OBJECTIVETo investigate celluar toxicity and antibacterial property of nano-silver coating modified denture base and to provide a theortical basis for clinical application.

METHODThe samples were divided into coating group and denture base group. Samples in coating groups were treated with silver ion sputtering and were further divided into the 10, 20, 40, 60, 80, 100 s subgroups according to their sputtering time. Surface microstructure of samples in coating groups and denture base group were observed by scanning electron microscopy (SEM), and composition of material surface were determined with energy dispersive spectrum (EDS) analysis. Methyl thiazolyl terazolium (MTT) method was used to analysis L929 cells proliferation rate and cell toxicity grade while the coating groups (n = 6) and group test specimens (n = 6), negative control (polyethylene, PE) (n = 6) and positive control group (PVC-org.Sn) (n = 6) were co-cultured with L929 cells. The antibacterial properties of coating groups were investigated by using the bacterial membrane adhering method with Streptococcus mutans and Candida albicans.

RESULTSSEM observation showed that the surface of control group specimens were smooth, whereas dense and uniform distributed nano silver particles were visible on the surface of coating group specimens. The silver particles were round, and the diameter size was 10 nm. MTT assay showed that after being co-cultured with specimens in control group, L929 cell had higher proliferation rate than 100% at 24, 48, 72 h, and cytotoxicity were graded 0. The membrane adhering method results showed that all of bacterial colonies were found in control group, but without anything at the coating groups.

CONCLUSIONSDeposition of nano silver on the denture base surface by ion sputtering method is a viable method. There's no cytotoxicity of series Ag-coating material. Nano-silver modified denture base material benefits L929 cell surface proliferation and has antibacterial action.