This document discusses the history, physics, and applications of ultrasonics and sonics in endodontics. It begins with definitions of key terms like ultrasound, ultrasonic instrumentation, and endosonics. It then covers the physics behind ultrasonics and sonics, including how piezoelectric and magnetostrictive transducers work. Biophysical effects like cavitation and acoustic streaming are also discussed. The document concludes by outlining various ultrasonic tips categorized by approach (surgical vs nonsurgical) and use (access, removal, etc.), and applications in endodontic procedures.