Vasanthan Asvin, Kim Hyunbin, Drukteinis Saulius, Lacefield William
Department of Periodontics, School of Dentistry, University of Missouri at Kansas City, Kansas City, MO 64108, USA.
J Prosthodont. 2008 Jul;17(5):357-64. doi: 10.1111/j.1532-849X.2008.00307.x. Epub 2008 Jun 9.
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.
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.
The surface roughness alteration following PLD was a decrease of 0.2 mum, whereas following plasma spraying the decrease was 1.0 microm. 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<or= 0.05).
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.
等离子喷涂羟基磷灰石（HA）涂层植入物由于结合强度差而在涂层与基底界面处出现失效情况。我们分析了通过脉冲激光沉积（PLD）获得的HA涂层，并将其与商业使用的等离子喷涂涂层在与钛合金（Ti-6Al-4V）的结合强度以及两种沉积方法各自产生的表面粗糙度变化方面进行了比较。
在商业植入物涂层条件下对12个钛合金圆盘进行等离子喷涂，并用PLD对24个钛合金圆盘进行涂层处理。所有涂层均通过不同磷酸钙（CaP）相的存在进行表征。等离子喷涂涂层（n = 12）主要为HA，脉冲激光沉积涂层为羟基磷灰石（n = 12）和具有磷酸四钙（TTCP）相的HA涂层（n = 12）。在涂层处理前后分析表面粗糙度，以评估涂层对表面粗糙度的改变。测试并比较这些涂层与基底钛合金的粘结强度。使用Scheffé检验分析数据的统计学意义。
PLD后表面粗糙度变化为降低0.2μm，而等离子喷涂后降低1.0μm。粘结强度如下[单位为MPa的平均值（标准差）]：脉冲激光沉积HA涂层：68.3（17.8）；含磷酸四钙的脉冲激光沉积HA：55.2（21.1）；等离子喷涂HA：17.0（2.8）。多变量Scheffé检验显示，与等离子喷涂的HA涂层相比，通过PLD获得的HA涂层粘结强度显著提高（p≤0.05）。
通过PLD获得的HA涂层对钛合金的附着力更强。PLD提供了一种替代方法，可生产出具有更好附着性能的更薄涂层，并能精确控制沉积过程。
