Open Collections

Inelastic Deformation and Microcracking Process in Human Dentin

Centre for Hip Health and Mobility

Dentin is a mineralized collagen tissue with robust mechanical performance. Understanding the mechanical behaviour of dentin and its relations to the dentinal structure can provide insight into the design strategies to achieve tooth functions. This study focuses on the inelastic deformation of human dentin and its underlying mechanisms. By combining four-point bending tests with fluorescent staining and laser scanning confocal microscopy, it was found that human dentin, especially root dentin, exhibited significant inelastic deformation and developed extensive microdamage in the form of microcracks prior to fracture. Similar to bone, dense and wavy microcracks spread uniformly across the tensile surface of root dentin, while compressive microcracks formed cross-hatched patterns. The presence of peritubular dentin in coronal dentin dramatically decreased the extent of microcracking, reducing inelasticity. Dentinal tubules were found to be initiation sites of both tensile and compressive microcracks. A unique crack propagation process was observed in root dentin under tension: numerous ring-shaped cracks formed at each dentinal tubule ahead of a growing crack tip. The advance of the tensile microcrack occured by the merging of those ring-shaped cracks. The current findings on the microcracking process associated with inelastic deformation helps to understand the nature of strength and toughness in dentin, as well as the mechanical significance for structural variations across the whole tooth.

Article; Postprint

eng

Vancouver : University of British Columbia Library

10.14288/1.0319070

Applied Science, Faculty of; Other UBC; Non UBC; Materials Engineering, Department of

Reviewed

Elsevier

DSpace