Comparison of dental plaque reduction after use of electric toothbrushes with and without QLF-D-applied plaque visualization: a 1-week randomized controlled trial.

BACKGROUND: To evaluate the efficacy of a newly developed electric toothbrush in reducing dental plaque via a quantitative light-induced fluorescence-digital (QLF-D)-applied visualisation system in the brush head. METHODS: Participants included 20 adults aged 19 to 28 years. Participants were randomly assigned either (i) an electric toothbrush with a monitor to visualise red-fluorescent dental plaque via a camera built into the brush head (monitor usage group, n = 10) or (ii) an electric toothbrush without a monitor (monitor-non-use group, n = 10). The amount of dental plaque was assessed by personal hygiene performance (PHP) at baseline and 1 week later. RESULTS: In the monitor-usage group, PHP score was significantly lower at the 1-week follow-up than at baseline (6 vs 16; range, 0-12 vs 13-21; P = 0.029). This change was not observed in the monitor-non-use group (14 vs 13; range, 6-21 vs 2-26; P = 0.778). After 1 week, the change in PHP scores in the monitor usage group was significantly greater than that in the monitor non-use group (- 10 vs 0; range, - 21 to 9 vs - 8 to 16; P = 0.021). CONCLUSIONS: Our results clearly demonstrate that brushing teeth while looking at a monitor that depicts red-autofluorescent dental plaque via application of QLF-D improved the efficacy of dental-plaque removal relative to brushing teeth without a monitor. TRIAL REGISTRATION: Trial registration number: UMIN000033699. Name of registry: Study on effect of new devise for oral care on dental plaque clearance. Date of registration: 8th September 2018. Status of registration: Completed.

Efficacy of an Electric Toothbrush With Monitor in Dental Plaque Removal: A Crossover Randomized Controlled Trial.

BACKGROUND AND PURPOSE: Plaque control is very important in the treatment of periodontitis. However, plaque is difficult to remove because one cannot see one's own oral cavity. The purpose of this study was to verify the plaque removal effect of a prototype device that has a built-in image sensor in the head of an electric toothbrush, enabling the user to brush while checking the condition of the tooth surface on a monitor in real time and to assess their sense of use. MATERIALS AND METHODS: The subjects were 10 fifth-year students from the Graduate School of Dental Science, Fukuoka Dental College, Fukuoka, Japan. The subjects were divided into those who used electric toothbrushes while having the condition of the tooth surface checked with a monitor (monitor group) and those without a monitor (non-monitor group). O'Leary plaque control records before and after brushing and the brushing time were measured, and questionnaires were given to the subjects after brushing. Scaling and professional tooth cleaning were performed after completing the questionnaire. One week later, subjects were switched to the opposite group and had the same measurements and questionnaires. The Wilcoxon signed-rank test was used to compare both groups before and after the examination at a 5% significance level. RESULTS: The monitor group had significantly better plaque removal than the non-monitor group. In addition, the monitor group spent significantly more time brushing than the control group. CONCLUSION: Brushing while monitoring oral conditions in real time using an electric toothbrush with a built-in image sensor showed that significantly better plaque removal can be achieved with a longer brushing time.

Facilitation of H2O2-induced A172 human glioblastoma cell death by insertion of oxidative stress-sensitive TRPM2 channels.

The melastatin-like transient receptor potential M2 (TRPM2) channel is a Ca2+ permeable channel that is activated by reactive oxygen species (ROS), and its activation induces necrotic cell death. The effect of insertion of TRPM2 into A172 human glioblastoma cells (A172 cells) was investigated. The insertion of TRPM2 channels enhanced cell death induced by H2O2 in the A172 cells. An H2O2-induced Ca2+ increase was observed in TRPM2-expressing cells, but not in wild-type cells. Proliferation, migration and invasion activities were not affected by the expression of TRPM2. TRPM2 seems to be a candidate for gene therapy in glioblastoma cells, since the insertion of TRPM2 into A172 cells can facilitate cell death through Ca2+ increase after H2O2 treatment without increasing malignancy.