Investigations on the potential of a novel diode pumped Er:YAG laser system at high mean laser power for hard tissue preparation in dentistry

摘要

Several studies have shown the potential of the diode pumped Er: YAG laser for medical applications. Benefits are the efficient and precise ablation of both hard and soft tissue with adjustable thermal effects. Aim of this study is the investigation of the ablation process on dentin and enamel using the diode pumped Er:YAG laser even at higher mean laser power and two different handpieces (free beam vs. contact). At first the laser radiation of the diode pumped Er:YAG laser (DPM-25, PANTEC Engineering AG) was coupled into a standard dental fiber delivery system (KEY3 laser, KaVo GmbH) with the two handpieces for cavity preparation. An appropriate experimental setup was realized including a computer controlled translation stage with sample holder to move the dentin or enamel slides of extracted human teeth with a defined velocity while irradiation by various laser parameters. After irradiation, the cut kerfs were analyzed by light microscopy and laser scanning microscopy. The results show a good ablation quality for both handpieces and a higher ablation rate in dentin and enamel using the non-contact handpiece compared to the contact handpiece. The calculated ablation efficiency is remarkable high (dentin: 0.094 - 0.172 mm~3/J, enamel: 0.025 - 0.093 mm~3/J) and exceeds all published values. The results of the high-speed camera observations explain the differences between the handpieces. In conclusion these experiments with the diode pumped Er:YAG laser system demonstrate its ability for efficient and very fast cavity preparation.