Restoration failures resulting from tooth fracture are one of the primary obstacles to lifelong oral health. The overall hypothesis of our study is that the fracture of restored teeth is fostered by a reduction in the fatigue crack growth resistance of dentin with age. Our preliminary studies have shown that fatigue cracks are often present in the dentin of restored teeth and that the fatigue properties of dentin are a function of both the tubule orientation and patient age. Despite distinct changes in the structure of dentin with age, and identification that tooth fractures occur more frequently in seniors, the influence of aging on the fatigue properties of dentin has remained unknown. With the increase in partially and full dentate seniors, the role of aging on restored tooth failures has become increasingly important. We propose to quantify the fatigue crack growth properties of dentin as a function of patient age, gender and dentin tubule orientation, distinguish at what age the most detrimental changes take place, and identify, the fundamental mechanisms responsible for reduction in crack growth resistance. Fatigue crack initiation axnd growth will be evaluated in human dentin specimens prepared from the coronal dentin of extracted virgin molars. The mechanisms of crack initiation and cyclic crack extension will be characterized using a novel application of digital image correlation and evaluated in terms of the patient's age and gender. Changes in the structure and chemistry of dentin will also be evaluated using analytical microscopic techniques. Results of the investigation will provide a fundamental understanding of the fatigue crack growth properties of dentin that enable development of detailed structure-property relationships. Based on both quantitative results and an understanding of contributing mechanisms, we expect to identify the critical aspects of existing restorative treatments on tooth fracture and the potential need for new approaches in treatment of the aging dentate population. The results are expected to support development of clinical techniques for arresting cracks in tooth structure that involve both mechanical and chemical approachesto repair. Hopefully our findings will help identify approaches for strengthening the fatigue resistance of tooth tissues, regardless of age. These achievements should reduce the incidence of restorative failures associated with tooth fracture, resulting in billions of dollars in savings of health care costs, as well as a reduction in human suffering.
| Elbahie, Enas; Beitzel, Dylan; Mutluay, Mustafa Murat et al. (2018) Durability of adhesive bonds to tooth structure involving the DEJ. J Mech Behav Biomed Mater 77:557-565 |
| Arola, Dwayne D; Gao, Shanshan; Zhang, Hai et al. (2017) The Tooth: Its Structure and Properties. Dent Clin North Am 61:651-668 |
| Orrego, Santiago; Xu, Huakun; Arola, Dwayne (2017) Degradation in the fatigue crack growth resistance of human dentin by lactic acid. Mater Sci Eng C Mater Biol Appl 73:716-725 |
| Arola, Dwayne (2017) Fatigue testing of biomaterials and their interfaces. Dent Mater 33:367-381 |
| Orrego, Santiago; Melo, Mary Anne; Lee, Se-Han et al. (2017) Fatigue of human dentin by cyclic loading and during oral biofilm challenge. J Biomed Mater Res B Appl Biomater 105:1978-1985 |
| Melo, Mary Anne; Orrego, Santiago; Weir, Michael D et al. (2016) Designing Multiagent Dental Materials for Enhanced Resistance to Biofilm Damage at the Bonded Interface. ACS Appl Mater Interfaces 8:11779-87 |
| Yahyazadehfar, Mobin; Zhang, Dongsheng; Arola, Dwayne (2016) On the importance of aging to the crack growth resistance of human enamel. Acta Biomater 32:264-274 |
| Majd, B; Majd, H; Porter, J A et al. (2016) Degradation in the fatigue strength of dentin by diamond bur preparations: Importance of cutting direction. J Biomed Mater Res B Appl Biomater 104:39-49 |
| Yahyazadehfar, Mobin; Arola, Dwayne (2015) The role of organic proteins on the crack growth resistance of human enamel. Acta Biomater 19:33-45 |
| Ryou, Heonjune; Romberg, Elaine; Pashley, David H et al. (2015) Importance of age on the dynamic mechanical behavior of intertubular and peritubular dentin. J Mech Behav Biomed Mater 42:229-42 |
Showing the most recent 10 out of 43 publications
