三种分层充填方法对牙本质黏结强度的影响

目的:对比研究3种分层充填方法对牙本质黏结的微拉伸强度的影响。方法:选取因正畸需要拔除的前磨牙15个,随机分为3组。去除面釉质,暴露平的牙本质表面,在其中央制备3.5mm×3.5mm×3mm的盒形洞。使用Single Bond黏结剂,按使用说明进行牙本质黏结,用Z100复合树脂充填窝洞:A组:分3层水平充填;B组:分3层斜向充填(第一层水平充填,第二、三层近远中向斜向充填);C组:分3层斜向充填(第一、二层近远中向斜向充填,;第三层水平充填)。用硬组织切片机将实验牙切成黏结面积约0.9mm×0.9mm的正方形小条作为试件,用以测试牙本质微拉伸黏结强度。在体视显微镜和扫描电镜下观察样本的断裂界面。结果:C组的微拉伸黏结强度测试值(31.99±5.27)高于A组(24.56±4.90)和B组(31.19±3.90),3种分层充填方法对牙本质微拉伸黏结强度的影响有统计学意义(P<0.05)。体视显微镜和扫描电镜下观察测试样本的断裂多数为黏结界面破坏。结论:3种分层充填方法对牙本质黏结的微拉伸强度存在影响,其中C组的分层充填方法略优于另外两组。因此,在修复较深的牙体缺损时,采用合适的分层充填方法有利于获得良好的黏结效果。     

不同表面处理对聚乳酸可吸收桩与树脂核间粘结性能的影响

目的:探讨不同表面处理方法对聚乳酸桩与树脂核粘结性能的影响。方法:将25根聚乳酸桩随机分为A、B、C、D、E 5组(n=5),A组表面仅涂布粘结剂;B组表面涂布氯仿后再涂布粘结剂;C组表面涂布氯仿与粘结剂按1∶1混合5 s后的混合物;D组表面涂布氯仿与粘结剂按1∶2混合5 s的混合物;E组表面涂布氯仿与粘结剂按2∶1混合5 s的混合物;另取5根玻璃纤维桩作为F组(对照组),表面涂布粘结剂。处理后的各组桩分别与Filtek Z350树脂核粘结制成棒状试件后进行微拉伸测试;体视显微镜观察各样本的断裂类型,SEM观察桩-树脂核断裂界面;并对数据进行统计分析。结果:C组微拉伸强度最高(20.58±3.35)MPa,与其他各组相比P<0.05;随后依次为E组(13.35±3.21)MPa、D组(12.80±2.77)MPa、F组(12.24±1.40)MPa、B组(10.91±1.61)MPa、A组(5.03±1.48)MPa,两两相比,B组与E组比较,P<0.05,D、E、F组间比较P>0.05,其余各组间差异P<0.05;各组断裂模式两两相比P<0.05,C组以树脂内聚破坏为主。结论:将氯仿和粘结剂按1∶1的比例混合后处理聚乳酸桩表面可提高聚乳酸桩-树脂核的粘结强度。     

Nd:YAG激光联合不同黏结系统对非龋性硬化牙本质黏结强度的影响

目的:通过微拉伸黏结强度实验,检测Nd:YAG激光联合3种不同黏结系统处理的硬化牙本质与复合树脂的黏结强度。方法:选择15颗硬化牙本质视觉分级为3级以上的面磨损牙,将面硬化牙本质分为面积近似相等的两部分,随机分为A(A1、A2)、B(B1、B2)、C(C1、C2)3组,以1W、10Hz Nd:YAG激光处理硬化牙本质表面后,按照随机数字表,使每颗牙分割的两部分进入不同的处理组,A2、C1联合ScotchbondTM处理,Z350复合树脂充填;A1、B1联合Adper Prompt L-Pop处理,Z350复合树脂充填;B2、C2联合Clearfil SE Bond处理,Z350复合树脂充填。置于37℃生理盐水中24h后,制作微拉伸试件,测试黏结强度,在体视显微镜下观察断裂模式并分类。采用SPSS13.0软件包对试件微拉伸黏结强度值做单因素方差分析。结果:Nd:YAG激光联合3种黏结剂处理后的微拉伸黏结强度分别为ScotchbondTM(A2、C1)处理组(22.96±4.93)MPa,Adper Prompt L-Pop(A1、B1)处理组(18.73±4.71)MPa,Clearfil SE Bond(...     

不同固化充填方法对Z350纳米树脂微渗漏和压缩强度的影响

目的 对比研究整体固化和分层固化充填方法 对光固化复合树脂微渗漏和压缩强度的影响。方法 选取下颌恒磨牙36颗,面中央制备标准Ⅰ类洞,随机分为3组。A组:整体固化充填;B组:水平分层固化充填;C组:斜向分层固化充填组。每组均用SingleBond2粘结,Z350纳米树脂充填,冷热循环500次,2%亚甲基蓝染色,沿牙体长轴颊舌向切片,体视显微镜下观察染料渗透情况。制备Z350整体固化及分层固化试样,万能材料试验机上测定材料的抗压缩强度。结果 微渗漏方面,A组最大,C组最小,三组之间比较皆有显著性差异(P<0.01)。抗压缩强度方面,A组最小,B组最大,A组与B组、C组比较有显著性差异(P<0.05),B、C组间无显著性差异(P>0.05)。结论 斜向分层充填技术既能减少微渗漏,又能保证树脂的抗压缩强度,是Ⅰ类洞树脂充填的首选方案。     

激光共聚焦显微镜观察不同光照模式对复合树脂充填体微渗漏的影响

目的:激光共聚焦显微镜下观察比较不同光固化模式下复合树脂固化后微渗漏的差别。方法:选取30个离体牙在颊面备4 mm×4 mm×2 mm窝洞,光固化树脂(3M Z350)分层固化充填,并随机分为A、B、C 3组,分别用弱光引导(A组)、间歇光照(B组)和高强度光照(C组)3种不同光照固化模式进行固化。标本充填完成后在37℃水浴条件下分别置于1 g/L罗丹明B荧光染料浸染,24 h后激光扫描共聚焦显微镜测量染液渗入深度,定量评价微渗漏程度,并对检测结果进行统计学分析。结果:A、B、C 3组微渗漏差异无统计学意义(P>0.05)。结论:弱光引导和间歇光照技术对复合树脂的边缘封闭性无明显影响。     

自酸蚀粘结系统及唾液污染分别对窝沟封闭剂微拉伸粘结强度的影响

目的 评价Clearfil S3 Bond自酸蚀粘结系统和唾液污染对窝沟封闭剂拉伸粘结强度的影响.方法 15颗离体前磨牙,随机分为3组,每组5颗.A、B组分别经35%磷酸酸蚀、Clearfil S3 Bond自酸蚀处理,C组35%磷酸酸蚀后唾液污染,3组均用Estiseal F窝沟封闭剂分层固化堆积形成5 mm高封闭剂小柱.再将样本切成1 mm×1 mm×10 mm大小的试件,微拉伸仪检测其拉伸粘结强度.结果 使用自酸蚀粘结系统与常规磷酸酸蚀组的微拉伸粘结强度无显著区别(P＞0.05),而唾液污染组显著低于常规磷酸酸蚀组的微拉伸粘结强度(P＜0.05).结论 临床操作过程中应严格避免唾液污染,而关于自酸蚀粘结剂对封闭剂与牙釉质的微拉伸粘结强度的影响需进一步研究.     

不同表面处理的纤维桩微拉伸粘接强度研究

目的:通过微拉伸粘接强度测试法测试在纤维桩表面经过6种不同的处理后与核树脂的粘接强度,探索何种表面处理方法能显著提高纤维桩与核树脂的粘接强度,为临床应用提供参考。方法:将30根石英纤维桩随机分成6组,每组5根。A组纤维桩表面涂布粘接剂,B组涂布硅烷处理剂,吹干后涂粘接剂,C组5%氢氟酸酸蚀30sec,流水冲洗吹干后处理同A组,D组5%氢氟酸酸蚀30sec,流水冲洗吹干后处理同B组,E组24%双氧水处理,后操作同A组,F组24%双氧水处理后操作同B组。在桩周分层固化核树脂,用低速锯沿纤维桩外周平行片切,再垂直粘接面片切成横截面约0.9mm×0.9mm的长方柱状试件,每组15个,用微拉伸粘接强度测试法测试纤维桩与核树脂的微拉伸粘接强度,体视显微镜观察断裂类型。结果:A组微拉伸粘接强度8.78±2.20MPa,B组9.35±1.92MPa,C组15.50±2.87MPa,D组22.98±3.24MPa,E组16.64±2.70MPa,F组24.88±3.9 0MPa。用氢氟酸酸蚀的C组和D组和用双氧水处理的E组和F组的微拉伸粘接强度明显高于A组B组(P<0.05)。用氢氟酸酸蚀后再硅烷化处理的D组比C组、用双氧水处...     

自酸蚀粘结剂不同涂布方式对乳牙粘接强度的影响

［摘要］目的:比较自酸蚀粘结剂三种不同涂布方式对乳牙牙本质微拉伸强度的影响。方法: 选取30颗离体乳磨牙,分为2组（AE组和XV组）,根据不同涂布方式分为6个亚组,暴露牙本质,用Z350 树脂充填,制备成横截面积为1.0mm2的微拉伸试件,进行微拉伸强度测试,试件断裂面的形态在透射电镜（SEM）下观察。结果:本实验中,AE2组测得的微拉伸强度最大,与其他组比较比较,有统计学意义（P＜0.05）。连续涂布两次获得微拉伸强度比其他两种方式获得微拉伸强度高,且有统计学意义（P＜0.05）。扫描电镜下观察,断裂类型大部分呈牙本质-树脂界面破坏和混合破坏。结论:该实验中,乳牙进行树脂充填时,Adper TM Easy One连续涂布两次固化一次的涂布方式产生的粘接强度好,可在临床推广。     

不同粘接系统联合硅烷偶联剂对陈旧性复合树脂粘接效果的影响

目的:研究不同粘接系统或联合硅烷偶联剂对陈旧性复合树脂粘接粘接强度和微渗漏的影响.方法:使用纳米型复合树脂制作树脂块,并储存在(37±1)℃的蒸馏水中2个月,表面经金刚砂车针打磨后,按表面处理方式不同分为5组:A:对照组(不进行化学处理);B:两步法自酸蚀粘接系统(Clearfil SE Bond,CSE组);C:硅烷偶联剂预处理+两步法自酸蚀粘接系统(硅烷+CSE组);D:通用型粘接系统(Single Bond Universal,SBU组);E:硅烷偶联剂预处理+通用型粘接系统(硅烷+SBU组).上述表面处理后,使用新鲜树脂分别进行充填、固化.使用低速金刚石切割机分别沿两个垂直方向纵向片切样本,每组制备10个横截面积为1.0 mm2的试件条,进行微拉伸测试,并在体视显微镜下观察样本断裂模式.将粘接完成后的样本,通过亚甲基蓝染色法观察粘接界面的微渗漏.结果:实验组微拉伸粘接强度显著大于对照组(P<0.05),硅烷可以增大新旧树脂间粘接强度,且硅烷+SBU组微拉伸粘接强度最大(P<0.05).体视显微镜下显示实验组样本断裂模式均以内聚断裂为主,对照组多为粘接界面断裂.实验组新旧树脂间微渗漏显著小于对照组(P<0.05);4个实验组新旧树脂间微渗漏无明显差异(P>0.05).结论:表面使用粘接剂或联合硅烷偶联剂均可显著提高陈旧性树脂与新鲜树脂之间的粘接强度,并降低新旧树脂间微渗漏;硅烷偶联剂联合通用型粘接剂修复效果更佳.     

三种树脂粘接剂对可切削复合树脂与牙本质粘接强度的比较研究

目的 通过比较3种树脂粘接剂对聚甲基丙烯酸甲酯-纳米二氧化硅-二氧化锆(polymethylmecrylate/nano SiO2-ZrO2,PNSZ)可切削复合树脂与牙本质的粘接强度的差异,寻找适合PNSZ可切削复合树脂的树脂粘接剂,为临床应用提供参考.方法 使用树脂粘接剂A(RelyX ARC)、B(Panavia-F)和c(Variolink II)粘接PNSZ可切削复合树脂与牙本质,测试剪切粘接强度和微拉伸粘接强度(各分为A、B、C 3组,每组10个试件),并采用50倍立体显微镜观察断裂模式.结果 剪切测试中A、B、C组试件的粘接强度分别为(14.07±4.67)、(13.17±4.63)、(12.10±2.18)MPa,差异无统计学意义(P＞0.05);微拉伸测试中A、B、C组试件的粘接强度分别为(11.49±4.90)、(9.66±4.15)、(10.11±4.20)MPa,差异无统计学意义(P＞0.05).立体显微镜观察显示,3种粘接剂的断裂模式均以牙本质-粘接剂界面的断裂为主.结论 3种树脂粘接剂对PNSZ可切削复合树脂与牙本质的粘接效果相近.PNSZ可切削复合树脂一粘接剂界面的粘接优于牙本质-粘接剂界面.     

Eighteen‐month clinical evaluation of microhybrid,packable and nanofilled resin composites in Class I restorations

Summary The aim of this article was to report the results of an 18‐month longitudinal randomized clinical trial that evaluated the clinical performance of microhybrid, packable and nanofilled resin composite restorations placed in Class I cavities of molar teeth. Three Class I resin composite restorations were placed in each of 35 patients. Each patient received one microhybrid (‘Point 4’; Kerr, Orange, CA, USA), one packable (‘Packable Premise’; Kerr, Orange, CA, USA) and one nanofilled (‘Nanofilled Premise’; Kerr, Orange, CA, USA) resin composite restoration. Clinical evaluation was performed at baseline (2 weeks after placement), and after 6, 12 and 18 months after placement using modified Ryge criteria. No patients were lost from the study. At the final appointment (after 18 months), 95·4%, 93·7% and 96·2% respectively of the microhybrid (‘Point 4’), packable (‘Packable Premise’ and nanofilled (‘Nanofilled Premise’) resin composite restorations received Alfa ratings. Regardless of the type of restorative material, no significant changes were observed in the modified Ryge criteria at the baseline and 18‐month recalls (P ≤0·05). Three restorations (one from each group) exhibited post‐operative sensitivity at the baseline and 6‐month appointment. After 18 months, one packable resin composite restoration failed because of secondary caries, while secondary caries was not detected on any of the other restorations. The clinical performance of microhybrid (‘Point 4’), packable (‘Packable Premise’) and nanofilled (‘Nanofilled Premise’) resin composite restorations was acceptable after 18 months. Further studies with longer follow‐up periods are recommended to investigate the long‐term survival of these restorations.     

30-Month randomised clinical trial to evaluate the clinical performance of a nanofill and a nanohybrid composite

Objective

To evaluate the clinical performance of a nanofill and a nanohybrid composite in restorations in occlusal cavities of posterior teeth in a randomised trial over 30 months.

Methods

Forty-one adolescents participated in the study. The teeth were restored with a nanofill (Filtek Z350, 3M ESPE), a nanohybrid (Esthet-X, Dentsply); Filtek Z250 (3M ESPE) was used as a control. After 30 months, the restorations were evaluated in accordance with the US Public Health Service (USPHS) modified criteria. The McNemar and Friedman tests were used for statistical analysis, at a level of significance of 5%.

Results

There were significant differences in the roughness of Filtek Z250 (p = 0.008) and Filtek Z350 (p < 0.001) when the four time periods (baseline, 6 months, 12 months and 30 months) were compared. There were significant differences in the marginal adaptation of Filtek Z250 (p = 0.001), Filtek Z350 (p < 0.001) and Esthet-X (p = 0.011). Except for one of each composite restoration, all the modifications ranged from Alpha to Bravo. There were significant differences in the surface roughness (p = 0.005) when the three composites were compared after 30 months.

Conclusions

The materials investigated showed acceptable clinical performance after 30 months. Long-term re-evaluations are necessary for a more detailed analysis of these composites (CEP: #1252).     

Surface roughness of flowable and packable composite resin materials after finishing with abrasive discs

The aim of this study was to compare surface roughness of flowable (Admira Flow, Filtek Flow, Tetric Flow) and packable (Admira, Filtek P60, Tetric HB) composite resin restorative materials finishing with Sof-Lex discs by means of average surface roughness (Ra) measurement using a surface profilometer and scanning electron microscopy (SEM). For each test group five specimens were prepared and roughness was measured in five different positions using a profilometer with a traversing distance of 4 mm and a cut-off value of 0.8 mm. The radius of the tracing diamond tip was 5 microm and measuring force and speed was 4 mN and 0.5 mm/s, respectively. The surface roughness of each individual disk was taken as the arithmetic mean of the Ra values measured in five different positions. Additionally, one specimen of each test group after finishing was observed under SEM with the magnification of x800 and x2500. Before finishing with Sof-Lex discs, flowable composite materials showed a smoother surface than packable composites restoratives (P < 0.05). However, after the finishing procedures similar surface textures were observed both from packable and flowable composites (P > 0.05).     

Highly translucent dental resin composites through refractive index adaption using zirconium dioxide nanoparticles and organic functionalization

ObjectivesFor dental resin composites, high translucency is important. Therefore, the aim of the study was to create a biocompatible and highly translucent resin-based composite, and to investigate the effect of material thickness on translucency.MethodsA biocompatible ORMOCER® resin matrix was reinforced with dental glass powder as fillers. To reach a high translucency, refractive index matching of the matrix and fillers was done in the two ways: (1) Highly refractive ZrO₂ nanoparticles were incorporated into the resin. (2) The resin was modified via addition of 4-Methylthiophenol. The corresponding refractive indices were acquired on an Abbe refractometer (n = 5). In both cases, the dental glass powder was added and translucency of the resulting minifilled and nanohybrid composites were measured using spectral photometry (n = 5). Additionally, the translucency of the experimental composites was determined as a function of specimen thickness in the range 10 μm–2 mm (n = 5). One-way ANOVA was performed to determine the significant differences in various optical parameters among different amounts of modifications and thicknesses at α = 0.05. Furthermore, cytotoxicity tests (extract and direct contact tests) were conducted according to ISO 10993 to classify the biocompatibility of the composites (n = 6).ResultsThe translucency values of the composites with 47 wt.-% dental glass powder and a specimen thickness of 2 mm, could be increased from 26% up to 71% by increasing the refractive index of the matrix through incorporating ZrO₂ nanoparticles. Moreover, it can also be increased to 67% via addition of 4-Methylthiophenol. Further results showed that the translucency significantly depended on the sample thickness following an exponential function. The effect of all tested parameters was significant among the materials (p < 0.001). The composites did not show any cytotoxic effect.SignificanceHighly translucent and biocompatible resin composites were developed. They show attractive properties for the use as dental enamel material in direct and indirect restorations.     

血管化复合组织瓣修复全上颌骨缺损的临床进展

上颌骨、软腭、颊等组成的面中份结构不仅支撑面部外形、决定个人的面容,同时参与完成咀嚼、吞咽、语音和维持正常视觉等重要功能。因此,上颌骨重建是头颈部缺损修复中最复杂、最有争议的临床课题之一,其中以保留眶内容物的全上颌骨缺损（James Brown Ⅲb类）重建尤为困难。本文对保留眶内容物全上颌骨缺损的血管化复合组织瓣的修复重建目标、方法选择以及相关问题作一综述。     

Direct restoration of severely damaged incisors using short fiber-reinforced composite resin

OBJECTIVES: The aim of this in vitro study was to evaluate the static load-bearing capacity and the failure mode of endodontically treated maxillary incisors restored with complete crowns made of experimental composite resin (FC) with short fiber fillers, with and without root canal posts. Further aim was to evaluate the effect of fiber-reinforced composite resin (FRC) on the failure mode of the restoration. MATERIAL AND METHODS: The experimental composite resin (FC) was prepared by mixing 22.5 wt.% of short E-glass fibers (3mm in length) and 22.5 wt.% of semi-interpenetrating polymer network (IPN) resin with 55 wt.% of silane treated silica fillers. The clinical crowns of 30 human extracted maxillary incisors were sectioned at the cemento-enamel junction. Five groups of direct complete crowns were fabricated (n=6); Group A: made from particulate filler composite resin (PFC) (Grandio Caps, VOCO, control), Group B: PFC with fiber post (everStick, StickTeck), Group C: made from PFC with everStick fiber post and FRC-substructure, Group D: made from FC, Group E: made from FC with FRC-substructure. The root canals were prepared and posts were cemented with resin cement (ParaCem Universal). All restored teeth were stored in water at room temperature for 24h before they were statically loaded with speed of 1.0 mm/min until fracture. Data were analyzed using ANOVA (p=0.05). Failure modes were visually examined. RESULTS: ANOVA revealed that restorations made from experimental fiber composite resin had higher load-bearing capacity (349N) (p<0.05) than the control restorations (173N). No significant difference was found in load-bearing capacity between restorations reinforced with FRC-substructure and those without (p>0.05). CONCLUSIONS: Restorations made from short glass fiber containing composite resin with IPN-polymer matrix showed better load-bearing capacity than those made with either plain PFC or PFC reinforced with fiber post.     

两种含氟流动树脂释氟能力的体外研究

目的：体外比较2种含氟流动树脂Beautifil Flow Plus F00和Dyad Flow的短期释氟量,以探讨2种材料释氟能力的差异。方法选取含氟流动树脂F00、DF和不含氟树脂Valux,制备直径10mm,厚1mm的样本,每组10个。将样本分别浸泡于5ml去离子水,第1、2、3、7、14、21、28d使用氟离子选择电极测量去离子水中的氟离子浓度,Va组为对照,比较F00和DF组前3d的单日氟释放及28d内各时间点的累积氟释放情况。结果 F00和Dyad Flow的释氟浓度均第1d最高;前3d单日释氟浓度呈下降趋势,差异有统计学意义(P<0．01);28d内2实验组均有缓慢持续的氟释放,随着时间延长累积释氟量增加;各个时间点,Dyad Flow组累积释氟量高于F00组,差异有统计学意义(P<0．01)。结论2种含氟流动树脂F00和Dyad Flow第1d氟释放最多,在测试时间内均有低量但持续的释氟能力,Dyad Flow释氟量略高于F00。     

间接法树脂高嵌体修复磨牙残冠的临床评价

目的:评价间接法树脂高嵌体修复磨牙残冠的临床效果。方法:分别应用HRi美塑树脂通过间接法制作树脂高嵌体和直接法树脂充填修复68颗磨牙残冠的邻牙合面龋损,分别在修复后6、24、36个月随访,对边缘密合、邻接关系、牙周健康及修复体完整性等临床修复效果进行统计学分析并给予评价。结果:第6个月时两组无差别;第24个月时,两组除了在邻接关系方面嵌体组要优于直接组外(P<0.05),其余方面并没有明显差别;但在36个月时,用间接法树脂高嵌体修复的患牙在边缘密合、邻接关系及牙周健康方面与直接法修复有显著性差异(P＜0.05)。结论:应用间接法树脂高嵌体修复磨牙残冠能获得更好的临床修复效果,更能符合不同层次患者的功能及美学需求。     

Influence of polymerisation method and type of fibre on fracture strength of endodontically treated teeth

The aim of this study was to investigate (i) the effect of direct or indirect polymerisation of adhesive‐impregnated ribbon fibre under 4‐mm bulk‐filled composites on fracture strength; (ii) to compare polyethylene ribbon fibre‐reinforcement composites with short fibre‐reinforced composite; and (iii) the effectiveness of polyethylene ribbon fibre according to the restorative materials used (low‐viscous bulk‐fill composite, high‐viscous flowable composite or conventional paste composite). Seventy molars were divided into seven groups; (groups 1–2) Ribbond‐reinforced Surefil‐SDR; (group 3) Ribbond‐reinforced G Aenial Flo; (group 4) Ribbond‐reinforced G Aenial Posterior; (group 5) short fibre‐reinforced composite everX Posterior; (group 6) unfilled cavity; (group 7) intact teeth. Ribbond was adopted to cavity walls by impregnating an adhesive and using a flowable composite. In group 1, adhesive‐impregnated Ribbond was polymerised directly using a light‐curing‐unit, and indirectly in group 2 under 4‐mm bulk‐filled composite. Direct or indirect polymerisation of adhesive impregnated ribbon fibre under 4‐mm bulk‐filled composite did not change the fracture strength results. Polyethylene ribbon fibre‐reinforced groups (groups 1–4) and short fibre‐reinforced composite group (group 5) displayed similar results. Polyethylene ribbon fibre can be used safely under 4‐mm bulk‐filled composites. Ribbond‐reinforced low‐viscous bulk‐fill, high‐viscous flowable, and conventional paste composite exhibited similar fracture strength results.