The 'balanced force' concept for instrumentation of curved canals revisited.
The principal characteristics of K-type files are described and the succession of operations as prescribed by the 'balanced force' method of preparation of root canals, particularly curved root canals, examined. On the basis of a simple mathematical model, the motions of a file in a straight canal and in a curved canal are successively considered, and the merits of the recommended method highlighted and confirmed.
D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D003799:Dental Stress Analysis; D006801:Humans; D008962:Models, Theoretical; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*; D014092:Tooth Root / Q000033:anatomy & histology*