Evaluation of Fracture Resistance in Aqueous Environment under Dynamic Loading of Lithium Disilicate Restorative Systems for Posterior Applications. Part 2

Abstract

Based on the findings of this study, it may be reasonable to consider a crown thickness of 1.5 mm or greater for clinical applications of milled monolithic lithium disilicate crowns for posterior single teeth.

“Digitally Oriented Materials”: Focus on Lithium Disilicate Ceramics

“…Microcracks usually initiate in load bearing and/or stress concentration areas, eventually fusing under dynamic loads and creating major flaws that could weaken the lithium disilicate structure; when the ultimate mechanical strength is overcome, catastrophic failures occur [19–22]. …”

“…According to in vitro results of dynamic loading, CAD-CAM lithium disilicate SCs should have a thickness of at least 1.5 mm to withstand occlusal loads in posterior areas [22]. Being a filled glass-ceramic, lithium disilicate's final performance as a dental material is strongly related to the type of adhesive cement and accuracy of procedure [31].…”

Survival rate of lithium disilicate restorations at 4 years: A retrospective study

“…2 However, clinical longevity cannot be accurately predicted based on these properties or from in vitro load-to-failure tests. [3][4][5][6] Most of these systems have been brought to market with almost no independent clinical testing. Ninety-five percent of metal ceramic restorations are intact and functioning at 11 years.…”

Experimental Analyses for The Mechanical Behavior of Pressed All-Ceramic Molar Crowns with Anatomical Design

“…Different studies evaluated failure of glass ceramic crowns of thicknesses between 1 and 2 mm. Crowns with 2-mm occlusal thickness sustained 1.7 times more cycles and 1.5-mm occlusal thickness, 1.5 times more cycles than 1-mm thick crowns [21]. Ceramic materials are known for their relatively high fracture resistance and improved aesthetics, but brittleness remains a concern [22].…”