Relationship between elastic and mechanical properties of dental ceramics and their index of brittleness


Autoria(s): Yoshimura, Humberto Naoyuki; Gonzaga, Carla Castiglia; Cesar, Paulo Francisco; Junior, Walter Gomes Miranda
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

12/10/2013

12/10/2013

2012

Resumo

The purpose of the study was to verify the effects of a number of materials' parameters (crystalline content; Young's modulus, E; biaxial flexure strength, sigma(i); Vickers hardness, VH; fracture toughness, K-Ic; fracture surface energy, gamma(f); and index of brittleness, B) on the brittleness of dental ceramics. Five commercial dental ceramics with different contents of glass phase and crystalline particles were studied: a vitreous porcelain (VM7/V), a porcelain with 16 vol% leucite particles (d.Sign/D), a glass-ceramic with 29 vol% leucite particles (Empress/E1), a glass-ceramic with 58 vol% lithium-disilicate needle-like particles (Empress 2/E2), and a glass-infiltrated alumina composite with 65 vol% crystals (In-Ceram Alumina/IC). Discs were constructed according to manufacturers' instructions, ground and polished to final dimensions (12 mm x 1.1 mm). Elastic constants were determined by ultrasonic pulse-echo method. sigma(i) was determined by piston-on-3-balls method in inert condition. VH was determined using 19.6 N load and K-Ic was determined by indentation strength method. gamma(f) was calculated from the Griffith-Irwin relation and B by the ratio of HV to K-Ic. IC and E2 showed higher values of sigma(i), E, K-Ic and gamma(f), and lower values of B compared to leucite-based glass-ceramic and porcelains. Positive correlations were observed for sigma(i) versus K-Ic, and K-Ic versus E-1/2, however, E did not show relationship with HV and B. The increase of crystalline phase content is beneficial to decrease the brittleness of dental ceramics by means of both an increase in fracture surface energy and a lowering in index of brittleness. (C) 2012 Elsevier Ltd and Techna Group Sri. All rights reserved.

FAPESP

FAPESP

CNPq

CNPq

CAPES

CAPES

Identificador

CERAMICS INTERNATIONAL, OXFORD, v. 38, n. 6, supl. 4, Part 1-2, pp. 4715-4722, AUG, 2012

0272-8842

http://www.producao.usp.br/handle/BDPI/34164

10.1016/j.ceramint.2012.02.056

http://dx.doi.org/10.1016/j.ceramint.2012.02.056

Idioma(s)

eng

Publicador

ELSEVIER SCI LTD

OXFORD

Relação

CERAMICS INTERNATIONAL

Direitos

closedAccess

Copyright ELSEVIER SCI LTD

Palavras-Chave #MECHANICAL PROPERTIES #FRACTURE #TOUGHNESS #BIOMEDICAL APPLICATIONS #CERAMICS #FRACTURE SURFACE-ENERGY #SLOW CRACK-GROWTH #FLEXURAL STRENGTH #POSTERIOR FPDS #PORCELAINS #TOUGHNESS #INDENTATION #HARDNESS #GLASS #ALUMINA #MATERIALS SCIENCE, CERAMICS
Tipo

article

original article

publishedVersion