The dental handpiece has a handpiece body having a mixture transfer line for transferring a mixture of air and powder, and a nozzle connected to the handpiece body for injecting the mixture transferred through the mixture transfer line, and performs dental treatment by injecting the mixture onto tooth surface. The nozzle is rotatably connected to the handpiece body via rotary means. With this nozzle connection, during subgingival treatment with the nozzle being inserted subgingivally at its end and moved along the tooth surface, the entire handpiece body is not required to be moved from side to side over a wide amplitude, which improves work efficiency in dental treatment.
