粘接银汞修复后牙体的抗折力研究

目的:评价不同的银汞粘接剂应用于粘接银汞修复时,修复后牙体的抗折力差异.方法:选50个健康的上颌前磨牙,除10个作空白对照外,其余40颗在(牙合)面制备近远中邻(牙合)洞,分为4组(直接银汞充填组;树脂加强型玻璃离子水门汀组;玻璃离子水门汀组;树脂型银汞粘接剂组).样品37℃水浴72 h,5℃到55℃水浴循环2 500次,然后用振动动态测试系统进行抗折实验,直至破裂,记录时间.结果:对照组在5组中显示出最高的抗折力,用ANOVA和t检验显示其与各组间均有显著差异;树脂加强型玻璃离子组较其他实验组有更高的牙齿抗折力.结论:粘接银汞修复是一项有效的技术,用树脂加强型玻璃离子作粘接剂能更有效地提高牙体的抗折力,值得在临床推广应用.     

四种充填材料修复根面龋的微渗漏研究

目的比较四种充填材料修复根面龋的充填体边缘微渗漏情况。方法将制备洞型后的44颗离体牙随机分为4组,每组11个牙,备洞后分别采用复合体(3M F2000,简称Co组)、粘结银汞合金(黏结剂为3M Adper Prompt,简称Ad组)、银汞合金(杭州银亚新高铜球形银汞胶囊,简称Am组)和玻璃离子(3M Ketac,简称Ke组)材料充填,进行染料渗透试验。在Olympus GM型暗视野实体显微镜下观察并测量次甲基兰渗漏深入的部位,取根面龋离体牙20个,采用4种临床常用材料分别充填后在扫描电镜下观察充填材料和牙齿密合度并拍摄照片。结果使用复合体充填产生的微渗漏最小(0．03-0．76mm),其次为黏结银汞(0．44- 0．82mm)和银汞(0．89-1．59mm),玻璃离子产生的微渗漏最大(1．73-2．58mm)。结论复合体充填材料能够更好地预防继发龋和充填物脱落。     

根尖充填的微渗漏——银汞和玻璃离子粘固粉的离体比较

作者在离体牙上比较银汞合金和玻璃离子粘固粉(以下简称玻离)逆充填时的微漏现象。材料和方法单根管离体前牙,截冠,经常规根管制备、脱水后,行氯仿牙胶侧压充填。通过摄片,选出64只根充密合牙,斜切去根尖2～3mm,备洞。随机分三组,第一组(21只牙)作银汞逆充填,第二组(23只牙)作玻离充填,第三组(20只牙),仅用热牙胶封闭。为研究逆充填远期的渗漏,再随机分A组(10只银汞,10只玻离,10只牙胶)与B组(11只银     

三类常用牙体充填材料界面微渗漏的激光扫描共聚焦显微镜观测

目的 观察银汞舍金、复合树脂和玻璃离子三类常用牙体充填材料在体外充填后的微渗漏情况.比较材料的边缘封闭性.方法 选取新鲜无龋前磨牙,备洞,充填材料,37℃水浴条件下0.1%罗丹明B荧光染料浸泡,激光扫描共聚焦显微镜测量荧光剂渗入深度,定量评价微渗漏程度.结果 三类材料与牙体界面均有不同程度的荧光染料渗入,渗漏程度由小到大依次为玻璃离子(23.63±3.06μm)、银汞合金(31.68±10.97μm)、复合树脂(32.86±11.67μm).玻璃离子与复合树脂相比有显著差异,在亚组中,使用玻璃离子预处理与银汞直接充填有显著差异,自酸蚀与全酸蚀粘结树脂也有显著统计学意义.其余各组比较无显著差异.结论 三类材料中玻璃离子与牙体界面的微渗漏最小;使用玻璃离子预处理后获得的边缘封闭性优于银汞直接充填;全酸蚀复合树脂与牙体的密合性较自酸蚀更佳.     

粘结剂与核材料微漏的体外研究

目的 :讨论常用的粘结材料与核材料对修复体边缘微漏的影响。方法 :选用 4 5颗大小相似的完好前磨牙 ,随机分为 9个实验组。对离体牙进行标准的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、铸造合金 )充填窝洞。常规方法铸冠 ,用 3种不同的粘结材料 (锌汀、聚羧酸、玻璃离子 )进行粘固。温度循环、染色、包埋后 ,片切标本 ,镜下观察冠边缘及核下微漏。结果 :银汞核与树脂核下微漏小于铸造核 (P<0 .0 5 ) ,玻璃离子粘结剂抗微漏性能优于聚羧酸和锌汀 (P <0 .0 5 )。结论 :本实验提示 :玻璃离子抗微漏性能优于锌汀与聚羧酸。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。粘结剂的选择对微漏有影响     

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。     

3种银汞黏接剂抗微渗漏的效果研究

目的检验三种银汞黏接剂应用于粘接银汞修复时,其抗微渗漏的能力,寻找一种简单有效的黏接材料。方法选28颗新鲜前磨牙,在其近中及远中邻面制备边长分别是2 mm和4 mm的长方形,使其龈壁位于牙本质-牙骨质界,牙合壁位于牙釉质。28颗前磨牙按黏接材料的不同分为4组:空白对照组,树脂加强玻璃离子水门汀组,玻璃离子水门汀组,树脂型银汞黏接剂组。充填后,37℃水浴7 d,然后浸入亚甲蓝染色液中,37℃恒温染色48 h,统计其微渗漏结果。结果非参数统计显示实验组微渗漏小(P<0.01),树脂加强型玻璃离子组无微渗漏,与其他组有着显著差异(P<0.05),釉质侧的渗漏低于牙本质-牙骨质侧。结论粘接银汞修复是一项有效的技术,并且用树脂加强型玻璃离子作黏接剂有着更有效的防微渗漏效果,值得在临床推广应用。     

三种银汞合金黏结修复方法修复缺损后牙冠抗裂强度的比较

目的 评价三种不同的银汞黏接剂应用于黏接银汞修复时,修复后牙冠的抗裂强度的差异.方法 选40颗因正畸需要拔除的新鲜上颌第一前磨牙,在牙合面制备近远中三面洞形,分为4组(直接银汞充填组;树脂加强型玻璃离子水门汀组;玻璃离子水门汀组;树脂型银汞黏接剂组).样品在37℃水浴72h,5℃到55℃水浴循环2500次,然后用振动动态测试系统进行抗折实验,记录时间.结果 ANOVA和T检验显示直接银汞合金充填组与其余各组间均有显著差异,树脂加强型玻璃离子组与树脂型银汞黏接剂组较其他实验组有更高的牙冠抗折力.结论 黏接银汞修复是一项有效的技术,并且用树脂加强型玻璃离子作黏接剂能更有效地提高牙冠的抗折力,值得在临床推广应用.     

树脂加强型玻璃离子水门汀粘结性能和防龋性能的研究

目的对比树脂加强型玻璃离子水门汀与临床普遍使用的复合树脂型正畸釉质粘结剂的抗剪切力,探讨树脂加强型玻璃离子水门汀对牙釉质面脱矿的影响.方法本研究实验一把45颗离体牙随机分成3组,分别使用复合树脂型正畸釉质粘结剂,树脂加强型玻璃离子水门汀及在牙面用厂家提供的处理液进行表面处理后使用树脂加强型玻璃离子门汀粘结正畸托槽.使用材料万能试验机测量各样本的抗剪切力.实验二在离体条件下,对分别使用树脂加强型玻璃离子水门汀,复合树脂型正畸釉质粘结剂粘托槽的釉质面进行人工脱矿,用偏振光显微镜观察釉质面的脱钙程度.结果使用树脂加强型玻璃离子水门汀粘结托槽时,其抗剪切力与临床普遍使用的复合树脂型正畸釉质粘结剂接近,使用树脂加强型玻璃离子水门汀粘结托槽,釉质面未见明显脱矿区.结论树脂加强型玻璃离子水门汀可能是一种适合临床使用的理想托槽粘结剂.     

玻璃离子衬垫对银汞充填后微渗漏的影响

玻璃离子衬垫对银汞充填后微渗漏的影响山东省滨州医学院附属医院（２５６６０３）王青山舒静媛赵波崔秀英银汞合金具有优良的抗压抗磨性能，是目前后牙缺损充填中应用最多的材料，但它与洞壁之间的密合性较差［１］。本研究采用离体牙在洞壁上垫衬一薄层玻璃离子（ＧＩＣ...     

Effect of Nd:YAG laser irradiation on shear bond strength of glass-lonomer luting cement to dentin surface

PURPOSE: The purposes of this study were to evaluate the shear bond strength of luting glass-ionomer cement to a dentin surface treated by pulsed Nd:YAG laser irradiation, and to prove the hypothesis that the bond strength of glass-ionomer luting cement to dentin is favorably altered after Nd:YAG laser irradiation. MATERIALS AND METHODS: Sixty-four extracted human molars with an exposed flat dentin surface were divided into four groups (n = 16). After painting black ink on their surfaces, the teeth of groups 1, 2, and 3 were irradiated by an Nd:YAG laser at 1.064-microm wavelength at 1, 2, and 3 W, respectively; group 4 was untreated and served as a control. Some specimens of each group were used for morphologic and atomic analytic study, and the others were used for shear bond testing. The shear bond test was performed after cylindric titanium specimens were cemented with glass-ionomer cement on a circular dentin area and specimens were immersed in distilled water. The tested specimens were also morphologically investigated. RESULTS: Shear bond strength of group 3 was significantly higher than that of the control group. Morphologic observation of the cement-dentin interface showed good adaptation of the luting cement to laser-treated dentin. Analysis of atomic contents on the dentin surface showed a significant increase of calcium:phosphorus ratio after laser irradiation. CONCLUSION: The dentin surface was modified morphologically and chemically, and the shear bond strength of glass-ionomer luting cement to dentin was increased by Nd:YAG laser irradiation at 3 W.     

Shear bond strength of amalgam reinforced with a bonding agent and/or dentin pins

STATEMENT OF PROBLEM: The use of dentin pins can cause crazing in dentin. Bonding agents represent a more conservative approach to retention but may not ensure a comparable shear bond strength. PURPOSE: This study compared the shear bond strength of amalgam to dentin with the application of dentin pins, a bonding agent, and a combination of both forms of retention. MATERIAL AND METHODS: Forty-five freshly extracted, intact molar teeth of similar size were ground flat approximately 2 mm coronal to the cemento-enamel junction and then embedded in acrylic resin blocks. The teeth were randomly divided into 3 groups of 15 specimens each. In group 1, Panavia-Ex was applied to exposed dentin surfaces, and the amalgam was condensed with a copper ring. In group 2, two Pinlock dentin pins were placed 3 mm apart; Panavia-Ex was applied to the dentin, and the amalgam was condensed. In group 3, two Pinlock pins were placed 3 mm apart, and the amalgam was condensed. All materials were mixed and applied according to the manufacturers' directions. After the amalgam had set for 10 minutes, the specimens were stored at 37 degrees C for 24 hours, after which they were thermocycled 1500 times at 5 degrees to 55 degrees C with a dwell time of 30 seconds. Specimens then were loaded in shear mode in a universal testing machine at a crosshead speed of 0.5 mm/min until fracture occurred. A 1-way analysis of variance and a Tukey multiple range comparison test were used for statistical analysis (P<.05). RESULTS: Significant differences were found among all groups. The highest bond strength (181.86 kg/cm(2)) was obtained for group 2 specimens, which were restored with 2 dentin pins and the bonding system tested. CONCLUSION: Within the limitations of this study, the combined use of dentin pins and Panavia-Ex significantly increased the retention of the amalgam core material.     

Shear bond strength of light-cured glass ionomer to enamel and dentin

The shear bond strengths of a light-cured glass-ionomer cement to enamel and dentin were determined with use of extracted human maxillary permanent canines and molars. Bonding sites on the ground, etched enamel and ground dentin surfaces were demarcated by the punching of a hole, 3 mm in diameter, in an adhesive tape. The mixed glass-ionomer cement was transferred to the demarcated site, cured by exposure to visible light for 30 s, and the cement surface treated with Scotchprep Dentin Primer followed by Scotchbond 2 Light Cure Dental Adhesive. The embedded teeth were positioned in an assembly apparatus, and Silux composite was bonded to the glass-ionomer-cement surfaces. The specimens were disassembled after 15 min and subjected to a shear load (in an Instron machine) immediately after disassembly; after storage in water at 37 degrees C for 24 h, without and with temperature cycling; and after storage in water for four weeks, without and with temperature cycling. The shear bond strength of the glass-ionomer cement to etched enamel was in the order of 12 MN.m-2, and to dentin it was 9 MN.m-2. Temperature cycling and duration of storage had no adverse effect on the shear bond strength. The enamel and dentin aspects of fractured test specimens were examined, and the percentage of the bonding area that failed in the cement was estimated. Most of the test specimens failed partly at the enamel and dentin interfaces and within the glass-ionomer cement.     

Nd:YAG激光对水门汀与牙本质剪切强度的影响

目的:评价脉冲Nd:YAG激光对水门汀与牙本质间剪切强度的影响,并观察激光照射前后的牙本质表面结构变化。方法:取人前磨牙30个,暴露牙本质粘接面形成60个测试样本,随机分为激光组和对照组。激光组以0.8W、10Hz脉冲Nd:YAG激光照射牙本质表面25sec,联合3种水门汀充填;对照组直接使用3种水门汀充填于牙本质表面,置于37℃生理盐水24h后,测试剪切强度,并进行统计学分析,在根管显微镜下观察断裂模式并分类。扫描电镜观察激光照射前后的牙本质表面形态。结果:聚羧酸锌组、玻璃离子组和树脂加强玻璃离子组在Nd:YAG激光照射前(后)的剪切强度分别为4.63±1.39(4.77±0.97)MPa、5.15±0.67(5.26±1.21)MPa和0.92±0.46(0.99±0.35)MPa,激光照射前后的差别均无统计学意义(P>0.05)。扫描电镜观察,0.8W、10Hz的Nd:YAG激光照射会使牙本质表面熔融,玷污层基本去除,大部分牙本质小管封闭,且在局部会出现裂纹。结论:Nd:YAG激光(0.8W、10Hz)处理牙本质,对聚羧酸锌和玻璃离子水门汀与牙本质间的粘接强度无影响。     

In vitro shear bond strength of resin-based luting cements to dentin

The aim of this study was to determine how resin cement, self-adhesive resin cement, and resin-modified glass ionomer cement affected shear bond strength to dentin. Sixty composite resin disks (3 mm in diameter x 3 mm in length) were prepared and divided into four groups (n = 15): Group 1, composite disk bonded to dentin with composite resin and a bonding agent; Group 2, composite disk bonded to dentin with a self-adhesive resin cement; Group 3, composite disk bonded to dentin with a different self-adhesive resin cement; and Group 4, composite disk bonded to dentin with a resin-modified glass ionomer cement. The composite resin was loaded into a syringe (internal diameter 3 mm), photocured in an oven, and cut into 3 mm slices with a low-speed saw. The samples were bonded to dentin per the manufacturer's instructions. All specimens were stored in distilled water (at 37 degrees C) for 24 hours. The shear bond strength test was conducted using a universal testing machine at a crosshead speed of 0.5 mm/min until failure. Conventional resin cement and a bonding agent exhibited significantly higher shear bond strength values than all other materials tested.     

Shear resistance of silver- and stainless steel-reinforced glass-ionomer cements bonded to enamel and dentin.

The shear bond strength to human dentin and enamel was evaluated for four glass-ionomer cements: an experimental stainless steel-reinforced glass-ionomer cement, two commercially available silver-reinforced cements, and a conventional glass-ionomer cement. Bonded specimens were stored in distilled water for 7 days during which time they were subjected to thermocycling in water baths at 5 degrees C and 55 degrees C for a 1-minute dwell time per bath and 1500 cycles. Specimens were then shear tested. The experimental stainless steel-reinforced glass-ionomer cement had a significantly higher bond strength to enamel (P < .01) and dentin (P < .05) than did the commercially available cements.     

Effect of dentinal pretreatment on bond strength between glass-ionomer cement and dentin

Removal of the dentinal smear layer prior to placement of glass-ionomer cement is thought to maximize the strength of glass-ionomer cement/dentin bonding. This study evaluated the effect of three polyacrylic acid pretreatments on bond shear strength between glass-ionomer cement and dentin. Extracted human molars were divided into four groups of 30 specimens each. One group (the control) received no pretreatment. Specimens in the remaining groups were pretreated with one of three commercially available polyacrylic acid conditioners, used according to the manufacturers' recommendations. The results indicated significant differences in shear strength among pretreatment conditions. Since the manufacturers' recommendations varied, it is not clear if these results were due to differences in polyacrylic acid concentration or to other factors, such as application time or placement procedure.     

Shear bond strength of dental amalgam bonded to dentin

The objective of this study was to determine the shear bond strength of dental amalgam bonded to dentin with adhesives. Four groups of 15 permanent posterior teeth were used in this study. The occlusal enamel of the teeth was removed to produce a flat dentin surface. The teeth were embedded in phenolic rings with acrylic resin. Vinyl polysiloxane ring molds 4 mm thick with 4.5 mm circular openings were attached to the exposed dentin surface. Adhesives applied to the dentin surfaces prior to amalgam placement and condensation included: Amalgambond, a 4-META/TBB-MMA, HEMA based system (A), Panavia EX, a modified phosphate ester of Bis-GMA luting system (P), and Ketac-Cem, a glass ionomer luting cement (K). A dentin bonding agent and composite resin restoration system (Scotchbond 2/Silux Plus) was included for comparison. The specimens were stored in 37 degrees C water for 7 days prior to testing. Shear bond tests were done in an Instron machine at a crosshead speed of 0.02 inches per minute. The data were analyzed by ANOVA at 5% level of significance. The differences in shear bond strengths of the four test groups were not statistically significant (P = 0.115). Fracture patterns of the bonded amalgams, examined by SEM, were adhesive in appearance for Groups A and K and cohesive for Group P.     

Dentin bond strength of light-cured glass-ionomer cements.

The purpose of this study was to investigate the influence of surface treatments and irradiation conditions on the bond strength of light-cured glass-ionomer cements to dentin. The light-cured glass-ionomer cements used in this study were Vitrabond, XR Ionomer, and Fuji Lining LC. Three experiments were designed to study the influence of the following factors on bond strength to dentin: (1) effect of the surface treatment of the dentin, (2) effect of the irradiation time, (3) effect of an increase in the interval between mixing of the cement and irradiation. Samples were stored in water for 24 hours, after which shear bond testing was performed at a cross-head speed of 1 mm/min. For Vitrabond, the Scotchprep and Gluma 2 treatments gave the greatest shear bond strengths. For XR Ionomer and Fuji Lining LC, the Scotchprep treatment gave the greatest shear bond strengths. The bond strengths for all cements increased with prolonged irradiation time. Bond strengths decreased with a longer elapsed time between mixing and light-curing. This means that light-curing should be done soon after the cement is placed. The failure mode was found to be cohesive in the ionomer.     

Maximum bond strength of dental luting cement to amalgam alloy

Although dental amalgam is used frequently under artificial crowns for restoration of severely damaged teeth, there is little information available on the bond between luting cements and this alloy. This study was designed for determination of the strength of the bond between a dental amalgam alloy and three crown-luting cements. Cylinders of dental amalgam were joined in pairs, with use of a zinc-phosphate, a glass-ionomer, and an acrylic-adhesive resin cement. The tensile-fracture stress of 45 samples of each cement was measured with a universal testing machine, and subjected to a Weibull analysis. The fractured surfaces were examined under low magnification with use of a light microscope, and at low and high magnifications with use of a scanning electron microscope, for evaluation of the appearance of the fractured joints. The Weibull analysis demonstrated that the adhesive resin cement provided a stronger and more predictable bond than either the zinc-phosphate or the glass-ionomer cement. The appearance of the fractured surfaces gave no indication of the strength of the joints, a feature that is common to brittle materials. The results suggest that crowns placed on teeth offering a large amalgam-alloy surface could be retained more predictably with an adhesive resin cement.