Semester of Graduation

Fall 2019


Master of Electrical Engineering (MEE)


Electrical and Computer Engineering

Document Type



Oral health is indicative of a person’s overall health. Even with advances in medical science, dental diseases are very much prevalent in our society. Dental imaging techniques help in the early detection of these dental diseases and eventually avoids the risk of poor oral health as well as medical expenses. Current dental imaging techniques rely mostly on X-ray imaging whose ionizing property is a concern amongst the population. Near-infrared spectrum is known to have tissue penetration property and they belong to the non-ionizing part of the electromagnetic spectrum. This study utilized a contrast agent assisted near-infrared imaging for common dental diseases. In specific, the advantages of using near-infrared window I (650nm-950nm) and near-infrared window II (950-nm -1700nm) with Indocyanine Green (ICG) as an imaging contrast agent in the detection of common dental diseases were explored and compared with X-ray dental imaging. ICG assisted near-infrared fluorescence (ICG-NIRF) imaging was successfully able to identify dental caries, dental decays as well as dental cracks. This study was able to detect enamel cracks which 3-D reconstructed X-ray failed to detect. ICG-NIRF provided enhanced contrast in the detection of enamel-dentin junction. It was observed that within a small immersion time a good contrast and fluorescence were seen using ICG-NIRF technique. Another major advantage of this method compared to the traditional radiographs is that it is a real time dental imaging technique. Lastly, the cost of the whole equipment is around $18,000 which is much lower than the 3-D X-ray equipment which is at least $100,000. This makes the equipment cost 5.5 times less than the currently used 3-D X-ray machines. Overall, this study has shown that ICG-NIRF provides good results in visualizing dental diseases and thus can be used as an alternative to X-ray imaging.

Committee Chair

Xu, Jian