PROBLEM TO BE SOLVED: To provide a dental handpiece by which flow rate of powder sprayed can be stabilized with increased retainability for a long time even while enhancing cutting efficiency.SOLUTION: A pair of two nozzles 37 are provided along the inner circumferential surface 21a of a concavity 21, air is blown out in a space from a blowout hole 37a provided at a tip end portion of the nozzle from a side where the nozzle 37 is provided to be directed to an opposite side along the inner circumferential surface of the space and the powder contained in the concavity 21 is blown up in the space, whereby the condition of the powder mixed with the air within the space is improved. Further, the powder near the surface of the accumulated powder of the concavity 21 is blown up by the air blown out from the blowout hole formed in the side face of the nozzle 37 in the case where the amount of the powder contained in the concavity 21 is large. Furthermore, the powder is blown up from the bottom portion 21c in the concavity 21 by the air blown out from the blowout hole formed in the side face of the nozzle 37 in the case where the residual amount of the powder in the concavity 21 is reduced.COPYRIGHT: (C)2009,JPO&INPIT【課題】切削効率を高めながらも、粉末の噴出流量の安定化を図り、粉末の持ちを向上させることのできる歯科用ハンドピースを提供することを目的とする。【解決手段】二本一対のノズル37を凹部21の内周面21aに沿うように設け、先端部の吹出孔37aから、空間においてノズル37が設けられた側から反対側に向けて空間の内周面に沿うように空気を吹き出し、空間内において凹部21に収容された粉末を舞い上げ、空間内の空気との混合状態を良好なものとする。さらに、凹部21内に収容された粉末の量が多い状態の場合、ノズル37の側面に形成した吹出孔から吹き出す空気により、凹部21内に堆積した粉末の表面近傍の粉末を舞い上げる。凹部21内の粉末の残量が少なくなった状態では、ノズル37の側面に形成した吹出孔から吹き出した空気により、凹部21内の底部21cから粉末を舞い上げる。【選択図】図3
