Bone formation of the porous layer formed of Ti-Ag mesh for GBR membrane applications

본 연구의 목적은 마이크로 표면 위에 나노 단위의 다공성 구조를 갖는 티타늄-은 메쉬를 제작하고 메쉬의 골 형성능을 평가하는데 있다. 우선 시편 제작을 위해 cp-Ti에 비해 부식저항성이 뛰어난 티타늄-은 합금을 은 2.0 at%을 첨가시켜 제작하였다. 그리고 표면에 다공성 구조를 형성하기 위해 알루미나 입자를 사용하여 시편을 블라스팅 처리한 뒤 0.5% 불산 전해액에서 60분 동안 20 V 전압을 가하여 양극산화 처리하였다. 시편의 표면 형태는 주사전자현미경을 통해 관찰하였다. 골 형성능을 평가하기 위해 토끼의 두개골을 천공한 뒤 파절편을 제거하고 그 위에 시편을 식립하였다. 각각 2주와 4주 뒤 메쉬 주위의 골 조직 형태를 3D 스캔 이미지로 관찰하였고 생성된 골의 부피를 측정하였다. 시편 표면 형상 관찰 결과 마이크로 단위의 반구 형태 구조 위에 나노 단위의 다공성 구조를 관찰할 수 있었고, 골 형성능 결과에서는 대조군으로 메쉬를 식립하지 않은 경우에서 보다 티타늄-은 합금 메쉬를 식립한 경우에서 2주와 4주 모두 유의하게 더 많은 골 형성량을 보였다(p<0.05). 따라서 이 연구 결과로 미루어 보아 티타늄-은 합금에 마이크로 표면 위에 나노 다공성 구조를 형성할 수 있었으며 골 형성능 역시 우수하여 골유도 재생술을 위한 메쉬로서 유용하게 사용할 수 있을 것이라고 사료된다.ope

Surface Characteristics of Nanostructure Formed on Sand Blasted with Large Grit and Acid Etched Dental Implant

The purpose of this study was to apply nanotechnology to dental implant for improved osseointegration. Titania nanostructures were fabricated on the sand blasted with large grit and acid etched (SA) titanium (ASTM grade 4) implants (TSIII SA®, Osstem, 3.5 x 5 mm) using potentiostatic anodic oxidation in HF. The nanostructures were uniformly formed on the SA surface. The mean pore size of nanostructure was about 30 nm. In the result of torque test, the nanostructure formed on SA surface was preserved from the torque, even after the loading of 40Ncm. An amorphous titania nanostructure was annealed at 400 °C. Through heat treatment, the amorphous titania nanostructure was turned into anatase phase. Hydrofluoric acid was used as the electrolyte to form nanostructure. In the result of ion release test, however, fluoride ions were not detected at the heat treated group. Therefore, such nanostructured SA implant (Nano-SA) will be suitable for dental implantope

Antibacterial effect and cytocompatibility of nano-structured TiO(2) film containing Cl.

The aim of this study was to investigate the antibacterial effect and cytocompatibility of a nano-structured TiO(2) film that contained Cl and had been coated onto commercially pure titanium. First, we prepared nano-structured TiO(2) by anodization with hydrofluoric acid. Then, to confer an antibacterial effect, we performed a second anodization with NaCl solutions of different concentrations (0.5 M, 1 M, 2 M). The morphology, composition, and wettability of the surface were investigated by SEM, EDS, and a video contact angle measuring system. The antibacterial effect was evaluated by film adhesion method. And cytotoxicity was determined by the viability of MG-63 cells in a MTT assay. The SEM and EDS results showed that the TiO(2) nano-structure containing Cl had successfully formed after the second anodization. The contact angle analysis showed that the anodized titanium had a hydrophilic character. The results of this in vitro investigation demonstrated that the TiO(2) nano-structure film anodized in 1 M NaCl had an antibacterial effect and good cell compatibilityope

The biomimetic apatite-cefalotin coatings on modified titanium.

Dental implant failure often occurs due to oral bacterial infection. The aim of this study was to demonstrate that antibiotic efficacy could be enhanced with modified titanium. First, the titanium was modified by anodization and heat-treatment. Then, a biomimetic coating process was completed in two steps. Surface characterization was performed with scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. Release of antibiotic was evaluated by UV/VIS spectrometry, and the antibacterial effect was evaluated on Streptococcus mutans. After the second coating step, we observed a thick homogeneous apatite layer that contained the antibiotic, cefalotin. The titanium formed a rutile phase after the heat treatment, and a carbonated apatite phase appeared after biomimetic coating. We found that the modified titanium increased the loading of cefalotin onto the hydroxyapatite coated surface. The results suggested that modified titanium coated with a cefalotin using biomimetic coating method might be useful for preventing local post-surgical implant infections.ope

Biological evaluation of micro-nanoporous layer on Ti―Ag alloy for dental implant

This study examined the biocompatibility of the micro-nanoporous layer formed on a titanium-silver (Ti-Ag) alloy. The porous layer was formed by grit-blasting and anodic oxidation. The surface of the porous layer was rougher and more hydrophilic compared to a simple machined specimen and the expressions of bone-related genes were greater for cells grown on the porous layer compared to that of cells cultured on a control surface. Also the bone-to-plate contact rate in vivo test was significantly improved for porous layer plate compare to simple machined specimen (P < 0.05). The porous layer on Ti-Ag alloy enhanced the peri-implant bone formation at the early healing stage and it was believed that this porous layer on the Ti-Ag alloy will be suitable for dental implant applications.ope

Properties of experimental titanium-silver-copper alloys for dental applications

The aim of this study was to develop Ti-Ag-Cu alloys with a higher corrosion resistance, better biocompatibility, and better mechanical properties than commercially pure titanium and its alloys. The microstructure, corrosion resistance, mechanical property and cytotoxicity of the Ti-Ag-Cu alloys were investigated. The corrosion resistance was evaluated by open circuit potential measurements and potentiodynamic polarization tests in artificial saliva at 37 degrees C. The mechanical properties were evaluated using tensile and microhardness tests. The biocompatibility was tested by evaluating the cytotoxicity of the alloys using an agar-overlay test and MTT assay. It was found that the open circuit potentials of the Ti-Ag-Cu alloys were higher than that of pure Ti. However, the passive current densities of the Ti-Ag-Cu alloys were similar to that of pure titanium. The mechanical properties improved with increasing Ag and Cu content. All the Ti-Ag-Cu alloys examined were found to be noncytotoxic similar to pure Ti. Therefore, Ti-Ag-Cu alloys can be used as biomaterials in the dental field.ope

Characterization of hydroxyapatite containing a titania layer formed by anodization coupled with blasting

OBJECTIVES: The modification of dental implant surface by increasing the surface roughness or/and altering chemical composition have been attempted. Among them, hydroxyapatite (HA) coatings are typically bioactive. On the other hand, titania coatings have good corrosion resistance and biocompatibility. Therefore, the objective of this study was to fabricate HA containing a titania layer using an HA blasting and anodization method to benefit from the advantages of both, followed by surface characterization and biocompatibility. MATERIALS AND METHODS: HA blasting was performed followed by microarc oxidation (MAO) using various applied voltages (100, 150, 200, 250 V). For surface characterization, the microstructure of the surface, surface phase and surface roughness were observed. Bonding strength was measured using a universal testing machine and potentiodynamic corrosion testing was performed. Biocompatibility was evaluated based on bioactivity and cell proliferation test. RESULTS: The porous titanium oxide-containing HA was formed at 150 and 200 V. These surfaces were a lower corrosion current compared to the titanium treated only with HA blasting. In addition, composite treated titanium showed a rougher surface and tighter bonding strength compared to the titanium treated only with MAO. Biocompatibility demonstrated that HA/Titania composite layer on titanium showed a rapid HA precipitation and also enhanced cell proliferation. CONCLUSIONS: These results suggested that HA containing titania layer on titanium had not only excellent physicochemical, mechanical and electrochemical properties, but also improved bioactivity and biological properties that could be applied as material for a dental implant system.restrictio

Modification of TiO(2) nanotube surfaces by electro-spray deposition of amoxicillin combined with PLGA for bactericidal effects at surgical implantation sites

OBJECTIVE: To fabricate the antibiotic-releasing coatings on TiO(2) nanotube surfaces for wide applications of implant and bone plate in medical and dental surgery, the optimal deposition time of amoxicillin/PLGA solution simultaneously performing non-toxicity and a high bactericidal effect for preventing early implant failures was found. MATERIALS AND METHODS: FE-SEM, ESD and FT-IR were used for confirming deposition of amoxicillin/PLGA on the TiO(2) surface. Also, the elution of amoxicillin/PLGA in a TiO(2) nanotube surface was measured by a UV-VIS spectrophotometer. The bactericidal effect of amoxicillin on the TiO(2) nanotube surface was evaluated by using Staphylococcus aureus (S. aureus). The cytotoxicity and cell proliferation were observed by WST assay using MC3T3-E1 osteoblast cells. RESULTS: The results indicated that the TiO(2) nanotube surface controlled by electro-spray deposition time with amoxicillin/PLGA solution could provide a high bactericidal effect against S. aureus by the bactericidal effect of amoxicillin, as well as good osteoblast cell proliferation at the TiO(2) nanotube surface without toxicity. CONCLUSIONS: This study used electro-spray deposition (ESD) methodology to obtain amoxicillin deposition in nanotube structures of TiO(2) and found the optimal deposition time of amoxicillin/PLGA solution simultaneously performing non-toxicity and a high bactericidal effect for preventing early implant failures.restrictio

The release behavior of CHX from polymer-coated titanium surfaces

Titanium has been successfully used in dental implants due to its favorable biological response. However, implant failures caused by infection often occurred with a complex microbial exposure. Chlorhexidine (CHX) is effective against a wide variety of bacteria as well as fungi. The aim of the present study is to investigate the release behavior of CHX from CHX-containing polylactide (PLA)-coated titanium. Commercially, pure titanium was anodized with surfaces exposed to an anodic-forming voltage of 250 V for 3 min. The anodized titanium surfaces were then coated with a PLA/CHX solution. Topographic evaluation was performed using a SEM, and the antibacterial effect was evaluated. The concentrations of CHX were measured using a UV spectrophotometer. In the surface morphology analysis, the uncoated titanium surface showed a porous structure, but the surfaces coated with a polymer displayed nonporous structures and wrinkled surfaces. In addition, there were no differences in the surface roughness between the uncoated and coated surface. On the basis of the comparative analysis of both the UV absorbance of CHX and the surface characteristics, we concluded that the PLA coating can effectively control the release of CHX on anodized titanium surfaces.ope

Micro-Nano Structure Formation on Ti-Ag Alloy for Dental Implants

Surface topography is crucial for the short and long term success of dental implants. It is known that surface roughness in the range of 1-10 ㎛ maximizes the interlocking between the bone and the surface of the implant. On the other hand, it is reported that osseointegration is promoted on surfaces of nano-metric level because surface profiles in the nano-metric level play an important role in the adsorption of proteins. Therefore hybrid surface consisted of micro and nanopore is expected to be the new surface treatment on Ti-Ag alloy for dental implants. The titanium-silver alloy developed for biomedical applications had better mechanical properties and corrosion resistance than pure titanium. And there has been no research on surface modification of titanium-silver alloy for dental implants. Therefore, the present paper reported on the formation of hybrid surface on titanium-silver alloy. The specimens were grit-blasted to obtain micro pore on the surface. After grit-blasting, the specimens were anodized at different anodizing voltages (20, 50 and 80V) for different times (10, 20, 40 and 60 min), in 0.5% HF aqueous solution at room temperature using a DC power supply. The surface topography of titanium-silver alloy was characterized by field emission scanning electron microscope (FE-SEM). It was believed that the topography of the hybrid surface was affected by electrochemical conditions. When titanium-silver alloy was anodized at 20 V for 1 hour, hybrid surface was uniformly formed. Therefore, it was considered that this surface treatment would be adapted cautiously to titanium-silver alloy for dental implants.ope