Cytotoxic and Pro-Inflammatory Effects of Miniscrews Subject to Corrosion in Oral Cell Cultures

Cytotoxic and pro-inflammatory effects of mini-screws subject to corrosion in oral cells culture. To analysis the products of corrosion of three different commercial orthodontic mini-screws and evaluate the cytotoxicity and pro-inflammatory effects in culture with human gingival fibroblast cells (HGFs) and human osteoblast-like bone surface cells (HBCs). An experimental in vitro study was carried out with 3 different type of mini-screws: Vector-Tas®, Forestadent ORTHOEasy®, Bio-Ray® (n = 30/gp). The samples were subjected to accelerated corrosion for 24, 48, 72 and 96 hours, which were observed with a stereomicroscope and scanning electron microscope. The corrosion products were analyzed by inductively coupled plasma with mass spectrometry. The direct and indirect cytotoxicity was tested in culture with HGFs and HBCs, cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The pro-inflammatory effect was determined by the expression of prostaglandin E2 (PGE2) with the ELISA test. The data were subjected to Shapiro-Wilks normality tests, paired t-tests and Tukey's post hoc ANOVA. The mini-screw topography showed significant morphological changes after corrosion. The main ions after corrosion were Al, Ti, and Fe. Corrosion products by direct and indirect contact with cells slightly reduced (P < 0.05) cell viability, considered non-cytotoxic. The expression of PGE2 was not increased by the presence of the corrosion products even in a previous pro-inflammatory state. The corrosion products were not cytotoxic and did not induce a pro-inflammatory state in culture with HGFs and HBCs.