Effect of Whitening Agents on Dentin Bonding

Background: Several studies have shown a reduction in enamel bond strengths when the bonding procedure is carried out immediately after vital bleaching with peroxides. This reduction in bond strengths has become a concern in cosmetic dentistry with the introduction of new “in‐office” and “waiting‐room” bleaching techniques. The aim of this in vitro study was to evaluate the effect of three bleaching regimens: 35% hydrogen peroxide (HP), 35% carbamide peroxide (CP), and 10% CP, on dentin bond strengths. Materials and Methods: One hundred and twenty fresh bovine incisors were used in this study. The labial surface of each tooth was ground flat to expose dentin and was subsequently polished with 600‐grit wet silicon carbide paper. The remaining dentin thickness was monitored and kept at an average of 2 mm. The teeth were randomly assigned to four bleaching regimens (n = 30): (A) control, no bleaching treatment; (B) 35% HP for 30 minutes; (C) 35% CP for 30 minutes; and (D) 10% CP for 6 hours. For each group, half of the specimens (n = 15) were bonded with Single Bond/Z100 immediately after the bleaching treatment, whereas the other half was bonded after the specimens were stored for 1 week in artificial saliva at 37°C. The specimens were fractured in shear using an Instron machine. Results: For the groups bonded immediately after bleaching, one‐way analysis of variance (ANOVA) followed by the Duncan's post hoc test revealed a statistically significant reduction in bond strengths in a range from 71% to 76%. For the groups bonded at 1 week, one‐way ANOVA showed that group B (35% HP for 30 min) resulted in the highest bond strengths, whereas 10% CP resulted in the lowest bond strengths. Student's t‐test showed that delayed bonding resulted in a significant increase in bond strengths for groups B (35% HP) and C (35% CP); whereas the group bleached with 10% CP (group D) remained in the same range obtained for immediate bonding. Storage in artificial saliva also affected the control group, reducing its bond strengths to 53% of the original.     

原花青素对不同深度牙本质粘接耐久性的影响

目的:探讨原花青素(Proanthocyanidins,PA)对不同深度牙本质粘接耐久性的影响。方法:将40颗第三磨牙随机分为8组(n=5):A、A1组:浅层+6.5%PA;B、B1组:浅层+乙醇;C、C1组:深层+6.5%PA;D、D1组:深层+乙醇。A1、B1、C1、D1组样本进行老化处理。各组试件测试抗剪切强度后统计断裂模式,并在扫描电镜下观察断裂面。结果:“老化”、“牙本质深度”、“PA”的单独主效应均具有统计学意义(P<0.05),但其二阶、三阶交互效应均不具有统计学意义。混合断裂是主要的断裂模式。A1、C1组见粗大的树脂突严密充填于牙本质小管中,B1、D1组出现牙本质小管及树脂溶解现象。结论:PA可增强浅、深层牙本质即刻抗剪切强度并改善粘接耐久性,牙本质浅层抗剪切强度高于深层。     

牙本质粘接循环载荷的研究进展

许多研究常使用静态载荷实验检测牙本质的粘接性能.然而,临床中的粘接界面性能是在循环载荷作用下,复合多种影响因素,逐渐退化、失效的.循环载荷实验可大致分为老化实验、疲劳极限实验两种,本文将对老化实验的装置、参数设置、应用、附加实验因素及疲劳极限实验分别进行综述.     

空气喷磨机喷磨牙釉质牙本质的抗剪切力比较研究

空气喷磨机（ＫＣＰ１０００）是近年来发展迅速的新型牙体预备系统．本文通过测量抗剪切力，比较ＫＣＰ处理牙釉质、牙本质８ｓ，磷酸酸蚀牙釉质３０ｓ后与复合树脂间抗剪切力．结果表明：３组之间抗剪切力无显著差别．因此我们得出：ＫＣＰ喷磨系统无需酸蚀，仅喷磨８ｓ即可达到磷酸酸蚀牙釉质的粘结强度；ＫＣＰ处理牙本质后能够显著提高表面粘结力，使之达到磷酸酸蚀牙釉质后的效果     

Effect of the Tenure Dentin Bonding System on Leakage of Light-Activated Liners

This study investigated the effect of the Tenure dentin bonding system on the sealing properties of four light-activated liners. Dentinal slot preparations were made in extracted human molars and "restored" with Cavalite, TimeLine, VLC Dycal, and Zionomer liners. Samples were immersed in 0.05 percent crystal violet solution for 2 hours, then embedded in clear casting resin, sectioned, and examined with an optical microscope. Our results indicated that the Tenure dentin bonding system reduced dye penetration around each of the light-activated liners tested. The Tenure/VLC Dycal system provided a more effective seal than the other liners.     

Bonding of Resin-based Sealers to Root Dentin

This study compared the microshear bond strength of three resin-based sealers to root dentin and assessed whether sealer cements behave differently in thin and thick films. Extracted maxillary premolars were sectioned buccolingually, and 45 root halves were randomly allocated for microshear bond testing with the three resin sealers in thin and thick films. The microshear bond strength was then calculated in MPa. Failure modes were examined under light and scanning electron microscopy. Data were analyzed by using analysis of variance, with significance set at p < 0.05. Overall, the epoxy resin-based sealers had the highest microshear bond strength to root dentin compared with urethane dimethacrylate–based sealers (p < 0.001). Bond strengths for the thick sealer group were significantly higher than the thin sealer group (p < 0.001) and may reflect different patterns of behavior when the sealer is present as a thin layer.     

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。     

Bonding of Composite Resin to Contaminated Human Enamel and Dentin

Purpose The purpose of this in vitro study was to evaluate the bond strengths of a bonding agent and composite resin system to human enamel and dentin treated with five contaminants (saliva, plasma, zinc oxide–eugenol cement, noneugenol zinc oxide cement, and handpiece lubricant) using air, moisture, and water as controls. Materials and Methods A commercial bonding agent (Gluma 2000; Bayer AG, Dormagen, Germany) and its composite (Pekafill; Bayer AG) were applied to tooth structure under two conditions (contaminated and re-etched). Samples were debonded in tension after 24 hours using an inverted, truncated cone bond test. Results Among the controls, the highest bond strengths were obtained to enamel (20 MPa) and dentin (12 MPa) with air drying. Contaminants lowered the bond strength by 20% to 100%. Re-etching without additional mechanical preparation resulted in bond strengths similar to the air control. Conclusions Bond strength of Gluma 2000/Pekafill to tooth structure is sensitive to common forms of contamination but can be improved by re-etching after contamination occurs.     

提高通用粘接剂与牙本质粘接性能的研究进展

口腔粘接剂在牙体组织修复治疗中具有重要作用.通用粘接剂逐渐在口腔临床应用普及,它可以应用于不同的粘接模式,粘接多种材料,简化了粘接过程,提高了粘接效率.但由于牙本质的高蛋白和高含水量,通用粘接剂与牙本质的粘接仍然存在缺陷,许多研究正在寻找提高通用粘接剂与牙本质粘接性能的方法.本文旨在对如何提高通用粘接剂与牙本质粘接性能...     

黄芩素与葛根素对牙本质粘接持久性的影响

目的:探讨基质金属蛋白酶抑制剂黄芩素,葛根素结合乙醇湿粘接对牙本质粘接持久性的影响.方法:选取128颗离体牙,随机分为8个组,每组16个,A组对照组无处理;B组乙醇处理;C、D、E组分别为0.05％、0.1％、0.5％黄芩素乙醇处理;F、G、H组分别为0.05％、0.1％、0.5％葛根素乙醇处理,每组随机抽取8个试件进...     

表面状态对乙醇-水基黏接剂强度和界面的影响

目的　研究干燥或湿润的牙本质表面状态对乙醇 -水基黏接剂黏接强度与黏接界面微观结构的影响 ,探讨黏接强度与黏接界面微观结构之间的内在联系。方法　选用两种含有乙醇和水的湿黏接系统OptiBondSolo和SingleBond ,将Chrisma树脂分别黏结在干燥或湿润的人牙本质表面 ,测试各组试件的微拉伸强度 ,并在扫描电镜下观察和比较各组试件黏接界面超微结构的异同。结果　湿黏接时黏接剂对牙本质表面的渗透较为充分 ,混合层均匀 ,厚度为 4～ 5 μm ,并可观察到牙本质小管和侧支小管中均有明显的树脂突形成 ;干燥黏结时形成的界面形态与湿黏接时没有明显区别。干燥黏接时 ,两种黏接系统的微拉伸强度均降低 ,下降幅度最高为 2 3% ,微拉伸破坏的方式主要是黏接界面的破坏。结论　微拉伸强度测试可客观反映黏接强度的大小     

Er:YAG激光处理对牙本质与树脂粘结强度的影响

目的:探讨Er:YAG激光处理对牙本质表面性能及树脂粘结强度的影响。方法:选取30颗无龋坏、无修复体的人离体磨牙,用高速涡轮手机在流水冲洗下磨除釉质层。每个牙冠以髓腔为中心沿近远中向切开成颊/舌两部分,最终选取50个样件,按不同的表面处理方法随机分为5组(A~E组),每组10个样件。每组2个样件扫描电镜观察,其余8个样件分别在处理后的牙本质表面粘结光固化复合树脂,进行剪切强度测试。结果:C组最高,为(7.11±1.73) MPa,E组次之,E组与A、C、D组无统计学差异, B组较低,其中B组与C、D、E组均有统计学差异。扫描电镜观察:酸蚀组可见部分牙本质小管口开放,管径未增大;管周牙本质与管间牙本质界限不明显。激光+酸蚀组可见牙本质表面清沽,牙本质小管开放,周围白晕环绕。激光组可见牙本质表面清洁、粗糙,无玷污层,呈片状、蜂窝状外观,管周牙本质与管间牙本质界限清晰。结论:Er:YAG激光处理能增加牙本质与树脂的剪切粘结强度,但是合适的能量参数有待进一步研究。     

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.     

简化乙醇湿粘结对龋影响牙本质粘结强度的影响

目的:评估简化乙醇湿粘结技术对龋影响牙本质粘结强度的影响。方法:选取人慢性龋离体第三磨牙36颗去龋备洞后保留龋影响牙本质。随机分为6组,分别使用自制疏水性粘结剂,Prime & Bond NT(PB),Adper Single bond plus(SB)进行粘结,堆砌树脂厚度约4~5 mm。实验组采用简化乙醇湿粘结法,对照组采用传统水湿粘结法。制作1 mm ×1 mm ×8 mm的条形微拉伸强度试件,每组选取8个。采用万能材料试验机测试微拉伸强度并记录,观察断裂界面。结果:在自制疏水性粘结剂组中,实验组粘结强度较对照组有显著提高(P<0.05)。结论:简化乙醇湿粘结技术可以提高CAD界面的粘结强度,尤其是在与疏水性粘结剂联合运用时,有显著提高。     

Dentin Bonding: Overview of the Substrate with Respect to Adhesive Material

The current challenge in adhesive dentistry is to develop dentin bonding systems that will reproducibly achieve high bond strengths similar to those obtained between resins and acid-etched enamel. Some of the limitations of dentin as a bonding substrate are that it changes its structure as it is prepared deeper, it is difficult to dry, and its smear layer is weak. Further, it is difficult to avoid contaminating proximal boxes with blood. Such contamination lowers dentin bond strengths to very low values. Decontamination of such dentin must be done prior to resin placement. The forces of polymerization contraction depend, in part, on the shape of cavities and how they are filled. Bulk filling of class I cavities can lead to conditions in which the forces of polymerization contraction exceed dentin bond strength with some materials and locations. The future development of resin systems that do not shrink on polymerization would eliminate many current problems in adhesive dentistry.     

Effects of Dentin Bonding Agents on the Cell Cycle of Fibroblasts

The aim of this study was to evaluate the effects of 3 dentin bonding agents on cell survival and proliferation and on cell cycle progression of cultured cells. The experiments were performed on RPC-C2A and L929 cells. Specimens of the 3 dentin bonding agents (Clearfil Tri-S, AdheSE, and XP BOND) were placed in culture medium, and the extraction media were applied to cells as experimental material. The effect of the bonding materials on cell survival and proliferation was assessed by a modified sulforhodamine B staining assay, and the effect on DNA synthesis was assessed by bromodeoxyuridine uptake. Flow cytometry was used for cell cycle analysis. Cell viability and proliferation decreased in a dose-dependent manner after exposure of cells to the tested materials. XP BOND expressed the highest activity of all tested bonding agents (P < .05). The self-etch bonding agents tested did not produce any significant effects on cell cycle distribution. However, exposure of cells to the total-etch agent XP BOND induced a G₂-phase arrest in both cell lines, and this effect was more evident in L929 cells than in RPC-C2A cells.     

Principles and Mechanisms of Bonding with Dentin Adhesive Materials

This article reviews six dentin bonding agents with regard to composition of the individual components of each of the systems. Adhesion mechanisms are discussed relative to the chemical compounds mediating the bond. Adjunctly, inspection of the bonding sites between the different adhesives and human dentin by scanning electron microscopy elucidates the bonds formed as far as detail reproduction as an indicator for wetting ability or mechanical interlocking.     

Intrapulpal Pressure and Thermal Cycling: Effect on Shear Bond Strength of Eleven Modern Dentin Bonding Agents

This in vitro study reports on a modified method for testing shear bond strengths of dentin bonding agents (DBAs). In order to imitate the surface of vital human dentin better, all DBAs used in this investigation (10 commercially available and one experimental) were tested under intrapulpal pressure (13.6 mm Hg to 25 mm Hg) and exposed to thermal cycling (x 1500, 5° to 55°C).
The difference between this testing method and a commonly used method (applying the DBA onto a dry dentinal surface and then storing in water at 37°C for 24 hours) was highly significant (p <.001, two-way AN OVA).
In group A (composite group) the bonding agent was light cured before the application of the composite resin. In group B (cementation group) the bonding agent and the composite resin were light cured simultaneously.
The shear bond strengths recorded in this study were generally lower than other published results. A.R.T. Bond and P-Bond (experimental dentin bonding agent) had the best average results in both testing groups.