# Assessment of dental pulp response to caries via MR T2 mapping and histological analysis

## TL;DR

This study shows that MRI can accurately assess dental pulp health and caries progression by correlating T2 relaxation times with histological findings.

## Contribution

The study demonstrates MRI's potential as a non-invasive tool for evaluating dental pulp status in relation to caries.

## Key findings

- MRI T2 relaxation times correlated with macrophage and T lymphocyte density in healthy teeth.
- Vascular density in ICDAS 1 teeth positively correlated with T2 relaxation times.
- MRI T2 relaxation times showed high correlation with histological validation, supporting its clinical relevance.

## Abstract

The aim of our study was to assess the correlation between T2 relaxation times and their variability with the histopathological results of the same teeth in relation to caries progression. Materials and methods: 52 extracted permanent premolars were included in the study. Prior to extractions, patients underwent magnetic resonance imaging (MRI) scanning and teeth were evaluated using ICDAS classification. Pulps of extracted teeth were histologically analysed. Results: MRI T2 relaxation times (ms) were 111,9 ± 11.2 for ICDAS 0, 132.3 ± 18.5* for ICDAS 1, 124.6 ± 14.8 for ICDAS 2 and 112. 6 ± 18.2 for ICDAS 3 group (p = 0,013). A positive correlation was observed between MRI T2 relaxation times and macrophage and T lymphocyte density in healthy teeth. There was a positive correlation between vascular density and T2 relaxation times of dental pulp in teeth with ICDAS score 1. A negative correlation was found between T2 relaxation times and macrophage density. There was a positive correlation between T2 relaxation time variability and macrophage and T lymphocyte density in teeth with ICDAS score 2. In teeth with ICDAS score 3, a positive correlation between T2 relaxation times and T2 relaxation time variability and lymphocyte B density was found. Conclusion: The results of our study confirm the applicability of MRI in evaluation of the true condition of the pulp tissue. Clinical relevance: With the high correlation to histological validation, MRI method serves as a promising imaging implement in the field of general dentistry and endodontics.