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

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Immobilization of 3,5-dimethylphenylcarbamates of cellulose and amylose onto silica gel using (3-glycidoxypropyl)triethoxysilane as linker.

The 3,5-dimethylphenylcarbamates of cellulose and amylose were effectively immobilized onto plain silica gels as chiral packing materials (CPMs) for HPLC by means of intermolecular polycondensation of triethoxysilyl groups introduced with (3-glycidoxypropyl)triethoxysilane. The immobilization and chiral recognition abilities of the obtained CPMs prepared with different amounts of (3-glycidoxypropyl)triethoxysilane were investigated. In addition, the solvent compatibilities of the immobilized-type CPMs were examined with eluents containing chloroform and THF. When these eluents were used, for most of the tested racemates, the chiral resolving abilities of the obtained CPMs were improved.

Color and gloss evaluation of titanium dioxide coating for acrylic resin denture base.

PURPOSE: We examined the clinical appearance (color, gloss, and surface roughness) of TiO(2) coating on polymethyl methacrylate (PMMA) resin dentures. METHODS: A spraying method, using air brushes, was used to generate thin uniform TiO(2) coating. PMMA resin, primer-coated PMMA, and TiO(2)-coated PMMA (with primer) specimens were compared. RESULTS: The Commission Internationale de l'Eclairage (CIE) color system revealed color variations between the with/without coated samples. The TiO(2)-coated PMMA specimen displayed high levels of glossiness, highlighting the efficient self-cleansing actions of the denture. The measured surface roughness decreased upon primer coating, and increased following TiO(2) coating. CONCLUSIONS: The thin TiO(2) coating afforded high levels of glossiness while maintaining the color of the denture base material.