Study on enhancing adhesion of dental aghesive restorative materials to tooth hard tissue.

各种粘结促进剂已经开发出来，并得到了广泛的应用。然而，牙本质作为附着物的治疗是一个更重要的问题。本研究评价了牙本质边缘复合树脂修复体的预处理对其微渗漏的影响。磨光牛牙的唇面，直至露出牙本质。两个标准化的圆腔并排制备。四种清洗剂；将3%乳酸铝、10%抗坏血酸、10%柠檬酸和10%磷酸分别涂抹在其中一个空腔中60秒。另一个没有清洗。粘接后，将复合树脂插入腔内。在染料浸泡24小时之前，对修复的牙齿进行热循环。单独使用牙本质粘接剂不能有效地阻止染料在颈牙本质边缘的渗透，在粘接剂前对牙本质进行预处理可以有效地减少微渗漏。我们研究了激光照射处理涂抹层的可能性。用激光照射涂抹层表面，在扫描电镜下观察其变化。用Nd-YAG激光器和CO_2激光器进行离焦。结果表明，两种激光都引起了涂膜层的变化。根据照射水平的不同，管状牙本质上的涂抹层得到了满意的处理，管状孔关闭。接下来，我们测定了两种激光在不同条件下照射牙本质表面时1%亚甲基蓝的穿透率。研究发现，当染料涂抹在未照射的牙本质表面时，染料在整个牙本质区域渗透得很深，而照射过的牙本质表面则阻挡了染料的渗透。在25-50 J/cm^2的低能量密度下也观察到这一发现，从保存牙髓的角度来看，这是非常有趣的。

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. This study evaluated the effects of the pretreatment of the cavity on microleakage of the composite resin restorations with dentin margens. The labnial surfaces of bovine teeth were ground until the dentin was exposed. Two standardized round cavities were prepared side by side. Four kinds of cleaning agents; 3% aluminum lactate, 10% ascorbic acid, 10% citric acid and 10% phosphoric acid were applied for 60 seconds to one of the two cavities. The other was left without cleaning. After bonding, a composite resin was inserted into cavity. The restored teeth were thermocycled, prior to immersion in dye for 24 hours.The dentin bonding agent singly could not prevent dye penetration at the cervicaal dentin margin, and prior to bonding the pretreatment of dentin with some cleaning agents was effective for decreasing microleakage.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 Nd-YAG laser and CO_2 laser were used in defocus. The results showed that both lasers induced changes in the smear layer. Depending on the irradiation level, the smear layer on the intertubular dentin was satisfactorily treated, with the tubular orifices closed.Next, we determined the penetration of 1% methylene blue form the dentin surface when irradiated by both lasers under various conditions. It was found that while the dye applied to a non-irradiated dentin surface penetrated deeply over the entire area, an irradiated surface blocked dye penetration. This finding was also observed at low energy densities of 25-50 J/cm^2,which is very interesting from the standpoint of preserving dental pulp.