【作者】 徐飞；

【导师】 陈蕾；

【作者基本信息】 中南大学 ， 口腔临床医学， 2011， 硕士

【摘要】 临床上行全冠修复时,为了预备出修复体的空间以及取得共同就位道,必须切割牙体组织,导致牙本质暴露,而且修复过程中暂时冠或修复体的质量不佳,边缘不密合等,均可造成术后敏感。根据流体动力学说,机械封闭暴露的牙本质小管,可以防止牙本质敏感及保护牙髓。因此,众多的脱敏产品应运而生,大量的临床实践证明该方法行之有效。然而,涂布牙本质脱敏剂是否会影响粘接剂的粘接强度,目前的报道较少。[目的]本课题旨在观察涂布脱敏剂后牙本质小管的微观形貌特征,研究脱敏剂对粘接剂粘接剪切强度的影响,为临床上选用脱敏剂和粘接剂提供实验依据。[方法]用金刚砂车针均匀磨除离体牙牙合面釉质,暴露牙本质。按不同分组分别涂布Hybrid Coat、Prime&Bond NT、脱敏牙膏,再用扫描电镜观察牙本质小管的微观形貌特征。分别用玻璃离子水门汀(GIC)、聚羧锌酸水门汀(PCC)、树脂粘接剂(RC),将钻铬合金粘接接头粘接到经脱敏剂处理的牙本质表面,在万能试验机上测试样本的粘接剪切强度。[结果]1.扫描电镜观察：Hybrid Coat、Prime&Bond NT几乎能封闭所有的牙本质小管口,而脱敏牙膏涂布后有少量牙本质小管口开放,小管中均可见沉积物。2.剪切实验：Hybrid Coat能增加GIC的粘接剪切强度,而对PCC、RC的粘接剪切强度没有显著影响；Prime&Bond NT显著降低了PCC的粘接剪切强度,而对GIC、RC没有显著影响；高露洁专效抗敏牙膏可以增加PCC、RC的粘接剪切强度,而对GIC没有显著影响；本实验选用的三种粘接剂中,GIC的粘接剪切强度最低,RC的粘接剪切强度最高。[结论]1. Hybrid Coat、Prime&Bond NT、脱敏牙膏均可以封闭牙本质小管。2.临床上用GIC粘接钴铬合金修复体,宜选用Hybrid Coat脱敏处理；用PCC粘接钻铬合金修复体,应避免与Prime&Bond NT配伍；用RC、PCC粘接钻铬合金修复体,宜选用高露洁专效抗敏牙膏脱敏处理。更多还原

【Abstract】 Full crown restoration needs tooth preparation in order to obtain the space and the common insertion path for prosthesis. It has been shown that a lot of dentinal tubules were exposed after tooth preparation, which increased the potential of postoperative dentine sensitivity. What’s more, many other factors can also induce hypersensitivity such as temporary crowns or final restorations of poor quality and marginal microleakage. According to the hydrodynamic theory which has been widely accepted, we can prevent hypersensitivity and protect pulp tissue by mechanical closure of exposed dentinal tubules. As a result, many desensitizers come into being. And a great number of clinical trials have proved that they can effectively reduce the extent of sensitivity. However, reports about the effect of desensitizers on bond strength of luting agents are few.Objective:The purpose of this study was to observe the microscopic characteristics of dentinal tubules after using desensitizers, to test their effect on the bond strength of cementing agents and to provide an experimental basis for the selection of desensitizers and adhesives in clinic.Methods:Freshly extracted human premolars were prepared with a speed handpiece and the dentinal tubules were exposed. After using Hybrid Coat, Prime&Bond NT, anti-sensitivity toothpaste in corresponding groups, the microscopic characteristics of dentinal tubules were observed with scanning electron microscopy. After all the dentine surfaces had been treated by the selected desensitizers, castings of cobalt-chromium alloy were bonded to them by glass ionomer cement(GIC), zinc polycarboxylate cement(PCC), resin adhesive(RC) respectively. The shear bond strength of each specimen was obtained using a universal testing machine.Results:1. Hybrid Coat, Prime&Bond NT could occlude almost all the exposed tubules while anti-sensitivity toothpaste could only seal the majority of tubules. Sediments were visible no matter which desensitizer was used.2. Hybrid Coat could significantly increase the shear bond strength of GIC, but had no effect on the bond strength of PCC and RC. Application of Prime&Bond NT reduced the shear bond strength when PCC was used, but did not affect the shear bond strength of GIC, RC. The use of anti-sensitivity toothpaste obviously enhanced the shear bond strength of RC and PCC, but had no negative impacts on the shear bond strength of GIC, RC. Among the selected luting agents, GIC had the lowest shear bond strength while RC had the highest.Conclusion:1. Hybrid Coat, Prime&Bond NT and anti-sensitivity toothpaste are able to seal dentinal tubules.2. When use GIC as adhesive agent, we shoud choose Hybrid Coat as dentine desensitizer; if we choose PCC, the use of Prime&Bond NT should be avoided; if RC or PCC is selected, anti-sensitivity toothpaste is applicable.更多还原