Quality of Restorations Performed with QSP Mode

SUMMARY Er:YAG lasers represent a promising technology with various applications in every field of Dentistry. Compared with other lasers, Er:YAG can effectively alter enamel and dentin surface because of its 2940 nm wavelength emission, which is coincident with the main absorption band of water and OH- groups in hydroxyapatite.[1] Laser irradiation parameters define the exact interaction of the laser on the tissue. Pulse duration is an important factor for the ability of a laser to perform surface modification.[2] Active electronic control of laser pulse duration and amplitude is possible today with the development of Variable Square Pulse® technology (Fotona, Ljubljana, Slovenia). With VSP, the duration of pulses can be adjusted from 50 μs (super-short pulse) to 100 μs (very short pulse), 300 μs (short pulse), 600 μs (long pulse) and 1,000 μs (very long pulse). Because of its higher energy in the shorter pulses, the energy loss through heat is lower. As a result of this, ablation becomes more effective and a thermal effect is not evident on the tissue.[3]