Bioceramics-Dr. Carls 2 - G.-Wiehebrink

The advantages and use
of
ceramics in medicine
G. Carl
Friedrich-Schiller-Universität Jena
Otto-Schott-Institut
(now with JSJ Jodeit GmbH Jena)
ORTHOSONIC CERAMIC CONFERENCE Saturday 6 th July 2002

ioceramics
bioceramics
bioglasses
bioglass-ceramics

dens, nonporous
/porous
granules
/powder
bioceramics
coatings
components
of
composites

ioinert
- alumina ceramic
- zirconia ceramic
- glassy carbon
biotolerant
-glass-ceramics
without
apatite crystals
bioceramics
bioactive
-hydroxyapatite
-bioglasses
-bioglass-ceramics
with apatite
bioresorbable
- ß-TCP
- bioglasses
- bioglass-ceramics

alumina bioceramic
- high-density / high-purity -
⇒ good biocombatibility
⇒ excellent corrosion resistance
⇒ high wear resistance
⇒ low coefficient of friction
⇒ very low surface roughness values
⇒ high strength
⇒ high fracture toughness

properties
Al 2 O 3 content [wt-%]
density [g/cm³]
average grain size [µm]
hardness [HV]
bending strength [MPa]
Youngs Modulus [GPa]
properties of alumina bioceramic
compressive strength [MPa]
fracture toughness [MPa*m -1/2 ]
alumina
bioceramic
> 99,8
> 3,93
3-6
2300
4500
550
380
5-6
ISO alumina
standard 6474
≥ 99,5
≥ 3,9
< 7
> 2000
400

microstructure
alumina bioceramic
contact angle

one
screws
hip
prostheses
balls &
sockets
alveolar
ridge
keratoprostheses
corneal
replacements
alumina
ceramic
maxillofacial
reconstructions
knee
prostheses
middle ear
implants
dental
implants

clinical applications of alumina bioceramic

properties
density [g/cm³]
average grain size [µm]
hardness [HV]
bending strength [MPa]
Youngs Modulus [GPa]
properties of zirconia bioceramic
ZrO 2 / Al 2 O 3 content [wt-%]
fracture toughness [MPa*m -1/2 ]
zirconia
bioceramic
> 97
5,6 – 6,1
1
1300
1200
200
15
alumina
bioceramic
≥ 99,8
≥ 3,93
3-6
2300
550
380
5 - 6

Moje zirconia implants

iotolerable bioglass-ceramics
♠ systems
⇒ mica glass-ceramics (machinable) - Bioverit ® II
microstructure of mica glass-ceramics with plate like (right) and curved
mica crystals (left, Bioverit ® II), scanning electron micrograph

iotolerable bioglass-ceramics
♠ systems
⇒ mica glass-ceramics (machinable)
⇒ leucite glass-ceramics
⇒ lithium silicate glass-ceramics
♠ properties
⇒ biocompatible, non-toxic
⇒ high chemical resistance
⇒ good mechanical properties
♠ clinical applications
⇒ dental restorations
⇒ middle ear implants
⇒ skull reconstructions

skull cap
biotolerable mica bioglass-ceramic Bioverit ® II
dental restorations - inlays
middle ear implants

ioactive bioceramics
hydroxyapatite – Ca 10(PO 4) 6(OH) 2
♠ clinical applications
⇒ bone void filler
(nonporous, porous – coraline)
⇒ coatings
♠ properties
⇒ high biocompatibility
⇒ high bone bonding ability
⇒ high chemical resistance
⇒ low mechanical strength
microstructure of a porous hydroxyapatite ceramic

ioactive bioceramics
hydroxyapatite – Ca 10(PO 4) 6(OH) 2

ioactive bioceramics
bioglass ®
♠ sytem: Na 2 O-CaO-SiO 2 -P 2 O 5 -(F - )

ioactive bioceramics
bioglass ®
♠ properties
⇒ excellent biocompatibility
⇒ high bio reactivity
⇒ high bone bonding ability
⇒ low chemical resistance
⇒ low mechanical strength
♠ clinical applications
⇒ bone void filler
⇒ coatings
⇒ composites
⇒ middle ear implants
⇒ dental implants

ioglass-ceramics
System
crystal phases
bone bonding
ability
chemical
resistance
mechanical
strength
apatite
low
low
bioactive bioceramics
bioglass-ceramics
Ceravital ®
Na 2 O-CaO-SiO 2 -
P 2 O 5
very high
apatite,
wollastonite
very high
high
high
Cerabone ®
MgO-CaO-SiO 2 -
P 2 O 5 -F -
Na 2 O-K 2 O-MgO-
Al 2 O 3 -CaO-SiO 2 -
P 2 O 5 -F -
apatite
mica
high
high
high
Bioverit ®

electron-beam microprobe
investigation of
the intergrowth zone
between bone (left) and
bioglass-ceramic
Bioverit ® I (right)
bioactive bioglass-ceramic Bioverit ® I
intergrowth between
bone and glassceramic
Bioverit ® I
(scanning electron
micrograph)
intergrowth between
bone (yellow) and glassceramic
Bioverit ® I
(optical micrograph)

ioactive bioceramics
bioglass-ceramics
♠ clinical applications
⇒ bone spacer
⇒ coatings
⇒ composites
⇒ distance-keeping implants in osteotomy
⇒ artificial vertebras
⇒ dental implants
glass-ceramic implants of Bioverit ® I

ioresorbable bioceramics
♠ systems
⇒ ß-TCP (ß-tri calcium phosphate)
⇒ phosphate glasses and glass-ceramics
♠ properties
⇒ high biocompatibility
⇒ controlled resorption or biodegratation
⇒ low chemical resistance
⇒ poor mechanical strength
♠ clinical applications
(powder, porous solid, dens solid)
⇒ bone void filler

coatings with bioactive ceramics
* technology:
⇒ plasma spraying
⇒ sputtering
⇒ sol-gel-process
⇒ sintering
* requirements:
⇒ good biocompatibility, bone bonding
⇒ similar thermal expansion coefficients
⇒ high chemical stability
⇒ good adhesive strength of the coating
⇒ no changes of the substrates by the coating process

ioactive glassceramic
Bioverit ® I
coated zirconia
endoprostheses
Bioverit ® I coating on Moje zirconia prostheses
* coating process
milling
(d ~ 10 µm)
zirconia
endoprostheses
sintering process
at 1200 – 1300 °C
mixing of the
powder with water
painting of the slip
and drying

Bioverit ® I coating on Moje zirconia prostheses
* results
⇒ good biocompatibility, bone bonding ability
⇒ dense and crack-free layer
⇒ long term stability
⇒ good adhesive strength of the coating
⇒ no changes of the zirconia ceramic
microstructure of the coating,
scanning electron micrograph
intergrowth of coating and bone,
optical photomicrograph

⎮Bioceramics:
summary
wide range of biological properties
different chemical compositions
various chemical and mechanical properties
different shape and size
wide range of clinical applications

Ergänzungsfolien

ioceramics – interface range

ioactive bioglass-ceramic Bioverit ® I
bone connection
bone connection in dependence of the time of implantation in an animal experiment –
glass-ceramic Bioverit ® I implants in comparison to corundum implants