A histomorphometric study on the effect of surface treatment on the osseointegration / 대한치과보철학회지

STATEMENT OF PROBLEM: Many studies have been conducted to improve the primary stability of implants by providing bioactive surfaces via surface treatments. Increase of surface roughness may increase osteoblast activity and promote stronger bonding between bone and implant surface and it has been reported that bioactive surface or titanium can be obtained through alkali and heat treatment. PURPOSE: The purpose of this study was to evaluate the stability of alkali and heat treated implants via histomorphometric analysis. MATERIAL AND METHODS: Specimens were divided into three groups; group 1 was the control group with machined surface, the other groups were treated for 24 hours in 5 M NaOH solution and heat treated for 1 hour at 600degrees C in the atmosphere (group 2) and vacuum (group 3) conditions respectively. Surface characteristics were analyzed and fixtures were implanted into rabbits. The specimens were histologically and histomorphometrically compared according to healing periods and change in bone composition were analyzed with EPMA (Electron Probe Micro Analyzer). RESULTS: 1. Groups treated with alkali and heat showed increase of oxidization layer and Na ions. Groups 2 which was heat treated in atmosphere showed significant increase of surface roughness (P<.05). 2. Histomorphometric analysis showed significant increase in BIC (bone to implant contact) according to increase in healing period and there was significant increases in groups 2 and 3 (P<.05). 3. BA(bone area) ratio showed similar results as contact ratio, but according to statistical analysis there was significant increase according to increase in healing period in group 2 only (P<.05). 4. EPMA analysis revealed no difference in gradation of bone composition of K, P, Ca, Ti in surrounding bone of implants according to healing periods but groups 2 and 3 showed increase of Ca and P in the initial stages. CONCLUSION: From the results above, it can be considered that alkali and heat treated implants in the atmosphere have advantages in osseointegration in early stages and may decrease the time interval between implantation and functional adaptation.

Surface characteristics and stability of implants treated with alkali and heat / 대한치과보철학회지

STATEMENT OF PROBLEM: Bioactive materials must have the ability to spontaneously form a bone like apatite layer on their surface and induce direct biochemical bonding to bone. A simple chemical treatment via alkali and heat has been revealed to induce bioactivity in titanium. PURPOSE: The purpose of this study was to evaluate the surface characteristics and stability of alkali and heat treated implants. MATERIAL AND METHODS: Specimens were divided into three groups; group 1 was the control group with machined surface implants, groups 2 and 3 were treated with alkali solutions and heat treated in the atmosphere and vacuum conditions respectively. The surface characteristics were observed with FESEM, XPS, TF-XRD and AFM. Stability was evaluated with the resonance frequency analysis, periotest and removal torque values. One-way ANOVA and Duncan test were used for statistical analysis. RESULTS: 1. Groups treated with alkali and heat showed similar characteristics. Groups 2 and 3 showed high compositions of Na ions on the surface with sub-micron sized pores compared to group 1. Group 2 showed mixed compositions of anatase and rutile with superior contents of rutile. 2. Resonance frequency analysis : The ISQ of group 2 showed significantly higher values than that of groups 1 and 3 at 12 weeks. The ISQ of groups 1 and 2 showed significant increase after 4 weeks, and the ISQ of group 3 increased significantly after 2 and 4 weeks respectively (P < .05). 3. Periotest: The PTV of groups 1 and 2 showed significant decrease after 4 weeks, and the PTV of group 3 showed significant decrease after 2 and 4 weeks respectively (P < .05). 4. Removal torque analysis: The removal torque value of group 2 was significantly higher than those of groups 1 and 3 at 2, 4 and 8 weeks. The removal torque values of groups 1 and 3 showed increase at 4 and 12 weeks, but the removal torque value of group 2 showed increase after 4 weeks (P < .05). CONCLUSION: An oxide layer with appropriate crystal structure and amorphous sodium titanate layer can be obtained on titanium implants through alkali and heat treatment in the atmosphere, and even alkali and heat treatment in vacuum conditions, provided a bioactive surface containing sodium. These surface layers can be considered to be effective for enhancement of osseointegration and reduction of healing period for implant treatment.

Compound implant surface produced by alkaline and sandblast treatment on titanium / 实用口腔医学杂志

objective: To produce titanium dioxide hydrogel layer on the pure rough titanium(Ti) surface. Methods: Pure Ti discs( d =15mm) were polished to 600 grind, sandblasted and etched with acid, socked in 60 ℃ 5 mol/L NaOH solution for 24 h and then heated to 600℃ for an hour to get goughening, alkaline and heat treated Ti(RAH). The smooth, rough and RAH surfaces were analyzed with scanning electron microscope(SEM) and energy despersive X ray analysis(EDXA). Results: On smooth surfaces only regular polished grooves could be seen, while holes in different diameters formed on rough surfaces. A porous framework was found on the surfaces of the RAH observed by SEM. EDXA showed that the smooth and rough surfaces were consisted of 100% Ti, while there were a lot ofoxygen and sodium in RAH discs. Apatite formed on the RAH Ti surfaces when it is soaked in simulated body fluid for two weeks. Conclusion: A porous Ti dioxide hydrogel layer forms on the rough titanium substrate during alkaline and heat treatment.