【作者】 李津乐；

【导师】 张晓；

【作者基本信息】 郑州大学 ， 口腔临床医学， 2010， 硕士

【摘要】 修复根管治疗后的牙体组织,需要满足美观、功能的双重要求。纤维桩由于具有良好的美观性能和生物力学性能,临床应用日益广泛。临床研究证实使用纤维桩能够降低根折率、延长根管治疗后牙齿的存留时间,但粘结失败仍是纤维桩修复失败的主要原因。纤维桩在根管内的固位强度受到诸多因素的影响,例如粘结系统、纤维桩的外形设计及成分以及粘桩的操作过程。目前临床上常用于粘固纤维桩的树脂粘结系统主要包括三类：全酸蚀粘结系统、自酸蚀粘结系统和自粘结树脂水门汀。自粘结树脂水门汀结合粘结剂和水门汀处理一步完成,不需要对根管进行任何前处理,满足了简化临床操作的趋势。但是目前国内外关于自粘结树脂水门汀用于粘固纤维桩的研究尚少,有限的研究都是使用3M公司生产的RelyX Unicem,对粘结效果的评价并不一致,也缺乏对自粘结水门汀作为一种粘结系统的整体认识。与此同时,对于自粘结树脂水门汀与不同纤维桩粘结强度对比研究的报道很少。通过分析根管不同深度牙本质-树脂-纤维桩粘结界面的形态学特征、粘结强度和失败模式之间的关系,有助于了解纤维桩修复系统在桩道内固位的薄弱环节,为临床选择纤维桩和粘结系统提供理论依据。第1章不同粘结系统对纤维桩桩道内界面形态学和剪切粘结强度的影响目的：比较自粘结树脂水门汀、全酸蚀、自酸蚀粘结系统粘固玻璃纤维桩后在桩道不同深度的粘结界面形态,从形态学解释剪切粘结强度和界面破坏方式。方法：筛选27颗新鲜离体单根管前磨牙于釉牙骨质界上2 mm处截冠,随机分成三组,常规根管充填、桩道预备后分别用A：自粘结树脂水门汀(Embrace WetBond)、B：全酸蚀粘结系统(DenTASTIC UNO+ResiLute)、C：自酸蚀粘结系统(DC BOND+DC CORE)粘固玻璃纤维桩,生理盐水常温保存24小时后包埋并按桩道深度切割试样,薄片推出实验测试剪切粘结强度,体式显微镜观察粘结界面气泡率、裂缝率和破坏方式,记录数据并统计分析。结果：C组的剪切粘结强度(10.59±0.75 MPa)显著高于A组(6.54±0.80MPa)和B组(7.41±0.76 MPa)(P<0.001)；A组和B组的剪切粘结强度从桩道颈部到根尖区域呈下降趋势(P<0.05),C组在桩道中、下部差异没有显著性(P>0.05)；体视显微镜观察显示B组树脂层气泡率为64.2%,显著高于A组(5.8%)、C组(14.8%)(P<0.001)；界面裂缝主要出现在桩道颈部、中部试样,各组界面裂缝率没有统计学意义(P>0.05)；试样的破坏方式主要为粘结材料与根管壁间粘结破坏(51.6%)。结论：1.自粘结树脂水门汀对纤维桩的粘结强度与全酸蚀粘结系统一致；2.界面裂缝和粘结层厚度有关；3.树脂粘结系统对纤维桩的粘结效果在根颈部更可靠。第2章两种玻璃纤维桩剪切粘结强度和界面形态的对比研究目的：比较自粘结树脂水门汀、全酸蚀粘结系统粘固两种玻璃纤维桩后在桩道不同深度的粘结界面形态,从形态学解释剪切粘结强度和界面破坏方式。方法：筛选36颗新鲜离体单根管前磨牙于釉牙骨质界上2 mm处截冠,随机分成四组,常规根管充填、桩道预备后使用各组粘结系统将纤维桩粘固于根管中。实验各组分别是A：自粘结树脂水门汀(Embrace WetBond)和POPO纤维桩；B：全酸蚀粘结系统(DenTASTIC UNO+ ResiLute)和POPO纤维桩；C：自粘结树脂水门汀和Para Post Fiber White纤维桩；D：全酸蚀粘结系统和Para Post Fiber White纤维桩。生理盐水常温保存24小时后包埋并按桩道深度切割试样,薄片推出实验测试剪切粘结强度,体式显微镜观察粘结界面气泡率、裂缝率和破坏方式,记录数据并统计分析。结果：纤维桩与粘结系统两影响因素间有明显交互作用(P<0.001)；C组的剪切粘结强度(9.90±0.93 MPa)显著高于A组(6.54±0.80 MPa)、B组(7.41±0.76 MPa)和D组(6.48±0.78 MPa)(P<0.001)；A组、B组和C组的剪切粘结强度从桩道颈部到根尖区域呈下降趋势(P<0.05),D组在桩道中、下部差异没有显著性(P>0.05)；界面形态学观察显示,B组、D组树脂层气泡率分别为64.2%和70.6%,显著高于A组(5.8%)、C组(13.7%)(P<0.001),D组树脂-牙本质界面裂缝率(23.8%)显著高于A组(13.5%)和C组(11.8%)(P<0.0083)；除A组与B组间外(P=0.69),其它各个组间试样的破坏方式差异具有统计意义(P<0.0083)。结论：1.自粘结树脂水门汀与Para Post Fiber White纤维桩联合使用的粘结效果最佳；2.粘结界面树脂层的气泡率与使用的树脂粘结系统有关；3.树脂粘结系统对纤维桩的粘结效果在根颈部更可靠；4.纤维桩-树脂-牙本质粘结界面形态特征与破坏方式间存在差异,两个界面的性能共同决定纤维桩在桩道内的粘结固位力。更多还原

【Abstract】 Fiber posts have been proposed for the restoration of endodontically treated teeth. They have favorable physical properties and could reduce the risk of root fracture comparing to conventional cast posts or prefabricated metallic posts. Clinical studies indicated that fiber post systems had satisfactory performance but post loosening was observed as the main failure mode. Bonding capacity of fiber post systems may be influenced by various factors, such as adhesive systems, design and composition of fiber posts and adhesive approach. Currently available adhesive systems include etch-and-rinse, self-etch, and self-adhesive cement. Self-adhesive cement which most recently introduced does not require any pretreatment of dentin and meets the general trend to simplify the clinical procedures. The studies on the performance of self-adhesive cement in fiber post cementation are limited and the results are contradictory although the same self-adhesive cement (RelyX Unicem, 3M ESPE, Germany) was investigated. Information on the interaction between self-adhesive cements and fiber posts is currently lacking in the literature. Moreover, analysis of correlations between the morphological characteristics of the root dentin-resin luting agent-fiber post adhesive interface, bond strength and failure modes in different root region might identify weaknesses of fiber post restorative systems with respect to the bonding behavior inside the canal.PartⅠMorphological and bond strength study of fiber posts cemented using different adhesive systems in dowel spaceObjective:To investigate the correlation of morphological characteristics, shear bond strength and failure mode of fiber posts cemented with luting agents that utilize three currently available adhesive systems:self-adhesive, etch-and-rinse, and self-etch.Methods:Twenty-seven intact single-rooted human premolars were collected and removed the crown 2mm above the cement-enamel junction. After root canal therapy, teeth were randomly divided into 3 groups (n=9). A:self-adhesive (Embrace WetBond), B:etch-and-rinse (DenTASTIC UNO+ResiLute), C:self-etch (DC BOND+DC CORE). In each group, the resin cement with its adhesion (if needed) and a fiber post were used. The resin cement was placed into the root canal using a specific syringe with needle. After storage in water for 24 h, each root was sectioned into six 1-mm-thick serial slices. Then the shear bond strength between the post and the root canal walls was assessed using the thin-slice push-out test. The dentin-cement-post adhesive interface and failure mode were evaluated by stereomicroscope observation.Results:The self-etch adhesive system(10.59±0.75 MPa) resulted in significantly higher shear bond strengths than the self-adhesive system(6.54±0.80 MPa) and etch-and-rinse(7.41±0.76 MPa) (P<0.001). Bond strengths decreased significantly from coronal to apical root canal regions for self-adhesive system and etch-and-rinse (P<0.05) but had no differences between middle and apical thirds for self-etch system (P>0.05). Interface morphology observed by stereomicroscope indicated that voids present in etch-and-rinse cement layer were significantly highly(64.2%,P<0.001), interface gaps appeared in the coronal and middle third and the failure mostly occurred at the resin-dentine interface.Conclusion:1. Shear bonding strength using the self-adhesive system is as good as that of etch-and-rinse system.2. Interface gaps correlated with resin cement thickness.3. Bonding at the coronal level of the root canal is more reliable than at the apical level.PartⅡMorphological and bond strength study of different fiber posts luted with different adhesive systems to root dentinObjective:To investigate the correlation of morphological characteristics, shear bond strength and failure mode of two types of glass-fiber posts luted with self-adhesive resin cement and etch-and-rinse adhesive system. Methods:Thirty-six intact single-rooted human premolars were collected and removed the crown 2mm above the cement-enamel junction. After root canal therapy, teeth were randomly divided into 4 groups (n= 9). A:self-adhesive (Embrace WetBond) with POPO fiber posts, B:etch-and-rinse (DenTASTIC UNO+ResiLute) with POPO fiber posts, C:self-adhesive with Para Post Fiber White, D: etch-and-rinse with Para Post Fiber White. In each group, fiber posts were luted in prepared root canals using resin cement with its adhesion (if needed) followed the respective manufacturer. The resin cement was placed into the root canal using a specific syringe with needle. After storage in water for 24 h, each root was sectioned into six 1-mm-thick serial slices. A push-out test was performed on thin-slice sections from the coronal, middle and apical parts of each specimen to measure shear bond strength. The dentin-cement-post adhesive interface of each specimen and failure modes after fracture were evaluated by stereomicroscope observation.Results:There was significant interaction between the post systems and adhesive system(P<0.001). The group C(9.90±0.93 MPa) resulted in significantly higher shear bond strengths than A(6.54±0.80MPa),B(7.41±0.76 MPa) and D(6.48±0.78 MPa) (P<0.001). Bond strengths decreased significantly from coronal to apical root canal regions for group A, B and C (P<0.05),but had no differences between middle and apical thirds for group D(P>0.05). Interface morphology observed by stereomicroscope indicated that voids present in group B and D were significantly highly (P<0.05), interface gaps appeared at the resin-dentine interface in group D (23.8%) were significantly highly than A(13.5%) and C(11.8%) with P<0.0083, and the failure modes in each group were significantly different (P<0.0083) except for A and B(P=0.69).Conclusion:1. Shear bonding strength using the self-adhesive cement and Para Post Fiber White provided significantly better post retention.2. Voids present in cement layer were associated with the luting agent involved.3. Bonding at the coronal level of the root canal is more reliable than at the apical level.4. Morphological characteristics of the fiber post-resin luting agent-root dentin adhesive interface were discrepant with failure modes in different root region.更多还原