The invention provides a cannula for a multifunction dental syringe, the cannula comprising a fastener bushing (1200) that is defined by a circular opening (1210), an end wall (1220), and a side wall comprising a circular cylinder, the cannula also including at least two channels (1120) enabling fluids to be conveyed separately or together from said end wall (1220, 1125) to fluid projection orifices, the two channels beginning in said end wall (1220) beside each other, the cannula being characterized in that the circular cylinder presents a cutout (D) in the thickness of its wall, which cutout comprises, going from the opening (1210): at least one segment (1265) extending in a direction other than the axial direction of the cylinder followed by a longitudinal segment (1270) extending towards the end wall (1220).本發明提供一種用於多功能牙科注射器之插管,該插管包括由一圓形開口(1210)、一端壁(1220)及一側壁界定之一扣件套管(1200),該側壁包括一圓形圓柱,該插管亦包含至少兩個通道(1120),其使得流體從該端壁(1220、1125)單獨或一起輸送至流體注入孔口,始於該端壁(1220)之該等兩個通道彼此相鄰,該插管特徵在於該圓形圓柱具有在其壁厚度中之一切口(D),始於該開口(1210)之該切口包括:在不同於該圓柱之軸向方向之一方向上延伸之至少一段(1265);接著是朝該端壁(1220)延伸之一縱向段(1270)。1000‧‧‧插管1100‧‧‧管1120‧‧‧通道1125‧‧‧通道1200‧‧‧扣件套管1210‧‧‧開口1220‧‧‧端壁1290‧‧‧加固件/接合構件1300‧‧‧加固件/接合構件/拱形部1400‧‧‧加固件/接合構件/角支架D‧‧‧切口
