Purpose: The effect of diode laser treatment on the sealing ability of several retrograde filling materials was examined. Materials and methods: One hundred eight bovine root sections, each 3 mm thick and with a central lumen 2.6 mm in diameter were prepared and divided in two equal groups of 45 specimens each; the remaining 20 roots served as positive and negative controls. The lumen of the first group was lased, and 15 specimens from each group were filled with amalgam, another 15 with glass-ionomer cement, and the rest with ZnO-eugenol cement. After setting, leakage was measured at 2 h, 3 months, and 6 months using a fluid transport model. Results: More leakage was recorded on the lased specimens compared to the control group for all materials tested and for all time intervals with the exception of glass-ionomer cement specimens (of both subgroups), which showed no leakage at the first time interval (24 h). Conclusion: Because of detrimental effects on apical sealing, diode laser should not be used to treat retrograde cavities in apicoectomies.
Keywords: diode laser, apical sealing, retrograde, leakage, sealing ability, amalgam, IRM, glass ionomer