Thermal analysis of laser-softened gutta-percha.

The aim of this work is to examine the behaviour of laser treated gutta-percha (a–b) after heating, to test the validity of a new obturation technique. Samples of laser- and no laser- treated gutta-percha have been examined by the thermal/thermogravimetric analysis and compared. All samples have been submitted to four runs of heating from the temperature of 25–130 C, followed by spontaneous cooling. It was found that some samples have shown the typical behaviour of the alpha-gutta-percha; others have shown characteristics similar to the conventional beta-gutta-percha. The laser treated gutta-percha has shown a significant mass loss after the first run of heating, while the mass tends to stabilize after the third run. It has been demonstrated that the 980 nm diode laser used with cited parameters does not alters thermal behaviour of gutta-percha cones.