Title: 2435 - Enhancing the Detection of Cavitated Proximal Lesions Using Near Infrared Transillumination


Marwa Abdelaziz (Presenter)
University of Geneva

Ivo Krejci, University of Geneva
Daniel Fried, University of California - San Francisco


Objectives: To investigate the use of near infrared transillumination and a near infrared absorbent dye for detection of cavitated proximal lesions.

Methods: Forty-five extracted teeth with proximal caries, 15 cavitated (CAV) and 30 non-cavitated (15 white spot lesions (WSL) and 15 brown spot lesions (BSL)) were scored visually and imaged using near infrared transillumination at 780-nm (DIAGNOcam (DC)) and polarization sensitive OCT (PS-OCT) at 1300-nm. PS-OCT was used to confirm activity and cavitation state of each lesion.
A water soluble near infrared absorbing dye (indocyanine green (ICG)) was used in 3 different forms (liquid, gel, thick paste)
Lesions were imaged before the application of ICG, after the application of ICG powder mixed with glycerine, after 24h in water (washed out ICG) and with ICG powder diluted in water, 3 weeks after being stored in water to wash out the ICG and finally using thicker form of ICG (half the amount of glycerine used before) making a thick paste.
On each image the contrast was calculated using the grey level (GL) change formula: (sound GL- Lesion GL/sound GL) providing a contrast change value that ranges from 0 to 1.

Results: The contrast results (Table 1) confirmed that ICG enhances the contrast of cavitated lesions significantly (p<0.05). ICG in thick gel form produced the most significant increase in contrast, making the difference between cavitated and non cavitated lesions most visible.

Conclusions: ICG in a thick gel form is best suited for the detection of cavitated proximal lesions by near infrared transillumination.


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Student Presenter

This abstract is based on research that was funded entirely or partially by an outside source:
Swiss National Science Foundation (SNSF)

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: None