Lee Bor Shiunn, Lin Chun Pin, Lin Feng Huei, Lan Wan Hong
Department of Dentistry, National Taiwan University Hospital, Taipei 10016, Taiwan.
Lasers Surg Med. 2002;30(3):246-52. doi: 10.1002/lsm.10038.
The use of Nd:YAG laser has been proposed for endodontic treatment. However, its ability to reduce dentin permeability, which is important for the success of root canal treatment, remains controversial.
STUDY DESIGN/MATERIALS AND METHODS: Nd:YAG laser irradiation was performed in pulsed mode on human dentin. The parameters were: pulse energy (100 mJ), rate (10 pps), and total irradiation time (4 seconds). The crystalline phases, electron diffraction patterns, morphology, and microstructure of specimens after laser irradiation were observed by dark-field emission transmission electron microscope (TEM).
Three ultrastructural zones could be delineated in the dentin: (1) an outer zone with an ordered columnar structure composed of hydroxyapatite and beta-tricalcium phosphate, (2) an intermediate zone composed of an amorphous substance (about 40-70 nm in diameter), and (3) an inner zone of well-crystallized hydroxyapatite grains. These three zones were free of pores or voids.
Our study demonstrated that laser-irradiation might be used to reduce dentin permeability.
已有人提出使用钕钇铝石榴石（Nd:YAG）激光进行牙髓病治疗。然而，其降低牙本质渗透性的能力对于根管治疗的成功至关重要，但仍存在争议。
研究设计/材料与方法：对人牙本质进行脉冲模式的Nd:YAG激光照射。参数为：脉冲能量（100 mJ）、频率（10次/秒）和总照射时间（4秒）。通过暗场发射透射电子显微镜（TEM）观察激光照射后标本的晶相、电子衍射图谱、形态和微观结构。
牙本质中可划分出三个超微结构区：（1）外层具有由羟基磷灰石和β - 磷酸三钙组成的有序柱状结构；（2）中间层由无定形物质（直径约40 - 70纳米）组成；（3）内层为结晶良好的羟基磷灰石颗粒。这三个区域均无孔隙或空洞。
我们的研究表明，激光照射可能用于降低牙本质渗透性。
