Tay F R, Gwinnett J A, Wei S H
Department of Children's Dentistry and Orthodontics, Prince Philip Dental Hospital, University of Hong Kong, Hong Kong.
Dent Mater. 1996 Jul;12(4):236-44. doi: 10.1016/s0109-5641(96)80029-7.
The goal of this study was to illustrate and define the micromorphological spectrum which exists at the resin-dentin interface when two water-free, acetone-based, single-bottle primer/adhesive systems (One-Step, Bisco, and Prime & Bond, Dentsply/L.D. Caulk) were applied to acid-conditioned dentin under different dry and wet bonding conditions.
Forty-eight 1 mm dentin discs were each conditioned with 10% phosphoric acid and rinsed for 20 s. They were randomly divided into 4 groups based upon the status of the remaining surface moisture; Group I (30 s dry); Group II (3 s dry); Group III (blot dry) and Group IV (overwet). Bonded dentin disc pairs were then demineralized in EDTA and embedded in epoxy resin for transmission electron microscopic examination.
The micromorphological spectra of the two bonding systems were essentially similar. Both were effected by even mild desiccation (3 s), resulting in incomplete intertubular resin infiltration. Optimal intertubular resin infiltration was achieved when the collagen network was kept moist and appeared relatively unaffected by the presence of excess surface moisture. On the other hand, intratubular resin infiltration was severely compromised in the presence of excess water within the dentinal tubules and at their openings in the dentin surface. The continuity of the resin layer deteriorated; blister-like spaces formed on the dentin surface and resin globules were found around the tubular orifices and on the surface of the hybrid layer. In addition, a complex phase separation pattern was observed in Prime & Bond that was characterized by phase inversion in the presence of surface moisture.
The "window of opportunity" for optimal interfacial integrity for both water-free systems appeared to depend upon keeping the demineralized collagen network moist, coupled with the complete evaporation of excess and "displaced" water from tissues prior to light-curing the prime/adhesives.
本研究的目的是阐明并界定在不同干湿粘结条件下，将两种无水、丙酮基、单瓶底漆/粘结剂系统（一步法，Bisco公司；Prime & Bond，登士柏/L.D. Caulk公司）应用于酸蚀牙本质时，树脂-牙本质界面存在的微观形态谱。
48个1毫米厚的牙本质片均用10%磷酸处理并冲洗20秒。根据剩余表面湿度状况将它们随机分为4组；第一组（干燥30秒）；第二组（干燥3秒）；第三组（吸干）和第四组（过度湿润）。然后将粘结的牙本质片对在乙二胺四乙酸中脱矿，并嵌入环氧树脂中进行透射电子显微镜检查。
两种粘结系统的微观形态谱基本相似。两者均受到即使是轻微干燥（3秒）的影响，导致管间树脂浸润不完全。当胶原网络保持湿润且似乎相对不受过多表面水分存在的影响时，可实现最佳的管间树脂浸润。另一方面，当牙本质小管内及其在牙本质表面的开口处存在过多水分时，管内树脂浸润会严重受损。树脂层的连续性变差；牙本质表面形成水泡样间隙，在小管口周围和混合层表面发现树脂球。此外，在Prime & Bond中观察到一种复杂的相分离模式，其特征是在表面有水分时发生相转变。
两种无水系统实现最佳界面完整性的“机会窗口”似乎取决于保持脱矿胶原网络湿润，以及在对底漆/粘结剂进行光固化之前，使组织中多余的和“置换出”的水分完全蒸发。
