Initial osteoblast-like cell response to pure titanium and zirconia/alumina ceramics.
OBJECTIVE
Outstanding mechanical properties, resistance to scratching and high biocompatibility make zirconia/alumina ceramics interesting for dental applications. To solve the problem of the well-known low temperature degradation and to provide stable mechanical properties a novel zirconia alloy ((Y,Nb)-TZP/alumina) was developed. The aim of this study was to investigate the initial bone cell response to this new zirconia/alumina composite ceramic.


METHODS
HOS cells were cultured on zirconia/alumina composite (Zc) and pure titanium (Ti) discs. Surface topography was examined by atomic force microscopy (AFM), cell morphology by scanning electron microscopy (SEM). Cell proliferation (MTS) and alkaline phosphatase activity was measured at 1, 4 and 8 days. The mRNA expression of Cycline D1, the cell cycle regulating gene, integrin beta 1, osteonectin (ON) and beta-actin were evaluated by RT-PCR analysis after 12, 24 and 48 h.


RESULTS
Both substrates showed a very smooth character with R(a)-values in the range of 0.002-0.113 microm supporting a continuous cellular growth. After 8 days, cell proliferation on Zc was higher than on Ti. The mRNA expression of cyclin D1 showed similar activity after 48 h on both surfaces, ALP activity was higher on Zc after 8 days. ON expression however showed no difference between the two groups.


CONCLUSIONS
Our data demonstrate that this new zirconia composite ceramic showed at least equivalent or slightly better biological response of osteoblast-like HOS cells than pure titanium during a short-time cell culture period.
Ko
Hee-Cheol
HC
Department of Oral Rehabilitation, Graduate School, Korea University, Republic of Korea.
Han
Jung-Suk
JS
Bächle
Maria
M
Jang
Jun-Hyeog
JH
Shin
Sang-Wan
SW
Kim
Dae-Joon
DJ
D000537:Aluminum Oxide / Q000494:pharmacology; D001672:Biocompatible Materials / Q000494:pharmacology; D002448:Cell Adhesion; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000096:biosynthesis; D003776:Dental Porcelain / Q000494:pharmacology*; D003799:Dental Stress Analysis; D006801:Humans; D019012:Integrin beta1 / Q000096:biosynthesis; D008422:Materials Testing; D016876:Metal Ceramic Alloys / Q000494:pharmacology*; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D015676:Osteonectin / Q000096:biosynthesis; D054457:Tissue Scaffolds; D014025:Titanium / Q000494:pharmacology; D015040:Zirconium / Q000494:pharmacology
D001672:Biocompatible Materials; D019012:Integrin beta1; D016876:Metal Ceramic Alloys; D015676:Osteonectin; D003776:Dental Porcelain; D019938:Cyclin D1; D015040:Zirconium; D014025:Titanium; D000537:Aluminum Oxide; C028541:zirconium oxide