Apparatus and methods for endodontic treatment of teeth provide effective cleaning of organic material (such as pulp and diseased tissue) from the root canal system. In an embodiment, a compressor system generates high pressure liquid (e.g., water) that flows through an orifice to produce a high-velocity collimated jet of liquid. The high-velocity jet is directed toward a surface of a tooth, for example, an exposed dentinal surface, and impingement of the jet onto the surface generates an acoustic wave that propagates throughout the tooth. The acoustic wave effectively detaches organic material from dentinal surfaces and tubules. The detached organic material is flushed from the root canal system by the liquid jet and/or by additional irrigation.
