A kind of electric rotary interdental brush and its fixation device； Wherein electric rotary interdental brush system include lower fixed seat,Upper fixed lid is formed with rotary teeth space brush head and ontology； Lower fixed seat on fixed device system teeth space brush head is combined with what upper fixation was covered,Lower fixed seat is pivoted on the axis of what teeth space brush head,It is rotated by the linkage driving in teeth space brush head,Lower fixed seat is equipped with the axial direction of interdental brush and the L-type fixing groove of horizontal handover,And clamp together fixed lid slides laterally groove,The slot that upper fixed lid has sliding shoe relatively and interdental brush axial restraint slot is allowed to wear thoroughly,Slot extends into horizontal side channel to side at long hole shape one end,In order it is fixed cover on lower fixed seat transverse shifting,To limit the opening and closing of the horizontal fixing groove of lower fixed seat.一種旋轉式電動牙縫刷暨其固定裝置；其中旋轉式電動牙縫刷係包含下固定座、上固定蓋與旋轉式牙縫刷頭及本體組成；固定裝置係牙縫刷頭上之下固定座與上固定蓋之組合，下固定座樞設於牙縫刷頭之軸上，受牙縫刷頭內之連動裝置驅動得以旋轉，下固定座設有牙縫刷之軸向與水平交接之L型固定槽，以及鉗合上固定蓋之橫向滑動溝槽，上固定蓋相對具有滑動塊及讓牙縫刷軸向固定槽透穿之槽孔，槽孔成長孔狀其一端向一側延伸成水平側槽，令上固定蓋得在下固定座上橫向移動，以限制下固定座水平固定槽之啟閉。
