To provide a method and a device for evaluating bacterial plaque removal performance of a dentifrice using a bacterial plaque model, indicating high conformity with a human validity test and capable of easily and simply evaluating a bacterial plaque removal performance of the dentifrice and a toothbrush.SOLUTION: A method for evaluating bacterial plaque removal performance of a dentifrice comprises the steps of: (A) arranging a head of a toothbrush so as to be perpendicular to a bacterial plaque surface of a bacterial plaque model and determining a fixed point by fixing the head at the contact point of a brush tip of the toothbrush and a bacterial plaque surface； (B) applying the dentifrice to be evaluated to a bacterial plaque model surface brushed by the toothbrush and a brush part of the toothbrush； (C) brushing the bacterial plaque surface of the bacterial plaque model using the toothbrush impregnated with the dentifrice to be evaluated under the conditions that a brushing load is 10 to 500 gf, a reciprocation speed is 80 to 120 rpm, and a reciprocation frequency is 10 to 300 times； and (D) calculating a bacterial plaque removal rate on the basis of a measured value of a residual amount or a removal amount of an alcohol-based ink. A viscosity of the dentifrice to be evaluated is B8H viscosity 2000 dPas s or higher.SELECTED DRAWING: Figure 2【課題】ヒト有効性試験と高い一致性を示し、簡単かつ簡便に歯磨剤や歯ブラシの歯垢除去性能を評価することのできる、歯垢モデルを用いた歯磨剤の歯垢除去性能の評価方法、および評価用装置を提供する。【解決手段】（Ａ）歯ブラシのヘッドを歯垢モデルの歯垢面に対して垂直となるように配置し、かつ歯ブラシのブラシ先端部と歯垢面の接触点で固定して固定点を決定する工程、（Ｂ）歯ブラシの刷掃する歯垢モデル表面および歯ブラシのブラシ部に評価対象の歯磨剤を塗布する工程、（Ｃ）評価対象の歯磨剤を染み込ませた歯ブラシで、歯垢モデルの歯垢面を刷掃荷重１０～５００ｇｆ、往復速度８０～１２０ｒｐｍ、および往復回数１０～３００回の条件で刷掃する工程、（Ｄ）アルコール系インキの残存量又は除去量の測定値をもとに、歯垢除去率を計算する工程を備え、評価対象の歯磨剤の粘度をＢ８Ｈ粘度２０００ｄＰａｓ・ｓ以上とする。【選択図】図２
