# Evaluation of surface topography of two different heat treated NiTi file systems used with sodium hypochlorite: A stereomicroscope and SEM study

## TL;DR

This study compares how two types of NiTi dental files perform under stress and sodium hypochlorite, finding differences in deformation and surface changes.

## Contribution

The study introduces new empirical findings on the performance of heat-treated NiTi files in curved canals with preheated sodium hypochlorite.

## Key findings

- One Curve files showed earlier deformation and distortion compared to TruNatomy in curved canals.
- Preheated sodium hypochlorite affected surface topography and fatigue resistance of the files.

## Abstract

The surface grooves on endodontic files act as stress concentration and it lowers their susceptibility to fatigue fracture. Hence, 80
first mandibular molars were prepared with 40 rotary instruments, 20 One Curve (OC; Micro-Mega) and 20 TruNatomy (TN; Dentsply Sirona,)
rotary files. The files were rotated in mesial curved canals with irrigation with 5.25% sodium hypochlorite (Normal temperature and
preheated) and inspected under SEM for surface roughness. Stereomicroscope analysis was done for Unwinding and Distortion. One Curve
files showed signs of deformation and distortion earlier as compared to TruNatomy in curved canals. Sodium hypochlorite (Preheated form)
affects the surface topography and fatigue resistance of the files.