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