Study Of Toothbrush Factors Influencing Both Cleaning Efficacy And Gentleness

To investigate the toothbrush design factors that influence the balance between cleaning efficacy and gentleness, aiming to effectively prevent periodontal disease. To evaluate cleaning efficacy, a red PVA/MA copolymer solution, simulating human dental plaque, was applied to the buccal surface of the maxillary right first molar on a jaw model. Brushing was performed using a brushing machine under controlled and reproducible conditions, and plaque removal rates were quantified through image analysis. To evaluate gentleness, a compression tester and a pressure sensor were used to measure the load and pressure distribution during vertical compression of the tufted surface. Comparative analysis revealed that a wide-head toothbrush (head width: 18 mm) with densely tufted bristles (hole diameter equivalent to Φ1.5 mm) demonstrated significantly superior plaque removal and a more even distribution of brushing force compared to a standard toothbrush (grid arrangement, head width: 10.5 mm). This study demonstrates that optimizing tufting density in wide-head toothbrushes can reduce gingival stress during brushing while maintaining high plaque removal efficacy, suggesting that appropriate control of structural parameters may contribute to the prevention of periodontal disease.