Human Photonics Laboratory

Dental Health

Scanning Fiber Endoscopy

The scanning fiber endoscopy (SFE) technology has been applied to near-infrared dental imaging for detection of carious lesions. Near-infrared light penetrates much deeper into the dental enamel layer than visible lights. Furthermore, it captures carious lesions due to increasing scattering coefficient caused by demineralization, without interference from stains and non-calcified plaque. Thus, it’s a great alternative to visual and tactile examinations and especially radiography which have limitations on specificity, sensitivity and safety. However, the current near-infrared camera suffers from bulky size and can’t move around flexibly in oral cavity to acquire optimal perspectives. SFE has the advantages of miniature probe (rigid length of 9mm, diameter of 2.4mm), flexible shaft, low cost and sufficient resolution (~150um) and field of view (60 degrees). Thus, SFE is a great candidate for miniature, low-cost NIR imaging system. A multispectral NIR SFE system with 1310nm ,1460nm, 1550nm laser diode channels as well as a 1310nm SLD channels is developed in Human Photonics Lab. A quantitative study was conducted on ex-vivo imaging of artificial early demineralization on 20 bovine enamel sections. Reflection imaging with 1310nm and 1460nm was able to detect demineralization with sensitivity of 96% and specificity of 85% and has a moderate positive correlation with microCT measurements [1]. Ex-vivo occlusal-view imaging of 19 artificial inter-proximal lesions on extracted human teeth was also studied. The study showed that NIR SFE can detect inter-proximal lesions buried under enamel layer with thickness up to 4mm. Diagnosis from a non‐blinded trained user by looking at real‐time occlusal‐side nirSFE videos indicate true positive rate of 78.9% and false positive rate of 0 [2]. Furthermore, to improve the ease of use for this dental imaging modality, we developed a system for AR-assisted visualization and guidance for dental imaging of lesions based on OCT, SFE and Magic Leap One AR headset [3].

Relevant publications:

  1. Lee, R.C.; Zhou, Y.; Finkleman, S.; Sadr, A.; Seibel, E.J. Near-Infrared Imaging of Artificial Enamel Caries Lesions with a Scanning Fiber Endoscope. Sensors 2019, 19, 1419.
  2. Zhou, Y. , Lee, R. C., Finkleman, S. , Sadr, A. and Seibel, E. J. (2019), Near‐infrared multispectral endoscopic imaging of deep artificial interproximal lesions in extracted teeth. Lasers Surg. Med., 51: 459-465.