# Comparative evaluation of fracture toughness between zirconia and lithium disilicate ceramics: An in vitro study

## TL;DR

This study compares the crack resistance of two dental ceramics, finding that zirconia is stronger and tougher than lithium disilicate.

## Contribution

The paper provides a direct in vitro comparison of fracture toughness between zirconia and lithium disilicate ceramics.

## Key findings

- Zirconia showed significantly higher fracture toughness than lithium disilicate.
- Zirconia also exhibited greater hardness compared to lithium disilicate.
- Zirconia's superior crack resistance supports its use in high-stress dental applications.

## Abstract

Fracture toughness is a critical determinant of long-term success in all-ceramic restorations, yet comparative data between major
ceramic systems remain limited. Therefore, it is of interest to evaluate and compare the fracture toughness of yttria-stabilized zirconia
and lithium disilicate ceramics. Forty CAD/CAM-fabricated specimens were tested using Vickers indentation and fracture toughness was
calculated via the indentation fracture method. Zirconia showed significantly higher fracture toughness (408.61 ± 44.21 MPa.m1/2)
and hardness than lithium disilicate (359.40 ± 19.00 MPa.m1/2) (p <0.0001). Zirconia demonstrates superior crack
resistance compared to lithium disilicate, supporting its use in high-stress clinical applications.