Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

In 2012, the Canadian Institute for Health Information estimated that over $11 billion dollars was spent by Canadians on dental care, with this number projected to rise. One primary area of importance to dentistry is the periodontal ligament (PDL), connective tissue joining the tooth to the surrounding alveolar bone. The PDL plays a critical role in tooth support, distributing applied loads, and facilitating tooth movement during orthodontic treatment. As a result, having a complete understanding of PDL response to applied loading is vital to the field of dentistry. The objective of this program is to investigate the viscoelastic behavior of the PDL and further our understanding of how it effects load distribution in the tooth-PDL-bone complex (TPBC).

A combination of experimental and mechanical modeling approaches will be utilized in the study of PDL mechanics. Creep-strain and stress-relaxation experiments will be conducted for isolated PDL tissue, and this experimental data will be used to develop and validate nonlinear viscoelastic mechanical models in both loading modalities. Interrelation methods will also be used to explore relating model coefficients in creep-strain to those in stress-relaxation, and vice versa. Finite element analysis (FEA) methods will be employed to study the mechanics of the complete TPBC. Viscoelastic models developed in our research will be incorporated into the predictive FEA model for PDL tissue. In addition, fibre optic strain measurement techniques will be used to gather ex vivo data from the PDL in complete TPBC experiments towards FEA model development and validation; something that has yet to be achieved in the literature. One PhD, two MSc, and at least one undergraduate student per year will be trained throughout this program.

The proposed projects include modeling and experimental streams, and form a well-rounded methodology to investigate PDL response to applied loading. This research has direct implications towards understanding load transfer between a tooth and surrounding bone through the PDL. Such information is vital to general dentists, restorative dentists (e.g. implant mechanics), and orthodontists. In the long-term, this research will lead to improved implant and orthodontic appliance design and development for dental care recipients. Furthermore, the methods used in this program will have applications in other areas of research where nonlinear viscoelastic materials are of interest. Such materials would include polymer composites or other biological tissues (e.g. tendons or ligaments).