A comparison of the sealing properties of different retrograde techniques: an autoradiographic study.

Single-rooted teeth were instrumented and filled in vitro with a lateral condensation of gutta-percha with sealer. Following obturation, the tooth apices were treated by various retrograde procedures. The teeth were then coated with ethyl acetate, immersed in 45Ca solution, washed, and sectioned, and autoradiographs were used to compare the leakage of the various techniques. Statistical analysis indicated that lateral condensation produced a significantly better seal than any retrograde technique tested except retrofilling with Super EBA cement and that a significantly worse seal was obtained with amalgam retrofill when compared to all retrograde techniques except cold-burnished gutta-percha following apicoectomy. No significant difference existed between other group combinations.