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. 1997 Mar;13(2):118-27. doi: 10.1016/s0109-5641(97)80021-8.
The overwet phenomenon was first reported when a moist bonding technique was used with an earlier commercial version of All-Bond 2 (Bisco) that contained BPDM in primer B. This study investigated whether ultrastructural features of the overwet phenomenon could also be detected in other commercially available two-component acetone-based primers containing BPDM, PMDM and PMGDM, as well as an experimental two-component primer containing DSDM.
Thirty 1 mm dentin discs prepared from third molars were each conditioned with 10% H3PO4 for 20 s and rinsed for 20 s. They were randomly divided into 5 groups: Group I (Bond-It, Jeneric/Pentron:PMGDM); Group II (Wet Bond, Chameleon Dental Products:PMGDM); Group III (Tenure S, Den-Mat:PMDM); Group IV (present commercial version of All-Bond 2, Bisco:BPDM) and Group V (Experimental two-component primer system containing DSDM in primer B). Following a moist bonding technique using the respective system, discs from each group were further bonded together to form three disc pairs using a chemical-cured resin. Bonded disc pairs were demineralized in EDTA and processed for TEM examination. For this ultramicroscopical study, results such as the features of the overwet phenomenon were analyzed by visual inspection of the specimens in each group (n = 12).
Isolated blister-like spaces of variable dimensions were observed within the primer layer in all groups and possessed the following characteristics: 1) a layer of resin-impregnated dentin was always present along the base of the primary blister; 2) surface primer globules, sometimes containing secondary blisters, were identified within these primary blisters; 3) dentinal tubules within the blister-like spaces were not completely sealed; 4) primer globules were circumscribed by a halo of fine kinked strands of material.
Although the technique of moist bonding is based on valid biological principles, incorporation of resin monomers that are immiscible with water rendered the application of current two-component, acetone-based primers very technique-sensitive in terms of tubular seal, when used on moist, acid-conditioned dentin. Further studies should be directed at elimination of this type of oil-in-water (O/W) "macroemulsion" formation through optimal micellar solubilization of these resin monomers in water.
首次报道在使用早期商业版含BPDM的All-Bond 2（Bisco公司）进行湿粘结技术时出现过度湿润现象。本研究调查了在其他市售的含BPDM、PMDM和PMGDM的双组分丙酮基底漆以及含DSDM的实验性双组分底漆中，是否也能检测到过度湿润现象的超微结构特征。
从第三磨牙制备30个1mm厚的牙本质片，每个牙本质片用10%的H3PO4处理20s，冲洗20s。将它们随机分为5组：第一组（Bond-It，Jeneric/Pentron公司：PMGDM）；第二组（Wet Bond，Chameleon Dental Products公司：PMGDM）；第三组（Tenure S，Den-Mat公司：PMDM）；第四组（All-Bond 2的现行商业版，Bisco公司：BPDM）和第五组（底漆B中含DSDM的实验性双组分底漆系统）。使用各自的系统采用湿粘结技术后，将每组的牙本质片进一步用化学固化树脂粘结在一起形成三个牙本质片对。将粘结的牙本质片对在EDTA中脱矿并进行透射电镜检查。对于这项超微结构研究，通过目视检查每组标本（n = 12）分析过度湿润现象的特征等结果。
在所有组的底漆层内均观察到大小不一的孤立水泡样间隙，其具有以下特征：1）在主水泡底部始终存在一层树脂浸渍的牙本质；2）在这些主水泡内可识别出表面底漆小球，有时还含有次级水泡；3）水泡样间隙内的牙本质小管未完全封闭；4）底漆小球被一圈细小的扭结状物质所环绕。
尽管湿粘结技术基于有效的生物学原理，但当用于湿润的、经酸处理的牙本质时，由于加入了与水不混溶的树脂单体，使得目前的双组分丙酮基底漆在管腔封闭方面的应用对技术非常敏感。进一步的研究应致力于通过这些树脂单体在水中的最佳胶束增溶作用来消除这种水包油（O/W）“宏观乳液”的形成。
