Effects of fluoride-modified titanium surfaces on osteoblast proliferation and gene expression.
OBJECTIVE
The objective of this study was to test the hypothesis that fluoride-modified titanium surfaces would enhance osteoblast differentiation. Osteoblast growth on a moderately rough etched fluoride-modified titanium surface (alteration in cellular differentiation) was compared to osteoblast growth on the same surface grit-blasted with titanium dioxide. The potential role of nanometer-level alterations on cell shape and subsequent differentiation was then compared.


METHODS
Human embryonic palatal mesenchymal (HEPM) cultures were incubated on the respective surfaces for 1, 3, and 7 days, followed by analysis for cell proliferation, alkaline phosphatase (ALP) -specific activity, and mRNA steady-state expression for bone-related genes (ALP, type I collagen, osteocalcin, bone sialoprotein [BSP] II, Cbfa1, and osterix) by real-time polymerase chain reaction (PCR).


RESULTS
The different surfaces did not alter the mRNA expression for ALP, type I collagen, osterix, osteocalcin, or BSP II. However, Cbfa1 expression on the fluoride-modified titanium surface was significantly higher (P < .001) at 1 week. The number of cells on this surface was 20% lower than the number of cells on the surface TiO2-blasted with 25-microm particles but not significantly different from the number of cells on the surface TiO2-blasted with 125-microm particles. Cells grown on all the titanium surfaces expressed similar levels of ALP activity.


CONCLUSIONS
The results indicated that a fluoride-modified surface topography, in synergy with surface roughness, may have a greater influence on the level of expression of Cbfa1 (a key regulator for osteogenesis) than the unmodified titanium surfaces studied.
Isa
Zakiah M
ZM
Department of Prosthetic Dentistry, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia.
Schneider
Galen B
GB
Zaharias
Rebecca
R
Seabold
Denise
D
Stanford
Clark M
CM
D000134:Acid Etching, Dental; D000704:Analysis of Variance; D002448:Cell Adhesion / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000494:pharmacology; D050659:Core Binding Factor Alpha 1 Subunit / Q000096:biosynthesis*; D005459:Fluorides / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
D020099:Coated Materials, Biocompatible; D050659:Core Binding Factor Alpha 1 Subunit; C009495:titanium dioxide; D014025:Titanium; D005459:Fluorides