Zakrzewski Wojciech, Dobrzynski Maciej, Kuropka Piotr, Matys Jacek, Malecka Malgorzata, Kiryk Jan, Rybak Zbigniew, Dominiak Marzena, Grzech-Lesniak Kinga, Wiglusz Katarzyna, Wiglusz Rafal J
Department of Experimental Surgery and Biomaterial Research, Wroclaw Medical University, Bujwida 44, 50-345 Wroclaw, Poland.
Department of Conservative Dentistry and Pedodontics, Wroclaw Medical University, Krakowska 26, 50-425 Wroclaw, Poland.
Materials (Basel). 2020 Jul 7;13(13):3027. doi: 10.3390/ma13133027.
Recently, the defects of the tooth surface in the cervical region are often restored using composite filling materials. It should meet the needs of the patients regarding esthetics and material stability. The aim of the study was to analyze the tooth root surface at the cervical region after the removal of the composite filling material by means of the Erbium-doped Yttrium Aluminium Garnet (Er: YAG) laser or drill using the scanning electron microscopy (SEM) and fluorescence microscopy.
For the purposes of this study, 14 premolar teeth ( = 14) were removed due to orthodontic reasons. The rectangular shape cavities with 3 mm in width and 1.5 mm in height were prepared with a 0.8 mm bur on high-speed contra-angle in the tooth surface just below cemento-enamel junction (CEJ) and filled with the composite material. The composite material was removed with the Er: YAG laser at a power of 3.4 W, energy 170 mJ, frequency 20 Hz, pulse duration 300 μs, tip diameter 0.8 mm, air/fluid cooling 3 mL/s, and time of irradiation: 6 sec, at a distance from teeth of 2 mm (G1 group, = 7) or a high-speed contra-angle bur (G2 group, = 7). After the removal of composite material, the surfaces of teeth were examined using the scanning electron microscopy (SEM) and fluorescence microscopy.
The Er: YAG irradiation allowed to remove completely the composite material from the tooth cavity. The study confirmed, that the ends of collagen fibers were only partially denatured after the Er: YAG laser application.
It has been proved that using the Er: YAG laser is an effective and safe method of composite removal for the dentin surface.
近年来，颈部区域牙面缺损常采用复合充填材料修复。修复应满足患者在美观和材料稳定性方面的需求。本研究旨在通过扫描电子显微镜（SEM）和荧光显微镜，分析使用掺铒钇铝石榴石（Er:YAG）激光或牙钻去除复合充填材料后颈部区域的牙根表面情况。
本研究中，因正畸原因拔除14颗前磨牙（n = 14）。在牙骨质-釉质界（CEJ）下方的牙面上，用0.8 mm的高速车针制备宽3 mm、高1.5 mm的矩形窝洞，并用复合材料充填。采用功率3.4 W、能量170 mJ、频率20 Hz、脉冲持续时间300 μs、尖端直径0.8 mm、空气/液体冷却3 mL/s、照射时间6秒、距牙齿2 mm的Er:YAG激光去除复合材料（G1组，n = 7），或用高速车针去除（G2组，n = 7）。去除复合材料后，用扫描电子显微镜（SEM）和荧光显微镜检查牙齿表面。
Er:YAG激光照射可完全去除牙洞内的复合材料。研究证实，应用Er:YAG激光后，胶原纤维末端仅部分变性。
已证明使用Er:YAG激光是去除牙本质表面复合材料的一种有效且安全的方法。
