occasionally penetrate into the adjacent enamel. Although they constitute weak interfaces, the tufts are nevertheless filled with organic matter, and appear to be stabilized against easy extension by self-healing, as well as by mutual stress-shielding and decussation, accounting at least in part for the capacity of tooth enamel to survive high functional forces.
authors: Ceramics Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
authors: Sangwon
authors: S
authors: Myoung
authors: James
authors: J
authors: Lee
authors: Paul
authors: P
authors: Constantino
authors: Peter
authors: P
authors: Lucas
authors: Herzl
authors: H
authors: Chai
authors: Brian
authors: B
authors: Lawn
mesh_terms: D001696:Biomechanical Phenomena; D003743:Dental Enamel / Q000293:injuries* / Q000473:pathology; D003804:Dentin; D006801:Humans; D008964:Molar, Third / Q000293:injuries* / Q000473:pathology; D014082:Tooth Fractures / Q000473:pathology*