# Infrared Methods for Lesion Activity Assessment

> **NIH NIH F30** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2021 · $47,604

## Abstract

PROJECT SUMMARY
The overall objective of this proposed research is to develop methods for the clinical assessment of lesion
structure and activity. Improved imaging technologies employing non-ionizing radiation will significantly
improve caries diagnosis and management. It is not sufficient to simply detect carious lesions, methods are
needed to assess the activity of the lesion and determine if chemical intervention is needed. The central
hypothesis underlying this proposal is that there are structural differences between active lesions due
to caries, arrested lesions and developmental defects, and these differences can be quantified using
optical imaging methods. There is a transparent highly mineralized outer surface zone presented on arrested
lesions formed due to remineralization, which leads to decreased permeability to fluids including water and
plaque generated acids. Previous studies have shown that the thickness of this surface zone can be measured
nondestructively using polarization sensitive optical coherence tomography (PS-OCT), and have demonstrated
that near-IR (NIR) reflectance and thermal imaging coupled with dehydration can be used to measure changes
in the permeability of lesions in enamel and dentin. The overall objective of this proposal will be achieved
through the following specific aims: (1) To test the hypothesis that the thickness of the highly mineralized
transparent surface zone formed during remineralization correlates with the lesion permeability and activity; (2)
To test the hypothesis that thermal and NIR reflectance dehydration methods can be used to measure the
activity of secondary carious lesions around composite restorations; (3) To test the hypothesis that compact
thermal and NIR reflectance probes for lesion activity assessment can be fabricated that are suitable for in vivo
use. This project will allow us to determine the structural changes needed to arrest active lesions and provide
methods for assessing the activity of lesions in a single examination to avoid unnecessary treatment and cavity
preparations.

## Key facts

- **NIH application ID:** 10229553
- **Project number:** 5F30DE027264-05
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** Nai-Yuan Nicholas Chang
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $47,604
- **Award type:** 5
- **Project period:** 2017-09-01 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10229553

## Citation

> US National Institutes of Health, RePORTER application 10229553, Infrared Methods for Lesion Activity Assessment (5F30DE027264-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10229553. Licensed CC0.

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