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目的评价根管封闭剂iRootSP的根尖封闭效果。方法选择2012年9—12月中国医科大学口腔医学院口腔外科拔除的单根管前牙50颗,随机分为2个实验组（A、B组,每组20颗）和2个对照组（c组为阳性对照组,D组为阴性对照组,每组5颗）。所有牙均常规开髓、拔髓,采用机用ProTaper设备根管至F2。A、B组分别采用根管封闭剂iRootSP加单尖充填技术和根管封闭剂AHPlus加单尖充填技术充填根管,c、D组均不做任何根管充填;4组牙齿均用光固化复合树脂充填髓腔及开髓孔。A、B、c组在除根尖孔2mm外的整个牙根表面均匀涂布指甲油2遍,D组在牙根表面及根尖孔全部涂布指甲油2遍。采用染料渗透法检测根尖微渗漏情况,对各组染料渗透长度进行比较分析。结果A、B组均有不同程度的根尖微渗漏,A组染料渗透长度为（1．62±0．20）mm,B组为（1．80±0．20）mm,两组间差异无统计学意义（P〉0．05）。作为阳性对照的c组,染料渗透长度为（10．75±1．28）mm,几乎渗入牙根全长;作为阴性对照的D组,则无染料渗入牙根。结论根管封闭剂iRootSP的根尖封闭性能与AHPlus相似。由于单尖充填技术操作简便,副损伤小,省时省力,具有良好的临床应用前景。     

An in vitro evaluation of four materials as barriers to coronal microleakage in root-filled teeth

AIM: To assess the ability of IRM, Coltosol, Vidrion R and Scotch Bond to seal the pulp chamber following root-canal treatment. METHODOLOGY: Root-canal treatment was completed on 100 extracted human mandibular molars. The teeth were divided into five groups of 20 teeth each, one group for each barrier material and one control group without barrier material. Two millimetres of the restorative material was placed on the pulp chamber floor. The teeth were thermocycled and evaluated for microleakage using India ink. Specimens were cleared and measurements made to the maximum point of dye penetration. The mean dye penetration for each group was compared by the Kruskal-Wallis test. RESULTS: All groups showed dye penetration. Coltosol and IRM sealed significantly better than the other groups, preventing the coronal leakage in 84% and 75% of the specimens, respectively. Scotch Bond exhibited the highest leakage (54% of specimens with dye penetration), which did not differ significantly from the positive control group (62% with dye penetration). CONCLUSIONS: None of the materials were able to prevent microleakage in all specimens. Vidrion R and Scotch Bond demonstrated the poorest results when used as barriers to coronal microleakage, whilst IRM and Coltosol were significantly better in preventing microleakage.     

Effect of Resin Coating and Chlorhexidine on the Microleakage of Two Resin Cements after Storage

Purpose: This study evaluated the effect of resin coating and chlorhexidine (CH) on microleakage of two resin cements (Panavia F2.0, Nexus 2) after water storage. Materials and Methods: Class V cavities were prepared on the facial and lingual surfaces of 120 intact human molars with gingival margins placed 1 mm below the cementoenamel junction. Indirect composite inlays were fabricated. The specimens were randomly assigned into six groups (n = 40). Indirect composite inlays (Gradia) were cemented as follows: Group 1 (control): inlays were cemented with Panavia F2.0 according to the manufacturer's instructions. Group 2: the ED‐primed (ED Primer, Kuraray Dental, Tokyo, Japan) dentin was coated with a resin layer before cementation of the inlays with Panavia F2.0. Group 3: a 2% CH solution was applied before bonding with Panavia F2.0. Group 4: after CH application, the primed dentin was coated with a resin layer before cementation with Panavia F2.0. Group 5: (control) after applying Optibond Solo Plus, the inlays were cemented with Nexus 2. Group 6: after etching, CH was applied, and cementation was performed similarly to group 5. Half the specimens in each group were stored in distilled water for 24 hours, while the other half were stored in distilled water for 6 months. After storage, the teeth were placed in 1% methylene blue dye for 24 hours, sectioned, and evaluated under a 20× stereomicroscope. Dye penetration was scored using 0 to 3 criteria. Data were analyzed using nonparametric tests. Results : Resin coating of ED primer for Panavia F2.0 significantly reduced microleakage at the gingival margins after 6 months (p < 0.05). CH application in Panavia F2.0 did not lead to a significant difference in the microleakage at both margins, after 24 hours and 6 months (p > 0.05). The application of CH showed significantly less microleakage than that of the control group at the gingival margins of Nexus 2 after 6 months. In general, gingival margins showed more microleakage than occlusal margins. Conclusion: An additional resin layer applied to a self‐etch cement can improve long‐term dentinal sealing for indirect restorations, while CH cannot; however, CH reduces gingival microleakage in an etch‐and‐rinse cement after aging.     

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良好的封闭是桩冠修复成功的标准之一,微渗漏的检测是对其封闭性进行评价的主要方法。微渗漏是牙体缺损修复后普遍存在的一种临床现象,是指口腔中的细菌、唾液及其他有害物质渗入修复材料与牙体组织之间的微     

Microbial microleakage and pulpal inflammation: A review

Abstract The evidence relating microbial microleakage and pulpal inflammation is reviewed. In vitro experiments show that all current dental materials permit fluid microleakage at the material/cavity wall interface. in vivo, this fluid microleakage is accompanied by bacterial growth, unless the material has lasting antibacterial properties. An association does exist between the presence of bacteria at the material/cavity wall interface and the presence of pulpal inflammation. The role of the smear layer m minimizing the harmful effects of microbial microleakage and of chemical toxicity of restorative material is reviewed. Further research should be aimed at eliminating microleakage by the development of more fully adhesive materials or by improving their antibacterial properties.     

Replica patterns on composite restorations performed in vitro with different acid-etch procedures and dentin adhesives

Abstract — 160 experimental Class V restorations using two chemically cured composite resins were inserted in extracted human teeth wjth conventional and modified acid-etch restorative procedures. The modifications included cavity treatment with non-composite resin, ethanol, or four different dentin adhesives. Following deemineralization of the teeth the fillings were examined in the SEM cuncerning their replica patterns 01 the etched cavity walls. In vitro conditions favored resin penetration into pretreated cnarnel and dentin; but resulted in minor variations between diltrerent acid-etch procedures compared with those previously seen on resin restorations plawd in viva in teeth with vital pulps.     

In Vitro Study on the Adhesive Performance of Some Resin-Based Materials Used to Restore Class II Cavities

The study aimed to evaluate the adhesive performances of two ormocer materials and two micro-hybrid composites placed to restore class II cavities. We tested the null hypothesis, which considered that the adhesive behaviors of tested materials did not differ. On each extracted tooth, two class II cavities were prepared having an enamel located cervical margin and a cementum located cervical margin, respectively, and were restored using two different restoration techniques. The teeth followed a tooth impregnating protocol and were sectioned and evaluated by optical microscopy to highlight the marginal microleakage around restorations. Cervical and occlusal microleakage as well as microleakage ratios were calculated. The microleakage test showed that all tested materials exhibited some degree of dentinal microleakage both on cervical and occlusal areas irrespective of the restoration technique. Some significant differences were recorded in adhesion performance of the materials. The cervical microleakage ratio was significantly increased for one of the micro-hybrid resin composites in comparison with one of the ormocer materials (p = 0.0159). Significantly differences were observed in occlusal microleakage ratios when the two micro-hybrid composites were compared (p = 0.047). The results failed to reject the null hypothesis. The present study could not demonstrate the superiority of ormocer-materials relative to conventional composites.     

桩道预备时机对两种根尖封闭剂封闭效果影响的研究

目的：研究不同桩道预备时机对两种根管封闭剂充填的根管封闭效果的影响。方法：70个单根管离体牙,采用逐步后退法预备根管,随机分为2组,分别采用AHPlus和Cortisomol根管封闭剂加牙胶尖侧方加压充填根管,对两组标本分别进行即刻和延迟一周桩道预备,每组抽取5颗牙为阴性对照不进行桩道预备,观察根尖部染料微渗漏情况。结果：AHPlus组较Cortisomol组能够更好地封闭根尖,但两者微渗漏值无明显统计学差异。延迟桩道预备组根尖微渗漏值显著高于阴性对照组和即刻预备组,差异有统计学意义。结论：即刻桩道预备能够更好地保护根尖封闭效果。     

不同粘结剂与桩核材料微渗漏发生的实验研究

目的：评价不同核材料修复后的牙齿经铸造金属全冠修复后边缘微渗漏的情况。方法：将90个大小相似的完好前磨牙,随机分为9个实验组。对离体牙进行铸造金属全冠及固定尺寸的Ⅱ类洞牙体预备后,分别用3种不同的核材料（树脂、银汞合金、铸造合金）充填窝洞。常规方法铸造镍铬合金全冠,用3种不同的粘结材料（聚羧酸锌、玻璃离子、树脂C＆B）进行粘固。温度循环、染色、包埋后,标本片切,镜下观察冠边缘及核下微漏情况。结果：银汞核与树脂核下微漏小于铸造核（P〈0.05）,树脂粘结剂抗微漏性能优于聚羧酸锌水门汀和玻璃离子粘结剂（P〈0.05）。结论：树脂粘接剂抗微漏性能优于玻璃离子与聚羧酸锌粘结剂。树脂核在预先对粘结面处理后,其抗微漏性能与银汞核近似,优于铸造合金核。     

继发龋的研究进展

继发龋是指使用充填材料治疗龋病后发生在充填体边缘的龋坏,是迄今临床上充填体更换最常见、最重要的原因之一。继发龋依据发生部位通常包括外层病损和洞壁病损2个部分。由于任何充填材料无法避免都会出现微渗漏,所以长久以来很多研究均集中于微渗漏和继发龋相关性的问题,但对此仍存在着争议。至今为止,继发龋的微生物学和特异性致病微生物没有明确的定论。现在大量的研究主要集中于各种充填材料的防龋作用,尤其是氟化物。本文将从以上这几方面作一综述。