Effects Of TiO₂ Blasted And Acid-etched Titanium Surfaces On Oxide-film And Osteoblast

[Objective] To study the effects of TiO₂ blasted and acid-etched surfaces of cp-titanium on changing composition of oxide-film and attachment and proliferation of osteoblasts in vitro.[Materials and Methods] cp-titanium discs (1.5mm diameter and 1mm thickness) were prepared and divided into 3 test groups:TiO₂ blasted(SB) , sandblasted and acid-etching (SLA₁ and SLA₂ ) and 1 control group :machine-turned surface(So) . SB surfaces were sandblasted by TiO₂ particles, sized 356-411μm.SLA surface were attacked with acidic solution (H₂SO₄/HCL) for 10min(SLA₁) and 60min(SLA₂) at 60-70℃. S₀ surfaces were prepared by hand grinding with SiC paper to 600 grits. Scanning electron microscopy, x-ray photoelectron spectroscopy (XPS) and Electron probe microanalysis (EPMA) were used to test surface morphology and composition of oxide-film. Osteoblasts derived from fetal rat calvarial bone were cultured on the 4 titanium surface. For attachment measurement, osteoblasts were cultured for 1, 4, 12 and 24 hours, evaluated by MTT Assay. For proliferation measurement, osteoblasts were cultured for l,3,5,and 7 days, evaluated by MTT Assay. Date were analyzed by one-way ANOVA (a = 0.05).[Results] In regard to surface roughness, average roughness (Ra) values varied from 3.0-3.9μm for test groups and 0.332 ±0.037μm for control group. The surface morphology showed porous structures for test groups and nonporous parrier film for the control group. Pore diameter range from 10-40μm on SB. Microporous range from 0.1-3μm on SLA. Analysis of oxide film: Oxygen ratio increased on SB (38.808%), contrarily, it decreased on SLA. A mixture of anatase and rutile-type crystals were observed in the SB. Smaller anatase were observed in the SLA₁ and SLA₂- The oxide thickness on SLA surface is thiner than on SB surface. Osteoblast Attachment After 1 hour culture, the number of cells on SB surfaces was the highest (P<0.05) while it was similar on So and SLA₁ surfaces(P>0.05 ). the number of cells on SLA₂ surface was lowest (P<0.05) .After 4 hours, the number of cells attachment on SB surfaces was higher than other groups (P>0.05) . after 12 hours. There was no difference...