Effects of four instrumentation techniques on curved canals: a comparison study.
Standardized canals (42 degrees curvature) in clear resin blocks were instrumented from size #15 to #35 by four different instrumentation techniques [SW (Senia-Wildey) instrumentation technique, "balanced force" technique, "step back" technique, and a technique combining a reaming motion and the "balanced force" technique] using Flexoreamer Batt-tip, Flex-R file, or K-Flexofile Batt-tip. Changes in canal shape were investigated under standardized conditions using a computer driven testing device. Changes in shape differed significantly (p < 0.05) between the three instruments and between the four techniques (p < 0.0001) in all of the 14 measuring points. Best results were obtained when the curved canals were first enlarged with Flexoreamer Batt-tip or Flex-R file #15 and #20 using a reaming motion followed by #25 to #35 instruments using the "balanced force" technique. Overall, under the conditions of this study, this combined technique provided satisfactory canal preparation with no ledging or canal transportation.
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Poliklinik fuer Zahnerhaltung A, Münster, Germany.
D003786:Dental Pulp Cavity / Q000033:anatomy & histology; D006801:Humans; D008961:Models, Structural; D015203:Reproducibility of Results; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods*