«Mechanics of Dental Enamel and Mineralized Bio-Nanocomposites» is the title of the talk delivered by Dr Chad S. Korach, June 28th, at the International Iberian Nanotechnology Laboratory (INL), in Braga. Dr Chad S. Korach is Assistant Professor and the Director of the Laboratory for Nanotribology and Wear Mechanics in the Department of Mechanical Engineering at Stony Brook University.
Enamel, the hardest substance in the human body, takes the form of a protective crown on teeth and is a human’s only exposed hard tissue. Though enamel is a robust biological composite with high hardness and rigidity, it is susceptible to significant localized wear in the form of cervical lesions. The aetiology of the lesions is attributed to high mechanical stresses in the cervical region and the abrasion of the surface combined with erosive.
The unique hierarchical microstructure of enamel plays an important role in the wear process. Here, the mechanics of enamel is studied by instrumented micro scratching and atomic force acoustic microscopy (AFAM) to observe the effects of erosive application on surface damage formation.
Relationships between applied stress and enamel erosion are developed. In addition, quantitative AFAM is used to measure the nanomechanical properties of enamel associated with microstructural locations. Differences in the mineral to the organic content of the enamel and crystallite directions lead to measurable elastic modulus changes. Modelling of the enamel microstructural mechanics is presented in the context of a representative volume element and applied to the micro indentation response of enamel. Differences in the elastic response of enamel due to the microstructure are determined by finite element analysis.
Lastly, the mechanical properties of a novel bio-nano composite are presented, which demonstrate a modulus and hardness on the order of natural mineralized tissue, and has application as a restorative dental material.
Chad Korach earned his Ph.D. in Mechanical Engineering from Northwestern University in 2004, where he was a Walter P. Murphy Graduate Fellow and held an NSF Integrative Graduate Education and Research Traineeship in Virtual Tribology. He received his M.S. and Bachelor of Mechanical Engineering from the Georgia Institute of Technology in 1999 and 1995, respectively.
Since 2004, he has been an Assistant Professor and the Director of the Laboratory for Nanotribology and Wear Mechanics in the Department of Mechanical Engineering at Stony Brook University. He is also an adjunct faculty member in the Department of Cariology and Comprehensive Care at the New York University College of Dentistry.
His research encompasses the fields of tribology and solid mechanics and has worked in the areas of thin films, carbon nanotubes, dental materials, bio-inspired composites, environmental degradation of composites, and chemical-mechanical polishing.