Removal of resin cement using a picosecond laser: An in vitro study.

Abstract

Statement of problem: The rapid and safe removal of resin cement from tooth surfaces is challenging. Whether removal with a picosecond laser might providing a practical solution is unclear.

Purpose: The purpose of this in vitro study was to explore the effect and mechanism of a picosecond laser acting on resin cement and whether the dental tissue is damaged.

Material and methods: A 50-μm-thick layer of resin cement was prepared on the enamel surface of extracted teeth. The specimens were scanned with a picosecond laser with different laser power. Pulp temperature was monitored during laser processing, and the surface and section morphology was observed with a 3-dimensional (3D) digital microscopy system and a scanning electron microscope. The ablation depth in the enamel was measured and calculated. Data were statistically analyzed with one-way analysis of variance (ANOVA). A Raman spectrometer was used to analyze component change in the resin cement.

Results: The surface morphology of cement, including volume expansion, color, and dislodgement from the enamel surface, was affected by the power of the laser. Charring was observed after 0.1 W, 0.2 W, and 0.4 W powered laser processing. The mean ablation depth of the enamel was limited to 20 µm. The pulp temperatures in all groups were about 42.5 °C during the laser processing, and an increase in laser power resulted in a rise in the maximum pulp temperature.

Conclusions: A picosecond laser can be used to remove resin cement rapidly and safely. The pulse impact effect and the carbonization effect were both present with laser processing.