title: Resistance form in tooth preparation.
abstract: Theoretical and clinical studies of resistance form are reviewed, supporting the basic prosthodontic principle that resistance form is an essential element in preparation design. Concepts of the"on-off" nature of resistance form, its application in guidelines for minimally acceptable preparation taper, and the controversy over whether there is a relationship with clinical success or failure are discussed. It is more challenging to obtain resistive molar preparations than resistive anterior preparations, and uneven preparation margins can make parallel 0 degree taper preparations lack resistance form. The usefulness of grooves, especially in molar preparations with uneven margins, is illustrated. The Lewis and Zuckerman techniques for evaluating resistive areas of a preparation are shown to be consistent with each other but not with the Weed method.
authors.affiliation: Department of Veterans Affairs Medical Center,Uptown Division, Dental Clinic, and Department of Oral Rehabilitation, Medical College of Georgia School of Dentistry, Augusta, USA. Harryparker1@comcast.net
authors.forename: M Harry
authors.initials: MH
authors.lastname: Parker
mesh_terms: D003442:Crowns; D000044:Dental Abutments; D017268:Dental Prosthesis Retention / Q000379:methods*; D019232:Dental Restoration Failure; D006801:Humans; D008963:Molar / Q000033:anatomy & histology; D019246:Tooth Preparation / Q000379:methods*