Department of Prosthodontics, Dental School, Albert-Ludwigs University, Freiburg, Germany.
Int J Oral Maxillofac Implants. 2012 Jul-Aug;27(4):753-61.
The topographic and physicochemical features of implant surfaces influence the process of osseointegration. The biologic properties of implant surfaces have been considered to remain stable over time, ie, the capability of osseointegration of implant surfaces presumably does not change over time after manufacturing. However, recent reports have demonstrated that titanium surfaces undergo a progressive change in their biologic characteristics over time, resulting in a significant decrease in osseointegration capability. In comparison to newly prepared titanium surfaces, 4-week-old titanium surfaces (ie, stored for 4 weeks after processing) required more than twice as much healing time to achieve a similar strength of osseointegration. The boneimplant contact percentage for the 4-week-old surfaces was less than 60%, as opposed to more than 90% for the new surfaces. In vitro, the 4-week-old surfaces showed only 20% to 50% of the levels of recruitment, attachment, settlement, and proliferation of osteogenic cells versus new surfaces. On the other hand, a series of recent papers reported the generation of highly cell-attractive and osteoconductive titanium surfaces by ultraviolet (UV) light treatment. The phenomenon, defined as photofunctionalization, caused a fourfold acceleration in the process of osseointegration and resulted in nearly 100% bone-implant contact. Remarkably enhanced behavior and response of osteogenic cells around UV-treated surfaces exceeded the levels observed for the newly prepared surfaces. These studies indicated that UV treatment reverses the time-dependent biologic degradation of titanium and even enhances the surface beyond its innate potential. The present paper summarizes the findings about the aging-like time-dependent biologic degradation of titanium surfaces as well as about the discovery of UV photofunctionalization as a solution for this phenomenon. It also provides a novel understanding of osseointegration and calls for immediate attention to a new avenue of exploration in the science and therapeutics of implant dentistry.
种植体表面的地形和物理化学特征影响着骨整合过程。人们认为种植体表面的生物学特性会随着时间的推移而保持稳定，也就是说，种植体表面的骨整合能力在制造后不会随着时间的推移而发生变化。然而，最近的报告表明，钛表面的生物学特性会随着时间的推移而逐渐发生变化，导致其骨整合能力显著下降。与新制备的钛表面相比，4 周龄的钛表面（即在加工后储存 4 周）需要两倍以上的愈合时间才能达到相似的骨整合强度。4 周龄表面的骨-种植体接触百分比不到 60%，而新表面则超过 90%。在体外，4 周龄表面的成骨细胞募集、黏附、定居和增殖水平仅为新表面的 20%至 50%。另一方面，最近的一系列论文报道了通过紫外线（UV）光处理生成高度细胞亲和性和骨诱导性的钛表面。这种现象被定义为光功能化，使骨整合过程加速了四倍，并导致近 100%的骨-种植体接触。令人瞩目的是，UV 处理表面周围成骨细胞的增强行为和反应超过了新制备表面的水平。这些研究表明，UV 处理逆转了钛的时间依赖性生物学降解，甚至增强了表面的固有潜力。本文总结了关于钛表面类似老化的时间依赖性生物学降解的发现，以及发现 UV 光功能化为解决这一现象的方法。它还提供了对骨整合的新认识，并呼吁立即关注种植牙科科学和治疗学的新探索途径。
