Effect of Sodium Ascorbate and the Time Lapse before Cementation after Internal Bleaching on Bond Strength between Dentin and Ceramic

Purpose: To evaluate the effects of the elapsed time (ET) after nonvital bleaching (NVB) and sodium ascorbate application (10%) (SAA) on the shear bond strength of dentin to ceramic. Materials and Methods: Bovine incisors were selected, internally bleached (35% carbamide peroxide) for 9 days and submitted to the following treatments (n = 10): G1, G2, G3—luting after 1, 7, and 14 days; G4, G5, and G6—luting after SAA, 1, 7, and 14 days, respectively. G7 and G8 were not bleached: G7—luting 24 hours after access cavity sealing; G8—luting 24 hours after access cavity sealing after SAA. After NVB, the vestibular dentin was exposed and flattened. The SAA was applied to the dentin (G4, G5, G6, G8) for 10 minutes, and it was then washed and dried. The dentin was etched (37% phosphoric acid), and an adhesive system (Single Bond 2) was applied. Feldspathic ceramic discs (VM7; 4‐mm diameter, 3‐mm thick) were luted with a dual‐resin agent (RelyX ARC, 3M ESPE Dental Products, St. Paul, MN). After 24 hours, specimens were submitted to shear test on a universal testing machine. The data (MPa) were submitted to ANOVA and Dunnet's test (5%). Results: The means (± SD) obtained were (MPa): G1 (14 ± 4.5), G2 (14.6 ± 3.1), G3 (14 ± 3.7), G4 (15.5 ± 4.6), G5 (19.87 ± 4.5), G6 (16.5 ± 3.7), G7 (22.8 ± 6.2), and G8 (18.9 ± 5.4). SAA had a significant effect on bond strength (p= 0.0054). The effect of ET was not significant (p= 0.1519). G5 and G6 presented higher values than the other bleached groups (p < 0.05) and similar to G7 and G8 (p > 0.05). Conclusions: After NVB, adhesive luting to dentin is recommended after 7 days if sodium ascorbate has been applied prior to dentin hybridization.     

不同复合树脂桩核材料与纤维桩微拉伸强度的对照研究

目的:比较3种复合树脂核材料与玻璃纤维桩的微拉伸粘接强度.方法:21个DT Light玻璃纤维桩随机分为3组(n=7),分别用3种不同的复合树脂核材料DC Core Automix(DC)、LuxaCore(Lc)、卡瑞斯玛前后牙通用复合树脂(CS)粘固制成桩核样本,制备好的样本切割成截面为1 mm×1 mm的条状试件用于微拉伸强度测试.结果:DC与纤维桩的微拉伸粘结强度显著高于LC和CS(P＜0.05),LC和CS与纤维桩的微拉伸粘结强度没有显著性差异(P＞0.05).结论:DC Core Automix与玻璃纤维桩的粘结性能优于另两种复合树脂核材料.     

脱敏剂对全酸蚀粘接剂剪切强度的影响

目的：研究3种牙本质脱敏剂处理牙本质表面后对全酸蚀粘接剂剪切强度的影响。方法：收集因正畸治疗需要拔除的双尖牙40颗。截去牙根,将牙冠切为颊、舌两部分。磨去颊、舌表面的釉质层,预备成牙本质平面,暴露牙本质面,将其余部分包埋于自凝树脂中。将80个样本分为8组,酸蚀前、酸蚀后依次用30％草酸钾、33％硝酸钾、极固宁、三蒸水处理牙本质表面。样本在37℃水浴中浸泡24h后测量剪切强度,加载速度为0．5mm／min。用双因素方差分析和Turkey’s检验对数据进行分析。结果：三蒸水处理组的剪切强度显著高于脱敏剂处理组。但无论使用哪一种脱敏剂在酸蚀前或者酸蚀后处理牙本质,对剪切强度影响无显著性差异。结论：本实验结果显示,使用脱敏剂处理牙本质表面会显著降低Single Bond的粘接强度。     

Influence of chlorhexidine and ethanol on the bond strength and durability of the adhesion of the fiber posts to root dentin using a total etching adhesive system

Introduction

The aim of this study was to investigate the effects of pretreatment of gel chlorhexidine (CHX) and ethanol (EtOH) on the bond strength and durability of the adhesion of the fiber post relined with resin composite to the root dentin using a total etch adhesive system.

Methods

Forty bovine incisor roots were divided into four groups after phosphoric acid etching: irrigation with physiologic solution (control), 5 minutes with CHX, 1 minute with EtOH, and 5 minutes with chlorhexidine followed by 1 minute with EtOH. Fiber posts relined with resin composite were cemented with either RelyX ARC (3M ESPE, St Paul, MN) and a total etch adhesive system Scotchbond Multi-Purpose (3M ESPE). Each group was randomly divided into two subgroups: 24 hours of storage and 12 months of storage. All roots were sectioned transversely, and the push-out test was performed. Failure modes were observed, and the bond strength means were analyzed by analysis of variance and the Tukey test (α = 0.05).

Results

CHX irrigation resulted in homogeneous bond strength values at 24 hours and 12 months of storage (P < .05). A significant bond strength decrease was noticed after 12 months of storage when irrigations were performed with physiologic solution and EtOH application only or associated with CHX (P < .05).

Conclusions

The use of CHX pretreatment could preserve the bond strength of the fiber post relined with resin composite to root dentin for 12 months. The use of EtOH and CHX followed by EtOH did not preserve the bond strength of the total etch adhesive system Scotchbond Multi-Purpose.     

固化光源对牙本质粘结强度的影响

目的：研究两种固化光源对牙本质粘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20颗,随机分成4组。去除殆面釉质,暴露平的牙本质表面,分别使用卤素光固化灯和发光二极管光固化灯固化粘结剂和复合树脂,形成3mm高的树脂冠：A组：卤素光固化灯固化粘结剂20s,卤素光固化灯固化树脂40s;B组：卤素光固化灯固化粘结剂20s,发光二极管光固化灯固化树脂30s;C组：发光二极管光固化灯固化粘结剂20s,发光二极管光固化灯固化树脂30s;D组：发光二极管光固化灯固化粘结剂20S,卤素光固化灯固化树脂40s。所有实验牙置于（37±1）℃的生理盐水中24h后,用硬组织切片机将其切成粘结面积约1．0mm×1．0mm的条形试件,用以测试牙本质微拉伸粘结强度。在扫描电镜下观察样本的断裂界面。结果：固化粘结剂的光源对牙本质微拉伸粘结强度的影响有显著的统计学意义（P〈0．05）。4组中微拉伸粘结强度最大值为（29．55±4．39）MPa,出现在C组。扫描电镜下观察测试样本的断裂多数为粘结界面破坏。结论：固化光源对牙本质粘结的微拉伸强度存在影响,牙本质的粘结强度主要与固化粘结剂的光源有关。本实验显示使用发光二极管光固化灯固化粘结剂20s,发光二极管光固化灯固化树脂30s时牙本质的粘结强度最好。     

加速老化对纤维增强树脂桩剪切强度和微结构的影响

目的：研究加速老化对不同品牌纤维增强树脂桩的剪切强度和微结构的影响。方法：将5种纤维桩（Mac-ro-lockTMPost、Luxa Post、Para Post Taper Lux、Ivoclar Vivadent FRC Postec Plus、Nordin Glassix＋plus）随机分为老化组和无老化组并测量剪切强度、显微结构及红外光谱图。采用双因素方差分析老化前后不同品牌样本剪切强度的差异（α=0.05）。结果：各品牌样本老化前后剪切强度差异有统计学意义（P〈0.05）,老化后纤维丝周围附着的基质大部分分离;老化后酯的红外光谱吸光度增加。结论：老化后基质发生了物理老化和氧化反应,交联密度增加,纤维丝/基质界面粘结力减弱并分离,剪切强度降低。     

固化光源光照角度对牙本质粘结强度的影响

目的：通过改变发光二极管光固化灯光照角度研究复合树脂固化后牙本质粘结强度。方法：选取因正畸需要拔除的前磨牙20颗,随机分成4组。去除面釉质,暴露平的牙本质表面,酸蚀后涂布粘结剂。发光二极管光固化灯固化粘结剂20s,复合树脂堆砌树脂冠,高2mm。A组：发光二极管光固化灯光导棒与树脂粘结面成30°光照。B组：成45°光照。C组：成60°光照。D：成90°光照。4组均光照30s。用硬组织切片机将实验牙切成粘结面积约为1mm×1mm的柱状小条,将样本放置于微拉伸测试仪上,测试髓壁的牙本质粘结强度。结果：发光二极管光固化灯投照角度为30°时,牙本质粘结强度最大（P〈0.05）。结论：固化光源投照角度对牙本质粘结强度有影响,随着角度增加微拉伸粘结强度呈降低趋势。     

4种牙本质粘结剂剪切强度的实验研究

目的：通过4种牙本质粘结剂剪切强度的比较及粘结界面的超微结构的差异,评价并指导其临床使用。方法：选用新鲜的离体前磨牙40颗,分成4组暴露牙本质面。选用全酸蚀的粘结剂：PB（Prime ＆ bond NT）,自酸蚀的粘结剂：XN（XenoⅢ）、IB（IBond）、AP（Adper^TMPrompt^TM）,按照说明书的要求和步骤分别使用后充填复合树脂Z250,制备成4mm×3mm的圆柱型试件。所有的样本通过Instron测试剪切强度,用SPSS11.5对剪切强度测试值进行统计学分析。利用SEM观察粘结界面的超微结构。结果：方差分析显示材料AP的剪切强度最低且较材料PB差异在统计学上有显著性意义（P〈0.05）,材料PB、XN、IB的剪切强度差异上无统计学意义。SEM镜下,材料PB、XN、IB均可见有明显的树脂层、混合层、树脂突。结论：新一代的粘结剂XenoⅢ和IBond可应用于临床。     

不同根管封闭剂及清洗方法对纤维桩粘接强度的影响

目的 研究不同根管封闭剂和清洗方法对纤维桩粘接强度的影响,探讨二者对纤维桩粘接强度是否存在交互影响作用。方法 48颗离体下颌前磨牙行完善根管治疗后,根据根管封闭剂随机分为两组,A组采用Endofil封闭剂（丁香酚类）,B组采用AH-plus封闭剂（树脂类）。桩道预备后每组再根据根管清洗方法分为3个亚组（每组8颗）：A1、B1组采用0.9%NaCl溶液清洗;A2、B2组采用17%乙二胺四乙酸（EDTA）+5.25%NaClO+0.9%NaCl溶液清洗;A3、B3组采用17%EDTA+5.25%NaClO+0.9%NaCl溶液+超声清洗。采用RelyX^TMUnicem树脂粘接剂黏固纤维桩1周后,行薄片推出实验。对结果进行三因素方差分析及Turkey检验。采用扫描电子显微镜（SEM）观察根管内壁的超微形态。结果 6组的纤维桩粘接强度分别为A1组（7.96±2.23） MPa,A2组（9.95±2.89）MPa,A3组（18.88±3.69）MPa,B1组（11.41±3.71）MPa,B2组（14.00±4.04）MPa,B3组（19.14±3.27）MPa。三因素方差分析表明：不同的根管封闭剂与清洗方法具有交互作用（P<0.05）; B1组粘接强度大于A1组,B2组大于A2组（P<0.05）,B3与A3组无明显差异（P>0.05）。SEM显示A3、B3组的根管内壁玷污层最少,牙本质小管完全开放。结论 采用0.9%NaCl溶液、17%EDTA+5.25%NaClO+0.9%NaCl溶液清洗根管时,使用丁香酚类根管封闭剂较树脂类根管封闭剂的纤维桩粘接强度降低;超声联合17%EDTA+5.25%NaClO+0.9%NaCl溶液清洗根管,两种根管封闭剂对纤维桩粘接强度的影响无明显差异。     

Effect of chlorhexidine and ethanol on the durability of the adhesion of the fiber post relined with resin composite to the root canal

Introduction

The aim of this study was to investigate the effects of pretreatment of gel chlorhexidine and ethanol on the bond strength and durability of the adhesion of the fiber post relined with resin composite to the root dentin.

Methods

Sixty bovine incisor roots were divided into four groups: irrigation with physiologic solution (control), 5 minutes with chlorhexidine, 1 minute with ethanol, and 5 minutes with chlorhexidine followed by 1 minute with ethanol. Fiber posts relined with resin composite were cemented with RelyX ARC (3M ESPE, St Paul, MN) and a self-etching adhesive system Clearfil SE Bond (Kuraray, Kurashiki, Japan). Each group was randomly divided into three subgroups: 24 hours of water storage, 12 months of water storage, and 12 months of oil storage. All roots were sectioned transversely in the coronal, middle, and apical regions, producing 1-mm thick slices, and the push-out test was performed. Statistical analysis was performed using analysis of variance and the Tukey test for post hoc comparisons (α = 0.05).

Results

Immediate groups showed similar bond strength values with or without chlorhexidine and/or ethanol pretreatment (P > .05). A significant decrease in the bond strength in the control group was observed after 12 months of storage in water and oil (P < .05). The use of chlorhexidine- and/or ethanol-preserved bond strength in the groups stored in water and oil for 12 months (P < .05).

Conclusions

Chlorhexidine and/or ethanol pretreatment were capable of preserving the bond strength of the fiber post relined with resin composite to root dentin for 12 months.     

矿化液对牙本质粘接系统粘结强度的影响

目的:研究矿化液在牙本质粘接中的作用,同时了解经过蛋白萃取剂处理牙本质后牙本质混和层再矿化是否受影响。方法:选择人正常双尖牙40颗去除牙合面釉质后随机分4组,制得酸蚀标本分别进行常规树脂修复 硅油浸泡(A组),常规树脂修复 人工唾液浸泡(B组),常规树脂修复 矿化液浸泡(C组)和NaC l溶液(蛋白萃取剂) 常规树脂修复 矿化液浸泡(D组)。12周后用能谱仪观察粘结界面混合层再矿化情况,同时用微拉力仪对牙本质粘结系统的粘结强度进行测试。结果:经矿化液浸泡组混合层钙磷比值显著升高(P<0.05),但0.5 mol/L NaC l溶液对混合层钙磷无影响(P>0.05),同时经矿化液浸泡组和硅油浸泡组的牙本质粘结系统微拉伸强度无统计学意义(P>0.05),但均显著高于人工唾液浸泡组(P<0.05)。结论:矿化液对牙本质粘结系统混合层的脱矿牙本质有再矿化作用,可相对提高粘结微拉伸强度;而0.5 mol/L NaC l溶液对增加牙本质粘结混合层再矿化能力无明显作用。     

Effect of Ultrasonic Activation of Endodontic Sealers on Intratubular Penetration and Bond Strength to Root Dentin

IntroductionThis study aimed to evaluate the effect of ultrasonic activation (UA) of endodontic sealers on dentin tubule penetration and the bond strength to root dentin.MethodOne hundred single-rooted teeth were prepared with 40.06 nickel-titanium instruments and divided into 2 groups: with or without UA. Three resin-based sealers (MTA Fillapex [Angelus Dental Solutions, Londrina, PR, Brazil], Sealer Plus [MK Life Medical and Dental Products, Porto Alegre, RS, Brazil], and AH Plus [Dentsply, DeTrey GmbH, Konstanz, Germany]; n = 20) and 2 calcium silicate–based sealers (Sealer Plus BC [MK Life Medical and Dental Products] and EndoSequence BC [Brasseler, Savannah, GA], n = 20) were used and subdivided (n = 10) according to the protocols. Fluo-3 (Thermo Fisher Scientific, Waltham, MA) and rhodamine B dyes were added to the calcium silicate- and resin-based sealers, respectively. In the UA groups, the activation was performed for 40 seconds followed by lateral compaction. Samples were transversely sectioned to evaluate the dentin tubule penetration and the bond strength to root dentin. The penetration data were analyzed with the Student t test, 1-factor analysis of variance, and Bonferroni tests. Bond strength was evaluated using the Student t test, Kruskal-Wallis, and Dunn post hoc test.ResultsResin-based sealers showed the highest tubule penetration without UA (P < .05). UA significantly enhanced MTA Fillapex and Endosequence BC dentin tubule penetration (P < .05). AH Plus and Sealer Plus BC improved their bond strength to root dentin after UA (P < .05). AH Plus/UA, Sealer Plus/UA, and Sealer Plus BC/UA presented the highest bond strength values (P < .05). Adhesive failures were predominant in all groups regardless of the use of ultrasound.ConclusionsUA interferes with tubule penetration and the bond strength to root dentin of resin- and calcium silicate–based sealers.     

纤维增强树脂桩钉与非金属核材料粘结性能的对照研究

目的 :研究纤维增强树脂桩钉 (s -glassfiberreinforcedcomposites,FRC)与 3种核成形材料的粘结性能。方法 :用 3种核成型材料在FRC桩钉上分别制作核桩试件 ,将试件按材料种类和制作方法分成 4组 :A组 :FRC桩钉 +Coreshade(日本松风 ) ;B组 :FRC桩钉 +AB双组分复合树脂 ;C组 :FRC桩钉 +Charisma通用型复合树脂 ;D组 :FRC桩钉 +釉质粘合剂 +Charisma通用型复合树脂。在万能力学试验机上测试桩钉与核的粘结力。结果 :不同的核材料与FRC桩钉的粘结力差异有显著性 (P <0 .0 5 ) ,由大到小的顺序为 :B组 >D组 >C组 >A组。其中B组的粘结力最大 ,为 (345 .0± 2 7.6 )N ,A组的值最低 ,为 (14 4 .7± 9.6 )N。结论 :不同的核材料与FRC桩钉的粘结力不同 ,临床使用FRC桩钉时应选用流动性较好、强度大的树脂类核材料     

根管口直径对纤维桩粘结后振动频率和粘接强度的影响

目的：体外实验测量不同根管口直径单根牙纤维桩粘固后的振动频率和拉伸强度,研究根管口直径对纤维桩粘结后振动频率和粘接强度的影响.方法：利用RTD纤维桩配套钻头制备不同根管口直径的试件,桩道预备后采用RelyX Unicem树脂粘结系统进行纤维桩核修复.将微型加速度传感器粘固于树脂核上,在一定外激励作用下,采集加速度变化信号,经过傅里叶转换,获得纤维桩的振动频率,采用万能试验机测试纤维桩的拉伸强度.结果：不同根管口直径组纤维桩粘接后的振动频率和粘结强度均存在统计学差异（P＜0.05）.结论：纤维桩粘结后的振动频率可以反映出根管口直径的变化,提示振动频率可以作为一项重要指标反映纤维桩的粘结性能.     

氯己定对FujiOrtho LC粘接托槽抗剪切强度的影响初探

目的探讨复方氯己定含漱液对树脂加强型玻璃离子（Fuji Ortho LC）粘接托槽抗剪切强度的影响。方法60颗前磨牙分3组,每组20颗,第1组对照组不用0.20%葡萄糖酸氯己定含漱液涂牙面常规粘接托槽,第2组每天用0.20%葡萄糖酸氯己定液涂牙面2次1周后进行常规粘接托槽,第3组每天2次用0.20%葡萄糖酸氯己定含漱液涂牙面1周,停涂1周后进行常规粘接托槽。粘接托槽后,所有标本储存于蒸馏水中,24 h后用专用仪器测量抗剪切强度,应用方差分析比较各组之间的抗剪切强度,应用卡方检验比较各组粘接剂的残留指数。结果第1组抗剪切强度明显高于第2组,第2组、第3组间抗剪切强度差异无统计学意义;在托槽脱落面形态观察中,各组间ARI指数有差异。结论应用0.20%葡萄糖酸氯己定含漱液后即刻粘接时,Fuji Ortho LC抗剪切强度会明显降低,并且残留在牙面上的粘接材料会有所增加。     

6种复合树脂粘接剂与纤维增强型复合树脂根管桩的粘接强度研究

目的评价6种复合树脂粘接剂与带有半渗透网状复合基质的纤维增强型复合树脂根管桩的粘接强度。方法实验分为6组,分别为纤维增强型复合树脂根管桩和6种复合树脂粘接剂模块,每组7个样本。用粘接树脂活化剂处理各组根管桩表面5min,将粘接剂模块粘接到根管桩表面并固化,37℃下储存各组样本20h后,万能实验机进行剪切粘接强度测定。结果6种不同复合树脂粘接剂与纤维增强型复合树脂根管桩粘接后,各组根管桩表面剪切粘接强度之间的差异无统计学意义（F=2.32,P=0.45）。结论6种复合树脂粘接剂均适用于纤维增强型复合树脂根管桩的粘接。     

极固宁对水门汀与牙本质间剪切强度的影响

目的：评价极固宁脱敏剂对5种水门汀剪切强度的影响。方法：收集双尖牙30颗。包埋牙齿,暴露牙本质面,用水砂纸打磨牙本质面。所有牙齿被分为实验组和对照组。实验组的牙本质面首先用极固宁脱敏处理,然后分别用5种水门汀将树脂小柱粘在牙本质表面。对照组的牙本质不涂脱敏剂,使用前述提到的水门汀粘固树脂小柱。所有试样放在37℃水浴中浸泡24h后测量剪切强度。结果：极固宁脱敏剂没有显著降低聚羧酸锌水门汀和玻璃离子水门汀的剪切强度,但却会使磷酸锌水门汀的剪切强度大幅下降。极固宁也使树脂加强玻璃离子水门汀和树脂水门汀的粘接强度下降。结论：极固宁对磷酸锌水门汀、树脂加强玻璃离子水门汀、树脂水门汀与牙本质间粘接强度有不利影响,对聚羧酸锌水门汀和玻璃离子水门汀与牙本质间粘接强度无不利影响。     

不同方法处理丁香油酚暂封面对牙本质粘接强度的影响

目的:评价用不同方法处理使用氧化锌丁香油糊剂(zinc oxide-eugenol,ZOE)的牙本质表面对牙本质粘接系统微拉伸强度的影响。方法:选择因正畸拔除的完整、无龋前磨牙。用慢速锯去除面牙釉质,对照牙表面不使用ZOE;实验牙在暴露的牙本质表面涂ZOE。1周后,实验试件分别用方法a:机械去除;方法b:超声波清洁 酒精擦拭;方法c:超声波清洁 浮石打磨,3种不同方法去除ZOE。再分别使用2种牙本质粘接系统,用微拉伸法测试粘接强度。结果:单因素方差分析提示不同处理ZOE的方法对牙本质粘接系统的微拉伸粘接强度有显著影响(P<0.05),使用方法a后微拉伸粘接强度仍有显著下降,有统计学意义(P<0.05)。使用方法b和方法c后对微拉伸粘接强度无显著影响(P>0.05)。结论:使用超声波清洁 酒精擦拭或者超声波清洁 浮石打磨能显著降低ZOE对自酸蚀系统Clearfil SE Bond和iBond粘接强度的不利影响。     

Effect of Root Dentin Conditioning on the Pushout Bond Strength of Biodentine

Introduction

Sodium hypochlorite (NaOCl) is the main irrigant to clean root canals. Decalcifying agents are advocated as additional means to condition the root dentin. The aim of this study was to evaluate the effect of alternating (EDTA) or continuous 1-hydroxyethane 1,1-diphosphonic (HEDP) chelation in conjunction with NaOCl irrigation on the pushout bond strength of Biodentine (Septodont, Saint Maur des Fosses, France).