Functional evaluation of toothbrushes using two standardized models

Manual toothbrushing is the most widely used method for daily plaque control. Although brushing techniques are crucial for plaque removal, it is very difficult to improve brushing techniques to maximize their effectiveness. Despite the variety of toothbrushes available, the objective evaluation of the functional index of a toothbrush remains elusive. This study aimed to develop a comprehensive and objective evaluation method for toothbrush function using standardizable models. For a comprehensive evaluation, we divided the evaluated surface into three elements (convex, concave, and flat). Further, we developed two standardized evaluation models: the smooth and interproximal surface model, which assesses the cleaning ability of both smooth and interproximal surfaces, and the single half cylinder model (SHC model), which measures the following ability of toothbrush bristles on convex surfaces. The results indicated that toothbrush G had equal or greater performance than toothbrush S across all tested angles in the smooth and interproximal surface model. The minimum following load necessary for effective cleaning without bristle bounce, was significantly lower for toothbrush G (1.25 N) than for toothbrush S (3.84 N), suggesting that toothbrush G is less dependent on brushing technique and more suitable for a wide range of individuals, regardless of their brushing skills. Currently, few comprehensive and objective evaluation methods for toothbrush function have been reported using standardized evaluation methods. Moreover, a single evaluation model to assess toothbrush function might be inadequate due to varying oral cavity morphologies. However, the use of multiple models could potentially address this challenge. This study used two models to clearly demonstrate the performance differences between toothbrushes. This method could serve as a standard for the comprehensive evaluation of toothbrush functionality.