Er:YAG激光去除Zenostar T全瓷冠的能量评估方法研究

目的 评估Er:YAG激光作用于不同厚度Zenostar T全瓷修复样品后的温度变化情况,探讨激光能量、材料厚度和温度变化之间的相关性,为临床使用Er:YAG激光去除Zenostar T全瓷冠提供初步的依据与指导.方法 选择Zenostar T全瓷修复材料,制成长和宽均为10 mm,厚度分别为1.0 mm、1.5 mm...

Energy assessment of Zenostar T all-ceramic crown removal using Er:YAG laser

Objective Improper energy setting may cause irreversible damage to oral tissue when Er:YAG laser was used to remove all-ceramic crowns.This study aimed to evaluate the temperature variation in Zenostar T samples of different thicknesses irradiated by Er:YAG laser,investigate the relationship between the changes in laser energy,material thickness,and temperature,and provide preliminary energy selection guidance for clinical practice in using Er:YAG laser to remove Zenostar T all-ceramic crowns.Methods All samples used in this experiment were Zenostar T all-ceramic materials,which were cut into squares of 10 mm×10 mm with thicknesses of 1.0 mm,1.5 mm,2.0 mm,2.5 mm,and 3.0 mm.Three samples of each thickness group were prepared.The chemical elements and groups of the samples were analyzed by X-ray energy spectroscopies and FTRI.SEM was used to observe the sample surface morphology changes before and after laser irradiation.Er:YAG laser with a wavelength of 2940 nm,a repetition rate of 15 Hz,and a pulse duration of 330μs was used.The laser spot diameter was 1.0 mm,and the laser irradiation duration was 5 s each time.The laser energy was irradiated three times at different positions of each sample,and the energy and temperature of the laser after penetrating the sample was recorded each time.Results With the increase of the laser energy,the r2 of energy results in the experiment groups were 0.9997、0.9973、0.9790,and the r2 of temperature results were 0.9883、0.9868、0.9950.The research showed that energy and temperature had an exponential fitting curve relationship with the sample thickness under the same energy.The SEM results showed that the structure of Zenostar T samples was damaged by laser irradiation.Conclusions When all ceramic crowns will be removed by Er:YAG laser,laser energy can be preliminarily estimated on the basis of the exponential curve fitted in the experimental results.