Data from: Do ‘passive’ medical titanium surfaces deteriorate in service in the absence of wear?

Globally, more than 1000 tonnes of titanium (Ti) is implanted into patients in the form of biomedical devices on an annual basis. Ti is perceived to be ‘biocompatible’ owing to the presence of a robust passive oxide film (approx. 4 nm thick) at the metal surface. However, surface deterioration can lead to the release of Ti ions, and particles can arise as the result of wear and/or corrosion processes. This surface deterioration can result in peri-implant inflammation, leading to the premature loss of the implanted device or the requirement for surgical revision. Soft tissues surrounding commercially pure cranial anchorage devices (bone-anchored hearing aid) were investigated using synchrotron X-ray micro-fluorescence spectroscopy and X-ray absorption near edge structure. Here, we present the first experimental evidence that minimal load-bearing Ti implants, which are not subjected to macroscopic wear processes, can release Ti debris into the surrounding soft tissue. As such debris has been shown to be pro-inflammatory, we propose that such distributions of Ti are likely to effect to the service life of the device.

全球范围内，每年有超过1000吨钛（Ti）以生物医学器械的形式被植入患者体内。钛因金属表面覆盖一层致密的钝化氧化膜（passive oxide film，厚度约4纳米）而被认定为具有良好的生物相容性（biocompatible）。然而，表面劣化会引发钛离子释放，而磨损和/或腐蚀过程也会产生钛颗粒。此类表面劣化可诱发种植体周围炎症（peri-implant inflammation），导致植入器械过早失效，或需要进行手术翻修（surgical revision）。研究人员采用同步辐射X射线微荧光光谱（synchrotron X-ray micro-fluorescence spectroscopy）与X射线吸收近边结构谱（X-ray absorption near edge structure），对工业纯颅部锚固装置（即骨锚式助听器，bone-anchored hearing aid）周围的软组织开展了分析检测。本研究首次提供实验证据表明，未承受宏观磨损作用的低承载钛植入物，可向周围软组织释放钛碎屑（Ti debris）。鉴于已有研究证实此类碎屑具有促炎性（pro-inflammatory），我们推测钛元素的此类分布很可能会影响植入器械的使用寿命。