Authors: Schilder H.
Title: Cleaning and shaping the root canal.
Journal: Dent Clin North Am
Date: Apr 1974
Citation: 18(2):269-96
Category: Access and Canal Instrumentation
Evidence-based Ranking: 5
Purpose/Objectives: This is a textbook chapter in DCNA which describes past and present (for the time it was written) considerations in cleaning and shaping the root canal system. Discussion: This paper presents the author’s ideas on cleaning and shaping theories and methods. He states that in order to achieve a predictable outcome, the “root canal system must be cleaned and shaped; cleaned of their organic remnants and shaped to receive a three-dimensional hermetic filling of the entire root canal space.” Cleaning includes the removal of all organic debris which could possibly serve as substrate for bacterial growth or as the source of periapical inflammation due to seepage of proteolytic breakdown products. Shaping implies the development of a unique shape for the root canal, directly related not only to the length but to the position and curvature of each individual root and root canal. He then discusses cleaning and shaping mechanics (design objectives for gutta percha cases, tapering funnel preparation, cross-sectional diameter, canal preparation and original canal, position of the foramen, small apical opening), design objectives for silver cone cases, biologic objectives of cleaning and shaping (confine instrumentation to the root canals, beware of forcing necrotic material beyond the foramen during canal preparation, remove all tissue debris from the root canal system, try to complete the cleaning and shaping of single canaled teeth in one visit and, whenever possible, prepare multi-canaled teeth one at a time, create sufficient space during canal enlargement to receive intracanal medicaments and to accommodate small amounts of periapical exudate), instruments for cleaning and shaping (barbed broaches, reamers and files, engine driven instruments, instrument stops), radiographic control, clinical preparation of root canals (serial reaming and filing and recapitulation), clinical preparation to receive gutta percha and silver cones. Reviewer’s Comments: This paper is a good comprehensive review of the basics of canal preparation. With the advent of NiTi rotary instrumentation, many of these ideas don’t apply, but there are many of the basic concepts and objectives that still hold true.