PROBLEM TO BE SOLVED: To provide a dental instrument capable of down-sizing a head part.SOLUTION: The dental instrument includes: a sleeve 32 that is provided inside a head part 30 and on which a tooth treatment appliance is mounted and a spindle 22 that is provided inside a grip part 20 connected to the head part and rotates the sleeve. The dental instrument further includes: a gear 44 that connects the spindle to the sleeve and transmits rotation of the spindle to the sleeve and bearings 35 and 36 that are disposed between an end face of the spindle and an outer peripheral face of the sleeve and rotatably support the sleeve in the head part.
