Biocompatibility of a titanium dioxide-coating method for denture base acrylic resin

Ease of denture cleaning is of paramount importance in geriatric patients and those with limited dexterity. We have previously investigated methods of coating dentures with titanium dioxide (TiO₂ ) and reported the effects (self-cleaning and antibacterial) of such treatments in in vitro studies. This study was to verify the biocompatibility of a TiO₂ -coated acrylic resin produced by the new coating method with spray-coating technique.

Specimens were prepared from denture base acrylic resin and polished up to grit #1000. The TiO₂ -coating agent was sprayed onto the specimens using an airbrush gun. Specimens were then divided into 'polymethyl methacrylate (PMMA)', 'primer-coated PMMA' and 'TiO₂ -coated PMMA' groups to be evaluated for biological safety using a hamster oral mucosa irritation test, a guinea pig skin sensitisation test and a rabbit intracutaneous test. The biological reaction was scored.

Reaction scores were considerably <1.0, the acceptable limit set by the ISO, in all three tests. Indeed, in most samples, there was no deleterious effect at all.

These results tested on animals demonstrate that denture base resin coated with TiO₂ by this method does not cause irritation or sensitisation of the oral mucosa, skin or intracutaneous tissue and is therefore good biocompatibility for use in close proximity to oral mucosa and skin.