Franke Margarete, Taylor Arthur Westphal, Lago Alexandre, Fredel Márcio Celso
Graduation Program in Materials Science and Engineering (PGMAT), Department of Mechanical Engineering, Federal University of Santa Catarina, Santa Catarina, Brazil.
Oper Dent. 2006 Sep-Oct;31(5):604-9. doi: 10.2341/05-110.
Hard tissue modification by means of laser irradiation is becoming popular in dentistry, since it promotes assorted responses between the tooth and the restorative material. Some studies on the bond strength of adhesive systems to Nd:YAG irradiated teeth have shown distinctive behaviors when irradiation was applied before or after the adhesive agent. This study evaluated the microtensile bond strength of a commercial adhesive system to dentin irradiated with Nd:YAG laser after adhesive application but prior to polymerization. The experiment was conducted in vitro, using freshly extracted human teeth as samples. For the microtensile test, the teeth were separated into 4 different groups according to the energy density of laser irradiation: 0, 5, 10 and 50 J/cm2. The data was analyzed with analysis of variance (ANOVA) and LSD tests, and the results indicated that the group that was irradiated with 5 J/cm2 had significantly higher bond strength values. Adhesive penetration on the etched dentin was observed by scanning electron microscopy, where the images showed better adhesive penetration on dentinal tubules after dentin irradiation with 5 J/cm2. Based on the results of this study, it is possible to conclude that irradiation of dentin with the Nd:YAG laser at low energy densities after application of the adhesive but prior to polymerization might be positive for the adhesive restorative process.
通过激光照射进行硬组织改性在牙科领域正变得越来越流行，因为它能促进牙齿与修复材料之间的各种反应。一些关于粘结系统与钕钇铝石榴石（Nd:YAG）激光照射牙齿的粘结强度的研究表明，在粘结剂应用之前或之后进行照射时会表现出不同的行为。本研究评估了一种商用粘结系统在粘结剂应用后但在聚合之前与经Nd:YAG激光照射的牙本质的微拉伸粘结强度。该实验在体外进行，使用新鲜拔除的人牙作为样本。对于微拉伸试验，根据激光照射的能量密度将牙齿分为4个不同的组：0、5、10和50 J/cm²。数据采用方差分析（ANOVA）和最小显著差异（LSD）检验进行分析，结果表明，接受5 J/cm²照射的组具有显著更高的粘结强度值。通过扫描电子显微镜观察了蚀刻牙本质上的粘结剂渗透情况，图像显示在牙本质接受5 J/cm²照射后，粘结剂在牙本质小管上的渗透更好。基于本研究的结果，可以得出结论，在应用粘结剂后但在聚合之前用低能量密度的Nd:YAG激光照射牙本质可能对粘结修复过程有积极作用。
