Kim Mee-Eun, Jeoung Deuk-Jin, Kim Ki-Suk
University Dental School, Chunan, Choongnam, Korea.
J Clin Laser Med Surg. 2003 Jun;21(3):139-44. doi: 10.1089/104454703321895581.
The aim of this study was to investigate the effect of water on dental hard tissue ablation using Er:YAG laser as it relates to energy and pulse repetition rate, and determine the water flow rate that produces the most effective ablation at a given irradiation condition.
Er:YAG laser application leads to volumetric expansion and micro-explosions that result in hard tissue ablation. Ablation efficiency is improved when combined with fine water spray.
Extracted, healthy human molars were sectioned into two pieces and categorized into small groups related to water flow rate (1.69, 6.75, and 13.5 mL/min), pulse energy (250 and 400 mJ), and pulse repetition rate (5, 10, and 20 Hz). Within the combination of irradiation parameters, a laser beam was applied over enamel and dentin surfaces of the specimens, and the ablation amount was determined by differences in weight before and after irradiation.
At a pulse energy of 250 mJ, the most effective ablation resulted from a water flow rate of 1.69 mL/min in both enamel and dentin. With 400 mJ/pulse, dentin removal was most effective at the water flow rate of 1.69 mL/min, whereas the efficiency of enamel ablation was the highest at 6.75 mL/min. Dental hard tissue ablated better as energy and pulse repetition rate increased.
Effective ablation of dental hard tissue using Er:YAG laser requires that the appropriate water flow rate correspond properly to irradiation conditions. The results of this study suggest the following parameters; a water flow rate of 1.69 mL/min for enamel and dentin ablation at a pulse energy of 250 mJ and for dentin ablation at 400 mJ/pulse, and a water flow rate of 6.75 mL/min for enamel ablation at a pulse energy of 400 mJ, regardless of pulse repetition rate of 5, 10, and 20 Hz.
本研究旨在探讨水对使用铒钇铝石榴石（Er:YAG）激光进行牙齿硬组织消融的影响，该影响与能量和脉冲重复率相关，并确定在给定照射条件下产生最有效消融的水流速率。
Er:YAG激光的应用会导致体积膨胀和微爆炸，从而导致硬组织消融。与精细喷水相结合时，消融效率会提高。
将拔除的健康人磨牙切成两片，并根据水流速率（1.69、6.75和13.5 mL/分钟）、脉冲能量（250和400 mJ）和脉冲重复率（5、10和20 Hz）分为小组。在照射参数组合内，将激光束照射在标本的釉质和牙本质表面上，并通过照射前后的重量差异确定消融量。
在250 mJ的脉冲能量下，1.69 mL/分钟的水流速率在釉质和牙本质中均产生了最有效的消融。在400 mJ/脉冲时，牙本质去除在1.69 mL/分钟的水流速率下最有效，而釉质消融效率在6.75 mL/分钟时最高。随着能量和脉冲重复率的增加，牙齿硬组织的消融效果更好。
使用Er:YAG激光有效消融牙齿硬组织需要适当的水流速率与照射条件相匹配。本研究结果表明以下参数：在250 mJ的脉冲能量下，用于釉质和牙本质消融以及400 mJ/脉冲时牙本质消融的水流速率为1.69 mL/分钟，在400 mJ的脉冲能量下，用于釉质消融的水流速率为6.75 mL/分钟，无论脉冲重复率为5、10和20 Hz。
