Microstructural characterization and comparative evaluation of physical, mechanical and biological properties of three ceramics for metal–ceramic restorations

Kontonasaki, Eleana; Kantiranis, Nikolaos; Papadopoulou, Lambrini; Chatzistavrou, Xanthippi; Kavouras, Panagiotis; Zorba, Triantafillia; Sivropoulou, Afroditi; Chrissafis, Konstantinos; Paraskevopoulos, Konstantinos M.; Koidis, Petros T.

doi:10.1016/j.dental.2008.03.002

« Previous Next »Dental Materials
Volume 24, Issue 10 , Pages 1362-1373, October 2008

Microstructural characterization and comparative evaluation of physical, mechanical and biological properties of three ceramics for metal–ceramic restorations

Eleana Kontonasaki
- School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
Nikolaos Kantiranis
- Geology Department, Aristotle University of Thessaloniki, Thessaloniki, Greece
Lambrini Papadopoulou
- Geology Department, Aristotle University of Thessaloniki, Thessaloniki, Greece
Xanthippi Chatzistavrou
- Physics Department, Aristotle University of Thessaloniki, Thessaloniki, Greece
Panagiotis Kavouras
- Physics Department, Aristotle University of Thessaloniki, Thessaloniki, Greece
Triantafillia Zorba
- Physics Department, Aristotle University of Thessaloniki, Thessaloniki, Greece
Afroditi Sivropoulou
- Biology Department, Aristotle University of Thessaloniki, Thessaloniki, Greece
Konstantinos Chrissafis
- Physics Department, Aristotle University of Thessaloniki, Thessaloniki, Greece
Konstantinos M. Paraskevopoulos
- Physics Department, Aristotle University of Thessaloniki, Thessaloniki, Greece
Petros T. Koidis
- School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
- Corresponding author at: Department of Fixed Prosthesis & Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, University Campus, Dentistry Building, GR 54124, Thessaloniki, Greece. Tel.: +30 2310 999659; fax: +30 2310 999676.

Received 20 October 2006; received in revised form 12 December 2007; accepted 3 March 2008.

Abstract

Objectives

A wide variety of dental ceramics compositions have been introduced in dental clinical practice in order to combine desired aesthetics with superior mechanical performance. The aim of the present study was to investigate the microstructural changes in three dental ceramics after their sintering according to manufacturers’ instructions and to comparatively evaluate some of their physical, mechanical and biological properties.

Methods

The analysis of the phases present in each material before and after sintering was performed with scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD). The thermal properties of ceramic specimens were evaluated with differential thermal and thermogravimetric analysis (TG-DTA). The mechanical properties evaluated were fracture toughness, Young's modulus and microhardness with the Vickers indentation method. MTT assay was used for cell proliferation assessment. One-way analysis of variance (ANOVA) with Bonferroni multiple comparisons tests was used to determine statistically significant differences (significance level of p<0.05).

Results

Results showed a remarkable variation among the three ceramic compositions of leucite content in the starting unheated ceramic powders ranging between 14 and 32wt.% and in the respective sintered powders ranging between 15 and 41wt.% The low fusing glass–ceramic and the high fusing leucite-based ceramic presented significantly higher fracture toughness (p<0.001) and microhardness and lower modulus of elasticity (p<0.05) compared to the low fusing feldspathic ceramic. The three ceramics were almost equivalent concerning their in vitro biological behavior.