Ponnaappa K C Deepak, Rao R Nageswar
Department of Conservative Dentistry and Endodontics, J.S.S. Dental College, Mysore, India.
Indian J Dent Res. 2002 Jul-Dec;13(3-4):147-57.
Extracated human molars were used for the study, flat dentinal surfaces were prepared on the occlusal surfaces, and then 4th and 5th generation dentin bonding agents were used in dry and moist conditions to bond composite resin onto the flat dentin surfaces. Shear Bond Strength was measured using Instron Universal Testing machine. Failures were recorded as adhesive, cohesive and mixed. Bond strength was highest in moist condition, because the moist surface permits more porous collagen network and hence greater infiltration of adhesive monomers, than do surfaces that are air dried. Moreover, those dentin bonding agents whose primers are based on acetone show improved bond strength, because acetone aggressively pursues and displaces water in the substrate, resulting in the primer resin being carried into tissue channels and porosities. When the dentin is air dried, the water that is supporting the collagen network evaporates causing the collagen network to collapse network is greatly reduced, which in turn decreases the premeability of intertubular dentin to adhesive resin and as a result causes decrease in bond strength. 5th generation dentin bonding agent showed significant improvement in the moist dentin bond strength.
本研究使用拔除的人类磨牙，在咬合面上制备平坦的牙本质表面，然后在干燥和潮湿条件下使用第四代和第五代牙本质粘结剂将复合树脂粘结到平坦的牙本质表面。使用英斯特朗万能试验机测量剪切粘结强度。将失败记录为粘结性、内聚性和混合性。粘结强度在潮湿条件下最高，因为与空气干燥的表面相比，潮湿表面允许更多的多孔胶原网络，因此粘结单体的渗透更大。此外，那些以丙酮为基础的底漆的牙本质粘结剂显示出改善的粘结强度，因为丙酮积极地追踪并取代底物中的水，导致底漆树脂被带入组织通道和孔隙中。当牙本质空气干燥时，支撑胶原网络的水蒸发，导致胶原网络塌陷，管间牙本质对粘结树脂的渗透性大大降低，结果导致粘结强度下降。第五代牙本质粘结剂在潮湿牙本质粘结强度方面有显著提高。
