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Glass-ceramics and ceramics as biomaterials for Glass-ceramics and ceramics as biomaterials for dental restorationdental restoration
Derby, UK, September, 2007
W. Höland, V. Rheinberger, E. Apel,
Ch. Ritzberger, H. Kappert
Ivoclar Vivadent AG, Li-9494 Schaan, Liechtenstein
Outline
II.II. Glass-ceramics as biomaterials for dental restorationGlass-ceramics as biomaterials for dental restoration
1. Leucite-apatite
2. Leucite
3. Lithium disilicate and apatite
III. Ceramics as biomaterials for dental restorationIII. Ceramics as biomaterials for dental restoration
1. ZrO2 2. Fusion of ceramic and apatite glass-ceramic
I. Fundamentals on ceramic and glass-ceramic technologyI. Fundamentals on ceramic and glass-ceramic technology
IV. SummaryIV. Summary
I. Fundamentals of ceramic technology
chemicalcomposition
microstructure
properties
application
nucleation
crystallization
processing
applied processing
I
W. Höland & G.H. Beall, Glass-ceramic technology. The American Ceramic Society, 2002, and J. Wiley, 2006
W. Höland, Glaskeramik, vdf / UTB, 2006
I. Fundamentals of ceramic technology
I
controlled nucleation and crystallization
relationship between microstructure and properties
designing of glass-ceramics and ceramics
II. Dental glass-ceramics as restorative BIOMATERIALS
1 2
3
II
glass-ceramic as single units (metal-free)
glass-ceramic on a metal framework
glass-ceramic as multi-unit bridge
(metal-free)
1. Leucite-apatite glass-ceramic
1 µmSEM (10 sec, 2.5% HF)
700 °C / 8 h +1050 °C / 1 h
leucite
powder monolith
apatite
700 °C / 8 h +1050 °C / 1 h
2 µm
II
2. Opal leucite glass-ceramic
surface crystallization and
volume
surface
volume phase separation
20 µm 1 µm
900 °C/1h SEM ,1.25 %HF, 4s 1020 °C/1h
II
Processing by moldingProcessing by molding
• glaciers• long term viscous flow
II
v i s c o u s f l o w
2. Leucite glass-ceramics
molding
furnace chamber(1075, or 1180 °C)
pressure unit
pressing plunger(1.8 - 2.0 MPa)
Al2O3 plunger
glass-ceramicingotspecimen investment
cylinder
II
IPS Empress®
lost wax technique
mold
processing by CAD/CAM:fast increasing technology
machinabilty
CAD System
II
leucite-type glass-ceramics
2. Leucite glass-ceramics
3.a) lithium disilicate and 3.b) apatite glass-3.a) lithium disilicate and 3.b) apatite glass-ceramicceramic
lithium disilicate gc apatite gc
IPS Empress® 2, IPS Eris®
II
3. Lithium disilicate glass-ceramics
Properties [1] Leucite glass-ceramic
Lithium disilicate glass ceramic (state of the art)
Flexural strength 140 ± 10 MPa 400 ± 40 MPa
KIC 1.3±0.1MPa•m0.5 3.3 ± 0.3 MPa • m0.5
Translucency 0.58 0.55
C.T.E. 15.0±0.25•10-6/K (25 – 500 °C)
10.6 ± 0.25 • 10-6/K (100 – 400 °C)
Chemical durability
100 µg/cm2 50 µg/cm2
[1] dental standard ISO 6872
II
3. Lithium disilicate glass-ceramic
5 µm
SEM (3 s, ceramex)
final productfinal product
920 °C, pressingcrystallinity: 65 Vol.%
Li2Si2O5
II
IPS e.max®
III. Ceramics as biomaterials for dental restorationIII. Ceramics as biomaterials for dental restoration III
1. ZrO2 2. Fusion of ceramic and apatite glass-ceramic
propertiesof the final product
1m
biocompatible
crystallite size ~0.5-0.65m
density ~99.5%
flexural strength>900MPa
KIC approx. 6 MPa· m1/2
100-400°C approx. 10.5 10-6 K-
1m/m
Sintramat
SEM
1 µm
SEM (3 % HF, 10 s)
apatite glass-ceramic natural dentin
biomimetic process nature as example
1 µm
Glass-ceramic as veneering material
III
2. fusion of ceramic and apatite glass-ceramic
IV. Summary
Glass-ceramic and ceramics as biomaterials for dental restoration
• designing the biomaterials: control the microstructure and to predict special properties based on new technologies
• high strength, tough, durable materials
• natural appearance, optical properties close to those of natural tooth
• processing: molding or machining - effective technologies
• veneering: sintering with fluoroapatite containing glass-ceramic
IV