四种窝洞清洁剂对高铜银汞合金充填密合度的影响

为研究清洁剂处理窝洞对高铜银汞合金充填密合度的影响，测量和比较了用与不用窝洞清洁剂处理，以及用不同的窝洞清洁剂处理对牙体硬组织与充填材料间微泄漏，结果发现微泄漏的程度由大到小依次为：１０％构橡酸（含３％三氯化铁液，简称１０－３液）、２０％草酸钾液、１０％ＥＤＴＡ液、２５％鞣酸液。其中２５％鞣酸、１０％ＥＤＴＡ、２０％草酸钾的微泄漏显著小于空白对照组和１０－３液组。表明充填前采用合适的清洁剂处理，能提高高铜银汞合金充填的密合度。提示２５％鞣酸、１０％ＥＤＴＡ液为良好的窝洞清洁剂。     

粘结技术对银燕合金充填体边缘微波的影响

目的研究粘结技术对银汞合金充填体边缘微漏的影响。方法将制备洞型后的４０颗离体牙髓机分为二组，一组采用粘结技术法充填银汞，另一组按常规充填银汞，所有标本均进行染料渗透试验，观测染料渗漏情况，并在ＳＥＭ下测量充填体与牙体间的微缝隙宽度。结果粘结组染料渗漏的例数少、程度轻，其微漏明显小于对照组（Ｐ〈０．０１）；扫描电镜观察发现，粘结组充填体边缘缝隙宽度明显小于对照组（Ｐ〈０．０１）。结论采用粘结技术可以明显减少银汞合金充填体的边缘微漏。     

粘结技术对银汞合金充填体边缘微漏的影响

目的 研究粘结技术对银汞合金充填体边缘微漏的影响。方法 将制备洞型后的40颗离体牙随机分为二组,一组采用粘结技术法充填银汞。另一组按常规充填银汞,所有标本均进行染料渗透试验,观测染料渗漏情况,并在SEM下测量充填体与牙体间的微缝隙宽度。结果 粘结组染料渗漏的例数少、程度轻,其微漏明显小于对照组(P<0.01);扫描电镜观察发现,粘结组充填体边缘缝隙宽度明显小于对照组(P<0.01)。结论 采用粘结技术可以明显减少银汞合金充填体的边缘微漏。     

银汞合金粘结修复后充填体边缘微漏的实验研究

目的 研究银汞合金粘结修复填体边缘的微漏情况,方法 将制备洞型后４０颗离体牙随机分二组,一组采用ＢＡＲ法充填银汞,另一组按常规充填银汞,所有标本均进行染料渗透试验,观测染料渗漏情况,并在ＳＥＭ下测量充填体与牙体间的微逢隙宽度,结果 ＢＡＲ组染料渗漏的例数少,程度轻,其微漏明显小于常规组（Ｐ〈０．０１）,扫描电镜观察发现,ＢＡＲ组充填体边缘缝隙宽度明显小于常规组（Ｐ〈０．０１）,结论 银汞合金粘结修     

喷砂制洞和复合树脂充填对邻牙合面洞细菌微渗漏影响的实验研究

目的通过离体牙细菌微渗漏实验,评估喷砂制洞、5种树脂类材料和银汞合金充填对邻牙合面洞边缘封闭质量的影响.方法将48个完整无龋的离体前磨牙及第三磨牙随机分为两个实验组,第一组采用常规涡轮机裂钻制备窝洞,第二组采用喷砂制洞.所有实验样本制备邻牙合面洞模型,近中牙合面洞的颈缘位于釉质区,远中牙合面洞的颈缘位于根部牙骨质区.用树脂材料充填窝洞,在37℃厌氧环境下浸泡于细菌悬液中20 h.然后通过组织学检查评估细菌渗漏情况.结果所有实验组与对照组银汞合金之间存在显著差异(P<0.01).CLEARFIL AP-X/SE BOND的边缘封闭质量与DURAFILL VS、P-50的差异最显著(P<0.01);喷砂制洞与传统切割制洞对于细菌渗漏情况的影响无明显差异(P>0.05);近(远)中壁微渗漏较颈壁严重(P<0.05).结论树脂材料比银汞合金具有更好的边缘封闭效果,更适合于后牙的充填修复;喷砂技术用于窝洞处理不能减少细菌的微渗漏.     

GA—HEMA处理牙本质玷污层对银汞合金粘接修复影响的实验研究

目的 研究戊二醛－甲基丙烯酸β羟乙酯（ＧＡ－ＭＥＭＡ）混合液处理牙本质玷污层对银汞合金粘接修复的影响。方法 将在Ｈｅ面制备无倒凹Ⅰ类洞的３０颗离体磨牙随机分成３组：实验组１,ＧＡ－ＨＥＭＡ处理窝洞后充填银汞合金;实验组２,ＧＡ－ＨＥＭＡ处理＋粘接剂涂布窝洞后充填银汞合金;对照组,直接充填银汞合金。３个组分别作拉力测试及扫描电镜观察。结果 抗脱位力实验组２最大,与实验组１、对照组相比有显著性意义（Ｐ〈０．０１）;电镜观察实验组２充填体与牙体组织间隙最小,实验组１次之,与对照组相比均有显著意义（Ｐ〈０．０１）。结论 ＧＡ－ＨＥＭＡ混合液处理牙本质玷污层后能显著增加银汞合金与牙体组织的密合度,与粘接剂同时使用能提高银汞合金的固位力。     

新型牙科充填材料--镓合金的边缘微漏实验研究

目的 研究新型牙科充填材料－镓合金的体外充填以后的边缘微渗漏。方法 选择２０颗离体牙，备洞后，随机分为两组，实验组用镓合金充填，对照组银汞合金充填。采用染料渗透实验，用测量显微镜测出染料渗入牙齿的深度。结果 实验组的染料渗入深度平均值为１０．４微米，对照组的平均值为１１．７微米。结论 镓合金与银汞合金的边缘微漏无显著性差异。     

Nd：YAG激光对Dyract复合体充填微渗漏的影响

目的　观察Nd :YAG激光照射洞缘牙釉质对复合体Dyract充填微渗漏的影响。方法　新鲜拔除的完整离体牙 5 0颗 ,随机分为实验组 ( 2 6颗 )和对照组 ( 2 4颗 )。在样本牙的颊舌面制备V类洞 ,对照组常规完成Dyract充填 ,实验组用Nd :YAG激光照射洞缘牙釉质后再行Dyract充填。所有样本经冷热循环处理后 ,再进行微渗漏实验。用体视显微镜和SEM观察并拍照记录。结果　激光光蚀组充填体边缘微渗漏比对照组明显低 (P <0 .0 5 )。微渗漏实验与扫描电镜观察结果一致。结论　Nd :YAG激光的光蚀作用有助于增强复合体Dyract与牙体组织的结合 ,改善边缘封闭 ,减少微渗漏 ,有利于充填成功     

六种常用牙体充填材料离体牙渗漏的实验研究

本文采用２％碱性品红液渗入检测法，对六种常用牙体充填材料进行离体牙充填渗漏实验。其目的是为临床提供最佳充填材料，实验结果表明，光敏固化材料与玻璃离子粘固粉渗漏最小，羧聚复合陶瓷及银汞合金次之，ＥＢ复合树脂和磷酸锌粘固粉渗漏最大，染液渗漏达洞底。     

玷污层和粘接剂对银汞合金充填体与洞壁密合度的影响

用颈部龋坏的离体牙６０颗,去龋备洞,１组,去除玷污层后充填;２组,去除玷污层加涂布化学粘接剂于窝洞壁后充填;３组,对照组;直接充填银汞合金,用扫描电镜和图像分析仪测量充填与窝洞壁间微缝隙的宽度,并观察充填体一牙体界面的形态。     

Effect of a copal varnish, ZOE or glass ionomer cement bases on microleakage of amalgam restorations

The purpose of this study was to evaluate the sealing ability of four cavity preparation treatment modalities under amalgam restorations. Class V cavity preparations were placed in 20 extracted teeth and randomly divided into four groups of five teeth each (10 restorations for each group): 1) no liner; 2) two applications of Copalite; 3) a base of IRM; and 4) a base of Chelon-Silver. After assigned cavity preparation treatment was accomplished, the teeth were restored with amalgam. The restored teeth were subjected to thermocycling and subsequently stained with basic fuchsin. The teeth were longitudinally sectioned and dye penetration recorded. Amalgam restorations with a Copalite or Chelon-Silver base exhibited significantly less microleakage than those amalgam restorations with an IRM base or no cavity preparation treatment. With the Copalite varnish, microleakage extended beyond the axial wall (toward the pulp chamber through the dentinal tubules) while with the Chelon-Silver base, microleakage was limited to the restoration-tooth interface.     

In vivo and in vitro evaluations of microleakage around Class I amalgam and composite restorations

This study evaluated and compared microleakage values of in vivo and in vitro placed Class I amalgam restorations with or without three different lining materials and posterior composite restorations with two dentin bonding agents. For the in vivo group, 72 standardized Class I cavities were prepared on the occlusal surfaces of molars scheduled for extraction. The test groups (n = 12) were: amalgam without lining (A), amalgam with cavity varnish (A+C), amalgam with Clearfil SE Bond (A+CSE), amalgam with Clearfil 2V (A+C2V), composite with Clearfil SE Bond (C+CSE) and composite with Protect Bond (C+PB). The restored teeth were extracted after seven days. The same grouping, materials and techniques were used in 72 extracted molars for the in-vitro part of the study. The specimens were immersed in basic fuchsin for 24 hours and sectioned. Microleakage was examined and scored at 20x magnification. Statistical analyses were performed with the Kruskal-Wallis and Mann-Whitney U-tests with the 5% level of significance. Overall, the in vivo and in vitro test groups were not different from each other. No significant differences in microleakage values were observed between the unlined and lined amalgam groups (p > 0.05). However, since lined amalgam restorations did not reveal any marginal leakage, the application of an adhesive bonding material under the amalgam restorations can be considered. In general, cavity varnish was not as effective as adhesive bonding agents in preventing microleakage in amalgam restorations. Composite restorations demonstrated higher leakage values than amalgam restorations (p < 0.05), except for A+C (p > 0.05) in the in vivo group. There was no significant difference between the two composite groups for in vitro and in vivo conditions (p > 0.05).     

Microleakage evaluation in amalgam restorations used with bases.

Marginal leakage in amalgam restorations often precedes the development of secondary caries. One potential way to improve the marginal seal of such restorations, and thus minimize the risk of caries development, is to apply a glass-ionomer base prior to amalgam placement. This study compared microleakage resistance among amalgam restorations placed with and without light-cured glass-ionomer base materials. Preparations were made in extracted human molar teeth. Four groups were studied, including copal varnish, which was used as a control. All specimens were restored with amalgam. Results indicated significantly greater leakage at the cavity wall/base interface for restorations with a copal varnish cavity liner than for those with a glass-ionomer base. Leakage differences among bases were also found at the amalgam/base interface. Best results were obtained with a dual-cure resin-based system. These samples showed minimal leakage at both the cavity wall/base and the base/amalgam interfaces. These findings suggest that light-cured glass-ionomer bases can be effective in the prevention of microleakage in amalgam restorations.     

Microleakage Evaluation in Amalgam Restorations Used with Bases

Marginal leakage in amalgam restorations often precedes the development of secondary caries. One potential way to improve the marginal seal of such restorations, and thus minimize the risk of carles development, is to apply a glassionomer base prior to amalgam placement.
This study compared microleakage resistance among amalgam restorations placed with and without light-cured glass-ionomer base materials. Preparations were made in extracted human molar teeth. Four groups were studied, including copal varnish, which was used as a control. All specimens were restored with amalgam. Results indicated significantly greater leakage at the cavity wall/base interface for restorations with a copal varnish cavity liner than for those with a glass-ionomer base. Leakage differences among bases were also found at the amalgam/base interface. Best results were obtained with a dual-cure resin-based system. These samples showed minimal leakage at both the cavity wall/base and the base/amalgam interfaces. These findings suggest that light-cured glass-ionomer bases can be effective in the prevention of microleakage in amalgam restorations.     

银汞合金充填应用树脂粘结剂的作用研究

目的：研究银汞合金充填时应用树脂粘结剂的作用。方法：进行染料渗透试验和扫描电镜观察。结果：使用粘结剂组染料渗漏的例数少、程度轻，差异性非常显著；扫描电镜可见粘结剂与洞壁和银汞合金均有较好粘结，密合度好。结论：银汞合金充填应用树脂粘结剂可以明显减少微渗漏和增加洞壁密合度。     

Effect of a resin-based desensitizing agent and a self-etching dentin adhesive on marginal leakage of amalgam restorations

AIM: The purpose of this study was to compare the marginal leakage of Class II amalgam restorations whose preparations were lined with a resin-based desensitizing agent, a self-etching adhesive system, and copal varnish. METHODS AND MATERIALS: Fifty-six freshly extracted human premolar teeth were divided into four groups. A Class II preparation was prepared with only a proximal box on the mesial and distal surfaces of each tooth. The cavities in one group were lined with a desensitizing agent (VivaSens) and a second group with an adhesive (Clearfil S3 Bond). A third group was lined with copal varnish (Copalite) and a fourth group was used as the control without any cavity liner. Spherical high copper amalgam was hand-condensed into each preparation, specimens were thermocycled, stained, and sectioned. Microleakage was graded using a stereomicroscope. Microleakage scores were calculated and analyzed using the Kruskal Wallis and the Mann-Whitney tests (alpha=0.05). RESULTS: Less microleakage was indicated with the VivaSens liner when compared with the other groups (P<0.05). Clearfil S3 Bond showed less microleakage than the control group (P<0.05), but the leakage with copal varnish and Clearfil S3 Bond was similar (P>0.05). CONCLUSION: VivaSens reduced the microleakage of Class II high copper amalgam restorations significantly more than the Clearfil S3 Bond and copal varnish.     

Microleakage of different amalgams bonded with dual cure resin cements.

INTRODUCTION: To reduce microleakage in high-copper amalgam restorations, bonding of amalgam was introduced. AIM: This study compared the microleakage of admixed and spherical amalgams when bonded with different bonding intermediates under thermo- and non-thermocycling conditions. METHOD AND MATERIALS: Class II butt-joint cavities were prepared in 200 extracted human molar teeth, and randomly divided into 5 groups. Calibra, Duo Cement Plus, RelyX ARC and Amalgambond Plus were applied to 4 of these groups. The fifth group was left untreated. The groups were further divided and restored with either Dispersalloy or Oralloy Magicap S. Ten specimens of each group were thermocycled between 5 degrees C and 55 degrees C, placed in basic fuchsin for 8 hours, sectioned and evaluated for dye penetration under 40X magnification. The mean microleakage scores were analysed using the chi-squared test at a confidence level of 95%. RESULTS: Microleakage of the non-bonded amalgams was significantly higher (p < 0.0001) than for the bonded amalgams (thermocycled and non-thermocycled). The microleakage of the different intermediates bonded to Dispersalloy (thermocycled and non-thermocycled) was not significantly different (p > 0.05). The microleakage of the different intermediates was not significant different except for Duo Cement compared to Calibra (p < 0.0001), RelyX (p < 0.0001) and Amalgambond (p = 0.0433) and Amalgambond compared to Calibra (p = 0.0433) and RelyX (p = 0.0433). The microleakage of the bonded amalgams was not significantly increased by thermocycling (p > 0.05). The microleakage of the two amalgams when bonded with the same resin cements (thermocycled and non-thermocycled) was not significantly different except for Duo Cement (thermocycled) (p = 0.0051) and RelyX (non-thermocycled) (p = 0.0356). CONCLUSIONS: Bonding amalgam restorations to tooth structure in butt-joint cavities will reduce microleakage of both admixed and spherical amalgam restorations. Thermal stress does not affect the bond adversely.     

Addition of Fresh Amalgam to Existing Amalgam: Microleakage Study

The purpose of this in vitro study was to determine whether adhesive lining materials reduce microleakage in amalgam restorations, and to observe the degree of microleakage at the interface between freshly placed (new) and existing (old) amalgam. Forty-eight specimens were used in the experimental groups. The materials used to study microleakage in this investigation were: copal varnish, a dentin bonding agent (Clearfil New Bond), and a 4-META adhesive (Amalgambond). No significant difference in microleakage was found at the interfaces between freshly placed and existing amalgam. Significantly less microleakage was noted in specimens using the 4-META adhesive and the dentin bonding agent as compared to specimens in which no lining material was placed. Significantly less microleakage was noted in specimens using the 4-META adhesive compared to specimens using cavity varnish.     

Addition of fresh amalgam to existing amalgam: microleakage study.

The purpose of this in vitro study was to determine whether adhesive lining materials reduce microleakage in amalgam restorations, and to observe the degree of microleakage at the interface between freshly placed (new) and existing (old) amalgam. Forty-eight specimens were used in the experimental groups. The materials used to study microleakage in this investigation were: copal varnish, a dentin bonding agent (Clearfil New Bond), and a 4-META adhesive (Amalgambond). No significant difference in microleakage was found at the interfaces between freshly placed and existing amalgam. Significantly less microleakage was noted in specimens using the 4-META adhesive and the dentin bonding agent as compared to specimens in which no lining material was placed. Significantly less microleakage was noted in specimens using the 4-META adhesive compared to specimens using cavity varnish.