Pretreatment of Dentin Surface by Laser Irradiation

已经开发了各种粘合促进剂并广泛使用。然而，牙本质作为附着体的处理是一个更重要的问题。已经提出了各种各样的程序来处理由切割牙本质表面产生的玷污层;但是，考虑到牙本质的渗透性和牙髓的保护，任何可能导致管周牙本质脱钙和牙本质小管开放和扩张的预处理方法都应该避免。我们研究了激光照射处理玷污层的可能性。用激光照射玷污层的表面，并在扫描电子显微镜下观察变化。用CO_2气体激光器（Satelec Lasersat CO_2）散焦。结果表明，激光引起的玷污层的变化。在能量密度为30-50 J/cm ^2的条件下，对牙本质小管间玷污层进行了满意的处理，关闭了小管口。当离焦状态下能量密度为60 J/cm^2的激光照射时，如果剩余牙本质到牙髓的厚度大于1 mm，则温度升高低于6 ° C。

Various adhesion promoters have been developed and are in wide use. However, the treatment of the dentin as an adherent is a more important issue. A variety of procedures have been proposed for the treatment of the smear layer produced by cutting the dentin surface ; but, in view of dentin permeability and protection of the dental pulp, any method of pretreatment that is likely to cause decalcification of the peritubular dentin, and opening and expansion of the dentinal tubules, should be avoided.We investigated the possibility of treating the smear layer by laser irradiation. The surface of the smear layer was irradiated with a laser, and the changes were observed under a scanning electron microscope. A CO_2 gas laser (Satelec Lasersat CO_2) was used in defocus. The results showed that the laser induced changes in the smear layer. The smear layer on the intertubular dentin was satisfactorily treated, with the tubular orifices closed at the energy densities of 30-50 J/cm^2.Next, we determined the temperature rise in the pulp by CO_2 laser irradiation. The temperature rise by laser irradiation at the energy density of 60 J/cm^2 in defocus showed below 6^ﾟC if the thickness of the remaining dentin to the pulp from the cavity floor was more thicker than 1 mm.