# Residual dentin thickness in maxillary first premolars with palatal groove after endodontic and restorative procedures: An e-Vol DX analysis

## TL;DR

This study measures how much dentin remains in maxillary first premolars with a palatal groove after endodontic and restorative procedures using advanced imaging software.

## Contribution

The study introduces a novel use of e-Vol DX software to analyze residual dentin thickness in teeth with palatal grooves.

## Key findings

- Dentin thickness in palatal walls dropped below 1 mm after instrumentation and post space preparation.
- Buccal and mesial walls also showed thickness below 1 mm after retreatment and post space preparation.
- Post space preparation significantly reduces dentin thickness, increasing the risk of root weakening.

## Abstract

This study aimed to measure residual dentin thickness in maxillary first premolars with a palatal groove after root canal instrumentation, filling material removal, and post space preparation using e-Vol DX, an advanced CBCT imaging analysis software.

Fourteen extracted maxillary first premolars with a palatal groove on the buccal root were selected. Dentin thickness was measured at 4 stages: initial (M1), after instrumentation (M2), after filling material removal (M3), and after post space preparation (M4). Measurements were taken in 3 root regions: cervical (1 mm coronal to the groove), middle (at the groove’s deepest point), and apical (2 mm apical to the groove). Data were analyzed using ANOVA and Tukey’s post hoc test (α = 5%).

Significant reductions in dentin thickness were found in all walls across treatment phases. In the palatal wall, dentin thickness dropped below 1 mm after instrumentation, retreatment, and post space preparation. In the buccal and mesial walls, thickness fell below 1 mm after retreatment and/or post space preparation. The distal wall was less affected. The average groove depth was 0.66 ± 0.20 mm, and average groove length was 5.72 ± 1.65 mm.

Post space preparation in maxillary first premolars with palatal groove on the buccal root significantly reduces dentin thickness, especially in the palatal wall, increasing the risk of root weakening. Clinicians should carefully assess the indication of intraradicular posts in such cases to avoid potential complications.

Key words:Cone-beam computed tomography, e-vol DX software, Maxillary first premolar, residual dentin thickness, root thickness.