不同性质的牙本质对牙本质粘接强度的影响

牙本质由于其复杂的组织结构和组成成分使得它比釉质粘接更复杂,本文主要针对不同性质的牙本质这一因素对牙本质粘接强度的影响作一综述。     

影响牙本质粘接的因素

由于牙本质结构的特殊性,在牙本质上进行粘接的机理和过程较为复杂,任何影响粘接过程的因素都会影响牙本质粘接的最终效果.本文回顾相关的基础理论和临床研究,分析介绍不同的牙本质粘接系统在成分、操作方法和粘接强度上的差异,以及牙本质表面性质、操作准确性和污染等因素对粘接强度的影响,以求为临床应用提供依据.     

牙本质表面处理对粘接性能的影响

目的探讨0.5mol/L乙二胺四乙酸（EDTA）和35%的磷酸以及前处理剂对受龋影响牙本质、正常牙本质与光固化复合树脂粘接密合性能的影响。方法实验用牙为拔除的患龋磨牙及正畸拔除的前磨牙各23颗,将受龋影响牙本质（CAD）和正常牙本质（CFD）分别用EDTA和磷酸处理,扫描电镜观察牙本质的超微结构。在离体牙标本上分别制备柱状牙本质洞形,分别经EDTA和磷酸处理后,再各取半数使用前处理剂甲基丙烯酸甘油单酯（GM）处理,全部样本用光固化复合树脂常规充填,光镜测量其洞底粘接断面最大收缩间隙,并对收缩间隙进行扫描电镜观察。结果EDTA和磷酸均能清除牙本质表面的玷污层,CAD表面的牙本质小管大部分被矿化结晶堵塞,EDTA不会使管周高钙化区脱钙;磷酸可使牙本质小管管周脱钙,使CFD牙本质小管呈喇叭口状开放,对CAD的矿化结晶体的影响不大。磷酸较EDTA处理牙本质的粘结断面出现的收缩间隙明显增加（P（0.05）,GM前处理对于降低CFD与复合树脂之间的收缩间隙有明显作用（P（0.05）,而对CAD与复合树脂之间的粘接无明显作用。结论EDTA处理牙本质可提高其与复合树脂之间的封闭性能。前处理剂GM可提高CFD与复合树脂之间的封闭性能,对CAD的作用不明显。对CAD适当的处理,亦可获得良好的粘接性能。     

牙本质的湿粘接

自Ｂｕｏｎｃｏｒｅ[1]开创牙齿酸蚀粘接技术以来,粘接材料及技术得到了很大发展,为牙齿修复注入了全新的概念和技术。传统洞型固位的方法已在一定程度上被较少磨削牙齿的粘接方法所取代,使修复的范围不断扩大。目前,粘接技术在临床已成为广泛使用的、可靠的技术方法。对牙齿硬组织的粘接包括对釉质的粘接和对牙本质的粘接。对釉质的粘接,不论粘接机制还是粘接剂都已相当成熟。由于牙本质的组成、结构的特点,对牙本质粘接远较釉质粘接困难得多,而且一直未能达到较高的水平,也是多年来粘接研究的热点。自1992年以来,牙本质粘接随着人们对其机…     

龋影响牙本质粘接强度的研究进展

对于大多数粘接剂而言,龋影响牙本质的粘接强度均低于正常牙本质的粘接强度。本文回顾近几年有关龋影响牙本质粘接强度的文献,着重介绍不同去龋方法、表面处理和粘接剂对龋影响牙本质粘接强度的影响。     

牙本质粘接效果的评价方法及影响因素

在牙本质粘接实验研究中,影响粘接强度测试结果的诸多因素如粘接基质、酸蚀、粘接处理、贮存方式和介质、实验方法等纷繁复杂,对此,许多学者至今一直努力建立标准化的牙本质粘接实验;随着新的牙本质粘接系统的推出,粘接强度的提高,微拉伸实验取代传统的测试方法可以最大程度的避免内聚力对粘接强度的影响,使测试值更加客观、真实。     

牙本质生物改性与牙本质粘接耐久性

树脂粘接修复技术以其独特的固位原理、突出的美观修复效果、便捷的临床操作等优势,已成为口腔临床了微创保存牙科不可或缺的治疗方式.牙本质粘接尽管可以获得足够的即刻粘接强度,但粘接界面在多因素作用下常会发生降解,导致边缘染色、渗漏,直接影响了修复体使用寿命.如何获得稳定的牙本质粘接界面是目前研究的重点,本文针对牙本质生物改性...     

磷酸和次氯酸钠联合处理对牙本质粘接的影响

牙本质的处理方法一直是牙本质粘接中的主要课题。近年来，有大量研究表明磷酸／次氯酸钠(phosphoric acid／sodium hypochloride，PA／SH)联合处理在牙本质表面形成一种新的粘接基质。本文就PA／SH联合处理的理论基础，对牙本质表面形态的改变、粘接力的影响及粘接界面的微渗漏等几个方面进行综述。     

牙本质粘接技术的进展

牙本质粘接修复的效果影响到修复成功率及修复质量。本文就牙本质的粘接材料、窝洞预备方法、洞型、He力等因素对牙本质粘接修复效果的影响作一综述，这有助于临床医生在此基础上提高修复质量。     

半胱氨酸组织蛋白酶对牙本质粘接耐久性的影响

半胱氨酸组织蛋白酶是组织蛋白酶家族的主要成员.牙本质酸蚀脱矿后裸露的胶原纤维被内源性蛋白酶降解是影响牙本质粘接耐久性的主要因素之一.除基质金属蛋白酶外,半胱氨酸组织蛋白酶也在粘接过程中被激活并参与混合层中胶原的破坏.本文就半胱氨酸组织蛋白酶与基质金属蛋白酶的相互作用、在牙本质粘接中的作用以及半胱氨酸组织蛋白酶抑制剂对提高牙本质粘接耐久性的作用的研究进展作一综述.     

The effect of prime-and-rinse approach using MDP micellar solutions on extrafibrillar demineralization and dentin bond performance

ObjectiveThis study investigated the effects of prime-and-rinse approach using 10-methacryloyloxydecyl dihydrogen phosphate (MDP) micellar solutions on extrafibrillar demineralization and dentin bond performance of etch-and-rinse adhesive.MethodsThe micellar solutions were prepared by adding 15% MDP in two ethanol-aqueous (75:25, 55:45 V/V%) solutions, referring to MDP/EtOH₇₅ and MDP/EtOH₅₅. After mid-coronal dentin surfaces were either etched (control) or conditioned with MDP/EtOH₇₅ and MDP/EtOH₅₅ and rinsed, they were applied with adhesive (Adpter Single Bond 2) in dry- or wet-bonding mode and placed with composite resin (Filtek Z350 XT). They were prepared into multiple micro-beams for micro-tensile bond strengths (MTBS) testing after storage in water for 24 h or subjecting to thermocycling. The other pretreated dentin surfaces were analyzed by TF-XRD, ATR-FTIR, HRTEM, FE-SEM, contact angle measurement and nanoindentation testing. The MTBS data was analyzed with two-way ANOVA followed by LSD post-hoc test.ResultsMDP/EtOH₇₅ produced significantly greater MTBS values than MDP/EtOH₅₅ and control after thermocycling aging in dry- or wet-bonding mode (P < 0.05). The ATR-FTIR spectrums shows that ratios of phosphate/monomer (1,034 cm^?1/1,716 cm^?1) on MDP/EtOH₇₅-, MDP/EtOH₅₅-treated dentin surfaces are 0.51 and 0.23, respectively. This is confirmed by HRTEM images and SAED pattern that intrafibrillar minerals were mostly preserved after treatment with MDP/EtOH₇₅. MDP/EtOH₇₅ produced significantly higher elastic modulus and nanohardness on pretreated dentin surface than MDP/EtOH₅₅ (P < 0.05). TF-XRD pattern shows some MDP-Ca salts remained on the primed dentin surface.SignificancePrime-and-rinse approach using MDP/EtOH₇₅ micellar solution could produce mostly extrafibrillar demineralization, and greatly increase dentin bond durability in dry- or wet-bonding mode.     

评价新型粘接剂在不同粘接模式下的牙本质粘接性能

目的评价1种新型单瓶型多模式粘接剂在不同粘接模式下与牙本质的粘接强度和粘接耐久性。方法制作3组牙本质/复合树脂粘接试件,其中每组牙本质在粘接前接受不同的表面调节。包括不处理(空白对照),Singlebond Universal粘接剂自酸蚀模式下调节牙本质,Singlebond Universal粘接剂在酸蚀冲洗模式下调节牙本质。测量各组粘接试件水储24 h和180 d的微拉伸粘接强度值并进行统计分析。以扫描电子显微镜观察各组试件的粘接界面。结果不论老化前还是老化后,3组间的粘接强度均存在显著性差异,其中空白组的粘接强度值最低,另两组间则无显著性差异。人工老化使空白组的粘接强度值显著下降,而对另两组则并无显著影响。结论 Singlebond Universal粘接剂在自酸蚀粘接模式和酸蚀冲洗粘接模式下均能够形成与牙本质良好的粘接。     

Improving the effect of NaOCl pretreatment on bonding to caries-affected dentin using self-etch adhesives

Objective

To evaluate the effect of sodium hypochlorite pretreatment on adhesion to normal and caries-affected dentin using self-etch adhesives.

Methods

Forty extracted human molars with coronal carious lesions were used in this experiment. The occlusal dentin surfaces including the caries-affected dentin in each group were treated as follows: group 1, rinsed with water; group 2, treated with 6% NaOCl for 15 s; group 3, treated with 6% NaOCl for 30 s; group 4, application with Accel for 30 s after NaOCl-30 s pretreatment. After rinsing with water and air-drying, the treated dentin surfaces were applied with self-etch systems (Bond Force and Clearfil Protect Bond) according to the manufacturers’ instructions, and built-up with resin composite. After 37 °C water storage for 24 h, the bonded normal or caries-affected dentin areas were isolated to create an hourglass configuration with a cross-sectional area of approximately 1 mm². The specimens were subjected to tensile stress at a cross-head speed of 1.0 mm/min.

Results

NaOCl-15 s pretreatment significantly improved the μTBS of both self-etch adhesives to caries-affected dentin, while the 30 s pretreatment did not affect them. For normal dentin, NaOCl-30 s pretreatment significantly reduced the μTBS of both self-etch adhesives although the 15 s pretreatment did not alter them. Furthermore, the application of Accel with a reducing effect increased the μTBS to normal and caries-affected dentin treated with NaOCl for 30 s.

Conclusions

The effects of NaOCl pretreatment on bonding of both self-etch adhesives were dependent upon type of dentin (normal and caries-affected dentin) and the treatment time.     

Dentin bonding: effect of tubule orientation on hybrid-layer formation

Schüpbach P. Krejci I, Felix L: Dentin bonding: effect of tubule orientation on hybrid-layer formation.
In an attempt to compare the morphology of the resin-dentin interface in areas where the dentinal tubules run perpendicularly or at an angle to the cavity surface with that of areas where they run parallel to it, we studied a dentin adhesive system using transmission electron microscopy and fluorescence confocal laser scanning microscopy. The design of the study included the simulation of the normal hydrostatic pressure within the pulp and the dentinal tubules. Following acid etching of the dentinal surface with maleic acid/HEMA, the smear layer was removed, and a superficial zone was demineralized in such a way that the exposed collagenous dentin matrix retained its integrity. Confocal laser scanning microscopal investigations using primer labeled with rhodamine B showed that the penetration of the primer occurred not only vertically via surface porosities, but mainly laterally, via the dentinal tubules. The adhesive resin labeled with fluorescein completely infiltrated the demineralized layer, thereby forming a hybrid layer. The orientation of the dentinal tubules had a profound effect on the formation of the hybrid layer. In areas with perpendicular tubule orientation, the layer was 3.2 ± 0.8 μm thick, showing solid 27.2 ± 0.8 μm long resin tags in the dentinal tubules, and a network of tiny tags in their side-branches. In areas with parallel tubule orientation, the layer was significantly thinner (1.3 ± 0.6 μm) and resin tags were absent.     

Effect of combining dentin bonding agents

Abstract The wall-to-wall polymerization contraction of a light-cured composite was measured in cylindrical dentin cavities treated with the bonding agents: Scotchbond, Clearfil Bond, Gluma/Scotchbond, Gluma/Silux Enamel Bond or Gluma/Clearfil Bond. Marginal gaps were prevented in 29 out of 30 cases when Gluma was used in combination with Clearfil Bond. This combination mediates a mean bond strength between composite and dentin of 20 MPa.     

杨梅素对脱矿牙本质再矿化及树脂-牙本质粘接效果的影响

目的 评价杨梅素(myricetin,MYR)对脱矿牙本质基质的再矿化效果及其对牙本质粘接强度的影响。方法 切取中层牙本质,使用600目碳化硅砂纸湿抛光模拟玷污层,35%磷酸酸蚀后分别给予蒸馏水浸泡、直接再矿化处理2 d和MYR预处理30 min后再矿化处理2 d。采用扫描电镜(scanning electron microscope,SEM)观察样本表面形态,X射线衍射(X-ray diffraction,XRD)和衰减全反射傅里叶变换红外光谱(attenuated total reflection Fourier transform infrared spectroscopy,ATR-FTIR)分析表面物质,微拉伸强度(micro tensile strength,μTBS)和纳米渗漏实验观察粘接效果。结果 SEM发现再矿化处理的各组牙本质片均可以形成晶体,其中经MYR预处理后再矿化的样本形成的晶体最为明显,新形成的晶体经XRD和ATR-FTIR分析为羟基磷灰石。μTBS和纳米渗漏实验发现MYR预处理后的牙本质试件再矿化可明显增加粘接强度,减少纳米渗漏。结论 MYR预处理可以促进脱矿牙本质的再矿化过程并改善树脂-牙本质粘接强度。     

三种牙本质黏结剂对人牙髓细胞的细胞毒性

目的：比较不同固化时间下3种牙本质黏结剂（Dentin bonding agents，DBA）对牙髓细胞的细胞毒性，指导临床上合理选择黏结剂和掌握固化时间。方法：组织块培养法进行人牙髓细胞原代培养，并以免疫组织化学染色法鉴定。采用MTT比色分析法来评价3种DBA（Prime＆BondNT，Pb；XenoⅢ，Xe；AdheSE，Ad）的细胞毒性。结果：经ANOVA和Dunnett—t检验，与对照组相比，固化10s和40s的3种牙本质黏结剂对牙髓细胞均有毒性（P〈0．001），与浸渍液作用24h后一些牙髓细胞变圆、皱缩、失去细胞突起。固化10s的3种DBA中Ad对细胞毒性最大，Pb毒性最小；固化40s的3种DBA中Xe毒性最大，Pb毒性最小。与固化10相比，Xe和Ad固化40s可以减轻对牙髓细胞的毒性，经student—t检验，P〈0．01。结论：3种牙本质黏结剂对体外培养牙髓细胞均有一定毒性，延长固化时间可以减轻对牙髓细胞的毒性。