Aging Causes Fracture Toughness Reduction in Dentin
Researchers led by Dr. Dwayne D. Arola of the University of Maryland, have recently examined the role of aging and its affect on the reduction in fracture toughness of human dentin. The article appears on the Journal of the Mechanical Behavior of Biomedical Materials (October 2009 issue, pages 550-559). Dr. Arola and colleagues found that the average fracture toughness of old dentin was approximately 30% lower than young dentin. The researchers observed that the fracture toughness seemed to depend on the number of lumens, which is important in determining the mineral-to-collagen ratio and the variation in the degree of age-related sclerosis, or embrittlement, throughout dentin. They were able to do this by examining the crack growth resistance of human coronal dentin using tissue obtained from patients 18 to 83 years of age and for crack extension oriented perpendicular to the … Read more