Effect of root curvature on post length in the restoration of endodontically treated premolars.

Two hundred and eighteen bi-rooted niaxillar\' premolars were examined radiogra]3hicall\' to determine the length from the apex at which root curvature occurred. The information may serve as a guide in determining ]:)ost preparation length. T h e result.s of the study indicated that the lingual root was slightly straighter than the buecal root. 'I'lie curvature of the root was on the average 6.47 mm from the apex on the buecal root and .5.48 mm h-oni the apex on the lingual root. Richard Zillich' and Peter Yaman^ 'University of Michigan. School ot Denfisfry, Deparfmenf of Endodontics. and ^Department of Operafive Denfisfry. Ann Arbor. Ml, USA