Synthesis and characterization of wollastonite glass-ceramics for dental implant applications

Selma A Saadaldin; Amin S Rizkalla

doi:10.1016/j.dental.2013.12.007

Synthesis and characterization of wollastonite glass-ceramics for dental implant applications

Dent Mater. 2014 Mar;30(3):364-71. doi: 10.1016/j.dental.2013.12.007. Epub 2014 Jan 17.

Authors

Selma A Saadaldin¹, Amin S Rizkalla²

Affiliations

¹ Medical Biophysics Department, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; Schulich Dentistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.
² Medical Biophysics Department, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; Schulich Dentistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; Chemical and Biochemical Engineering, Faculty of Engineering, Western University, London, ON, Canada. Electronic address: arizkalla@eng.uwo.ca.

PMID: 24444788
DOI: 10.1016/j.dental.2013.12.007

Abstract

Objectives: To synthesize a glass-ceramic (GC) that is suitable for non-metallic one-piece dental implant application.

Methods: Three glasses in a SiO2-Al2O3-CaO-CaF2-K2O-B2O3-P2O5-CeO2-Y2O3 system were produced by wet chemistry. Differential thermal analysis (DTA) was carried out to determine the glass crystallization kinetic parameters and the heating schedules that were used for sintering of GCs. Crystalline phases and crystal morphologies were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Mechanical properties of the GCs were determined by ultrasonic and indentation tests and its machinability were evaluated. Chemical durability was carried out according to ISO 6872, whereas testing chemical degradation in tris buffered solution was executed according to ISO 10993-14.

Results: XRD of the GC specimens showed that wollastonite was the main crystalline with other secondary phases; GC2 had cristobalite as an additional phase. SEM of the GCs revealed dense acicular interlocking crystals. Young's modulus of elasticity (E), true hardness (Ho) and fracture toughness (KIC) of the GCs were 89-100GPa, 4.85-5.17GPa and 4.62-5.58MPam(0.5), respectively. All GCs were demonstrated excellent machinability. The GCs exhibited various chemical durability and degradation rates. KIC values of the GCs following chemical durability testing were not significantly different from those of the original materials (p>0.05). GC2 exhibited significantly higher KIC value compared with GC1 and GC3 (p<0.05) and its chemical durability satisfied ISO 6872 specification for dental ceramics.

Significance: Wollastonite-cristobalite GC can be considered as a promising material for one-piece dental implant applications due to its strength, machinability and chemical durability.

Keywords: Brittleness index; Chemical durability; Cristobalite; Fracture toughness; Glass–ceramics; Machinability; Wollastonite.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Biocompatible Materials / chemistry
Calcium Compounds / chemistry
Ceramics / chemical synthesis*
Ceramics / chemistry
Crystallization
Dental Implants*
Dental Stress Analysis
Differential Thermal Analysis
Elastic Modulus
Hardness
Materials Testing
Microscopy, Electron, Scanning
Silicates / chemistry
Silicon Dioxide / chemistry
X-Ray Diffraction

Substances

Biocompatible Materials
Calcium Compounds
Dental Implants
Silicates
Silicon Dioxide
Glass ceramics
calcium silicate