有无洞缘斜面对聚合瓷嵌体微渗漏影响的实验研究

目的评估洞缘斜面对聚合瓷嵌体直接修复的边缘微渗漏的影响。方法 60颗人磨牙随机分成2组,每组30颗,在每颗牙的近中HE面制备典型的Ⅱ类洞,一种制备短斜面,一种不制备短斜面,聚合瓷嵌体直接修复经硝酸银染色后,每颗牙沿近远中方向经修复体切为3部分,取中间部分为观察对象。结果聚合瓷嵌体直接修复在HE面的微渗漏有明显差异（P〉0.05）。结论斜面组的微渗漏现象要比不做斜面的少,但是在HE面无明显差异（P〉0.05）,在龈壁则有显著差异（P〈0.05）。     

Correlation between microleakage and cement thickness in three Class II inlay ceramic systems

The objectives of this study include comparing the cement thickness and microleakage of Class II ceramic inlays built with three ceramic systems and verifying whether there was a correlation between those two variables. The ceramic systems used include: 1) Heat-pressed (IPS-Empress); 2) CAD-CAM (CEREC 2) and 3) Sintered (Colorlogic). Standardized MOD Class II inlay cavities with one proximal box extending below and the other extending above the cement-enamel junction (CEJ) were prepared in 30 extracted human molars and randomly assigned to three groups. The ceramic inlays were constructed according to manufacturer's instructions and cemented using a dual-cure resin cement (Variolink II). All teeth were mechanically cycled (100,000 cycles, 78N) and thermocycled (700 cycles, 5 degrees C-55 degrees C). After immersion in silver nitrate, the inlays were sectioned mesial-distally and evaluated with an optical microscope (40x). The cement thickness obtained by the Colorlogic system (enamel: 113 +/- 25 microm; dentin: 118 +/- 23 microm) was significantly higher than that obtained by CEREC (enamel: 78 +/- 14 microm; dentin: 87 +/- 13 microm) and Empress (enamel: 65 +/- 15 microm; dentin: 89 +/- 14 microm). Regarding dye penetration, there was no statistical difference among the three ceramic systems in enamel. At the dentin margins, the Colorlogic system resulted in a significantly higher penetration depth compared to CEREC and Empress, which had similar average values. No correlation was found between cement thickness and microleakage either in enamel or dentin for any of the ceramic systems.     

瓷嵌体与树脂嵌体边缘微渗漏的对比研究

目的：对比研究Ceramage聚合瓷嵌体和复合树脂嵌体、铸瓷嵌体的边缘微渗漏情况.方法：40颗离体牙按嵌体备洞原则制备近中邻（牙合）Ⅱ类洞,随机分为4组,每组10颗.分别用Ceramage、Z350、P60、IPS EmpressⅡ制作嵌体后使用Single Bond 2和Rely X ARC进行粘接.经冷热循环500次后品红染色,金刚砂片平行于牙体长轴沿近远中方向将修复体纵向剖开2次,在体式显微镜下测量染料渗入轴壁、龈壁的深度.结果：4种材料微渗漏长度经单因素方差分析有统计学意义（轴壁：F=6.667,龈壁：F=11.1,P＜0.01）,q检验进行组间两两比较,IPS EmpressⅡ的微渗漏值高于Ceramage、Z350、P60,差异有统计学意义（P＜0.05）,其他三组间差异无统计学意义（P＞0.05）;同材料组的龈方渗漏程度均显著高于轴壁,配对t检验显示差异有统计学意义（P ＜0.01）.结论：从微渗漏深度进行评价,Ceramage聚合瓷是临床上制作树脂嵌体较理想的材料;     

Comparison of the accuracy of bracket placement between direct and indirect bonding techniques.

An in vitro study was conducted to evaluate the accuracy of bracket placement for direct and indirect bonding techniques. Nineteen sets of duplicated Class II malocclusion models were divided into three groups: (1) one set for ideal bracket placement, (2) nine sets for direct bonding on mannequins, and (3) nine sets for indirect bonding. Both direct and indirect bonding were performed on all teeth except molars by nine faculty members from the Department of Orthodontics, University of Pennsylvania. The position of each bonded bracket from these two bonding groups was compared with that of the same tooth from the ideal group and to each other in terms of bracket height, mesiodistal position, and angulation. Our results indicated that both direct and indirect bonding techniques failed to execute ideal bracket placement. On individual teeth, there was no statistically significant difference in the accuracy of bracket placement between these two bonding techniques except for upper right second premolar and lower left central incisor, where indirect bonding yielded better results in bracket height (P < .05), and for lower left central incisor where indirect bonding was better in mesiodistal position (P < .05), and for upper right lateral incisor where direct bonding was closer to the ideal in angulation (P < .05). Overall, indirect bonding showed better bracket placement in bracket height (P < .05), whereas, no statistically significant difference was found between them regarding the angulation and mesiodistal position.     

Amalgam alternatives – microleakage evaluation of clinical procedures. Part II: direct/indirect composite inlay systems

SUMMARY This study investigated the degree of dye penetration of two composite inlay systems with different adhesive and bonding protocol. Forty whole extracted premolars and molars were collected. The teeth were immediately stored in water at room temperature. Class II cavity preparations were prepared and restored both, in the direct and the indirect techniques (Coltene Brilliant^®) and (Kulzer Estilux posterior CVS^®). The inlays were cemented with a composite luting cement (ART^®‐Bond) and (Kulzer, Adhesive cement^®). Specimens were subjected to 750 cycles of thermal stress. They were than immersed in 2% Basic fuchsin dye. The teeth were sectioned in three planes before being ranked as to the amount of dye penetration. The data were analysed by the Wilcoxon's rank test at the 95% confidence level. There was no statistically significant difference between the direct and indirect technique considered separately for each composite inlay material, at the cervical margin location. The fuchsin staining in the occlusal area was limited to the enamel in all groups. By using the composite inlay, the factor of adaptation and bonding of composites to dentine become the significant factor contributing to leakage.     

Radiopacity of direct ceramic inlay restoratives

The radiopacity of two new ceramic restorative materials (Dicor MGC and Cerec Vita Blocks) manufactured for use in producing direct inlays with the ‘Cerec CAD-CAM’ system was determined. Dicor MGC had a radiopacity significantly greater than that of enamel, while Cerec Vita Blocks had a radiopacity significantly less than that of dentine. It is concluded that Dicor MGC has a radiopacity suitable for its use as an intracoronal restorative for posterior teeth. The low radiopacity of Cerec Vita Blocks means that the use of radiopaque luting cement is essential to permit detection of secondary caries around restorations of this material. Furthermore, marginal overhangs around restorations made from Cerec Vita Blocks will be difficult to detect radiographically.     

树脂嵌体修复磨牙髓室底穿孔的形态学及微渗漏研究

目的研究树脂嵌体修复离体人恒磨牙髓室底穿孔的形态学及封闭效果。方法将50颗新鲜拔除的离体人恒磨牙随机分为A、B、C 3个实验组（每组15颗牙）和1个对照组（5颗牙）。制备髓室底穿孔后,A组采用树脂嵌体和AH Plus糊剂修复髓室底穿孔,B组采用树脂嵌体和玻璃离子修复髓室底穿孔,C组采用光固化复合树脂直接充填修复髓室底穿孔。对照组5颗离体牙,只开髓不制备髓室底穿孔。体视显微镜下观察髓室底穿孔修复后的外形恢复情况,葡萄糖氧化酶－蒽酮法测定微渗漏情况。结果嵌体法修复髓室底穿孔的形态恢复优良率为83.3%,直接充填法修复髓室底穿孔的形态恢复优良率为46.7%,两种方法修复的形态恢复优良率之间的差异有统计学意义（P<0.05）。3组在各个时间点上任意2组的日均葡萄糖浓度差异都有统计学意义,A组相似文献   

A comparison between the microleakage of direct and indirect composite restorative systems

The present study compares the microleakage of direct and indirect restorations. Two dentine bonding agents were evaluated with both techniques. Class V cavities, approximately 2 mm in depth and 4 mm in diameter, were prepared in extracted human molars. Cavities were placed in either mesial or distal surfaces and were centred at the amelodentinal junction. Microleakage was rated after silver nitrate staining. With both dentine bonding agents, the indirect method resulted in significantly (P less than 0.001) reduced microleakage. Choice of adhesive for the indirect method was also significant, perhaps due to polymerization shrinkage of the composite cement used for placement. It is suggested that the indirect method may be less technique sensitive and less dependent on the early bond strengths of different adhesives.     

干粘结和湿粘结对钛合金嵌体微渗漏的影响

目的对比3MESPE RelyXTMARC黏接水门汀在干燥和湿润两种状态下对钛合金嵌体微渗漏的影响。方法选择20颗因阻生新拔除的完整无隐裂、无磨耗的第三磨牙,随机分成2组,制备成邻牙合嵌体洞,分别在干燥和湿润两种状态下,用3MESPE RelyXTMARC黏接水门汀粘结钛合金嵌体,用体视显微镜观测嵌体密合度和嵌体微渗漏。结果两种粘接法嵌体密合度无显著差异(P>0.05),微渗漏深度有极显著差异(P<0.001)。结论以釉质壁为主的窝洞干粘结效果显著,以牙本质壁为主的窝洞湿粘结效果好。     

微瓷树脂嵌体和复合树脂嵌体微渗漏的对比研究

目的 对比研究1种微瓷聚合树脂嵌体和另外3种复合树脂嵌体的边缘微渗漏情况,为临床选择嵌体材料提供参考。方法 将80颗健康离体上颌前磨牙随机分为8组,每组10颗,嵌体窝洞制备后,分别用微瓷聚合树脂Ceramage（C）和复合树脂Brilliant new line(B)、Z350(Z)、P60(P)间接法制成嵌体,每种材料2组,使用即刻牙本质封闭(immediate dentin sealing,IDS)/延时牙本质封闭(delayed dentin sealing,DDS)技术粘结,冷热循环品红染色后,用金刚砂片将实验牙切开,体视镜下观察微渗漏。结果 4种树脂嵌体龈壁与轴壁微渗漏无显著性差异（P>0.05）,各IDS组与DDS组微渗漏亦无显著性差异（P>0.05）。无论龈壁还是轴壁,采用IDS或DDS粘结技术,4种材料之间皆有显著性差异（P<0.05）并且渗漏情况一致。微渗漏从小到大依次均为C、Z、P、B。结论 单从微渗漏方面评价,Ceramage和Z350均为制作树脂嵌体的良好选择。     

树脂直接充填与超瓷嵌体修复牙体缺损的微渗漏比较

目的 探讨用Filtek Z350复合树脂和超瓷嵌体修复Ⅰ类、Ⅱ类洞的边缘微渗漏的差异.方法 选取40颗新鲜拔除的第三磨牙,随机分成4组,每组10颗.A1组为Ⅰ类洞树脂直接充填,A2组为Ⅱ类洞树脂直接充填,B1组为Ⅰ类洞型超瓷嵌体修复,B2组为Ⅱ类洞超瓷嵌体修复.4组均置于1％碱性品红溶液染色21 d.用低速金刚砂锯沿牙体长轴近远中向切开,制备牙齿切片,体视显微镜观测粘接界面染色剂渗透深度.结果 （1）Ⅰ类（Z=5.909）、Ⅱ类洞（轴壁Z=5.504,龈壁Z=2.958）超瓷嵌体的边缘微渗漏都显著小于Z350复合树脂直接充填（P＜0.05）;（2）无论树脂直接充填（Z=1.413）还是嵌体修复（Z=0.455）,Ⅰ类、Ⅱ类洞的微渗漏差异无统计学意义（P＞0.05）.结论 超瓷嵌体修复是牙体缺损理想的修复方法.     

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目的：通过对比4种牙本质黏结剂处理牙面后Ceramage聚合瓷嵌体的微渗漏程度,为黏结剂的临床选择提供参考。方法收集2012年7-9月在周口市第二人民医院口腔科因正畸需要拔除的牙体发育正常、无龋的前磨牙40颗,随机分为4组,每组10颗。40颗离体牙均按照嵌体备洞原则制备近中邻牙合Ⅱ类洞,Ceramage聚合瓷制作树脂嵌体,各组分别涂布牙本质黏结剂Prime＆Bond NT、Adper Single Bond 2、Clearfil SE Bond、Clearfil S3 Bond,用Rely X ARC树脂水门汀黏结嵌体。所有试件经冷热循环500次及品红染色后,金刚砂片平行于牙体长轴沿近远中方向将修复体纵向剖开2次,在体视显微镜下测量染料渗入轴壁、龈壁的深度。结果轴壁：4组的微渗漏程度比较,差异有统计学意义（F=8.3125,P〈0.01）;Clearfil S3 Bond组的微渗漏程度高于Clearfil SE Bond （q=5.7708）、Adper Single Bond 2（q=6.4032）和Prime＆Bond NT组（q=4.0316）,差异有统计学意义（P〈0.01）,而其他3组间差异无统计学意义（P〉0.05）。龈壁：不同黏结剂之间的微渗漏差异无统计学意义（F=0.5897,P〉0.05）。同种黏结剂的龈壁微渗漏程度均显著高于轴壁,配对t检验显示差异有统计学意义（P〈0.01）。结论Clearfil S3 Bond对牙釉质的封闭效果较差;从微渗漏深度大小和操作方法上进行评价,Clearfil SE Bond是黏结树脂嵌体较理想的牙本质黏结剂。