Angiogenic property of cobalt and calcium-phosphorus doped coating on titanium surfaces in vitro / 口腔疾病防治

Objective@# To investigate the effect of cobalt (Co) and calcium-phosphate (Ca/P) doped coating on titanium surfaces and their angiogenic effect.@*Methods @# Microarc oxidation (MAO) was used to prepare Co-Ca/P-doped and Co-doped coatings. Titanium (Ti) sheet without MAO treatment was used as control. Scanning electron microscopy (SEM) was used to observe the surface micromorphology of the coatings. Energy dispersive spectrometry (EDS) was also applied to detect the doped chemicals and their contents. Standard soaking solutions of these coatings were prepared using an endothelial cell medium (ECM) solution for subsequent angiogenesis experiments. Human umbilical vein endothelial cells (HUVECs) were cultured on Matrigel with ECM soaking solutions for 4 h and 8 h. The microvessels were observed under a microscope, and the number of microtubules and their interconnecting nodes were analyzed with Image J software. @*Results@# Co doped and Co-Ca/P-doped coatings were successfully prepared by MAO, which was demonstrated by both SEM observation and EDS analysis. SEM observation showed that irregular crystals of the above chemicals were present on both Co and Co-Ca/P-doped coatings, commonly with a diameter <2 μm. However, more crystals were observed on the Co-Ca/P coatings than on the Co coating, and the distribution of the crystals was more homogenous on the Co-Ca/P coatings. However, only polishing scratches were observed on the Ti sample surface. EDS analysis indicated that in contrast to only Co in the Co coating, Co, Ca and P were doped within the Co-Ca/P coating, and none of the three elements were observed on the Ti plate surface. The number of vascular rings and nodes formed by HUVECs in the extract of the Co-Ca/P group was significantly higher than that of the Co group (P<0.05), and the angiogenic effect of these two components was significantly better than that of the Ti group (P<0.05). @*Conclusion@#The Co-Ca/P coating exhibits good angiogenic properties in vitro and is valuable for the development of new titanium implants with high surface bioactivity.

Effects of fluoride release and solubility of resin modified glass ionomer with surface coating agents

PURPOSE: This study aimed to investigate the correlation between the solubility and the amount of fluoride release when a resin surface coating agent is applied to RMGIC. MATERIALS AND METHODS: To measure the fluoride release and solubility, Fuji II LC®and Filtek™ Z350XT without a surface coating, Fuji II LC® with G coat plus™ and Fuji II LC® with Permaseal® were prepared. And the amount of fluoride release and solubility were measured. RESULTS: There was no significant difference in the daily fluoride release between the surface coating agents. The cumulative fluoride release was significantly different between the groups using RMGIC at 56 days (P < 0.05). In the solubility measurement, RMGIC without surface coating was significantly different only on the 7th day compared to the other three groups (P < 0.05). CONCLUSION: Surface coating agents can prevent the degradation of properties by the initial solvent in RMGIC. Therefore, fluoride is preserved inside the restorative material and the effect of surface coating after the addition is reduced, so that the effect on fluoride release and storage is also reduced.

Advances in titanium dental implant surface modification / 华西口腔医学杂志

Titanium dental implants have wide clinical application due to their many advantages, including comfort, aesthetics, lack of damage to adjacent teeth, and significant clinical effects. However, the failure of osseointegration, bone resorption, and peri-implantitis limits their application. Physical-chemical and bioactive coatings on the surface of titanium implants could improve the successful rate of dental implants and meet the clinical application requirements. This paper reviews the characteristics of surface modification of titanium implants from the aspects of physics, chemistry, and biology. Results provide information for research and clinical application of dental implant materials.

Preparation and Quality Evaluation of Carbinoxamine Maleate Sustained-release Suspension / 中国药房

OBJECTIVE:To prepare Carbinoxamine maleate sustained-release suspension,and evaluate its quality. METH-ODS:Using carbinoxamine maleate as raw material,drug-loaded resin was prepared by cation exchange resin;surface coating method was used to finally prepare sustained-release suspension,using Eudragit RS100 as sustained-release coating material to pre-pare sustained-release microparticles. HPLC was conducted to determine the content of carbinoxamine maleate,release degree of original preparations and self-made suspensions was compared,drug-loading capacity was calculated. RESULTS:The drug amount in preparing drug-loaded resin was 2%,reaction temperature was 25 ℃,and reaction time was 4 h;the drug-loading capacity in surface coating was 35%,amount of coating material was 10%,and reaction temperature was 40 ℃. The drug-loading capacities of sustained particles before and after coating were 35.23%,32.72%,respectively;the yield was 96.82%. The carbinoxamine ma-leate in prepared sustained-release suspension accounted for 98.76% of the labeled amount;release degree in 10 h reached about 80%,f2 was 65.73. CONCLUSIONS:Carbinoxamine maleate sustained-release suspension is prepared successfully,and its release is similar to the original preparation.

Improvement of powder flowability and hygroscopicity of traditional Chinese medicine extract by surface coating modification technology / 中国中药杂志

To study the improvement of powder flowability and hygroscopicity of traditional Chinese medicine extract by surface coating modification technology. The 1% hydrophobic silica nanoparticles were used as surface modifier, and andrographis extract powder was taken as a model drug. Three different techniques were used for coating model drugs, with angle of repose, compressibility, flat angle and cohesion as the comprehensive evaluation indexes for the powder flowability. The powder particle size and the size distribution were measured by Mastersizer 2000. FEI scanning electron microscope was used to observe the surface morphology and structure of the powder. The percentage of Si element on the powder surface was measured by energy dispersive spectrometer. The hygroscopicity of powder was determined by Chinese pharmacopoeia method. All of the three techniques can improve the flowability of powder extract. In particular, hygroscopicity of extract powder can also be improved by dispersion and then high-speed mixing, which can produce a higher percentage of Si element on the powder surface. The improvement principle may be correlated with a modifier adhered to the powder surface.

Biocompatible implant surface treatments.

Surface plays a crucial role in biological interactions. Surface treatments have been applied to metallic biomaterials in order to improve their wear properties, corrosion resistance, and biocompatibility. A systematic review was performed on studies investigating the effects of implant surface treatments on biocompatibility. We searched the literature using PubMed, electronic databases from 1990 to 2009. Key words such as implant surface topography, surface roughness, surface treatment, surface characteristics, and surface coatings were used. The search was restricted to English language articles published from 1990 to December 2009. Additionally, a manual search in the major dental implant journals was performed. When considering studies, clinical studies were preferred followed by histological human studies, animal studies, and in vitro studies. A total of 115 articles were selected after elimination: clinical studies, 24; human histomorphometric studies, 11; animal histomorphometric studies, 46; in vitro studies, 34. The following observations were made in this review: The focus has shifted from surface roughness to surface chemistry and a combination of chemical manipulations on the porous structure. More investigations are done regarding surface coatings. Bone response to almost all the surface treatments was favorable. Future trend is focused on the development of osteogenic implant surfaces. Limitation of this study is that we tried to give a broader overview related to implant surface treatments. It does not give any conclusion regarding the best biocompatible implant surface treatment investigated till date. Unfortunately, the eventually selected studies were too heterogeneous for inference of data.

The effects of Hydroxyapatite nano-coating implants on healing of surgically created circumferential gap in dogs / 대한치주과학회지

PURPOSE: The aim of this study is to compare the healing response of various Hydroxyapatite(HA) coated dental implants by Ion-Beam Assisted Deposition(IBAD) placed in the surgically created circumferential gap in dogs. MATERIALS AND METHODS: In four mongrel dogs, all mandibular premolars and the first molar were extracted. After an 8weeks healing period, six submerged type implants were placed and the circumferential cylindrical 2mm coronal defects around the implants were made surgically with customized step drills. Groups were divided into six groups : anodized surface, anodized surface with 150nm HA and heat treatment, anodized surface with 300nm HA and heat treatment, anodized surface with 150nm HA and no heat treatment, and anodized surface with 150nm HA, heat treatment and bone graft, anodized surface with bone graft. The dogs were sacrificed following 12 weeks healing period. Specimens were analyzed histologically and histomorphometrically. RESULTS: During the healing period, healing was uneventful and implants were well maintained. Anodized surface with HA coating and 430degrees C heat treatment showed an improved regenerative characteristics. Most of the gaps were filled with newly regenerated bone. The implant surface was covered with bone layer as base for intensive bone formation and remodeling. In case that graft the alloplastic material to the gaps, most of the coronal gaps were filled with newly formed bone and remaining graft particles. The bone-implant contact and bone density parameters showed similar results with the histological findings. The bone graft group presented the best bone-implant contact value which had statistical significance. CONCLUSION: Within the scope of this study, nano-scale HA coated dental implants appeared to have significant effect on the development of new bone formation. And additional bone graft is an effective method in overcoming the gaps around the implants.

Osteoinduction using by Human BMP-2-physio- functional Bioactive Ceramics / 대한정형외과학회잡지

PURPOSE: To assess the properties and the osteogenic potency of the calcium phosphate-recombinant human morphogenetic protein-2 (CaP-rhBMP-2 composite) on glass-ceramics. MATERIALS AND METHODS: Bioactive glass-ceramics,as a scaffold, and a calcium phosphate (CaP) solution (pH7.4) were prepared. Recombinant human bone morphogenetic protein-2 (rhBMP-2) was purified from CHO-K1 cells by transfecting the cells with BMP-2 cDNA. The glass-ceramics were soaked for 3 days at room temperature in saline, a CaP only solution, and a CaP solution containing rhBMP-2. Scanning electron microscopy (SEM), Fourier transform infrared reflection spectroscopy (FT-IR), thin film X-ray diffraction (TF-XRD) and immunofluorescent staining (IF) of the anti-human BMP-2 to composite-coated scaffold were performed to verify the characterization of the scaffold surface. In addition, RT-PCR of osteogenic marker gene and SEM photography were performed after adhering the mouse preosteoblast MC3T3-E1 cells in order to assess the osteoinductivity. RESULTS: CaP-rhBMP-2 composite was coated on the surface of glass-ceramics, as confirmed by SEM, FT-IR, TF-XRD spectrum, and IF. The CaP-rhBMP-2 composite on the glass-ceramic showed a globular shape covered with fine spikes while the CaP on the glass-ceramic showed a fine spike structure on the flat glass surface. The expression of collagen type I and alkaline phosphatase mRNAs had increased 4 hours after cell seeding. In addition, the level of osteocalcin mRNA expression had increased significantly by 3 days in the CaP-rhBMP-2 composite compared with the control and CaP group. The SEM photographs showed more active filopodia formation in the CaP-rhBMP-2 composite than the other groups. There was extensive newly synthesized extracellular matrix around the osteoblasts and CaP-rhBMP-2 composite nodule. CONCLUSION: The application of CaP-rhBMP-2 composite-surface coating technique on bioactive glass-ceramic is a powerful tool for osteoinduction.

A comparison of fracture strengths of porcelain-fused-to-titanium crown among titanium surface coating treatments / 대한치과보철학회지

STATEMENT OF PROBLEM: Titanium and its alloy, with their excellent bio-compatibility and above average resistance to corrosion, have been widely used in the field of dentistry. However, the excessive oxidization of titanium which occurs during the process of firing on porcelain makes the bonding of titanium and porcelain more difficult than that of the conventional metal-porcelain bonding. To solve this problem related to titanium-porcelain bonding, several methods which modify the surfaces, coat the surfaces of titanium with various pure metals and ceramics, to enable the porcelain adhesive by limiting the diffusion of oxygen and forming the adhesive oxides surfaces, have been investigated. PURPOSE: The purpose of this study was to know whether the titanium-porcelain bonding strength could be enhanced by treating the titanium surface with gold and TiN followed by fabrication of clinically applicable porcelain-fused-to-titanium crown. MATERIAL AND METHOD: The porcelain-fused-to-titanium crown was fabricated after sandblasting the surface of the casting titanium coping with Al2O3 and treating the surface with gold and TiN coating followed by condensation and firing of ultra-low fusing porcelain. To compare with porcelain-fused-to-titanium crowns, porcelain-fused-to-gold crowns were fabricated and used as control groups. The bonding strengths of porcelain-fused-to-gold crowns and porcelain-fused-totitanium crowns were set for comparison when the porcelain was fractured on purpose to get the experimental value of fracture strength. Then, the surface were examined by SEM and each fracturing pattern were compared with each other. RESULT: Those results are as follows. 1. The highest value of fracture strength of porcelain-fused-to-titanium crowns was in the order of group with gold coating, group with TiN coating, group with Al2O3 sandblasting. No statistically significant difference was found among the three (P>.05). 2. The porcelain-fused-to-gold crowns showed the highest value in bonding strength. The bonding strength of crowns porcelain-fused-to-titanium crowns of rest groups showed bonding strength reaching only 85%-94% of that of PFG, though simple comparision seemed unacceptable due to the difference in materials used. 3. The fracturing patterns between metal and porcelain showed mixed type of failure behavior including cohesive failure and adhesive failure as a similar patterns by examination with the naked eye and SEM. But porcelain-fused-to-gold crowns showed high incidence of adhesive failure and porcelain-fused-to-titanium crowns showed high incidence of cohesive failure. CONCLUSION: Above results proved that when fabricating porcelain-fused-to-titanium crowns, treating casting titanium surface with gold or TiN was able to enhance the bonding strength between titanium and porcelain. Mean value of masticatory force was found to showed clinically acceptable values in porcelain bonding strength in all three groups. However, more experimental studies and evaluations should be done in order to get better porcelain bonding strength and various surface coating methods that can be applied on titanium surface with ease.