IADR Abstract Archives
Effect of cementation surface modifications on flexural strength of Zirconia
Method: 40 zirconia plates, with its intaglio surface either glass infiltrated (GI, n = 20) or hydrophobic, nanocrystalline alumina coating (~240nm)(AC, n = 20), were fabricated. These surface modified zirconia plates (12x12x1.5 mm) were cemented (Multilink Automix, Ivoclar Vivadent) onto a restorative composite (Z100, 3M/ESPE) for normal load-to-fracture flexural tests. These tests were made using a tungsten carbide spherical indenter (r = 3.2 mm) on an universal testing machine. Plates of monolithic zirconia (n = 20) served as controls. Critical loads were recorded for the onset of flexural fracture at the zirconia intaglio (cementation) surface. Damage sustained in ceramic plates was evaluated using optical and scanning electron microscopy.
Result: All ceramics fractured from the intaglio surface. Critical loads for the onset of flexural fracture of all three specimen groups are tabulated below.
Group |
Mean Fracture Load, P (N) |
S.D. (N) |
||
Monolithic Y-TZP(control) |
2470 |
280 |
||
GI modified intaglio surface |
3260 |
450 |
||
AC modified intaglio surface |
2160 |
210 |
||
A 1-sample t-test showed significant differences (p < 0.001) between group GI & AC and group GI & control. No difference revealed between group AC & control.
Conclusion: Glass infiltration on the cementation surface has increased the load bearing capacity by ~30% compared to un-modified zirconia. These structures can be engineered in shades from white to yellow, and have potentially better resin bond properties than homogeneous zirconia.