Study on basic factors influencing cleaning effect of toothbrushing

本研究旨在探讨影响刷牙清洁效果的因素，以确定最佳的刷牙条件，使牙齿表面得到充分的清洁。利用专用刷洗机，根据摩擦功原理，研究了表面形状、刷毛韧性、刷洗行程、角度和刷洗力对刷洗效果的影响。根据这些结果，测量刷毛的弹性特性。通过临床研究和机器测试，确定了最佳刷牙条件。从这些研究的结果中，得出以下结论.刷牙的清洁效果受牙齿表面的形状、刷毛的韧性以及刷牙的行程、角度、力度、速度和频率的影响。一般情况下，表面形状、刷毛行程、角度和刷毛力之间存在交互作用，这些因素的影响随其他因素的变化而变化。2.在某些特定条件下，刷毛几乎不接触凹面（即，e.涂刷角度：90 °，力：200 gf）。在前磨牙和磨牙的凸面上，在某些特定的条件下（如：e.涂刷角度：90 °，行程：10 mm，力：400 gf）。这些可能是刷牙后牙菌斑残留的主要原因.为了在凸面和凹面上获得高清洁效果，建议使用以下条件。1)涂刷角度：90度，刷毛：高硬度，刷洗力：300- 400 gf，刷洗行程：10 mm和20 mm均用，2）刷洗角度：90 °，刷毛：高硬度，刷洗行程：10 mm，刷洗力：200 gf和400 gf均用，3）刷洗角度：45 °，刷毛：高硬度，刷洗力：300- 400 gf（在这种情况下，可能需要更长的刷牙时间。）

The purpose of the present study was to inveatigate the effects of some factors on cleaning by toothbrushing, and determine optimum conditions to sufficiently clean tooth surfaces. Using a special brushing machine, the effects of the surface configuration, the toughness of brush bristles, and the stroke, angle and force of brushing on the cleaning were investigated based on the principles of friction work. In relation to these results, the elastic properties of the bristles were measured. A clinical study and the machine testing were carried out to determine the optimal conditions of toothbrushing. From the results of these studies, the following conclusions are drawn.1. The cleaning effect of toothbrushing is affected by the configuration of a tooth surface, the toughness of bristles, and the stroke, angle, force, speed and frequency of brushing. Ingeneral, the surface configuration, the brushing stroke, angle, and force have interactions each other, and thus the effects of these factors vary with the change of the other factors. 2. The bristles hardly contact the concave surfaces under some specific conditions (i. e. brushing angle : 90ﾟ, force : 200gf). On the convex surfaces of a premolar and a molar, the contact and the frictional movement of the bristles are very little under some specific conditions (i. e. brushing angle : 90ﾟ, stroke : 10mm, force : 400gf). These may be the main reasons for remaining plaque after brushing.3. The following conditions are recommended to obtain high cleaning effect both on convex and concave surfaces. 1) brushing angle : 90ﾟ, bristles : high stiffness, brushing force : 300-400gf, brushing stroke : use both 10mm and 20mm, 2) brushing angle : 90ﾟ, bristles : high stiffness, brushing stroke : 10mm, brushing force : use both 200gf and 400gf, 3) brushing angle : 45ﾟ, bristles : high stiffness, brushing force : 300-400gf (In this case, longer brushing time may by required.)