This document discusses the WaveOne single-file reciprocating system for shaping root canals. It describes how WaveOne files utilize unequal clockwise and counterclockwise angles of rotation to optimize cutting efficiency while reducing risks. A single WaveOne file is generally sufficient to fully shape any canal. The document outlines guidelines for proper use of the WaveOne system, including creating a glide path, selecting the correct file size, irrigating after each cutting cycle, and using the file in a slow reciprocating motion until the working length is reached.