Glide path and apical width

The purpose of an endodontic treatment is to prevent or heal lesions of endodontic origin. In order to achieve this purpose the root canal system must be filled and sealed three dimensionally. For 3D obturation, the root canal system has to be successfully shaped and cleaned. For achieving this goal, a continuous tapering funnel shape preparation flowing with shape of the original canal from the coronal access to the apex must be achieved. The primary and one of the most important requisite for achieving predictable shaping is establishment of glide path. This glide path serves as the starting point for radicular preparation, without which proper cleaning and shaping becomes unpredictable or impossible.