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Full-Text Articles in Social and Behavioral Sciences
Predicting Failure In Mammalian Enamel, Brian Lawn, James Lee, Paul Constantino, Peter Lucas
Predicting Failure In Mammalian Enamel, Brian Lawn, James Lee, Paul Constantino, Peter Lucas
Paul J. Constantino
Dentition is a vital element of human and animal function, yet there is little fundamental knowledge about how tooth enamel endures under stringent oral conditions. This paper describes a novel approach to the issue. Model glass dome specimens fabricated from glass and backfilled with polymer resin are used as representative of the basic enamel/dentine shell structure. Contact loading is used to deform the dome structures to failure, in simulation of occlusal loading with opposing dentition or food bolus. To investigate the role of enamel microstructure, additional contact tests are conducted on twophase materials that capture the essence of the mineralizedrod/organicsheath …
Fracture Susceptibility Of Worn Teeth, Amanda Keown, Mark Bush, James Lee, Chris Ford, Paul Constantino, Brian Lawn
Fracture Susceptibility Of Worn Teeth, Amanda Keown, Mark Bush, James Lee, Chris Ford, Paul Constantino, Brian Lawn
Paul J. Constantino
An experimental simulation study is made to determine the effects of occlusal wear on the capacity of teeth to resist fracture. Tests are carried out on model dome structures, using glass shells to represent enamel and epoxy filler to represent dentin. The top of the domes are ground and polished to produce flat surfaces of prescribed depths relative to shell thickness. The worn surfaces are then loaded axially with a hard sphere, or a hard or soft flat indenter, to represent extremes of food contacts. The loads required to drive longitudinal cracks around the side walls of the enamel to …
Remarkable Resilience Of Teeth (How Are Teeth So Brittle Yet So Resilient), Paul J. Constantino
Remarkable Resilience Of Teeth (How Are Teeth So Brittle Yet So Resilient), Paul J. Constantino
Biological Sciences Faculty Research
Tooth enamel is inherently weak, with fracture toughness comparable with glass, yet it is remarkably resilient, surviving millions of functional contacts over a lifetime. We propose a microstructural mechanism of damage resistance, based on observations from ex situ loading of human and sea otter molars (teeth with strikingly similar structural features). Section views of the enamel implicate tufts, hypomineralized crack-like defects at the enamel–dentin junction, as primary fracture sources. We report a stabilization in the evolution of these defects, by ‘‘stress shielding’’ from neighbors, by inhibition of ensuing crack extension from prism interweaving (decussation), and by self-healing. These factors, coupled …