Micro/nano hierarchical structure of titanium surface promotes MC3T3-E1 adhesion proliferation and drug loading potential evaluation / 口腔疾病防治

Objective @# To investigate the effect of micro/nano hierarchical structures on the adhesion and proliferation of MC3T3-E1 cells, evaluate the drug delivery potential of titanium surfaces, and provide a reference for the modification of selected areas of titanium surfaces to enhance drug delivery and slow drug release. @*Methods @# Pure titanium samples (10 mm in diameter and 2.5 mm in thickness) were randomly divided into a polished group (T), anodized group (TO), and micro/nano hierarchical structure group (FTO) according to the surface treatment of the titanium. The T group was polished, the TO group was treated with anodic oxidation technology, and the FTO group was treated by femtosecond laser etching combined with anodic oxidation technology. The three surface morphologies were observed by scanning electron microscopy (SEM), the wettability of the surface was measured by the contact angle, and the surface chemical composition was analyzed by X-ray energy dispersive spectroscopy (EDS). The depth of the FTO structure and the surface roughness were measured by confocal laser scanning microscopy (CLSM). MC3T3-E1 cell adhesion proliferation and differentiation on the surface of each group of samples was assessed by immunofluorescence staining, CCK-8, and semiquantitative analysis of Alizarin staining. A freeze-drying method was applied to load recombinant human bone morphogenetic protein-2 (rhBMP-2), and an enzyme-linked immunosorbent assay (ELISA) was used to assess the drug-loading potential of different surface structures. @* Results@#SEM revealed that the surface of T group titanium plates showed uniform polishing marks in the same direction. The surface of the TO group was a nanoscale honeycomb-like titanium dioxide (TiO2) nanotube structure, and the FTO group formed a regular and ordered micro/nano layered structure. The contact angle of the FTO group was the smallest at 32° ± 1.7°. Its wettability was the best. The average depth of the first-level structure circular pores was 93.6 μm, and the roughness was 1.5-2 μm. The TO and FTO groups contained a high percentage of oxygen, suggesting TiO2 nanotube formation. The FTO group had the most significant surface cell proliferation (P<0.001) and the largest cell adhesion surface area (P<0.05). rhBMP-2 was slowly released for 14 d after loading in the FTO group and promoted extracellular matrix mineralization (P<0.001). @*Conclusion @#Titanium surface microprepared hierarchical structure has the effect of promoting MC3T3-E1 cell adhesion, proliferation, and osteogenic differentiation with drug loading potential, which is a new method of titanium surface treatment.

The effect of blasting and anodizing-combined treatment of implant surface on response of osteoblast-like cell / 대한치과보철학회지

PURPOSE: The purpose of this study is to examine characteristics of implant surface with RBM and anodizing treatments, and to evaluate the responses of osteoblast-like cell (MG-63 cell). MATERIALS AND METHODS: Grade IV titanium disks were fabricated (Diameter 10 mm, thickness 3 mm). Anodizing treatment (ASD) group, RBM and anodizing treatment (RBM/ASD) group, control (machined surface) group were divided. In this study, osteoblast-like cell was used for experiments. The experiments consist of surface characteristics evaluation by FE-SEM images, energy dispersive spectroscopy and stereo-SEM. In order to evaluate cell adhesion evaluation by crystal violet assay and observe cells form by confocal laser microscopy. To assess cell proliferation by XTT assay, cell differentiation by RT-PCR and mineralization by Alizarin red S stain assay. ELISA analyzer was used for Quantitative evaluation. Comparative analysis was run by one-way ANOVA (SPSS version 18.0). Differences were considered statistically significant at P<.05. RESULTS: In ASD group and RBM/ASD group, the surface shape of the crater was observed and components of oxygen and phosphate ions in comparison with the control group were detected. The surface average roughness was obtained 0.08 +/- 0.04 microm in the control group, 0.52 +/- 0.14 microm in ASD group and 1.45 +/- 0.25 microm in RBM/ASD group. In cell response experiments, ASD group and RBM/ASD group were significantly higher values than control group in cell adhesion and mineralization phase, control group was the highest values in the proliferative phase. In RT-PCR experiments, RBM/ASD group was showed higher ALP activity than other groups. RBM/ASD group in comparison with ASD group was significantly higher value for cell adhesion and proliferation phase. CONCLUSION: In the limitation of this study, we are concluded that the surface treatment with RBM/ASD seems more effective than ASD alone or machined surface on cellular response.

A Comparison of the Biocompatibility of Titanium-Base Alloy According to Surface Treatments / 대한정형외과연구학회지

PURPOSE: Various surface treatments are developed and adopted to get a biological fixation by the osseointegration. An anodizing treatment, used on the surface treatment of aluminium, is applied to the surface treatment of the dental implant recently. The purpose of this study was to determine the biocompatibility and osseointegration of the titanium-base alloys according to 4 different surface treatments. MATERIALS AND METHODS: Cylindrical rods were made of titanium-base alloys, and treated with machining, grit-blasted, anodizing, and plasma spray as four groups. The rods were implanted into the femur of the 8 adult dogs. Two dogs were allocated as controls. At the postoperative 1month and 9months, the histological and push-out test was done. RESULTS: No specific systemic reactions in terms of complete blood cell count, blood chemistry, urinalysis were observed. There were no tissue necrosis, foreign body reaction, and inflammatory response to the implanted rods on the histological findings. A load-displacement curve was recorded to compare an interfacial shear strength between bone and metal, the values of the grit-blasted, anodizing, and plasma-spray groups were larger than that of machining group (p0.05). CONCLUSION: The surface treatment with anodizing would be options for artificial joint because of its lower manufacturing price and excellent biomechanical and osseointegration nature.

On the surface characteristics and stability of implant treated with anodizing oxidation / 대한치과보철학회지

PURPOSE: This experiment examined the effects of anodization on commercially pure titanium implant fixtures. MATERIAL AND METHODS: The implant fixtures were anodized at three different voltage levels, producing three different levels of oxidation on the surface of the fixure. Implant were divided into four groups according to the level of oxidation. Group 1 consist of the control group of machined surface implants, Group 2 implants were treated by anodizing to 100 voltage, Group 3 implants were treated by anodizing oxidation to 200 voltage Group 4 implants were treated by anodizing oxidation to 350 voltage. Surface morphology was observed by Scanning Electron Microscope(SEM) and the surface roughness was measured using NanoScan E-1000(R). Implantation of the fixtures were performed using New Zealand white rabbits. Periotest(R) value(PTV), resonance frequency analysis(RFA), and removal torque were measured in 0, 2, 4, 8, 12 weeks after implantation. RESULTS: The results of the study were as follows: 1. Values for the measured surface roughness indicate statistically significant differences in Ra, Rq, and Rt values among group 1, 2, 3, and 4 at the top portion of the thread,(p<0.05) while values at the base of the threads indicated no significant difference in these values. 2. A direct correlation between the forming voltage, and surface roughness and irregularities were observed using scanning electron microscope. 3. No statistically significant differences were found between test groups regarding Periotest(R) values. 4. Analysis of the data produced by RFA, significant differences were found between group 1 and group 4 at 12 weeks after implantation.(p<0.05) CONCLUSIONS: In conclusion, no significant differences could be found among test groups up to a certain level of forming voltage threshold, beyond this forming voltage threshold, statistically significant differences occurred as the surface area of the oxide layer increased with the increase in surface porosity, resulting in enhanced bone response and osseointegration.

Effect of different surface treatments to increase biocompatibility of dental implant / 대한치과보철학회지

STATEMENT OF PROBLEM: Modification of titanium implant surface has potential to ensure clinically favorable performance that several surface modification technologies have been introduced. Among the methods, anodizing method and sol-gel hydroxyapatite coating method have gained much interest due to its roughness and chemical composition of the coating layer, but more of its biocompatibility result is required. PURPOSE: The purpose of this study was to compare bone-implant interface shear strength of four different surface treated implants as time elapsed. Resonance frequency analysis(RFA) and removal torque measurement methods were employed to measure implant stability at one week and six week after implantation. MATERAL AND METHOD: A total of 80 screw-shaped implant [20 machined, 20 resorbable media blasted(RBM), 20 anodized, and 20 anodized+hydroxyapatite sol-gel coated] were prepared, and one of each group was implanted in the tibia of a New Zealand white rabbit that total 20 of them were used. In order to test the implant stability and implant-tissue interface contact changing in the bone bed, each 10 rabbit were sacrificed 1 week and 6 week later while resonance frequency and removal torque were measured. One-way analysis of variance and the Tukey test were used for statistical analysis. RESULTS: The results were as follows. 1. There was no statistically significant difference of implant stability quotients(ISQ) value in RFA between individual groups after 1 week of implantation and 6 weeks(p>0.05). But, there was statistically significant increase of ISQ value in 6 weeks group compared to 1 week group(p0.05), but there was statistically significant increase in all 4 groups after 6 weeks compared to 1 week later(p 0.05), but significant difference was appeared in both groups compared to RBM group and smooth-machined group (p< 0.05). CONCLUSIONS: It can be suggested that changes in surface characteristics affect bone reactions. Anodized and anodized+hydroxyapatite sol-gel coating showed significantly improved bone tissue response to implants, but further study on the effect of hydroxyapatite dissolution is needed.

Study on the enhancing micro-roughness of porous surfaced dental implant through anodization / 대한치과보철학회지

STATEMENT OF PROBLEM: HA has been used as a coating material on Ti implants to improve osteoconductivity. However, it is difficult to form uniform HA coatings on implants with complex surface geometries using a plasma spraying technique. PURPOSE: To determine if Ti6Al4V sintered porous-surfaced implants coated with HA solgel coated and hydrothermal treated would accelerate osseointegration. MATERIALS AND METHODS: Porous implants which were made by electric discharge were used in this study. Implants were anodized and hydrothermal treatment or HA sol-gel coating was performed. Hydrothermal treatment was conducted by high pressure steam at 300 degrees C for 2 hours using a autoclave. To make a HA sol, triethyl phosphite and calcium nitrate were diluted and dissolved in anhydrous ethanol and mixed. Then anodized implant were spin-coated with the prepared HA sols and heat treated. Samples were soaked in the Hanks' solution with pH 7.4 at 37 degrees C for 6 weeks. The microstructure of the specimens was observed with a scanning electron microscope (SEM), and the composition of the surface layer was analyzed with an energy dispersive spectroscope (EDS). RESULTS: The scanning electron micrographs of HA sol-gel coated and hydrothermal treated surface did not show any significant change in the size or shape of the pores. After immersion in Hanks' solution, the precipitated HA crystals covered macro- and micro-pores. The precipitated Ca and P increased in Hanks' solution that surface treatment caused increased activity. CONCLUSION: This study shows that sol-gel coated HA and hydrothermal treatment significantly enhance the rate of HA formation due to the altered surface chemistry.

Effect of electrolyte concentration on the surface characteristics of anodized and hydrothermally-treated TI-6Al-7Nb alloy / 대한치과보철학회지

STATEMENT OF PROBLEM: Ti-6Al-7Nb alloy is used instead of Ti-6Al-4V alloy that was known to have toxicity. PURPOSE: This study was performed to investigate the effect of electrolyte concentration on the surface characteristics of anodized and hydrothermally-treated Ti-6Al-7Nb alloy. MATERIALS AND METHODS: Discs of Ti-6Al-7Nb alloy of 20 mm in diameter and 2 mm in thickness were polished sequentially from 300 to 1,000 SiC paper, ultrasonically washed with acetone and distilled water for 5 min, and dried in an oven at 50 degrees C for 24 hours. Anodizing was performed at current density 30 mA/cm2 up to 300 V in electrolyte solutions containing beta-glycerophosphate disodium salt hydrate (beta-GP) and calcium acetate (CA). Hydrothermal treatment was conducted by high pressure steam at 300 degrees C for 2 hours using a autoclave. All samples were soaked in the Hanks' solution with pH 7.4 at 36.5 degrees C for 30 days. RESULTS AND CONCLUSION: The results obtained were summarized as follows; 1. After hydrothermal treatment, the precipitated HA crystals showed the dense fine needle shape. However, with increasing the concentration of electrolyte they showed the shape of thick and short rod. 2. When the dense fine needle shape crystals was appeared after hydrothermal treatment, the precipitation of HA crystals in Hanks' solution was highly accelerated. 3. The crystal structures of TiO2 in anodic oxide film were composed of strong anatase peak and weak rutile peak as analyzed with thin-film X-ray diffractometery. 4. The Ca/P ratio of the precipitated HA layer was equivalent to that of HA crystal in Hanks' solution.

The evaluation of the removal torque and the histomorphometry of the Ca-P coating surface in rabbit tibia / 대한치과보철학회지

STATEMENT OF PROBLEM: Surface texture of the implant is one of the important factors of the implant success, especially in the immediate implant loading. Many methods of the surface treatment of implant have developed and introduced. PURPOSE: This study was to evaluate the effects of the Ca-P coating implant crystallized the hydroxyapatite on the surface by the removal torque test and the histomorphometric analysis in vivo. Material and methods: 135 screw type implants, 4.0mm in length and 3.75mm in diameter were used in this study. Implants were divided into 3 groups and treated in the different methods. Group I was not treated, Group II was treated in the SLA method, and Group III was treated in the Ca-P coating with the anodizing method and the hydroxyapatite was crystallized on the surface with the hydrothermal treatment. Firstly, the surface roughness of each group was measured. 45 rabbits were used in this experiment. Two implants were inserted on right tibial metaphysis and one implant was inserted on left side with the alternating order. After the healing periods of 3, 5, and 12 weeks, the rabbits were sacrificed to evaluate the osseointergration by the removal torque test and the histomorphometric analysis. RESULTS: 1. In the analysis for the surface roughness, Group II showed the highest roughness. And Group III showed higher secondly. There was a significant difference one another statistically. 2. In the removal torque test, Group III and II were significantly higher than Group I. There was no statistical difference between Group III and Group II. 3. For all Groups, the removal torque values at 12th week were significantly higher than at 3rd and 5th week. 4. In histomorphometric analysis, the bone implant contact rates of Group III and II were higher than that of Group I at 3rd and 5th week. There was a significant difference at 5th week. 5. In histomorphometric analysis, the bone implant contact rate of Group III and II increased from 3rd week to 5th week, but decreased at 12th week. In Group I, the contact rate at 12th week was significantly higher than at 3rd week and 5th week.

The effect of implant surface treated by anodizing on proliferation of the rat osteoblast / 대한치주과학회지

The surface characteristics of titanium have been shown to have an important role in contact ossseointegration around the implant. Anodizing at high voltage produces microporous structure and increases thickness of surface titanium dioxide layer. The aim of present study was to analyse the response of rat calvarial osteoblast cell to commercially pure titanium and Ti-6Al-4V anodized in 0.06 mol/l beta-glycerophosphate and 0.03 mol/l sodium acetate. In this study, rat calvarial osteoblasts were used to assay for cell viability and cell proliferation on the implant surface at 1, 2, 4, 7 days. 1. Surface roughness was 1.256micrometer at 200V, and 1.745micrometer at 300V. 2. The thickness of titanium oxide layer was increased 1micrometer with the increase of 50V. 3. The proliferation rate of osteoblastic cells was increased with the increase of the surface roughness and the thickness of titanium oxide layer. 4. There was no difference in cell viability and cell proliferation between commercially pure titanium and Ti- 6Al-4V anodized at the same condition. In conclusion, the titanium surface modified by anodizing was biocompatible, produced enhanced osteoblastic response. The reasons of enhanced osteoblast response might be due to reduced metal ion release by thickened and stabilized titanium dioxide layer and microporous rough structures.

Influences of electrolyzing voltages on chromatics of anodized titanium / 实用口腔医学杂志

Objective: To study the influences of electrolytic voltages on chromatics of anodized titanium. Methods:Titanium specimens were anodized in 0.5 mol/L sulfuric acid and 0.2 mol/L phosphate acid electrolyte using different voltages. The colors of anodized titanium were measured with a computer controlled spectrophotometer, and then evaluated in the CIE1976L*a*b* uniform color scale and Mussell notation. Result: One given volt created one distinguished color. The chromatic values expressed in L*a*b* were fluctuated in different voltage conditions. The hues in Mussell notation were distributed widely within R,Y,G,P of 5 basic colors and YR,GY,BG,PB of 5 interspace colors in the range of 5 to 80 volts. Anodizing with 10 or 45 volts, the specimen's colors appeared two kinds of brilliant goldish yellow, the former reddish slightly and latter greenish a little. The spectrums of the two colors were in the range of wavelengths of yellow to red. Conclusion: The color of the anodized titanium is dependent upon the volts applied. The goldish yellow may be used to improve the esthetics of titanium dentures.