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.

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.