Functionally gradient bonelike hydroxyapatite coating on a titanium metal substrate created by a discharging method in HBSS without organic molecules

PURPOSE: This study evaluated the quality of coatings on titanium surfaces prepared by discharging in Hanks' balanced salt solution without organic molecules (HBSS-). MATERIALS AND METHODS: 10 x 10 x 1.0-mm titanium plates were used as cathodes of a coating device developed in the laboratory and immersed in HBSS-. A piece of platinum foil was used as a counterelectrode. Discharging was maintained at 1 A and 10 V (416 mA/cm2) for periods of 90, 270, and 540 seconds. Crystal phases of the coatings were identified by x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). In addition, the surface characterization and Ca/P atomic ratio of the titanium surfaces were determined by x-ray photoelectron spectroscopy (XPS). Furthermore, the surface topography, the thickness of the coatings, and the bonds between coatings and titanium substrates were observed by scanning electron microscopy. RESULTS: The FTIR and XRD studies demonstrated that the deposits on the titanium after 540 seconds of discharging were crystalline hydroxyapatite. In addition, the thickness of the titanium suboxide layer increased during discharging. The XPS studies indicated that after 540 seconds of processing, the mean Ca/P ratio of the coatings on the titanium was 1.71, which is similar to that of human bone. DISCUSSION: In addition, the replacement of sodium ions with calcium ions seemed important for the promotion of crystallization of the coating. Furthermore, the XPS studies demonstrated that the coatings had a gradient function. Scanning electron microscopy showed that adhesion between coatings and the titanium substrate was close. The coatings were approximately 1 microm thick. CONCLUSION: These findings suggest that a very thin crystalline bonelike hydroxyapatite coating with a gradient function could be prepared on a titanium metal substrate in HBSS- by a discharging method.     

纤维连接蛋白与钙磷复合涂层的初步研究(一)复合涂层的制备

目的 探讨商用纯钛表面纤维连结蛋白与钙磷复合涂层的可行性。方法 采用纤维连结蛋白，钙磷共沉积的方法，对商用纯钛表面进行复合涂层的表面改性，结果 扫描电镜显示，单纯钙磷涂层和复合涂层的纯钛表面均见有晶体形成，但晶体形态存在一定的差异；EDX显示晶体的主要成份为钙磷，Ca/P=1.50。结论 本研究表明通过纤维连结蛋白与钙磷复合涂层对纯钛的表面改性具有可行性。     

Metal release from ceramic coatings for dental implants

Objectives

Two types of ceramic coatings on commercially pure titanium for dental implant applications with different Ca/P ratios in the range from 1.5 to 4.0, and two different thicknesses (∼5 and ∼15 μm) were examined with the aim of underpinning the effect of coating composition, thickness and microstructure on the corrosion behavior and hydroxyapatite forming ability in SBF.

Methods

Bioactive coatings were formed on Ti by plasma electrolytic oxidation (PEO). The composition, structure, and morphology of the materials were characterized before and after the immersion in simulated body fluid solution (SBF) at 37 °C for up to 4 weeks. All the materials were screened with respect to metal ion release into SBF.

Results

Only thick PEO coating with overstoichiometric Ca/P ratio of 4.0 exhibited capacity to induce the precipitation of hydroxyapatite over the short period of 1 week. Long term Ti⁴⁺ ion release from all PEO-coated materials was 2–3 times lower than from the uncoated Ti. Metal ion release is attributed mostly to chemical dissolution of the coating at initial stages of immersion.

Significance

The long term stability was greater for thin PEO coating with overstoichiometric Ca/P ratio of 2.0, which exhibited ∼95 ng cm⁻² of Ti⁴⁺ ions release over 4 weeks. Thin PEO coatings present economically more viable option.     

微弧氧化联合溶胶-凝胶工艺制备钛表面复合生物涂层的研究

目的探讨微弧氧化联合溶胶-凝胶工艺制备钛表面复合生物涂层。方法钛片根据表面处理工艺不同分为5组:对照组,MAO(微弧氧化组),MAO+Sol/gel(微弧氧化+溶胶-凝胶组),MAO+Sol/gel-LowZn(微弧氧化+溶胶-凝胶低锌组),MAO+Sol/gel-HighZn(微弧氧化+溶胶-凝胶高锌组)。利用扫描电镜(SEM)观察涂层表面形貌,X射线能谱分析仪(EDX)和X射线衍射仪(XRD)分析元素分布和成分,测厚仪测量涂层厚度;粗糙度测试仪测量表面粗糙度。结果 SEM下可见MAO组钛表面粗糙多孔,联合溶胶-凝胶处理后,钛表面更加平整紧密,EDX得出MAO+Sol/gel组钙磷元素的质量百分比分别为25.00%和15.49%,MAO+Sol/gel-Low Zn组和MAO+Sol/gel-High Zn组钙、磷、锌元素的质量百分比分别为22.87%、15.01%、1.82%与18.66%、15.60%、7.45%,XRD得出MAO+Sol/gel组、MAO+Sol/gel-Low Zn组和MAO+Sol/gel-High Zn组均可见特征性羟基磷灰石(HA)峰和Ca3(PO4)2峰,MAO+Sol/gel-High Zn组表面涂层厚度最高(10.40±0.49)μm(P<0.05),MAO+Sol/gel组表面粗糙度最高(1.17±0.10)μm(P<0.05)。结论应用微弧氧化联合溶胶-凝胶工艺,可在钛金属表面制备出HA涂层,并通过调节溶胶凝胶中Zn(NO3)2·6H2O的含量,制备出HA和不同含量锌离子的复合生物涂层。经过两种不同工艺联合处理后,钛表面涂层厚度逐渐增加,而粗糙度随着溶胶凝胶中锌离子的增加逐渐降低。     

钛表面载银HA-TCP溶胶凝胶涂层的制备及其抗菌性的研究

目的：用溶胶凝胶法在钛表面制备载银HA-TCP涂层，并观察其抗菌性能。方法：采用溶胶凝胶法将Ag^＋导入HA-TCP溶胶，并在钛表面涂层。用X射线衍射（XRD）和傅立叶变换红外光谱（FTIR）对涂层结构进行表征分析，用X射线能谱（EDS）分析涂层表面元素构成和分布，用扫描电镜（SEM）观察涂层表面形貌。观察涂层对牙龈卟啉单胞菌P.g、具核梭杆菌F.n、伴放线放线杆菌A-a的生长抑制作用，并计算抗菌率。结果：载银HA-TCP溶胶在钛表面涂层均匀，由大量的亚微米及细微的介孔组成。XRD检测出HA、钛、锐钛矿和β-TCP的衍射峰；FTIR分析涂层含有OH^-．PO4^3-及CO3^2-的特征吸收峰。EDS检测发现钙、磷、钛、碳、氧和银在涂层表面的分布。与对照组比较，载银HA-TCP涂层对牙龈卟啉单胞菌P.g、具核梭杆菌F.n、伴放线放线杆菌A.a具有明显的抗菌效果。结论：本试验在钛表面涂覆载银HA-TCP溶胶，使钛植入体获得了具有生物活性及抗菌性的仿生涂层。     

Long-term bone response to titanium implants coated with thin radiofrequent magnetron-sputtered hydroxyapatite in rabbits

PURPOSE: The present study was designed to investigate the long-term bone response around machined screw-type uncoated and calcium phosphate (CaP) -coated commercially pure titanium implants. MATERIALS AND METHODS: Using a magnetron sputtering technique, implants with a CaP coating similar in composition and CaP ratio to hydroxyapatite were produced. Heat treatment was subsequently used to increase the crystallinity of the coatings. Four types of coatings (0.1 and 2.0 microm amorphous and 0.1 and 2.0 microm crystalline) were manufactured; uncoated implants served as a control. Three hundred twenty implants (64 of each type) were randomly placed in the tibial cortical and trabecular femoral bones of 40 rabbits. The rabbits were sacrificed 9 months after implant placement. RESULTS: Histomorphometric evaluation carried out on ground sections revealed that the crystalline CaP coatings achieved the highest bone-implant contact in both tibiae and femora compared with amorphous CaP-coated and uncoated titanium. DISCUSSION: The present study suggests that submicron crystalline hydroxyapatite coating adds bioactive properties to titanium oral implants. CONCLUSION: An ultra-thin, 0.1-microm crystalline CaP coating can elicit and maintain an improved long-term bone response compared to amorphous coated or uncoated Ti implants, without any adverse tissue reactions.     

Characterization of hydroxyapatite films obtained by pulsed-laser deposition on Ti and Ti-6AL-4v substrates.

OBJECTIVES: Pulsed-laser deposition (PLD) is a development process to obtain hydroxyapatite (HA) thin film. It is an alternative to hydroxyapatite deposition techniques usually employed to cover orthopaedic or dental titanium implant surfaces. The aim of this study is to find out the characteristic ratio for Ca/P (1.66) deposit on titanium implant with the PLD process. METHODS: In a preliminary study, the coating parameters of pure and highly crystalline HA on Ti or Ti-6Al-4V substrates were verified by analysing the deposit by Rutherford backscattering spectroscopy (RBS). Ablation parameters to reach a stoichiometric hydroxyapatite composition (ideal Ca/P atomic ratio) and to control the growth of crystalline phases were: 575 degrees C for the substrate temperature, 0.4 mbar H2O vapour pressure in the ablation chamber, the target substrate distance was 40 mm and the deposition time was 120 min. In a second part, the film properties were analysed by means of XRD, SEM, AFM. The coating adhesion of the HA to the substrate was determined with a micro scratch tester. RESULTS: The analysed HA thin films showed a perfect crystallized and textured deposit. Sample observation and surface quality analysis demonstrated a surface roughness and adhesion of the films to the substrates compatible with biological applications. SIGNIFICANCE: These results suggest that pulsed-laser deposition is a suitable technique to obtain crystalline and adherent hydroxyapatite films on Ti or Ti-6Al-4V substrates. The quality of the HA deposit with the PLD process could be an interesting option for coating dental implant.     

In vitro evaluation of different heat-treated radio frequency magnetron sputtered calcium phosphate coatings

OBJECTIVES: Surface chemical compositions, such as calcium/phosphorus ratio and phase content, have a strong influence on the bioactivity and biocompatibility of calcium phosphate (CaP) coatings as applied on orthopedic and dental implants. MATERIAL AND METHODS: Hydroxylapatite (HA) and dicalcium pyrophosphate (DCPP) coatings were prepared on titanium substrates by RF magnetron sputter deposition. The surfaces were left as-prepared (amorphous HA coating; A-HA, amorphous DCPP coating; A-DCPP) or heat treated with: infrared (IR) at 550 degrees C (I-HA) or at 650 degrees C (I-DCPP), and a water steam at 140 degrees C (S-HA and S-DCPP). The surface changes of these coatings were determined after incubation in simulated body fluid (SBF). Also, the growth of rat bone marrow cells (RBM) was studied with scanning electron microscopy (SEM). RESULTS: Both IR and water steam heat treatment changed the sputter-deposited coatings from the amorphous into the crystalline phase. As-prepared amorphous coatings dissolved partially in SBF within 4 weeks of incubation, while heat-treated coatings supported the deposition of a precipitate, i.e., carbonated apatite on both I-HA and S-HA specimens, and tricalciumphosphate on the I-DCPP and S-DCPP specimens. The Ca/P ratio of the A-HA, I-HA, S-HA, A-DCPP, I-DCPP and S-DCPP coatings changed, respectively, from 1.98 to 1.12, 2.01 to 1.76, 1.91 to 1.68, 0.76 to 1.23, 0.76 to 1.26 and 1.62 to 1.55 after 4 weeks of incubation in SBF. Finally, the RBM cells grew well on all heat-treated coatings, but showed different mineralization morphology during cell culturing. CONCLUSION: The different heat-treatment procedures for the sputtered HA and DCPP coatings influenced the surface characteristics of these coatings, whereby a combination of crystallinity and specific phase composition (Ca/P ratio) strongly affected their in vitro bioactivity.     

纯钛表面涂层（Ca+Zn）/P比值与成骨细胞生物活性的关系

目的研究纯钛表面不同（Ca+Zn）/P比值对成骨细胞（MC3T3-E1）黏附、增殖和分化的影响,确定纯钛表面生物活性最佳的Ca、P、Zn含量。方法在微弧氧化的电解液中加入一定浓度的Ca、P和5种不同浓度的Zn（0、0.01、0.03、0.04和0.06 mol/L）,使Ca、P元素的摩尔比值接近羟基磷灰石的比值。在纯钛材料表面制备5种不同（Ca+Zn）/P比值的生物活性涂层,分别记为S₀、S₁、S₂、S₃和S₄组。应用XPS和SEM分析样品表面的元素组成、存在形式、（Ca+Zn）/P比值以及表面形貌;应用SEM、MTT法和ALP活性测定法分析材料表面培养的MC3T3-E1细胞黏附、增殖和分化情况。采用SPSS13.0软件包对数据进行统计学分析。结果随着电解液中Zn浓度的增加,S₀~S₄组（Ca+Zn）/P比值分别为2.94、2.64、2.71、2.87和2.72,其中,在S₃组时达到最大,S₄组时降低。MC3T3-E1细胞在5组材料表面黏附、增殖和分化能力,依次为S₃>S₄>S₂>S₁>S₀,各组之间差异具有显著性（P<0.05）。结论应用微弧氧化法在纯钛表面制备的不同含量Ca、P、Zn涂层,随着（Ca+Zn）/P比值的增大,成骨细胞的黏附、增殖和分化能力随之增强。其中,（Ca+Zn）/P比值为2.87时,细胞的生物活性最佳。     

Implant Surface Modification Using Laser Guided Coatings: In Vitro Comparison of Mechanical Properties

Purpose: Plasma-sprayed hydroxyapatite (HA)-coated implants show failures along the coating–substrate interface due to poor bond strength. We analyzed HA coatings obtained by pulsed laser deposition (PLD) and compared them to commercially used plasma-sprayed coatings with respect to their bond strength to titanium alloy (Ti-6Al-4V), as well as surface roughness alterations produced by each of the two deposition methods.
Materials and Methods: Twelve titanium alloy disks were plasma-sprayed under commercial implant coating conditions, and 24 titanium alloy disks were coated using PLD. All coatings were characterized by the presence of the different calcium phosphate (CaP) phases. The plasma-sprayed coatings (n = 12) were predominantly HA, and the pulsed laser-deposited coatings were hydroxydyapatite (n = 12) and HA coating with a tetra calcium phosphate (TTCP) phase (n = 12). The surface roughness was analyzed before and after the coating processes to assess roughness changes to the surface by the coatings. The adhesive bond strengths of these coatings to the substrate titanium alloy was tested and compared. Scheffé's test was used to analyze the statistical significance of the data.
Results: The surface roughness alteration following PLD was a decrease of 0.2 μm, whereas following plasma spraying the decrease was 1.0 μm. Bond strengths were as follows [mean (SD) in MPa]: pulsed laser-deposited HA coatings: 68.3 (17.8); pulsed laser-deposited HA with tetra-CaP: 55.2 (21.1); plasma-sprayed HA 17.0 (2.8). The multivariate Scheffé's test revealed that HA coatings obtained by PLD had significantly increased bond strengths compared with the plasma sprayed ones ( p ≤ 0.05).
Conclusions: HA coatings obtained by PLD showed greater adherence to titanium alloy. PLD offers an alternative method to produce thinner coatings with better adherence properties, along with precise control over the deposition process.     

含锌碳磷灰石的溶胶凝胶法制备及性能表征

目的通过溶胶凝胶法制备含锌的碳磷灰石（Zn- CHA）涂层材料,并探讨锌离子取代反应对羟磷灰石物理化学性质的影响。方法实验制备了锌离子取代量和钙磷比不相同的两组样本,其中钙足量组样本的钙磷比为1.67,锌离子取代4%的钙离子;钙不足量组的钙磷比小于1.67,锌离子取代8%的钙离子。采用X射线衍射仪（XRD）、傅立叶变换红外光谱仪（FTIR）对样本的物相结构和化学组成进行分析研究,并采用扫描电镜观察样本的表面形貌。此外,还采用原子吸收分光光度计（AAS）对样本的溶解特性与锌离子的关系进行研究。结果X射线衍射分析表明样本中含有羟磷灰石相,傅立叶变换红外光谱分析结果表明样本为碳磷灰石,溶解实验表明钙不足量组和钙足量组样本中分别存在锌离子整合到羟磷灰石晶格内和吸附在羟磷灰石晶体表面两种情况。结论研究表明含锌的碳磷灰石能够通过简单的溶胶凝胶法制备获得。     

The effect of three different calcium phosphate implant coatings on bone deposition and coating resorption: a long-term histological study in sheep

The present study investigated the hypothesis that hydroxyapatite (HA), tricalcium phosphate (TCP), and a HA-gel coated on endosseous titanium (Ti) implants by spark discharging (SD) and dip coating would achieve predictable osseointegration without evident bioresorption of the coatings on the long term. A costal sheep model was used for the implantation of the HA/SD, HA/TCP/SD, and HA-gel/SD specimens, which were retrieved 6 and 12 months following implantation. HA and Ti coatings on implants obtained by conventional plasma spraying (HA/PS, Ti/PS) were used as controls. Microscopy showed that osseointegration was achieved from all types of implants. No evidence for bioresorption of the HA/SD, HA/TCP/SD, and HA-gel/SD coatings was present but cohesive failure with disruption of the coating/implant interface was seen. A statistical analysis of the histomorphometrical data showed no time-dependent effect, however. HA/PS coatings achieved significantly higher bone-implant contact (BIC) percentages of the total implant surface (toBIC) than the other types of coatings (P=0.01). If the BIC percentages were traced separately for implant portions placed into cortical and cancellous bone (coBIC and caBIC, respectively), detailed analysis showed that the caBIC values of HA-gel/SD and HA/PS coatings were significantly higher than that of the other types of coatings (P=0.01). CaBIC values were highly correlated with toBIC values (P<0.001). The present study showed that the preparation techniques used produced thin, dense, and unresorbable coatings that achieved osseointegration. Compared with the control coatings, however, only HA-gel/SD coating can be recommended from the investigated preparation techniques for a future clinical use if a better coating cohesion is achieved.     

应用IBAD方法制备纯钛表面多孔TCP／HA涂层材料的微观分析

目的:为了改善钛种植体的生物相容性,对纯钛表面沉积多孔磷酸三钙/羟基磷灰石(Tricalciumphosphate/hydroxyapatite,TCP/HA)复合涂层材料的表面结构和化学成分进行分析,并与沉积羟基磷灰石(Hydroxyapatite,HA)的钛表面进行对比。方法:用离子束辅助沉积方法(Ionbeamassisteddeposition,IBAD)在纯钛表面沉积HA和TCP/HA涂层材料,通过扫描电镜(Scanningelectronmicroscope,SEM)、原子力显微镜(Atomicforcemicroscopy,AFM)、X射线能谱分析(EnergydispersiveX-rayanalysis,EDX)以及X射线衍射(X-raydiffraction,XRD)技术,检测两种涂层材料表面的微观形态和化学成分,并进行比较。结果:SEM和AFM显示TCP/HA涂层材料表面存在多孔结构,表面化学成分分析显示TCP/HA涂层的钙磷比低于HA,XRD证实TCP/HA涂层内同时存在TCP和HA两种化合物。结论:用IBAD方法在纯钛表面成功地沉积了具有多孔结构的TCP/HA复合涂层材料,该涂层材料和基体材料的结合牢固,改善了基体材料的生物相容性,是一种有应用前景的种植体表面涂层材料。     

The role of surface reactions in the dissolution of stoichiometric hydroxyapatite.

Stoichiometric hydroxyapatite was successively equilibrated in 0.1 M KCl under CO₂-free conditions at pH values ranging from 4.90 to 9.94. Following the removal of an irreversible surface which generated excessive Ca and P solution concentrations, the behaviour of the solid was reproducible. This surface of one atom-layer thickness or less was believed to have formed during the preparation of the solid. The molar Ca:P ratio in equilibrium solutions commonly deviated from 1.67 and was a function of pH and previous sample history. The influence of these parameters, surface:solution ratio and ionic strength on the solution Ca:P ratio was attributed to their effect on the relative contribution of surface and bulk dissolution and/or their direct effect on surface composition. With successive equilibration at any given pH, the solution Ca:P ratio reached a limiting value of 1.67 at which stage the hydroxyapatite was considered to possess a surface composition unique for that pH.     

钛合金种植体表面生物活性因子缓释涂层的构建及生物学评价

目的 探讨在纯钛及其合金种植体表面构建生物活性因子缓释涂层的可行途径。 方法 通过模拟体液仿生沉积法在钛合金种植体表面构建钙磷离子/神经生长因子(nerve growth factor,NGF)复合涂层,扫描电镜观察表面形貌、检测厚度,声发射划痕仪检测结合强度; ELISA法检测涂层所含NGF的总量及体外缓释规律;倒置相差显微镜观察释出的NGF对大鼠骨髓间充质干细胞定向成骨细胞分化诱导的影响。 结果 本实验制备的复合涂层具有粗糙的表面,平均厚度为（11.2±0.26）μm,平均临界载荷为（6.8±0.37）N;所含的NGF可在体外缓释2周以上,并具有生物活性。 结论 模拟体液仿生沉积法可在钛合金种植体表面成功构建具有缓释生物活性因子能力的复合涂层,其释出的NGF可促进成骨。     

Effects of a calcium phosphate coating on the osseointegration of endosseous implants in a rabbit model

Objectives: The aim of the present study was to evaluate a Ca–P coated implant surface in a rabbit model. The Ca–P surface (test) was compared to the titanium porous oxide surface (control) in terms of bone‐to‐implant contact (BIC) and removal torque value. Materials and methods: Two hundred and sixteen dental implants were inserted in the tibia and in the femur of 36 rabbits. One hundred and eight were represented by Ca–P oxidized surface implant and other 108 were titanium porous oxide surface modified implants. Each rabbit received six implants. Animals were sacrificed after 2, 4 and 9 weeks of healing. Each group included 12 rabbits. The femoral implant and the proximal implant of the tibia of each animal were subjected to the histologic analysis and the distal implants of the tibia underwent removal torque test (RTQ). Results: Histological analysis in terms of BIC and RTQ did not revealed any significant difference between the Ca–P oxidized surface and the oxidized surface at 2 and 4 weeks. At 9 weeks, the oxidized surface demonstrated better results in terms of RTQ in the tibia. Conclusion: In conclusion, findings from the present study suggested that the Ca–P coating had no beneficial effect in improving bonding strength at the bone–implant interface either at 2, 4 and 9 weeks. To cite this article:
Fontana F, Rocchietta I, Addis A, Schupbach P, Zanotti G, Simion M. Effects of a calcium phosphate coating on the osseointegration of endosseous implants in a rabbit model
Clin. Oral Impl. Res. 22 , 2011; 760–766
doi: 10.1111/j.1600‐0501.2010.02056.x     

钙对变形链球菌MT6R(血清型c)表面蛋白P1粘附的影响

测定变形链球菌ＭＴ６Ｒ菌株表面蛋白Ｐ１在钙溶液中对唾液包被的羟磷灰石的粘附量,探讨钙对蛋白Ｐ１粘附的影响。方法：将变形链球菌ＭＴ６Ｒ菌表面蛋白Ｐ１经＾１３１碘标记,分别测定其在钙逍度为０、０．１、０．２５、１．０、１．５及２．０ｍｍｏｌ／Ｌ的溶液中标记物＾１３１碘－蛋白Ｐ１对唾液包被的羟磷灰石（Ｓ－ＨＡ）的粘附量。结果＾１３１碘－蛋白Ｐ１在不同钙离子浓度的溶液中粘附量不同,当钙浓度从０．１ｍｏｌ／     

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目的    研究改良热分解法制备的钛金属表面钛酸钙复合涂层材料的特性。方法   应用改良热分解法在钛金属表面制备钛酸钙复合涂层材料,该涂层由含有无定形碳的钛酸钙（CaTiO3-αC）与羟基磷灰石（HA）组成。实验中通过控制钙磷比（Ca／P）、钙钛比（Ca／Ti）、烧结温度和烧结速率,使CaTiO3颗粒的晶体结构中含有摩尔分数为4%的无定形碳。结果    通过对HA中碳的检测,证实了存在碳酸磷灰石的结构。钛表面的黏附-分离实验显示,CaTiO3-αC／HA涂层的黏附强度是单纯HA涂层的2.5倍。结论    改良热分解法制备的CaTiO3-αC层（0.6 μm厚）和含有碳酸磷灰石的HA层（2.4 μm厚）组成的双层生物活性材料能够作为钛表面理想的涂层材料。     

Biomimetic calcium phosphate composite coating of dental implants

PURPOSE: The aim of the present study was to test the hypothesis that calcium phosphate coating of titanium screw-type implants enhances peri-implant bone formation in the jaw. MATERIALS AND METHODS: Ten adult female foxhounds received experimental titanium screw-type implants in the mandible 3 months after removal of all premolar teeth. Four types of implants were evaluated in each animal: implants with machined titanium surface (the control group), implants coated with collagen I (the collagen-only group), implants with a composite coating of calcium phosphate and mineralized collagen I (the composite group), and implants with calcium phosphate (hydroxyapatite [HA]) coating (the HA-only group). Peri-implant bone regeneration was assessed histomorphometrically after 1 and 3 months in 5 dogs each by measuring bone-implant contact (BIC) and the volume density of the newly formed peri-implant bone (BVD). RESULTS: After 1 month, BIC was significantly enhanced only in the group of implants with composite coating of calcium phosphate and mineralized collagen (P = .038). Volume density of the newly formed peri-implant bone was significantly higher in all coated implants after 1 month. No significant difference from baseline was found in BIC for the collagen-only and HA-only groups, but BVD was significantly higher in implants with composite coating (P = .041). After 3 months, BIC and BVD were significantly higher in all coated implants than in the controls with machined surfaces. CONCLUSION: It was concluded that composite coating of dental screw-type implant surfaces using calcium phosphate and collagen can enhance BIC and peri-implant bone formation.     

微弧氧化法在纯钛表面生成含羟基磷灰石陶瓷膜的研究

目的：利用微弧氧化法在纯钛表面直接生成含羟基磷灰石的陶瓷膜。方法：通过微弧氧化技术,采用双相脉冲电源,以0．4mol／L醋酸钙和0．2mol／L磷酸二氢钠为电解液体系,设定脉冲频率为60Hz,正相电流密度为20A／dm^2,处理时间分别为5rain、10min、20min、30min、60min,在纯钛表面制备陶瓷膜。利用扫描电镜观察膜层的表面形貌,能谱仪分析氧化膜的元素组成,X射线衍射仪分析膜层的相组成,电涡流涂层测厚仪测量膜层的厚度。结果：以0．4mol／L醋酸钙和0．2mol／L磷酸二氢钠为电解液体系,经微弧氧化处理后,在纯钛表面形成含有Ti、O、Ca和P元素的微孔结构的氧化膜,该膜由锐钛矿型TiO2、金红石型TiO2及羟基磷灰石组成。随微弧氧化反应时间的延长,膜层增厚,膜层表面微孔孔径增大,数量减少,粗糙度增大。钛元素的相对含量减少,Ca、P元素相对含量增加,O元素变化不明显。钛、锐钛矿型TiO2和金红石型TiO2的衍射峰逐渐减弱,羟基磷灰石的衍射峰逐渐增强。结论：应用微弧氧化技术,以0．4mol／L醋酸钙和0．2mol／L磷酸二氢钠为电解液体系,在纯钛表面能直接生成含有羟基磷灰石成份的微孔结构的陶瓷膜。