# The effect of different variables on push-out tests in 3D-printed oval and round-shaped root canals: a methodological study

## TL;DR

This study examines how factors like slice thickness and plunger size affect push-out resistance in 3D-printed root canals of different shapes.

## Contribution

The study introduces a methodological approach to evaluate push-out tests in standardized artificial oval and round root canals.

## Key findings

- Slice thickness of 1-mm showed higher dislocation resistance in round canals.
- Middle and coronal regions of oval canals showed similar resistance values.
- Plunger size significantly affected dislocation resistance in root canals.

## Abstract

This study aimed to evaluate the effect of slice thickness (ST), plunger size (PS), shape and region of the root canal on push-out tests using standardized artificial root canals.

Two teeth with round and oval root canal anatomy were selected using cone beam computed tomography. Teeth were prepared, scanned with micro computed tomography and stereolithography data were obtained. Seventy-two round and 72 long oval artificial root canals were produced using a 3D printer. Root canals were obturated, then divided into two main groups (oval-round) and further divided into six subgroups (n = 12) according to ST (1, 1.5, and 2-mm) and PS (0.5, 0.75, and 1-mm). Push-out tests were performed and dislocation resistance values were calculated. The data were analyzed using the ANOVA two-way test (p = 0.05).

Different STs showed similar results in oval canals (p > 0.05). 1-mm ST showed higher results in round canals (p < 0.05). There was a significant difference between 0.75 and 1-mm PSs (p < 0.05). Middle and coronal regions showed similar results in oval canals (p > 0.05), and coronal region showed lower results in round canals (p < 0.05).

ST, PS, root canal shape and region variables affected the dislocation resistance of core material in standardized root-filled canals.