9. Scanning electron microscopy(SEM) observation of
fibroblasts cultured on zirconia : cells grow on the
whole zirconia surface, covering it with a cellular layer.
14. Dental wear is defined as tooth loss or surface damage
caused by direct contact between teeth or between
teeth and other materials. Dental wear, one of the
physiological phenomena that are experienced in a
lifetime, occurs as a complex form of chemical and
mechanical wear.
The surface hardness and friction coefficient are
commonly used to estimate the degree of wear of
restorative dental materials. Conventionally, greater
hardness has been believed to cause more wear.
Therefore, more wear was expected from zirconia, as
zirconia has strong surface hardness.
According to scientific studies, however, there is no
significant correlation between the restoration
hardness and the degree of wear of antagonistic teeth.
On the other hand, the degree of wear is more affected
by the surface structure and the roughness of the
restorations or environmental factors.
16. Wear of Pediatric Enamel by Different
Ceramic Materials
Gary Frey, DDS
Davette Johnson, DDS
Houston Center for Biomaterials and Biomimetics
University of Texas School of Dentistry at Houston
7500 Cambridge St. Suite 5350
Houston, TX 77054-2008
Stylus Material X-axis wear Y-axis wear Depth
1 Zirconia 93.6 microns 98.8 microns 46 microns
3 Zirconia 118.2 microns 110.6 microns 112 microns
5 Zirconia 93.2 microns 75.1 microns 75 microns
7 Zirconia 94.8 microns 85.3 microns 41 microns
2 Alumina 100.2 microns 95.3 microns 42 microns
4 Alumina 101.6 microns 88.3 microns 57 microns
6 Alumina 94.3 microns 105.0 microns 54 microns
8 Alumina 87.3 microns 95.3 microns 66 microns
height width
Using a Leinfelder style in-vitro wear-test apparatus, 800,000 cycles
17. Zirconia Stylus Tips
Wear screening performed with
LEINFELDER testing instrument
What about wear to opposing primary teeth?
Frey et al., Houston Center for Biomaterials and Biomimetics (2012)
20. Use a football or coarse tapered diamond to
reduce the occlusal surface of the tooth 1-2mm
following occlusal contours.
Tooth Preparation
21. Carefully prep tooth supragingivally to avoid tissue
masceration. Reduce the tooth 20% overall or 0.5-
1.25 mm on all planes of the tooth.
Black stripe – 5855
22. Use a fine thin tapered diamond - create a
feather-edge margin 1-2mm subgingivally
Green Stripe - 6852
Make sure no subgingival shoulders
or ledges remain