Research Explores Radiation-Induced Changes in Tooth Structure
Most dental practitioners are familiar with the challenges of providing care to patients who have received radiotherapy to treat head and neck cancer. While the radiotherapy saves the lives of many of these patients, they face a lifetime of post-radiation complications that can include severe tooth breakdown, which can be very difficult to manage.
Unlike typical dental caries, postradiation dental lesions start with shear fracture of enamel at sites exposed to occlusal loading and flexure (cervical, cuspal, incisal). Post-radiation caries has been linked to radiation-induced salivary gland damage and associated xerostomia, but evidence from a previous NIH-funded clinical study at UMKC (Dr. Mary Walker–PI) suggests a direct effect of radiation on the dentition. Based on that information, the UMKC research team (Drs. Mary Walker, Yong Wang and Jeff Gorski) received funding for another NIH grant to understand possible radiationinduced changes in tooth structure.
The research project includes a systematic evaluation of tooth structure via innovative instrumentation and technology such as Raman microspectroscopy, atomic force microscopy/nanoindentation, confocal microscopy, and electron microscopy. Because the initial lesions start with Research Explores Radiation-Induced Changes in Tooth
Structure 3 n Explorer shear fracture of enamel from dentin, the research team is focused on evaluating the dentin-enamel junction (DEJ) and adjacent enamel and dentin prior to and after radiotherapy to potentially explain altered structure function characteristics of radiated teeth.
In addition to evaluating teeth after therapeutic radiation, the study requires baseline information from non-radiated teeth, so the team has learned updated information about enamel and its interface with dentin. Based on our results, enamel is more complicated than what you likely learned in dental school. For example, enamel is not a homogenous material in content or properties. Instead, we reported a property gradient across enamel with outer enamel being harder and stiffer than inner enamel, and the gradient appears to be associated with differences in the crystalline structure. As part our investigation, we also detected a layer of enamel-associated proteins adjacent to the DEJ; this was a very surprising finding since enamel has been considered essentially devoid of protein. Even more significant, these proteins may be a key component in bonding enamel to dentin. So while this information is critical for our study in terms of focusing on targets that might be susceptible to radiotherapy, a better understanding of enamel and its interface with dentin is also valuable for developing restorative materials. One possible application might be developing porcelain with graded properties similar to enamel to address chipping problems currently seen with zirconia-based all-ceramic restorations. The outcomes from studies such as ours reinforce the importance and benefits of research teams that integrate basic scientists and clinician scientists to address clinically relevant questions.
2013 Summer Explorer Contents:
- Message from the Dean
- Research Explores Radiation-Induced Changes in Tooth Structure
- It’s Almost Here
- ADA Officers Visit Midwest Dental Conference
- Enjoying an Enchanted Evening
- Class Reunions
- Rinehart Foundation Introduces Benefactor Pins
- A Charitable IRA Can Help You Help the School
- Dental Hygiene Announces New Scholarships
- My 50-Year Friendship with Sherry Burns
- 2013 Dental Alumnus of the Year
- 2013 Young Dental Alum of the Year
- Class Notes
- In Memoriam
- Student Brings “Discover Kansas City and Dentistry” Theme to Life
- Congratulations, Class of 2013
- UMKC Honors Tammy Woods with “Chancellor’s Education First Award”