|
Polarization-Sensitive OCT for Assessing Tooth Restorations: It is estimated that general dentists spend 50-60% of their time replacing restorations that fail mainly due to fractures and secondary (recurrent) caries. These failures are exacerbated by micron-scale defects and gaps that can grow under fatigue from chewing and/or demineralization processes, ultimately resulting in restoration fracture and/or secondary caries formation. Optical coherence tomography (OCT) is rapidly growing as a method for assessing defects within restorative materials because it is nondestructive, high speed, translatable to clinical imaging, and of sufficient resolution to detect cracks. Yet, typical OCT systems employed for restorative studies are limited to ~10 micon resolution, which diminishes the ability to detect micron-scale defects. Our laboratory employs an ultrahigh resolution, polarization-sensitive, (UHR-PS-) OCT system (2 micron axial resolution in teeth) to study defects in different types of dental restorations before and after mechanical stress.
UHR-PS-OCT is also useful in detecting microcracks in the restoration, such as those shown in Figure 2 in a specimen after being polished with a fluted-carbide bur. This work was recently published by Vasconcellos et al, 2016.
Future studies will focus on longitudinal monitoring of restoration integrity for different materials and mechanical stress tests. Additionally, we are developing a user-friendly computer application for dental researchers and clinicians to assess 3D OCT data, similar to our segmentation tools for other applications, including luminal cross-sections (Wijesundara et al, 2014), organoids in tissue culture (Oldenburg et al, 2015), and retinal cysts (Wilkins et al, 2012). This application will include auto-segmentation and 3D visualization of restorative materials and their defects, as demonstrated in Figure 3, which will speed the translation of the findings of this research into clinical practice.
intro page - research - publications - people - open positions UNC Physics & Astronomy - Biomedical Research Imaging Center - UNC Home |