Efficacy of a solar-powered TiO2 semiconductor electric toothbrush on P. gingivalis biofilm.

Abstract To determine the efficacy of a solar-powered TiO2 semiconductor electric toothbrush on Porphyromonas gingivalis biofilm. P. gingivalis cells were cultivated on sterilized coverslips under anaerobic conditions and were used as a biofilm. To evaluate the efficacy of the solar-powered TiO2 electric toothbrush on the P. gingivalis biofilm, the bacterial cell biofilm coverslips were placed into sterilized phosphate buffered saline (PBS) and brushed for 1 minute. Following mechanical brushing, the coverslips were stained with 1% crystal violet (CV) for 10 seconds at room temperature. The efficacy of P. gingivalis biofilm removal by the solar-powered TiO2 electric toothbrush was measured through the absorbance of the CV-stained solution containing the removed biofilm at 595 nm. The antimicrobial effect of the solar-powered TiO2 semiconductor was evaluated by the P. gingivalis bacterial count in PBS by blacklight irradiation for 0 to 60 minutes at a distance of 7 cm. The electrical current though the solar-powered TiO2 semiconductor was measured by a digital multimeter. The biofilm removal by the solar-powered TiO2 semiconductor was also evaluated by scanning electron microscopy (SEM). The biofilm removal rate of the solar-powered TiO2 electric toothbrush was 90.1 ± 1.4%, which was 1.3-fold greater than that of non-solar-powered electric toothbrushes. The solar-powered TiO2 semiconductor significantly decreased P. gingivalis cells and biofilm microbial activity in a time-dependent manner (P