Kreifeldt J G, Hill P H, Calisti L J
J Dent Res. 1980 Dec;59(12):2047-55. doi: 10.1177/00220345800590120401.
This study described a new in vivo methodology for measuring and comparing plaque removal efficiencies of different toothbrush designs and used it to quantify the loss of plaque removal efficiency of worn toothbrushes, as well as to elucidate the causes. Worn toothbrushes produce statistically significant and large decreases in plaque removal ability depending upon their state of wear. While both bristle matting and bristle tapering contribute to this loss, the former appears to be the more potent. Thus brush designs that are resistant to bristle matting should show markedly superior durability. An indirect conclusion from the bristle tapering results is that the softer a brush, the less plaque it will remove. As a practical conclusion, it is recommended that a standard toothbrush be discarded when it shows signs of matting, regardless of age.
本研究描述了一种新的体内测量方法，用于测量和比较不同牙刷设计的菌斑清除效率，并使用该方法量化磨损牙刷菌斑清除效率的损失，以及阐明其原因。磨损的牙刷根据其磨损状态会在统计学上产生显著且大幅的菌斑清除能力下降。虽然刷毛缠结和刷毛变细都会导致这种损失，但前者似乎影响更大。因此，抗刷毛缠结的牙刷设计应具有明显更优的耐用性。从刷毛变细的结果得出的一个间接结论是，牙刷越软，清除的菌斑就越少。作为一个实际结论，建议无论使用时长，当标准牙刷出现缠结迹象时就应丢弃。
