Dentistry

Abstract

Effect of TiO2 Nanotube Layers Thickness on Periodontal Ligament Cells

Ling Xu, Kai-ge Lv and Wei-qiang Yu

Periodontal ligament cells (PDLCs) remaining in the tooth-extraction socket are involved in osseointegration after immediate implantation; however, their interaction with different implant surfaces has not been investigated. The aim of this study was to compare PDLC growth on substrates composed of differently sized titanium dioxide (TiO₂) nanotubes with that on flat Ti. PDLC growth on Ti nanotubes was evaluated in terms of cell adhesion, proliferation, and osteogenic differentiation based on the expression of alkaline phosphatase (ALP), type 1 collage (COL-1), osteopontin (OPN), and Runt-related transcription factor 2 (RUNX2). We found that TiO₂ nanotubes of different diameters (30, 70, and 120 nm) manufactured on Ti surface by anodisation had a well-defined structure. PDLCs grown on nanotube layers demonstrated polygonal morphology with more filopodia than those on flat Ti, which was especially evident on the nanotubes of larger diameters. However, cell adhesion and proliferation was the highest on the smallest 30 nm nanotubes. Similarly, mRNA levels of the ALP, COL-1, OPN, and RUNX2 genes increased in PDLCs cultured on 30 nm TiO₂ nanotube layers compared to those in the cells grown on 70 nm and 120 nm nanotubes. In conclusion, small diameter (30 nm) nanotube layers can support PDLC adhesion, proliferation, and differentiation better than larger sized nanotubes, and consequently, have higher potential to promote bone formation and integration of an immediate implant.