Edge chipping and flexural resistance of monolithic ceramics

Abstract

Objective Test the hypothesis that monolithic ceramics can be developed with combined esthetics and superior fracture resistance to circumvent processing and performance drawbacks of traditional all-ceramic crowns and fixed-dental-prostheses consisting of a hard and strong core with an esthetic porcelain veneer. Specifically, to demonstrate that monolithic prostheses can be produced with a much reduced susceptibility to fracture. Methods Protocols were applied for quantifying resistance to chipping as well as resistance to flexural failure in two classes of dental ceramic, microstructurally-modified zirconias and lithium disilicate glass–ceramics. A sharp indenter was used to induce chips near the edges of flat-layer specimens, and the results compared with predictions from a critical load equation. The critical loads required to produce cementation surface failure in monolithic specimens bonded to dentin were computed from established flexural strength relations and the predictions validated with experimental data. Results Monolithic zirconias have superior chipping and flexural fracture resistance relative to their veneered counterparts. While they have superior esthetics, glass–ceramics exhibit lower strength but higher chip fracture resistance relative to porcelain-veneered zirconias. Significance The study suggests a promising future for new and improved monolithic ceramic restorations, with combined durability and acceptable esthetics.

Edge chipping resistance and flexural strength of polymer infiltrated ceramic network and resin nanoceramic restorative materials

“…The protocol used for the edge chipping resistance testing was similar to that of Zhang et al 27 that emphasized simulating occlusalsurface chipping while implementing the technical recommendations of Quinn et al 28 and 29 Square specimens (n=20/material) of approximate dimensions 10×10×2 mm were sectioned from commercially available CAD-CAM blocks using a diamond saw (IsoMet 11-1180-160 Low Speed Saw; Buehler Ltd) with a diamond wafering blade (IsoMet Wafering Blade 15LC; Buehler Ltd) under a load of 5 N and water irrigation. The 2 square faces were hand-ground using 1200-grit abrasive SiC disks (BuehlerMet II 600 [P1200]; Buehler Ltd) with water and polished with polishing cloths (PoliCloth; Buehler Ltd) and polishing paste (MicroPolish Alumina Suspension; Buehler Ltd).…”

An overview of monolithic zirconia in dentistry

“…Over the last five years, most in vitro studies have focused mainly on the effect of surface treatment on the wear of the material itself and/or antagonists,[24À35] surface roughness, [24,25,27,34,36À38] fracture resistance, [35,39À45] flexural strength, [23,44,46] chipping resistance, [23] compressive strength, [44] elastic modulus, [44] hardness, [33] laser transmission, [47] LTD [48] and CTE-generated stress fields in monolithic zirconia, [49] translucency and colour (Table 1). [35,46,50À56] Although the results from in vitro studies may not fully reflect the clinical performance of the materials due to the complexity of the clinical environment, they have still contributed to the accumulation of a growing body of useful information on the performance of monolithic zirconia.…”

“…These modifications may affect the mechanical and autocatalytic surface-transformation (low-temperature degradation (LTD)) properties of zirconia. [23] This mini-review examines the current scientific literature on the performance of monolithic zirconia (full-contour zirconia).…”

Fracture strength of ceramic monolithic crown systems of different thickness

“…This could affect the mechanical properties of the new material. However, few studies have analyzed possible differences in strength between high-translucent and low-translucent Y-TZP, and even fewer have compared these materials with glass-ceramics (8,9).…”