The adaptation achieved by four root canal filling techniques as assessed by three methods

Four root canal filling techniques--lateral condensation, McSpadden compaction, ultrasonic activation (Enac), and thermoplastic injection (Ultrafil)--were assessed for adaptation of the filling material to the canal wall. The adaptation and leakage were examined quantitatively using an electrochemical method and a linear dye penetration method, and qualitatively by radiographic evaluation. Using the electrochemical method, differences among obturation techniques were relatively small, although a greater proportion of the teeth that had been filled by lateral condensation exhibited no leakage. Radiographically, the techniques appeared to exhibit similar adaptation in the apical 6 mm. The techniques of lateral condensation and ultrasonic activation showed superior control of length of the root canal filling.