Abstract
This investigation demonstrates the effect of alkali modification of titanium on the metabolism of human osteoblasts. Polished titanium discs were subjected to alkalinization protocols with NaOH (5M) at 60°C or 120°C. Surface topography and roughness were evaluated using scanning electron microscopy (SEM). Osteoblasts were seeded onto titanium discs, followed by cell adhesion and viability analysis, total protein and collagen production, and alkaline phosphatase (ALP) activity. Gene expression of tumor necrosis factor-alpha (TNF-α) and beta-defensin 3 (HBD3) was evaluated after inflammatory stimulus with lipopolysaccharides (LPS) of Porphyromonas gingivalis (1 μg/mL) for 4 h. Discs subjected to modification with NaOH showed major irregularities, especially for 120°C-protocol. Increased adhered cell number was observed for surfaces modified by NaOH. Osteoblasts cultured on modified surfaces showed higher cell viability, total protein and collagen synthesis, and ALP activity than that of cells cultured on the polished discs. Osteoblast response to LPS exposure showed increased TNF-α gene expression by these cells when cultured on the polished discs, while increased expression of HBD3 was detected for all groups in the presence of LPS. Modification of titanium discs by NaOH at 60°C or 120°C promoted an increase in adhesion and metabolism of osteoblasts and favored the response to inflammatory stimulus.