Ablation threshold for composite resins and amalgam irradiated with femtosecond pulse laser

Abstract

The dental treatment using laser has been of great interest for many years, since laser interaction with tissue and other materials can be used for cavity preparation. The objective of the present study was to determine the fluency ablation threshold for composite resins and amalgam irradiated with femtosecond pulse laser (Ti:Sapphire). The laser operates at 830 nm, with 50 fs pulse duration and 1 kHz of repetition rate. Different energies were used in the samples irradiation (300 to 770 μJ). The samples were irradiated using with a computerized translation stage and two different methods and the volume ablation was determined by optical coherence tomography. After images analysis obtained by optical microscopy and scanning electron microscopy, the determined ablation threshold fluency was 0,35 J/cm2 for the composite resin Z-100 and Z350, and 0,25 J/cm2 for the amalgam. Thermal damage was not observed in none of the samples.