Cutting ability of Heliosonic, Rispisonic, and Shaper files.

The aim of this study was to investigate the cutting ability of the Heliosonic, Rispisonic, and Shaper files supplied with the MM 1500 sonic handpiece. A model system was used and the following variables evaluated; file type (Heliosonic, Rispisonic or Shaper), power (air inlet ring opening of half, three quarters or fully open), width (15, 25 or 35), and load (25, 50 or 100 grams). A 3(4) full factorial analysis with two replications was performed. A new file with water irrigation was used for each cut. The substrate used was 1 mm thick sections of bovine bone. The differences between the variables were significant (ANOVA, p < 0.001). The most significant variable to affect cutting was load, followed by file type, power, and width. It is suggested that operators should select the file type for use appropriately and press the file against the root canal wall for optimum cutting.