Division of Cariology and Endodontology, CUMD - University Clinics of Dental Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland,
Division of Cariology and Endodontology, CUMD - University Clinics of Dental Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
Am J Dent. 2024 Feb;37(1):39-46.
To investigate the differences between irrigant propagation and temperature changes using laser-activated irrigation (LAI) at different settings in an artificial root canal model.
Using an artificial resin root canal model, irrigant activation was achieved in 19 experimental groups with eight samples each. A 9,300 nm CO₂ laser, two diode lasers with different settings (wavelengths 455, 808, 970, and 980 nm) were compared to 2,940 nm Er:YAG laser and traditional needle irrigation. Er:YAG and CO₂ laser were activated in the pulpal chamber only, while diode lasers and needles were inserted into the main root canal. Lasers were activated for 5x 20 seconds resulting in 100 seconds of activation or rinsing for each sample. After each activation of 20 seconds, a photo was taken of the side canals and the propagation of the dye was measured with a digital measuring tool after calibration. Further, the temperature of the irrigant was reported after activation of 20 seconds and repeated 5 times. Data were checked for normality and statistically compared.
All lasers increased the irrigant propagation compared to conventional irrigation. Significant differences were found between groups regarding propagation and temperature (P< 0.0027). Er:YAG and CO₂ laser had similar effects on irrigant propagation in middle and apical located side-canals with specific power parameters and were superior to diode lasers and syringe irrigation. The irrigant's temperature increased significantly with the diode and CO₂ lasers.
Diode lasers and CO₂ lasers have not been established for irrigant activation. 9,300 nm CO₂ lasers absorb well in water and were shown to introduce vapor bubble formation and streaming in water. Diode lasers are highly accepted in periodontics. The laser light is not absorbed in water but interacts with bacteria as well as soft tissues and contributes therefore to infection control. With a modified laser tip it was however possible to introduce cavitation and streaming in irrigants.
在人工根管模型中，用不同设置的激光激活冲洗（LAI）来研究冲洗剂的传播和温度变化的差异。
使用人工树脂根管模型，在 19 个实验组中，每个组有 8 个样本。比较了 9300nm CO₂ 激光、两种不同设置的二极管激光（波长 455、808、970 和 980nm）与 2940nm Er:YAG 激光和传统的针冲洗。Er:YAG 和 CO₂ 激光仅在牙髓腔内激活，而二极管激光和针则插入主根管。激光每 20 秒激活 5 次，每次激活 100 秒。每次激活 20 秒后，对侧支进行拍照，并在标定后用数字测量工具测量染料的传播。进一步，在 20 秒激活后报告冲洗剂的温度，并重复 5 次。检查数据是否正态分布，并进行统计学比较。
与传统冲洗相比，所有激光都增加了冲洗剂的传播。在传播和温度方面，各组之间存在显著差异（P<0.0027）。在中侧支和根尖侧支中，特定功率参数的 Er:YAG 和 CO₂ 激光对冲洗剂的传播有类似的影响，优于二极管激光和注射器冲洗。二极管激光和 CO₂ 激光使冲洗剂的温度显著升高。
二极管激光和 CO₂ 激光尚未被确立用于冲洗剂激活。9300nm CO₂ 激光在水中吸收良好，并显示出形成蒸汽泡和水的流动。二极管激光在牙周病学中被广泛接受。激光光在水中不被吸收，但与细菌以及软组织相互作用，因此有助于控制感染。然而，通过修改激光尖端，可以在冲洗剂中引入空化和流动。
