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2012 年 11 月 08 日
Seminar - Bio-inspired Design of Dental Structures by Dr. Xinrui Niu

Date:   08 November 2012 (Thursday)

Time:   11:00 am – 12:00 pm

Venue:  EF305, The Hong Kong Polytechnic University

Abstract:

Dental health has heavy impact on people’s food and nutrition intake, and therefore influences people’s general health. Edentulousness – missing of tooth -- is a common dental disease that affects people of all ages. As a treatment, synthetic dental crowns were developed and implanted into oral cavity to restore the function of missing teeth. However, current synthetic crowns have poor strength and high failure rates. The failure of the crown systems is largely due to the stress concentration induced by the materials mismatch between different layers of crown. In comparison, natural crowns show superior performance which mostly thanks to their integrated structures. Although forming by parts with significantly different properties, natural teeth are capable to combine two or more dislike materials seamlessly together. One good example is the dentin-enamel-junction (DEJ) zone which is the interface between hard and brittle enamel and softer but durable dentin. Although only 10-50 micron thick, DEJ layer serves as a magic connect between interwoven structure of dentin and crystalline-like structure of enamel. With the help of this blended structure, DEJ serves as a cushion that reduces the stress concentration between dentin and enamel. Furthermore, it probably is the barrier that could deviate or even stop the cracks that generate in enamel from propagating into the dentin and therefore, protect the crown from bulk failure. This talk will present a recent design of synthetic dental adhesive that is inspired by the dentin-enamel-junction (DEJ) structure of the natural teeth. The dental multilayers bonded with new dental adhesives showed enhanced strength comparing to the conventional ones. The fatigue and fracture mechanism of the bio-inspired design of dental structure were examined both experimentally and computationally.

Biosketch:

Dr. Xinrui Niu received her B.S. and M.S. degrees in Engineering Mechanics and Solid Mechanics, respectively, from Tsinghua University, a M.S. degree in Mechanical Engineering from University of Notre Dame, and a Ph.D. degree in Mechanical Engineering from Princeton University. Before joining the Department of Mechanical and Biomedical Engineering at City University of Hong Kong as an Assistant Professor in fall 2011, she worked as a postdoc in the Department of Mechanical Engineering at Princeton University and then a senior R&D engineer at MicroPort Medical (Shanghai) Corporation. Her research interests include biomechanics, experimental and computational fracture mechanics, nano‐scale tribology and eco‐friendly materials.