Kim Jung-Ho, Kwon Oh-Won, Kim Hyung-Il, Kwon Yong Hoon
Department of Orthodontics, College of Dentistry, Kyungpook National University, Daegu, Korea.
Angle Orthod. 2006 Nov;76(6):1052-6. doi: 10.2319/11405-398.
To compare the effects of erbium-doped yttrium aluminum garnet (Er:YAG) laser ablation and of phosphoric acid etching on the in vitro acid resistance of bovine enamel.
Teeth were polished to make the surface flat. The polished enamel was either etched with 37% phosphoric acid for 30 seconds or ablated with a single 33 J/cm2 pulse from an Er:YAG laser. The control specimens were free from acid etching and laser ablation. Changes in crystal structure, dissolved mineral (calcium [Ca] and phosphorus [P]) contents, and calcium distribution in the enamel subsurface after a pH-cycling process were evaluated.
After laser treatment, poor crystal structures improved without forming any new phases, such as tricalcium phosphates. Among the tested enamels, dissolved mineral contents were significantly different (P < .05). Er:YAG laser-treated enamels had the lowest mineral dissolution (Ca, 13.78 ppm; P, 6.33 ppm), whereas phosphoric acid-etched enamels had the highest (Ca, 15.90 ppm; P, 7.33 ppm). The reduction rate and reduced depth of calcium content along the subsurface were lowest in Er:YAG laser-treated enamels.
The Er:YAG laser-treated enamels are more acid resistant to acid attack than phosphoric acid-etched enamels.
比较掺铒钇铝石榴石（Er:YAG）激光消融和磷酸酸蚀对牛牙釉质体外抗酸性的影响。
将牙齿打磨至表面平整。对打磨后的牙釉质，要么用37%磷酸酸蚀30秒，要么用Er:YAG激光以33 J/cm²的单脉冲进行消融。对照样本未进行酸蚀和激光消融。评估了pH循环处理后牙釉质的晶体结构变化、溶解矿物质（钙[Ca]和磷[P]）含量以及牙釉质次表面的钙分布。
激光处理后，较差的晶体结构得到改善，且未形成任何新相，如磷酸三钙。在测试的牙釉质中，溶解矿物质含量存在显著差异（P < 0.05）。Er:YAG激光处理的牙釉质矿物质溶解量最低（Ca，13.78 ppm；P，6.33 ppm），而磷酸酸蚀的牙釉质矿物质溶解量最高（Ca，15.90 ppm；P，7.33 ppm）。Er:YAG激光处理的牙釉质沿次表面的钙含量减少率和减少深度最低。
与磷酸酸蚀的牙釉质相比，Er:YAG激光处理的牙釉质对酸侵蚀的抗酸性更强。
