Effect of titanium surface microgrooves and thermal oxidation on in vitro osteoblast responses / 대한치과보철학회지

PURPOSE: We aimed to investigate the effect of combined various microgrooves and thermal oxidation on the titanium (Ti) and to evaluate various in vitro responses of human periodontal ligament cells (PLCs). MATERIALS AND METHODS: Grade II titanium disks were fabricated. Microgrooves were applied on titanium discs to have 0/0 microm, 15/3.5 microm, 30/10 microm, and 60/10 microm of respective width/depth by photolithography. Thermal oxidation was performed on the microgrooves of Ti substrata for 3 h at 700degrees C in air. The experiments were divided into 3 groups: control group (ST), thermal oxidation group (ST/TO), and combined microgrooves and thermal oxidation group (Gr15-TO, Gr30-TO, Gr60-TO). Surface characterization was performed by field-emission scanning microscopy. Cell adhesion, osteoblastic differentiation, and mineralization were analyzed using the bromodeoxyurdine (BrdU), Alkaline phosphatase (ALP) activity, and extracellular calcium deposition assays, respectively. Statistical analysis was performed using the oneway analysis of variance and Pearson's bivariate correlation analysis (SPSS Version 17.0). RESULTS: In general, the combined microgrooves and thermal oxidation group (Gr15-TO, Gr30-TO, Gr60-TO) showed significantly higher levels compared with the control (ST) or thermal oxidation (ST-TO) groups in the BrdU expression, ALP activity, and extracellular calcium deposition. Gr60-TO group induced highest levels of cell adhesion and osteoblastic differentiation. CONCLUSION: Within the limitation of this study, we conclude that the Ti surface treatment using combined microgrooves and thermal oxidation is highly effective in inducing the cell adhesion andosteoblastic differentiation. The propose surface is also expected to be effective in inducing rapid and strong osseointegration of Ti oral implants.

Effects of Oxidized Tallow on the Rabbit Serum Lipids and Antioxidant Activity of the In-vitro Lipids

This paper describes the effects of thermally oxidized tallow on the serum lipids profile and radical scavenging activity (RSA) of the lipids extracted from the different tissues of the rabbits. Tallow was thermally oxidized at 130degrees C for 9, 18, 27, 36 and 45 h respectively. Thermally oxidized tallow was fed to the local strain of Himalayan rabbits for one week. Results show that oxidation increases the formation of hydroperoxides and decrease the level of radical scavenging activity of the tallow. The rabbit serum lipids profile showed a dose dependent increase in triglyceride, total cholesterol and LDL-cholesterol. However, no statistically significant increase was observed in the HDL-cholesterol with an increase of oxidation time. Serum glucose and rabbits body weight decrease significantly (p < 0.05) and was highly correlated with the serum lipids profile. The percent RSA of the lipids extracted from the liver, brain and muscles tissues showed a significant decrease with respect to 0.5, 1.0 and 1.5 g/body weight as well as oxidation time. Data suggests that thermal oxidation and use of thermally oxidized beef tallow is harmful and therefore an alternative way of cooking should be used.

Biocompatibility evaluation of domestically-manufactured NiTi-alloys after thermal oxidation of surface / 第二军医大学学报

Obiective: To compare the tissue biocompatibility of domestically manufactured NiTi alloy before and after thermal surface oxidation under 3 different temperatures. Methods: Domestically manufactured NiTi alloy was oxidized in air (group A) and subjected to 30 min heat treatment at 400°C (group B),500°C, (group C),and 600°C (group D) to form different protective oxide surface layers in presence of argon (607.95 kPa). Wire samples from A, B, C and D groups were subcutaneously implanted in guinea pigs. Guinea pigs received 317L stainless steel transplantation(group E) and sham-operation group (F) were taken as control. The order of inflammatory cell infiltration and tissue hyperplasia around implanted materials were observed 1, 2, 4, and 8 weeks after implantation. Results: The peak time of inflammatory cell infiltration and fibrous hyperplasia were at the first and fourth week after implantation. The inflammatory cell infiltration and fibrous hyperplasia were both slight and all met the GB/T 16886. 6-1997 in vivo implantation standard. The order of inflammatory cell infiltration and thickness of capsule walls from low to high was F

Cytocompatibility of thermally oxidized Ti-Ag alloys / 대한치과보철학회지

STATEMENT OF PROBLEM: In its preceding work, change in surface characteristics were investigated in consideration that both microtopograpy and macroscopic configuration of implants surface are two of the most important factors, in that they can construct agreeable environment by raising surface energy, to affect osseointegration and biocompatibility explained by cell proliferation. PURPOSE: This study focused on examining cytocompatibility of dental implants materials Ti-Ag alloys, of which mechanical and electrochemical superiority to cp-Ti or Ti6Al4V were verified, in comparison with that of cp-Ti, and Ti6Al4V. MATERIALS AND METHODS: In this regard, MTT tests for L-929, the fibroblast connective tissues and cell proliferation tests for osteoprogenitor cells, MC3T3-E1 were performed on cp-Ti, Ti6Al4V, and Ti-Ag alloys following thermal oxidation according to appropriate heat treatment temperature(untreated, 400, 600, 800degrees C) and heat treatment duration(untreated, 0.5, 1, 4 hr). RESULTS: The MTT tests on fibroblasts L-929 resulted in cell viability of over 90% in all experimental group entities, where, especially, the 100% of the viability for Ti-Ag alloys specimens accounted for the slightest adverse effect of ions release from those alloys on the cell. In MC3T3-E1 proliferation tests, the population of cells in the experimental group was roughly increased as experimentation proceeded, after two to four days. Proliferation showed highest viability for most of specimens, including Ti2.0Ag, treated at 600degrees C. CONCLUSION: In conclusion, it is the heat treatment temperature, not the duration that has considerable effects on thermal oxidation of specimens. Ti-Ag alloys treated at 600degrees C proved to have the best surface morphology as well as cytocompatibility when compared with Ti or Ti6Al4V for short-term biocompatibility tests.

The Effect of TitaniumI Surface Treatment on Osteoblast-Like Cell Attachment and Proliferation / 대한치주과학회지

In clinical therapy, the current goal of dental implants is to enhance quantity and quality of osseointegration. Surface roughness and oxide structure are considered to influence the behavior of adherent cells. The purpose of this study is to evaluate the effect of different surface treatment on cellular response. The attachment and proliferation of osteoblast-like cell on sandblasted, sandblasted and etched, thermal oxidated surfaces have been compared. Sandblasting was done with Al2O3 particles(grain size of 50micrometer), etching was processed with NH4OH : H2O2 : H2O(1:1:5) at 90degrees C for 1 minute. Thermal oxidation was followed sandblasting and etching at 400degrees C, 600degrees C, 800degrees C for 2 hours. Measurement of surface roughness after the different treatment did not show any differences of Ra value between terated surfaces. Cell attachment and proliferation were increased during experiment period, but no difference was observed. SEM evaluation revealed a similar pattern of osteoblastlike cells, well attached with dendritic extension and producing numerous matrix vesicles on cell surface. The results of this study showed that oxide layer alteration by thermal oxidation did not affect the attachment and proliferation of osteoblast-like cells. This suggests the possibility that the cellular responses are further influenced by surface roughness than titaniun oxide structure. This study was supported by a grant(HMP-98-G-2-035-B) of the HAN(highly advanced National) Projected, Ministry of Health & Welfare, R.O.K

Biocompatibility evaluation of domestically-manufactured NiTi-alloys after thermal oxidation of surface / 第二军医大学学报

Objective:To compare the tissue biocompatibility of domestically manufactured NiTi alloy before and after thermal surface oxidation under 3 different temperatures.Methods:Domestically manufactured NiTi alloy was oxidized in air (group A)and subjected to 30 min heat treatment at 400℃(group B),500℃(group C),and 600℃(group D)to form different protective oxide surface layers in presence of argon(607.95 kPa).Wire samples from A,B,C and I3 groups were subcutaneously implanted in guinea pigs.Guinea pigs received 317L stainless steel transplantation(group E)and sham-operation group(F)were taken as control.The order of inflammatory cell infiltration and tissue hyperplasia around implanted materials were observed 1,2,4,and 8 weeks after implantation.Results:The peak time of inflammatory cell infiltration and fibrous hyperplasia were at the first and fourth week after implantation.The inflammatory cell infiltration and fibrous hyperplasia were both slight and all met the GB/T 16886.6-1997 in vivo implantation standard.The order of inflammatory cell infiltration and thickness of capsule walls from low to high was F