In vitro evaluation of optical coherence tomography and ultrasound probes used in the detection of intact dentin and various anomalies within root canals

Abstract

In dentistry optical coherence tomography (OCT) technology has shown some promise as a method to distinguish between enamel, dentin, and restorative materials of tooth specimens. Ultrasound (US) technology has been reported with applications in dentistry to image deep tissues which offers a means to further characterize various soft tissue anomalies. While it is believed that both US and OCT technologies have real-time imaging potential for dentistry, their ability to visualize multiple types of simulated defects within root canal systems has yet to be tested. This study was setup to help determine the efficacy of two catheter-based imaging probes in prepared root canals containing areas of interest. Areas of interest herein are cited as vertical fracture lines, simulated perforations, resorptive-like defects, sites of intact dentin, and void space variance of the lumen. 33 human teeth were selected and underwent root canal analysis using 2 commercially available intravascular catheter-based imaging probes integrated with either OCT or US technology. This study proved that intravascular OCT is a very powerful imaging modality capable of (1) detecting various areas of endodontic interest, (2) yielding superficial imaging data of root canal architecture, and (3) trans-imaging tooth specimens from the canal lumen to the external surface of intact teeth at various cross-sections. Intravascular US probe was not capable of producing useful imaging data per the methodology herein. To date there are no FDA approved OCT probes commercially available for use in endodontics. Hopefully this study furthers our understanding of how useful and multimodal OCT technology truly is.