Effect of titanium surface roughness on human osteoblast proliferation and gene expression in vitro.
OBJECTIVE
Cell proliferation and extracellular matrix formation are primary events in bone formation. At the dental implant-tissue interface, implant surface roughness modulates osteoblast functions. The aim of the present in vitro study was to investigate the effect of varying surface roughness of titanium implant material on cell proliferation and mRNA expression of specific markers of osteoblast phenotype.


METHODS
Primary cultures of osteoblasts derived from human mandibular bone were cultured on titanium surfaces. Three titanium surfaces were studied: machined titanium, microsandblasted titanium, and macro-sandblasted titanium (average surface roughnesses of 0.5 and 3 microm, respectively). Cell morphology was estimated by scanning electron microscope analysis and cell proliferation by measuring the amount of 3H-thymidine incorporation into DNA. mRNA expression of osteonectin, osteopontin, bone sialoprotein (BSP), and Runx2, which are markers of osteoblastic phenotype, were determined by reverse transcriptase polymerase chain reaction (RT-PCR) analysis.


RESULTS
Human osteoblasts cultured on machined titanium spread more and were flatter than cells cultured on rough titanium. All blasted surfaces showed significantly higher DNA synthesis than the machined surfaces. Osteonectin mRNA expression was similar on all surfaces. Other mRNA transcripts were increased in osteoblasts cultured on rough titanium surfaces, particularly the macrosandblasted surface.


CONCLUSIONS
An average surface roughness of 3 microm (macro-sandblasted titanium) is more suitable than an average surface roughness of 0.5 microm (micro-sandblasted titanium) in favoring osteoblast differentiation in vitro.
Marinucci
Lorella
L
Department of Experimental Medicine and Biochemical Science, University of Perugia, Italy.
Balloni
Stefania
S
Becchetti
Ennio
E
Belcastro
Salvatore
S
Guerra
Mario
M
Calvitti
Mario
M
Lilli
Cinzia
C
Calvi
Edoardo Maria
EM
Locci
Paola
P
D000704:Analysis of Variance; D002454:Cell Differentiation; D049109:Cell Proliferation; D048430:Cell Shape; D002478:Cells, Cultured; D050659:Core Binding Factor Alpha 1 Subunit / Q000096:biosynthesis; D015870:Gene Expression; D006801:Humans; D058574:Integrin-Binding Sialoprotein; D008334:Mandible / Q000166:cytology; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D015676:Osteonectin / Q000096:biosynthesis; D053495:Osteopontin / Q000096:biosynthesis; D012313:RNA / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins / Q000096:biosynthesis; D013499:Surface Properties; D014025:Titanium; D053781:Transforming Growth Factor beta2 / Q000096:biosynthesis
D050659:Core Binding Factor Alpha 1 Subunit; C546871:IBSP protein, human; D058574:Integrin-Binding Sialoprotein; D015676:Osteonectin; D012795:Sialoglycoproteins; D053781:Transforming Growth Factor beta2; D053495:Osteopontin; D012313:RNA; D014025:Titanium