Crown-Down Preparation: Gradual Tapering of the Root Canal
THE NEXT DDS
Upon watching this video, the viewer should:
the basics of the “crown-down” style technique
how to begin the process of remodeling the inner canal of the tooth
The primary goal of the crown-down preparation technique is to produce a
gradually tapering shape in the bulk of the root canal system, with the
narrowest diameter apically and the greatest diameter coronally. There should
be a smooth flow between the two coronal and apical sections. The preparation in
the apical 1/3 should be at least at a size 30 to allow good irrigant
penetration and facilitate obturation.
Following hand instrumentation, nickel-titanium instruments are rotated
at 150 to 350 rpm in a speed-reduction handpiece using an electric
torque-controlled motor. Instruments should be used sequentially in a crown
down manner. This will facilitate obturation. During mechanical preparation the
canal is repeatedly irrigated with sodium hypochlorite solution.
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