Evaluation of Enamel Wear caused By Various Ceramic Materials and Gold. Asmaa Elmaria DDS, MS Gary R. Goldstein, DDS T.V. Vijayaraghavan, PhD Raquel Z. Legeros, Ph.D NYU Kriser Dental Center. Enamel Wear. Occlusal contact - wear Enamel against enamel – 25-40 µm per/year*
Asmaa Elmaria DDS, MS
Gary R. Goldstein, DDS
T.V. Vijayaraghavan, PhD
Raquel Z. Legeros, Ph.D
NYU Kriser Dental Center
Smoother surface wears less
Bite and Chewing forces
Jacobi & Shillinburg, Monasky and Taylor, Hudson et al. Materials and Gold
abrasive nature of porcelain
Krejci et al. –
rate of enamel wear function; surface finish,& hardness
Krejci et al.
Polishing of pressed glass ceramic led to less wear than glazing.
Klausner et al.
Ra values same for polished/glazed
Raimondo et al.
auto-glazed better vs. polishedPrior studies
Materials Materials and Gold
Type III Gold
75% Au, 11.5% Ag, 10% Cu, 3%
Jeneric/Pentron, Wellingford, CT
63 SiO2, 17.7 Al2O3, 11.2 K2O, 4.2 Na2O, 1.6 CaO, 0.7BaO, 0.6 B2O3, 0.4 CeO2, 0.2 TiO2
Williams/Ivoclar, Amherst, NY
(Leucite content, %)
Na2O, K2O, Al2O3, SiO2, CaO, SnO2, Y2O3, CeO2
Procera/Sandvic AB, Stockholm, Sweden
Na2O, K2O, Al2O3, SiO2
Ceramco Inc. Burlington N.J.Restorative Materials
Material and Condition Materials and Gold
Subset for alpha = .05
.197Multiple comparisonsEnamel height loss
Material Materials and Gold
Glazed IPS Empress
Polished IPS Empress
0.002Surface roughness, Ra (mm)Before and after wear
(N=10 per group), Student's t-Test, significant differences based on p = 0.05
Left: low magnification (35X),the track created by the enamel cusp at 10,000 cycles.
Right: higher magnification(350X) showing polishing lines and smoother track region.
Ra: 0.09- 0.29 µm-before & after wear)
(35X). The track region has been outlined (continuous line) and reveals continuous grooves.
The background reveals a pitted appearance with dark isolated regions indicated by arrows
(background), suggesting removal of some micro-structural constituent .
(Ra: 0.37-0.44 µm - -before & after wear)
The track region is visible and reveals a smoother surface than the surrounding background. Polishing marks can be seen in the background region. Debris is visible as bright white discontinuous regions. (35 X) (Ra: 0.15-0.28 µm -before & after wear)
Left: low magnification (35X)
Right: Higher magnification (500X)
(Ra: 0.46-0.64µm - -before & after wear)
*Kingery WD: Introduction to Ceramics, John Wiley and Sons, Inc., 1960, 597-599.
Ranking of enamel cusp height loss