On the mechanistic role of the dentin-enamel junction in preventing the fracture of human teeth

Journal Article · Wed Sep 01 04:00:00 EDT 2004 · Nature Materials

OSTI ID:837935

Imbeni, V ^[1]; Kruzic, J J; Marshall, G W; Marshall, S J; Ritchie, R O

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1. LBNL Library

The dentin-enamel junction (DEJ), which is the interface between the dentin and outer enamel coating in teeth, is known for its unique biomechanical properties that provide a crack-arrest barrier for flaws formed in the brittle enamel. In this work, we re-examine how cracks propagate in the proximity of the DEJ, and specifically quantify, using interfacial fracture mechanics, the fracture toughness of the DEJ region. Additionally, we show that the vital function of the DEJ, in preventing cracks formed in enamel from traversing the interface and causing catastrophic tooth fractures, is not necessarily associated with the crack-arrest capabilities of the DEJ itself, but rather with the development of crack-tip shielding, primarily from uncracked-ligament bridging, in the mantle dentin adjacent to the DEJ. Measurements of the toughness of the DEJ region give estimates of G{sub c} {approx} 115 J/m{sup 2}, i.e., {approx}5 to 10 times higher than enamel and {approx}75 percent of that of dentin.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director. Office of Science. Office of Basic Energy Sciences. Materials Science and Engineering Division; National Institutes of health. National Institute of Dental and Craniofacial Research Grant R01 DE 13029 (US)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 837935
• Report Number(s): LBNL--56275
• Journal Information: Nature Materials, Journal Name: Nature Materials Vol. 4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COATINGS
DEFECTS
DENTIN
ENAMELS
FRACTURE MECHANICS
FRACTURE PROPERTIES
FRACTURES
SHIELDING
TEETH