Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam ACTA, University of Amsterdam, Amsterdam, The Netherlands.
J Clin Periodontol. 2013 Sep;40(9):841-9. doi: 10.1111/jcpe.12136. Epub 2013 Jul 22.
Titanium wear particles have been found in peri-implant tissues, but their role in the pathogenesis of peri-implantitis remains unclear. We aimed to determine the in vitro inflammatory responses of peri-implant granulation tissue fibroblasts (PIGFs) to titanium particles alone and in the presence of viable Porphyromonas gingivalis.
MATERIALS & METHODS: Peri-implant granulation tissue fibroblasts were challenged either with TiO2 particles, P. gingivalis or a combination of TiO2 particles and P. gingivalis. Gene expression and protein production of pro-inflammatory mediators by PIGFs were measured with PCR and ELISA, respectively.
Higher doses of TiO2 were toxic to PIGFs and in sub-toxic doses, TiO2 caused an increase in gene expression of tumour necrosis factor (TNF)-A and increased protein production of TNF-α, interleukin (IL)-6 and IL-8. A challenge with P. gingivalis alone induced gene expression of TNF-A, IL-1β, IL-6 and IL-8. A combined challenge with TiO2 and P. gingivalis caused a stronger increase in gene expression of TNF-A and protein production of TNF-α and MCP-1 than P. gingivalis alone.
TiO2 particles and P. gingivalis, individually, can induce pro-inflammatory responses in PIGFs. Furthermore, TiO2 particles and viable P. gingivalis further enhance gene expression and production of TNF-α by PIGFs. Therefore, Ti wear particles in the peri-implant tissues in combination with P. gingivalis infection may contribute to the pathogenesis of peri-implantitis by enhancing the inflammation in peri-implant tissues.
已在种植体周围组织中发现钛磨损颗粒，但它们在种植体周围炎发病机制中的作用尚不清楚。本研究旨在确定钛颗粒单独以及在有活力的牙龈卟啉单胞菌存在的情况下对种植体周围肉芽组织成纤维细胞（PIGFs）的体外炎症反应。
将种植体周围肉芽组织成纤维细胞分别用 TiO2 颗粒、牙龈卟啉单胞菌或 TiO2 颗粒和牙龈卟啉单胞菌混合物进行刺激。通过 PCR 和 ELISA 分别测量 PIGFs 前炎症介质的基因表达和蛋白产生。
较高剂量的 TiO2 对 PIGFs 具有细胞毒性，在亚毒性剂量下，TiO2 会导致肿瘤坏死因子（TNF）-A 的基因表达增加，并增加 TNF-α、白细胞介素（IL）-6 和 IL-8 的蛋白产生。单独用牙龈卟啉单胞菌刺激会诱导 TNF-A、IL-1β、IL-6 和 IL-8 的基因表达。TiO2 和牙龈卟啉单胞菌联合刺激会引起 TNF-A 的基因表达和 TNF-α 和单核细胞趋化蛋白-1（MCP-1）的蛋白产生比单独用牙龈卟啉单胞菌更强的增加。
TiO2 颗粒和牙龈卟啉单胞菌单独作用可诱导 PIGFs 产生前炎症反应。此外，TiO2 颗粒和有活力的牙龈卟啉单胞菌进一步增强了 PIGFs 中 TNF-α 的基因表达和蛋白产生。因此，种植体周围组织中的 Ti 磨损颗粒与牙龈卟啉单胞菌感染相结合可能通过增强种植体周围组织的炎症反应，促进种植体周围炎的发病机制。
