Department of Conservative Dentistry, Division of Biomaterials and Engineering, Showa University School of Dentistry.
Dent Mater J. 2022 Oct 2;41(5):655-659. doi: 10.4012/dmj.2021-231. Epub 2022 Apr 29.
The fixation of titanium implants in bone tissue is affected by the presence of a passive titanium oxide (TiO) layer. Specifically, oxidation products in the amorphous TiO matrix enhance the mechanical properties of mineralized tissues. In addition, in vitro mineralization mediated by primary osteoblasts on amorphous TiO generates stiff tissues in a process that resembles pathological mechanisms connected with tumors and proceeds through hydrogen peroxide-inducible clone-5 (Hic-5) expression. However, the relationship between surface-based peroxidation and stiff mineralized tissue formation remains unclear. In this study, titanium samples were processed using wire electrical discharge machining to generate oxidation products in amorphous TiO. The gene expression profiles of primary osteoblasts cultured on these specimens were characterized. Increased expression of Hic-5 was correlated with the presence of peroxidation products. The crystallization of amorphous TiO in these samples reduced the expression of both Hic-5 and lysyl oxidase, an enzyme that promotes matrix cross-linking.
钛植入物在骨组织中的固定受到存在的被动氧化钛（TiO）层的影响。具体来说，非晶态 TiO 基体中的氧化产物增强了矿化组织的机械性能。此外，在无定形 TiO 上由原代成骨细胞介导的体外矿化生成类似与肿瘤相关的病理机制的僵硬组织，该过程通过过氧化氢诱导克隆-5（Hic-5）表达。然而，表面过氧化物和硬矿化组织形成之间的关系尚不清楚。在这项研究中，使用线放电加工对钛样品进行处理，以在非晶态 TiO 中生成氧化产物。对在这些标本上培养的原代成骨细胞的基因表达谱进行了表征。Hic-5 的表达增加与过氧化物产物的存在相关。这些样品中非晶态 TiO 的结晶降低了 Hic-5 和赖氨酰氧化酶的表达，赖氨酰氧化酶是促进基质交联的酶。
