釉质粘结剂封闭牙本质小管的扫描电镜研究

在扫描电镜下可看到磨损的牙冠表面出现较多的牙本质小管开口,并与表面垂直。经过釉质粘结剂处理后,开放的牙本质小管部分或全部被树脂突样结构阻塞,封闭牙本质小管,从而可能阻断外界刺激,起到脱敏的效果。     

牙本质粘结剂治疗牙本质敏感症的疗效观察

目的 了解光固化牙本质粘结剂治疗牙本质敏感症的效果。方法 比较光固化牙本质粘结剂和局部涂氟化钠即刻、１月、１２月的疗效。结果 酸处理牙面后再行粘结剂治疗牙本质敏感症的近、远期疗效明显优于氟化钠甘油糊剂脱敏法（Ｐ〈０．０１）,非酸处理牙面行粘结剂脱敏的疗效也显著高于氟化钠甘油糊剂（Ｐ〈０．０５）,但远期疗效不如酸处理组（Ｐ〈０．０１）。结论光固化粘结剂治疗牙本质敏感症疗效好于传统的氟化钠甘油糊剂脱敏     

光固化粘结剂治疗牙本质过敏观察

光固化粘结剂治疗牙本质过敏观察广东省三水市西南镇医院健力宝口腔中心（５２８１００）应英牙本质过敏症是临床上常见的一种口腔内科疾病，以老年人牙龈萎缩根面暴露，重度面磨损，牙颈部缺损等最为常见，另外还见于青少年釉质发育不全以及一些医源性因素，临床症状主要...     

光固化粘结剂治疗牙本质敏感症的初探

采用单盲自身配对对照法，用光固化粘结剂和局部涂布氟化钠治疗牙颈部敏感症，平均疗效分别是７８．５％，６４．６％，经统计学处理ｐ＜０．０１，有高度显著性差别。故认为用光固化粘结剂治疗牙颈部牙本质敏感症优于氟化钠甘油糊剂脱敏法。实验组３月、６月、９月疗效分别为７４．２％、６１．３％、５８．７％，经统计学处理ｐ＞０．０５，表明其远期疗效较佳。     

光固化粘结剂治疗牙颈部牙本质敏感症的疗效观察

采用单盲自身配对对照法，用光固化粘结剂和局部涂布氟化钠治疗牙颈部敏感症，平均疗效分别是７８．５％，６４．６％，经统计学处理，Ｐ〈０．０１，有高度显著性差别。故认为用光固化粘结治疗牙颈部牙本质敏感症优于氟化钠甘油糊剂脱敏法。     

牙本质粘结剂的微拉伸强度测试

牙本质粘结剂微拉伸强度测试是近年来发展起来的一种新型测试方法和技术,较传统的剪切强度测试有许多独特优点。本文就微拉伸法的基本测试方法、特点、影响因素及体外临床粘结研究等问题进行综述。     

牙本质粘结剂应用于银汞充填的临床观察

评价临床上应用粘结技术粘结银汞充填体的效果,方法两种牙本质结剂被用于只有邻面箱状固位的Ⅱ类洞银汞充填体的粘结,并与传统的Ⅱ类洞银汞充填体进行临床比较研究。结果经二年的临床观察,两种牙本质粘结剂粘结的银汞充填体成功率二者间无显著性差异,但明显高于传统的银汞充填体的成功率。结论临床上牙本质粘结肯改善银汞充填体的固位力和密合度。     

牙本质粘结剂的微拉伸强度测试

牙本质粘结剂微拉伸强度测试是近年来发展起来的一种新型测试方法和技术,较传统的剪切强度测试有许多独特优点。本文就微拉伸法的基本测试方法、特点、影响因素及体外临床粘结研究等问题进行综述。     

5种牙本质粘结剂的细胞毒性研究

目的比较Clearfil S3 Bond和Single Bond,Clearfil SE Bond,XenoⅢBond,G Bond对L929细胞活力的影响。方法小鼠成纤维细胞L929在Clearfil S3 Bond,Single Bond,Clearfil SE Bond,XenoⅢBond,G-Bond五种牙本质粘结剂的不同体积分数浸渍液(100%、50%、25%、12.5%)作用不同时间(24 h、72 h、120 h)后,倒置相差显微镜观察细胞形态变化,MTT法测定细胞相对增值率(RGR);用5级毒性分类法评级,并进行统计分析。结果 5种牙本质粘结剂在不同体积分数浸渍液的作用下,L929细胞形态均发生不同程度的变化。在72 h、120 h后,12.5%Clearfil S3 bond组和Clearfil SE Bond组的RGR值显著高于其它各组的RGR值(P<0.05)。结论 5种牙本质粘结剂的体外细胞毒性均较弱,其中第7代牙本质粘结剂Clearfil S3Bond和第5代牙本质粘结剂Clearfil SE Bond的细胞毒性显著低于其他几种粘结剂,可以安全地应用于临床。     

牙本质粘结剂在前牙大面积缺损修复中的应用

目的观察牙本质粘结剂的临床修复效果。方法对52例患者87颗前牙,牙冠缺损1/2以上,经完善的根管治疗,采用牙本质粘结剂进行纤维桩树脂核全冠修复。结果经3个月~2年的随访观察,修复成功率为97.7%。结论牙本质粘结剂具有良好的粘结效果。     

Raman spectroscopy for early detection and monitoring of dentin demineralization

Early detection of dental caries and variations in composition/structure of both enamel and dentin represents an important issue in modern dentistry. Demineralization has been associated to teeth discoloration, development of caries, and formation of cavities.ObjectiveIn this study, we systematically monitored the processes of demineralization/remineralization in dentin samples by means of three different spectroscopic techniques, namely, Raman spectroscopy, X-Ray Photo-electron spectroscopy (XPS), and X-Ray Diffractometry (XRD).MethodsBovine dentin samples were first exposed to acidic solutions and their structure systematically monitored as a function of time and pH. Then, the samples were rinsed in artificial saliva to simulate remineralization.ResultsThe above three spectroscopic techniques provided quantitative structural information spanning from the nanometer to the millimeter scale of sample penetration depth. An irreversible level of demineralization was reached when dentin was exposed to pH 2 beyond a time threshold of 6 h, successive treatments with artificial saliva being unable to restore the mineral fraction. On the other hand, short-term treatments at pH 5 and long-term treatments at pH 6 could partially or completely recover the dentin structure within one week of remineralization treatment.SignificanceTwo specific Raman parameters, namely, the bandwidth of the symmetric phosphate-stretching signal and the mineral-to-matrix intensity ratio, showed strong correlations with XPS and XRD data, and matched laser microscopy observations. Such correlations open the path to apply Raman spectroscopy in monitoring dentin demineralization in vivo and provide quantitative working algorithms for the prevention of oral caries.     

五种牙本质粘接剂对乳牙牙本质边缘封闭性的比较

目的 检测5种牙本质粘接剂对乳牙牙本质的粘接性能,为牙本质粘接剂的临床使用提供依据.方法 将50颗因滞留而拔除的乳前牙按随机数表法分为5组,每组10颗.用棒状金刚砂车针EX-41在唇面中1/3处制备约直径1.5mm、深1mm的Ⅰ类洞,各组分别使用FL-BondⅡ、Clearfil Protect Bond、Clearfil SE Bond、AdperTMEasy One和AdperTM Single Bond 2,每组分别按说明进行粘接,树脂充填.冷热循环5000次,体视镜下观察充填物边缘染料渗入的深度、分级进行统计.结果 各组均发生微渗漏,各组间微渗漏程度差异无统计学意义(P＞0.05).结论 AdperTM Easy One组的边缘封闭性与其他4组相同,由于操作简便更适用于儿童乳牙的粘接.     

Effect of reducing agents on bond strength to NaOCl-treated dentin

Objective

The purpose of this study was to evaluate the effect of three antioxidant/reducing agents with different application times on microtensile bond strengths to sodium hypochlorite-treated dentin.

Methods

The occlusal surfaces of 24 extracted human third molars were horizontally cut to expose sound dentin. The teeth were divided into eight groups. The dentin surfaces of the teeth were treated as follows: group 1, no treatment; group 2, treated with 6% sodium hypochlorite (NaOCl) for 30 s; groups 3-8, applications of 10% sodium ascorbate solution, 100 μM rosmarinic acid solution or Accel for 5 or 10 s after the same treatment as in group 2. All treated dentin surfaces were bonded with a 2-step self-etching adhesive system (Clearfil Protect Bond) and restored with a resin composite (Clearfil AP-X). After storage in water for 24 h, the bonded specimens were subjected to the microtensile bond test at a crosshead speed of 1.0 mm/min. Data were analyzed by a one-way ANOVA and Tukey test (p < 0.05).

Results

The NaOCl-treated group had significantly lower bond strength than the control group (p < 0.05). The application of sodium ascorbate solution for 5 or 10 s did not significantly increase the compromised bonding to NaOCl-treated dentin (p > 0.05). On the other hand, Accel and rosmarinic acid solution had significant reversal effects with the same application times (p < 0.05).

Significance

The reversal effect on compromised bonding to NaOCl-treated dentin depended upon the type of antioxidant within the short application time. Applying Accel or rosmarinic acid for 5 or 10 s improved bond strengths to NaOCl-treated dentin.     

Effect of biomimetic mineralization on enamel and dentin: A Raman and EDX analysis

ObjectiveTo investigate the effect of an experimental biomimetic mineralization kit (BIMIN) on the chemical composition and crystallinity of caries-free enamel and dentin samples in vitro.MethodsEnamel and dentin samples from 20 human teeth (10 for enamel; 10 for dentin) were divided into a control group without treatment and test samples with BIMIN treatment. Quantitative analysis of tissue penetration of fluoride, phosphate, and calcium was performed using energy-dispersive X-ray spectroscopy (EDX). Mineralization depth was measured by Raman spectroscopy probing the symmetric valence vibration near 960 cm⁻¹ as a marker for crystallinity. EDX data was statistically analyzed using a paired t-test and Raman data was analyzed using the Student’s t-test.ResultsEDX analysis demonstrated a penetration depth of fluoride of 4.10 ± 3.32 μm in enamel and 4.31 ± 2.67 μm in dentin. Calcium infiltrated into enamel 2.65 ± 0.64 μm and into dentin 5.58 ± 1.63 μm, while the penetration depths for phosphate were 4.83 ± 2.81 μm for enamel and 6.75 ± 3.25 μm for dentin. Further, up to 25 μm of a newly mineralized enamel-like layer was observed on the surface of the samples. Raman concentration curves demonstrated an increased degree of mineralization up to 5–10 μm into the dentin and enamel samples.SignificanceBiomimetic mineralization of enamel and dentin samples resulted in an increase of mineralization and a penetration of fluoride into enamel and dentin.     

Analysis of the dentin–resin interface by use of laser Raman spectroscopy

OBJECTIVES: Adhesion of resin-bonding agents to dentin is currently believed to result from impregnation of adhesive resin into superficially demineralized dentin. The purpose of this study was to investigate the chemical composition of the resin-impregnated dentin (hybrid) layer using a micro-Raman spectroscopy. METHODS: Resin composites were bonded to bovine dentin with the two-step bonding systems, and specimens were sectioned parallel to dentinal tubules. These surfaces were then polished down to 1 microm diamond pastes. Raman spectra were successively recorded along a line perpendicular to the dentin-adhesive interface by steps of 0.2 microm on a computer controlled X-Y stage. The relative amounts of hydroxyapatite (960 cm(-1), P-O), adhesive resin (640 cm(-1), aromatic ring), and organic substrate (1450 cm(-1), C-H) in the dentin-adhesive bonding area were calculated. RESULTS: From the Raman spectroscopy results, the hybrid layer represents a gradual transition in the relative amount of adhesive from the resin side to dentin side. Evidence of poor saturation of the adhesive resin in the demineralized dentin with the one-bottle adhesive system was detected. SIGNIFICANCE: From the results of this study, inhomogeneity of the hybrid layer composition was detected, and the degree of resin impregnation was found to be different between the bonding systems tested.     

Durability of bonds and clinical success of adhesive restorations

Resin-dentin bond strength durability testing has been extensively used to evaluate the effectiveness of adhesive systems and the applicability of new strategies to improve that property. Clinical effectiveness is determined by the survival rates of restorations placed in non-carious cervical lesions (NCCL). While there is evidence that the bond strength data generated in laboratory studies somehow correlates with the clinical outcome of NCCL restorations, it is questionable whether the knowledge of bonding mechanisms obtained from laboratory testing can be used to justify clinical performance of resin-dentin bonds. There are significant morphological and structural differences between the bonding substrate used in in vitro testing versus the substrate encountered in NCCL. These differences qualify NCCL as a hostile substrate for bonding, yielding bond strengths that are usually lower than those obtained in normal dentin. However, clinical survival time of NCCL restorations often surpass the durability of normal dentin tested in the laboratory. Likewise, clinical reports on the long-term survival rates of posterior composite restorations defy the relatively rapid rate of degradation of adhesive interfaces reported in laboratory studies. This article critically analyzes how the effectiveness of adhesive systems is currently measured, to identify gaps in knowledge where new research could be encouraged. The morphological and chemical analysis of bonded interfaces of resin composite restorations in teeth that had been in clinical service for many years, but were extracted for periodontal reasons, could be a useful tool to observe the ultrastructural characteristics of restorations that are regarded as clinically acceptable. This could help determine how much degradation is acceptable for clinical success.     

Vibrational analysis by Raman spectroscopy of the interface between dental adhesive resin and dentin

The Raman microprobe technique was applied for analysis of the molecular components at the adhesive interface between 4-META/MMA-TBB resin and dentin. The Raman spectra showed that the 4-META molecules in monomer solution were mostly hydrolyzed into 4-MET molecules, which were then co-polymerized with MMA molecules to form resin and resin-reinforced dentin layers. On the basis of line analysis by the Raman microprobe, resin molecules were estimated to penetrate 6 microns into the dentin from the interface. Raman intensity studies indicated that the concentration of 4-MET molecular units in the resin-reinforced dentin was more than four times the concentration in the original monomer solution. This demonstrated the excellent infiltration ability of 4-MET monomer into dentin substrate in situ.     

Two-year clinical evaluation of three adhesive systems in non-carious cervical lesions

Objectives

Adhesive systems are continuously being introduced to Dentistry, unfortunately often without sufficient clinical validation. The aim of this study was to evaluate the clinical performance of cervical restorations done with three different adhesive systems.

Material and methods

158 non-carious cervical lesions of 23 patients were restored with a nanofilled composite resin (Filtek Supreme, 3M/ESPE) combined with Single Bond (3M/ESPE, group SI), Clearfil SE (Kuraray Medical Inc., group CL) and Xeno III (De Trey Dentsply, group XE). In groups SI-B, CL-B and XE-B, the outer surface of the sclerotic dentin was removed by roughening with a diamond bur before application of the respective adhesive systems. In groups CL-BP and XE-BP, after removal of the outer surface of the sclerotic dentin with the bur, the remaining dentin was etched with 37% phosphoric acid and the self-etch adhesive systems Clearfil SE and Xeno III were applied, respectively. Lesions were evaluated at baseline, and restorations after 3 months, 1 year and 2 years using modified USPHS criteria.

Results

After 2 years, no significant difference was found between the retention rates of the groups (p >0.05). Although groups CL and SI showed significantly better marginal adaptation than group XE (p<0.05) at 2 years, no significant difference was found between the marginal adaptation of the groups SI-B, CL-B and XE-B (p>0.05). After 2 years no significant difference was observed among the marginal staining results of all groups (p>0.05).

Conclusion

Although all adhesive systems showed similar retention rates, Clearfil SE and Single Bond showed better marginal adaptation than Xeno III after 2 years of follow-up.     

次氯酸钠处理对牙本质粘结强度的影响

目的研究NaOCl不同处理方法对临床常用粘结剂与牙本质粘结强度的影响。方法新鲜拔除的完整无龋人磨牙60颗，近远中向劈开后制备牙本质粘结面，随机分为5组：常规酸蚀处理组、NaOCl处理组、磷酸／NaOCl处理组，NaOCI／磷酸处理组，蒸馏水（空白对照组）。每组牙本质面处理后分别以One—Step（OS）。Prime＆Bond NT（PB）及SingleBond（SB）与复合树脂粘结。试件制备后于37℃蒸馏水中浸泡24h，测试抗剪切强度并进行统计学分析。结果常规酸蚀处理后，各粘结剂与牙本质的粘结强度无显著差异。NaOCI／磷酸处理后．与酸蚀处理相比OS的粘结强度显著增加，PB与SB的粘结强度下降（P〈0．05）。NaOCl处理后，PB与牙本质的粘结强度显著升高（P〈0．05）。结论Na0Cl去除胶原纤维层用于牙本质的粘结前处理具有较好的应用前景．但对于其粘结性能的评价及粘结机理还有待于进一步的深入研究。     

三种牙本质粘接系统微拉伸粘接强度的比较

目的　用微拉伸粘接强度检测法评价 3种不同类型的牙本质粘接系统与正常牙本质的粘接强度 ,用扫描电镜分析其断裂类型。方法　选择 15颗正畸治疗拔除的健康前磨牙 ,去除面釉质层 ,随机均分为 3组。选用 3种牙本质粘接系统All Bond 2 (AB2 组 ) ,Fluoro Bond (FB组 )和XenoⅢ (Xeno组 ) ,分别按厂商说明书要求用于暴露的表层牙本质面上 ,再用蓝色复合树脂恢复牙冠至要求高度。用低速锯将牙齿片切为横截面积约 0 81mm2 的长方体状样本 ,用微拉伸测试仪检测其粘接强度 ,加载速度为 1mm/min。用扫描电镜观察样本断端形态 ,对微拉伸粘接强度测试值和断裂类型进行统计学分析。结果　 3种牙本质粘接系统的微拉伸粘接强度分别为AB2 组 :( 2 9 5 6± 5 4 7)MPa ,Xeno组 :( 15 81± 7 6 7)MPa,FB组 :( 14 6 1± 4 5 0 )MPa。AB2 组的微拉伸粘接强度高于Xeno组和FB组 (P <0 0 1) ,后两者的测值间差异无显著性 (P >0 0 5 )。扫描电镜观察结果显示 ,绝大部分样本的断裂类型都是粘接面型断裂。结论　 3种牙本质粘接系统与正常牙本质的粘接强度存在差异 ,All Bond 2的粘接强度最高 ,但临床操作复杂 ,技术要求较高 ;Fluoro Bond和XenoⅢ使用方法较简单 ,对牙髓的影响可能较小。