Efficacy of Plasma-Polymerized Allylamine Coating of Zirconia after Five Years

• Main Authors: Nadja Rohr, Katja Fricke, Claudia Bergemann, J Barbara Nebe, Jens Fischer
• Format: Article
• Language: English
• Published: MDPI AG 2020-08-01
• Series: Journal of Clinical Medicine
• Subjects: zirconia implant; human osteoblasts; cell viability; cell spreading; gene expression; plasma-polymerized allylamine
• Online Access: https://www.mdpi.com/2077-0383/9/9/2776

Plasma-polymerized allylamine (PPAAm) coatings of titanium enhance the cell behavior of osteoblasts. The purpose of the present study was to evaluate a PPAAm nanolayer on zirconia after a storage period of 5 years. Zirconia specimens were directly coated with PPAAm (ZA0) or stored in aseptic packages at room temperature for 5 years (ZA5). Uncoated zirconia specimens (Zmt) and the micro-structured endosseous surface of a zirconia implant (Z14) served as controls. The elemental compositions of the PPAAm coatings were characterized and the viability, spreading and gene expression of human osteoblastic cells (MG-63) were assessed. The presence of amino groups in the PPAAm layer was significantly decreased after 5 years due to oxidation processes. Cell viability after 24 h was significantly higher on uncoated specimens (Zmt) than on all other surfaces. Cell spreading after 20 min was significantly higher for Zmt = ZA0 > ZA5 > Z14, while, after 24 h, spreading also varied significantly between Zmt > ZA0 > ZA5 > Z14. The expression of the mRNA differentiation markers collagen I and osteocalcin was upregulated on untreated surfaces Z14 and Zmt when compared to the PPAAm specimens. Due to the high biocompatibility of zirconia itself, a PPAAm coating may not additionally improve cell behavior.