Spencer P, Cobb C M, McCollum M H, Wieliczka D M
University of Missouri-Kansas City School of Dentistry, Department of Oral Biology 64108, USA.
J Periodontal Res. 1996 Oct;31(7):453-62. doi: 10.1111/j.1600-0765.1996.tb01409.x.
Morphologic and chemical characterization of root surfaces treated with either the CO2 laser, Nd:YAG, or Nd:YAG with water/air surface cooling (Nd:YAG-C) was completed using scanning electron microscopy (SEM) and FTIR photoacoustic spectroscopy (FTIR/PAS). Specimens for morphologic analysis consisted of 20 extracted single rooted teeth unaffected by periodontal disease. The specimens were exposed at varying energy densities to a single pass of the laser. SEM examination revealed, for all lasers, a direct correlation between increasing energy densities and depth of tissue ablation and width of tissue damage. The Nd:YAG-C required higher energy densities than either the CO2 or Nd:YAG lasers to achieve the same relative depth of tissue ablation. Regardless of energy density, and in contrast with other laser types, areas treated with the Nd:YAG-C did not exhibit collateral zones of heat damage. Specimens for spectroscopic examination consisted of 12 disks, 6 x 2 mm, cut from debrided root surfaces of extracted, unerupted human molars. The spectral results indicate a substantial reduction in the absorption bands attributable to protein and an additional band at 2015 cm-1 in specimens exposed to the Nd:YAG without water. In the presence of water/air coolant, the band at 2015 cm-1 appears only at a substanially higher energy density. The spectra of the CO2 treated specimens, with the char layer present, show a significant reduction in the protein bands and additional bands at 2015 and 2200 cm-1, that are tentatively assigned to the cyanamide and cyanate ions, respectively. These results suggest a reaction of the organic matrix and mineral with laser exposure.
使用扫描电子显微镜（SEM）和傅里叶变换红外光声光谱（FTIR/PAS）完成了用二氧化碳激光、钕钇铝石榴石激光或带水/空气表面冷却的钕钇铝石榴石激光（Nd:YAG-C）处理的牙根表面的形态学和化学特性分析。用于形态学分析的标本包括20颗未受牙周病影响的拔除单根牙。将标本以不同的能量密度单次暴露于激光下。SEM检查显示，对于所有激光，能量密度增加与组织消融深度和组织损伤宽度之间存在直接相关性。Nd:YAG-C比二氧化碳或钕钇铝石榴石激光需要更高的能量密度才能达到相同的相对组织消融深度。无论能量密度如何，与其他激光类型不同，用Nd:YAG-C处理的区域未表现出热损伤的旁侧区域。用于光谱检查的标本由从拔除的未萌出人磨牙的清创牙根表面切下的12个6×2毫米的圆盘组成。光谱结果表明，在未加水的情况下暴露于钕钇铝石榴石激光的标本中，归因于蛋白质的吸收带大幅减少，并且在2015厘米-1处出现了一个额外的吸收带。在有水/空气冷却剂的情况下，2015厘米-1处的吸收带仅在显著更高的能量密度下出现。存在炭层的二氧化碳处理标本的光谱显示蛋白质吸收带显著减少，并且在2015和2200厘米-1处出现了额外的吸收带，分别暂定归属于氰胺离子和氰酸根离子。这些结果表明有机基质和矿物质与激光照射发生了反应。
