Olmedo Daniel G, Tasat Déborah R, Duffó Gustavo, Guglielmotti Maria B, Cabrini Rómulo L
Department of Oral Pathology, School of Dentistry, University of Buenos Aires, National Research Council, Argentina.
Acta Odontol Latinoam. 2009;22(1):3-9.
Pure titanium or titanium alloys, and to a lesser extent, zirconium, are metals that are often used in direct contact with host tissues. These metallic biomaterials are highly reactive, and on exposure to fluid media or air, quickly develop a layer of titanium dioxide (TiO2) or zirconium dioxide (ZrO2). This layer of dioxide forms a boundary at the interface between the biological medium and the metal structure, determining the degree of biocompatibility and the biological response of the implant. Corrosion is the deterioration a metal undergoes as a result of the surrounding medium (electrochemical attack), which causes the release of ions into the microenvironment. No metal or alloy is entirely inert in vivo. Corrosion phenomena at the interlace are particularly important in the evolution of both dental and orthopedic implants and one of the possible causes of implant failure after initial success. This paper comprises a review of literature and presents results of our laboratory experiments related to the study of corrosion, with special emphasis on dental implants. In situ degradation of a metallic implant is undesirable because it alters the structural integrity of the implant. The issue of corrosion is not limited to a local problem because the particles pmduced as a result could migrate to distant sites, whose evolution would require further studies.
纯钛或钛合金，以及在较小程度上的锆，是常用于与宿主组织直接接触的金属。这些金属生物材料具有高反应性，在暴露于流体介质或空气时，会迅速形成一层二氧化钛（TiO₂）或二氧化锆（ZrO₂）。这层二氧化物在生物介质与金属结构的界面处形成一个边界，决定了生物相容性的程度以及植入物的生物学反应。腐蚀是金属由于周围介质（电化学侵蚀）而发生的劣化，这会导致离子释放到微环境中。没有金属或合金在体内是完全惰性的。界面处的腐蚀现象在牙科和骨科植入物的发展过程中尤为重要，并且是初始成功后植入物失败的可能原因之一。本文包括文献综述，并展示了我们实验室与腐蚀研究相关的实验结果，特别侧重于牙科植入物。金属植入物的原位降解是不可取的，因为它会改变植入物的结构完整性。腐蚀问题不仅限于局部问题，因为由此产生的颗粒可能会迁移到远处部位，其演变需要进一步研究。
