# Mechanical Performance of 3D-Printed Resins versus CAD/CAM PMMA for Provisional Crowns: New Evidence under Simulated Clinical Conditions

## TL;DR

This study compares the mechanical performance of 3D-printed resins and CAD/CAM PMMA for dental crowns under simulated aging conditions.

## Contribution

The study provides new evidence that 3D-printed resins outperform CAD/CAM PMMA after artificial aging in provisional crowns.

## Key findings

- 3D-printed restorations showed significantly higher fracture resistance than CAD-CAM milled crowns after artificial aging (p = 0.0064).
- No significant differences were observed between the two fabrication methods under non-aged conditions.
- All groups exceeded the minimum clinically acceptable values for fracture resistance.

## Abstract

Provisional restorations play a fundamental role in fixed prosthodontic rehabilitation. While current evidence has identified CAD/CAM-fabricated materials as the preferred option due to their excellent mechanical properties, 3D-printed resins have shown significant improvements in their performance in recent years. Therefore, the aim of the present study was to re-evaluate the fracture resistance of provisional crowns fabricated using 3D-printed resin and CAD/CAM-milled PMMA, considering the influence of artificial aging.

An in vitro study was conducted on 60 provisional crowns divided into four groups according to material type (3D-printed resin or CAD/CAM PMMA) and aging condition; thermocycling and simulated brushing were applied, fracture resistance was tested using a universal testing machine, and data were analyzed using the Student’s t-test at a 5% significance level.

After artificial aging, 3D-printed restorations showed significantly higher fracture resistance than CAD-CAM milled crowns (p = 0.0064). However, no statistically significant differences were observed between the two fabrication methods under non-aged conditions (p > 0.05). All groups exceeded the minimum values considered clinically accepTable.

3D printing demonstrated superior mechanical stability after artificial aging, supporting its clinical viability as an efficient, predicTable, and favorable option for provisional restorations in oral rehabilitation.

Key words:3D printing, CAD/CAM, Digital dentistry, Provisional restoration, fracture resistance.