Development of novel hydrophilic and antibacterial silicone rubber impression material for dental application

This investigation aimed to develop a novel hydrophilic and antibacterial silicone rubber impression material for dental application.

The basic formula of the new silicone rubber was determined on a preliminary study, and 6% polyether modified silicone oil was added as wetting agent to provide the hydrophilicity. No-vel nano-antibacterial inorganic fillers containing quaternary ammonium salt with long chain alkyl were incorporated into the hydrophilic silicone rubber impression materials at a mass fraction of 0%, 1%, 2%, 3%, 4%, or 5%. A commercial silicone rubber impression material was used as control. The mechanical properties, wettability, detail reproducibility, dimensional stability, and mixing time of silicone rubber materials were measured. Thin-film adhesion method and cell counting kit-8 method were used to detect the antibacterial property and cytotoxicity. Scanning electron microscopy (SEM) was chosen to observe the micromorphology of the novel silicone rubber.

When the content of antibacterial filler exceeded 4%, the mechanical properties of the new silicone rubber decreased significantly (P<0.05). Compared with those of the control group, the contact angle and linear size change rate of different groups had no significant change at different time nodes, and the detail reproducibility was intact (P>0.05). The addition of antibacterial fillers had no significant effect on the mixing time (P>0.05). Adding 4% antibacterial fillers could result in the antibacterial rate of 95.26%, showing good antibacterial properties. No significant difference was found in the cytotoxicity of all groups (P>0.05). The SEM pictures of the cross section of the silicone rubber sample showed that the fillers had good compatibility with the silicone rubber matrix and distributed in the matrix evenly.

A novel silicone rubber impression material containing 6% polyether modified silicone oil could obtain promising hydrophilic and antibacterial properties after being added with 4% antibacterial inorganic fillers.