Shear bond strength of orthodontic brackets to enamel after application of a caries infiltrant

Objective:To examine differences in the shear bond strength of orthodontic brackets on differently mineralized enamel surfaces after applying a caries infiltrant or conventional adhesive.Materials and Methods:A total of 320 bovine incisors were assigned to eight pretreated groups, and the shear force required for debonding was recorded. Residual adhesive was evaluated by light microscopy using the adhesive remnant index. Statistical analysis included Kolmogorov-Smirnov, analysis of variance (ANOVA), and Scheffé tests.Results:The highest bond strength (18.8 ± 4.4 MPa) was obtained after use of the caries infiltrant. More residual adhesive and fewer enamel defects were observed on infiltrated enamel surfaces. Brackets on demineralized enamel produced multiple enamel defects.Conclusions:Acceptable bond strengths were obtained with all material combinations. A caries-infiltrant applied before bracket fixation has a protective effect, especially on demineralized enamel.     

Adhesive performance of a caries infiltrant on sound and demineralised enamel

Objective

Resin infiltration is considered as a treatment option for initial caries lesions. As cavitated early lesions might require additional restorative intervention, a caries infiltrant might be also used for enamel conditioning prior to composite insertion. This study aimed to analyse the shear bond strength of a flowable composite to sound and demineralised enamel pretreated with a caries infiltrant, a conventional adhesive or a combination of both.

Methods

Flattened bovine enamel specimens (n = 120) were either demineralised (14 d, acidic buffer, pH 5) or remained untreated. Sound and demineralised specimens (each n = 20) were then treated with: (1) 35% phosphoric acid, conventional adhesive, (2) 15% hydrochloric acid, caries infiltrant or (3) 15% hydrochloric acid, caries infiltrant, conventional adhesive. Shear bond strength of a flowable composite was tested after 24 h water storage (37 °C) and statistically analysed (ANOVA, p ≤ 0.05). The mode of failure was assessed microscopically at 25× magnification.

Results

On demineralised enamel, the combination of caries infiltrant and conventional adhesive showed significantly higher shear bond strength values than the conventional adhesive alone, while both being not significantly different from group 2. No significant differences between the groups could be detected on sound specimens. A higher percentage of cohesive failures could be observed in demineralised samples of group 2 (40%) and 3 (65%), while all other specimens presented almost only adhesive failures.

Conclusion

The use of a caries infiltrant before application of a conventional adhesive did not impair bonding to sound and demineralised enamel and might be beneficial as a pretreatment in demineralised enamel.     

Effect of enamel protective agents on shear bond strength of orthodontic brackets

Background

This paper aimed to study the effect of two enamel protective agents on the shear bond strength (SBS) of orthodontic brackets bonded with conventional and self-etching primer (SEP) adhesive systems.

Methods

The two protective agents used were resin infiltrate (ICON) and Clinpro; the two adhesive systems used were self-etching primer system (Transbond Plus Self Etching Primer + Transbond XT adhesive) and a conventional adhesive system (37% phosphoric acid etch + Transbond XT primer + Transbond XT adhesive ). Sixty premolars divided into three major groups and six subgroups were included. The shear bond strength was tested 72 h after bracket bonding. Adhesive remnant index scores (ARI) were assessed. Statistical analysis consisted of a one-way ANOVA for the SBS and Kruskal-Wallis test followed by Mann-Whitney test for the ARI scores.

Results

In the control group, the mean SBS when using the conventional adhesive was 21.1 ± 7.5 MPa while when using SEP was 20.2 ± 4.0 MPa. When ICON was used with the conventional adhesive system, the SBS was 20.2 ± 5.6 MPa while with SEP was 17.6 ± 4.1 MPa. When Clinpro was used with the conventional adhesive system, the SBS was 24.3 ± 7.6 MPa while with SEP was 11.2 ± 3.5 MPa. Significant differences in the shear bond strength of the different groups (P = .000) was found as well as in the ARI scores distribution (P = .000).

Conclusion

The type of the adhesive system used to bond the orthodontic brackets, either conventional or self-etching primer, influenced the SBS, while the enamel protective material influenced the adhesive remnant on the enamel surface after debonding.     

瓷表面处理对正畸托槽与瓷黏结抗剪强度的影响

目的:探讨不同瓷表面处理技术对正畸托槽与瓷黏结抗剪强度的影响。方法:采用4组不同的瓷表面处理方式,使用光固化正畸黏结剂将瓷面分别与金属和陶瓷托槽黏结,每组再平均分为2组分别在37℃水浴24h和7d后冷热循环500次(5～55℃),测量黏结抗剪强度,并统计其黏结剂残留指数,在扫描电镜下观察其瓷面显微结构的变化。结果:4种瓷表面处理技术对2种不同材料托槽处理的结果近似,均可达到有效正畸黏结强度。结论:磷酸酸蚀结合硅烷偶联剂是正畸托槽与瓷黏结的较佳方式之一。     

季铵盐单体对正畸粘接剂粘接强度和抗菌性能的影响

目的 评价一种新型季铵盐类单体,甲基丙烯酸十六烷基二甲(dimethylaminohexadecyl methacrylate,DMAHDM)对正畸粘接剂粘接强度和抗菌性能的影响.方法 将DMAHDM以0％(对照组),1.5％,3％和5％的比例添加到商品化的正畸粘接剂中.测试托槽剪切粘接强度,使用人唾液培养所得的牙菌斑全菌生物膜模型来研究粘接剂的抗菌性能.结果 在正畸粘接剂中添加3％的DMAHDM不影响托槽的粘接强度.随着DMAHDM含量的增加,改性正畸粘接剂的抗菌性能不断增加.含有3％DMAHDM的改性组试件表面附着菌斑的代谢活性和乳酸产量大约是对照组的15％.活/死菌染色显示对照组试件表面黏附有大量的活细菌,含有3％DMAHDM的改性组试件的表面主要为死细菌.结论 DMAHDM改性正畸粘接剂在不影响托槽粘接强度的前提下,显著提高粘接剂的抗菌性能,具有一定临床应用价值.     

新型正畸粘接剂聚合特征和剪切粘接强度的研究

目的本研究测量一种新型丙烯酸类正畸粘接剂的聚合特征和剪切粘接强度,以评估其作为正畸粘接剂的可能性。方法将甲基丙烯酸甲酯、甲基丙烯酸羟乙酯、氟化钠和聚甲基丙烯酸甲酯按不同比例混合,构成3个实验组。分别测量样本的聚合特征、剪切粘接强度和粘接剂残留指数。聚合特征实验中的对照组为聚甲基丙烯酸甲酯,粘接强度实验中的对照组为光固化复合树脂（Transbond XT）。采用单因素或双因素方差分析和Kruskal-Wallis与Mann Whitney检验对数据进行统计分析。结果在同一温度下,实验组和对照组间的放热量无显著差异,实验组在23℃和37℃时的聚合时间均小于对照组。30min时实验组的粘接强度大于光固化复合树脂,1个月后光固化复合树脂的粘接强度大于实验组。1个月后实验组的粘接剂残留指数明显小于光固化复合树脂。结论这种新型粘接剂具有作为正畸粘接材料的潜力。     

两种复合树脂与牙本质剪切粘接强度的比较

目的 在离体牙牙本质上涂布粘接剂后分别予以声波技术充填 Sonicfill树脂及分层充填 P60树脂,评估应用两种复合树脂与牙本质的剪切粘接强度。方法 选择因牙周病拔除的磨牙 40颗,制成 40个牙本质试件,随机分为 2组。A 组为 Sonicfill树脂组,B 组为 P60树脂组。每组涂布粘接剂后,A 组采用声波技术充填树脂,B组采用分层技术充填树脂。经过循环温度为5 ℃及55 ℃的冷热循环疲劳试验,每个循环为3 min,共循环 500 次后,测试 2 组的剪切粘接强度（Shear Bond Strength,SBS）。结果 A 组的 SBS 为（10.32±1.13）MPa,B 组的 SBS 为（8.43±0.98）MPa,两者差别有统计学意义（P<0.05）。结论 运用声波技术的 Sonic‐fill树脂充填体相比采用分层充填的P60树脂拥有更高的剪切粘接强度。因此,在修复过程中使用声波充填技术不亚于传统分层充填树脂,且临床操作时间更短。     

Effects of surface treatment and artificial aging on the shear bond strength of orthodontic brackets bonded to four different provisional restorations

Objective:To evaluate the combined effects of material type, surface treatment, and thermocycling on the bond strength of orthodontic brackets to materials used for the fabrication of provisional crowns.Materials and Methods:Four materials were included in this study (ProTemp, Trim Plus, Trim II, and Superpont C+B). Sixty cylindrical specimens (1 × 3 cm) were prepared from each material and equally divided into three groups. The first group was ground with silica carbide paper, the second was polished with pumice, and the last group was sandblasted with 50-µm aluminum oxide particles. Stainless-steel maxillary central incisor brackets (Victory Series, 3M) were bonded to the provisional material specimens with Transbond XT light-cured composite resin, and half of the specimens from each group were thermocycled 500 times in 5°C and 55°C water baths. Then the brackets were debonded with shear testing, and the results were statistically analyzed by three-way analysis of variance and Tukey''s multiple-comparison tests at α  =  0.05. Adhesive Remnant Index (ARI) was also identified.Results:Before and after thermocycling, ProTemp materials showed the highest shear bond strength with orthodontic brackets (10.3 and 13.1 MPa, respectively). The statistical analysis indicated an interaction among the three independent variables (P < .05) and statistically significant differences in bond strength among provisional materials (P < .001), surface treatments (P < .001), and thermocycling (P < .05). According to the ARI, most groups demonstrated adhesive failure.Conclusions:The provisional material type, surface treatment, and artificial aging have a significant effect on bond strength. Sandblasting treatment exerts a beneficial effect on shear bond strength.     

Shear bond strength of composite resin to titanium according to various surface treatments

STATEMENT OF PROBLEM

When veneering composite resin-metal restoration is prepared, the fact that bond strength between Ti and composite resin is relatively weak should be considered.

PURPOSE

The purpose of this study is to evaluate the shear bond strength between the veneering composite resin and commercial pure (CP) Ti / Ti-6Al-4V alloy according to the method of surface treatment.

MATERIAL AND METHODS

The disks were cast by two types of metal. Their surfaces were treated by sandblasting, metal conditioner, TiN coating and silicoating respectively. After surface treatment, the disks were veneered by composite resin (Tescera™, Bisco, USA) which is 5 mm in diameter and 3 mm in thickness. The specimens were stored in water at 25℃ for 24 hours, and then evaluated for their shear bond strength by universal testing machine (STM-5®, United Calibration, USA). These values were statistically analyzed.

RESULTS

1. All methods of surface treatment were used in this study satisfied the requirements of ISO 10477 which is the standard of polymer-based crown and bridge materials. 2. The metal conditioner treated group showed the highest value in shear bond strength of CP Ti, silicoated group, TiN coated group, sandblasted group, in following order. 3. The silicoated group showed the highest value in shear bond strength of Ti-6Al-4V alloy, metal conditioner treated group, sandblasted group, TiN coated group, in following order.

CONCLUSION

Within the limitations of this study, all methods of surface treatment used in this study are clinically available.     

6种正畸粘结剂粘结强度的比较研究

目的 比较使用6种不同粘结剂在模拟口腔环境的体外实验中,抗剪切力的大小及托槽表面粘结接剂残余量。 方法 选择健康前磨牙60颗,随机分为6组,分别使用6种正畸托槽粘结剂：4款光固化型树脂粘结剂,1款光固化型玻璃离子粘结剂和1款化学固化牙釉质粘合树脂。6种粘结剂严格按说明操作粘结托槽,置于37 ℃的人工唾液中24 h后,用万能测力仪以1 mm/min的速度,记录托槽脱落的剪切力值,算出粘结剂的抗剪切力强度,结果用SPSS 17.0统计软件进行分析。在10倍放大镜下观察托槽的底板上残留粘结剂量,并进行ARI评分,将结果进行Kruskall-wallis H检验。 结果 Transbond XT光固化型树脂粘结剂组,Medicept光固化型树脂粘结剂组以及西湖巴尔公司产的光固化型树脂粘结剂组和非调拌型化学固化牙釉质粘合树脂组之间粘结强度无显著性差异（P>0.05）;虽然GC光固化型玻璃离子粘结剂组和Prime-Dent光固化型树脂粘结剂组之间粘结强度亦无显著性差异（P>0.05）,但与前4组粘结剂之存在显著性差异（P<0.05）,粘结强度相对较小;ARI评分结果进行Kruskall-wallis H检验显示各组间无显著性差异（P>0.05）。 结论 6种正畸粘结剂的粘结强度存在差异,但能够满足正畸临床工作需要。     

渗透树脂与前牙美学树脂颜色稳定性的比较研究

目的 通过分析不同树脂材料对饮料色素的着色效果,比较渗透树脂与前牙美学树脂颜色稳定性的差异。方法 选择3种前牙美学树脂（Filtek Z250、Filtek Z350 XT、Beautiful Flow Plus F00）及人工早期龋渗透树脂（Icon）处理样本各20例,不同树脂样本分别分为2组（每组10例）分别置于咖啡溶液及蒸馏水中浸泡1、2、3周。应用Crystaleye分光光度比色仪进行样本颜色分析。结果 人工早期龋渗透树脂处理表面的着色明显高于其他前牙美学树脂（P<0.05）。所有实验树脂及渗透树脂处理表面的着色均随时间延长而增加,但第1周的着色最为显著,明显高于第2周及第3周的着色（P<0.05）。结论 人工早期龋渗透树脂处理表面较前牙美学树脂更易发生颜色改变。     

封闭牙釉质表面的抗剪粘接强度研究

目的：研究Single bond与牙釉质表面的抗剪粘接强度。方法：30颗离体前磨牙随机均分为3组，牙釉质上分别粘接不同的测试材料，检测各组材料的抗剪粘接强度，并观察断裂发生的部位。结果：断裂均发生在粘接材料与牙釉质之间，Single bond的抗剪粘接强度达13Mpa。与牙釉质粘接前，牙面预涂京津釉质粘接剂涂剂，Single bond的抗剪强度没有出现显著性变化。这两组分分别与京津釉质粘接剂组比较，抗剪强度均有显著性差异。结论：Single bond与牙釉质的抗剪粘接强度满足正畸临床要求，京津釉质粘接剂涂剂不影响Single bond的临床应用。     

Shear bond strength of brackets bonded with hydrophilic and hydrophobic bond systems under contamination

Objective:To compare, in vitro, the shear bond strength (SBS) of two bond systems: Transbond XT/XT primer (TXT/XT) and Transbond Plus Color Change/Transbond Self Etching Primer (TPCC/TSEP).Materials and Methods:Each system was examined under four enamel surface conditions (dry, water, saliva, and blood), and 160 bovine teeth were divided into eight groups of 20 according to enamel surface condition. Group 1 used TPCC/TSEP and Group 2 used TXT/XT under dry conditions; Group 3 used TPCC/TSEP and Group 4 used TXT/XT with water; Group 5 used TPCC/TSEP and Group 6 used TXT/XT under saliva; and Group 7 used TPCC/TSEP and Group 8 used TXT/XT with blood. Brackets were bonded, and the samples were thermocycled 500 times between 5°C and 55°C; they were then submitted to a shear bond test with a universal testing machine with a 50 kgf load cell at 5 mm/min.Results:Although water and saliva affected TXT/XT more than they affected TPCC/TSEP, there were no significant differences among the groups (Groups 3 and 4: P  =  .940; Groups 3 and 5 and Groups 4 and 6: P  =  1.000; Groups 3 and 6: P  =  .988; Groups 4 and 5: P  =  .690; and Groups 5 and 6: P  =  .861).Conclusions:The presence of blood resulted in the lowest SBS from both bond systems, but especially from TXT/XT. TPCC/TSEP resulted in a higher SBS than TXT/XT under all conditions except the dry enamel surface.     

Kr:F准分子激光处理釉质与酸蚀釉质粘结强度的比较性研究

目的 探讨Kr:F准分子激光处理釉质表面后对粘接强度的影响。方法 牙齿釉质面分别经Kr:F激光照射或酸蚀后,与窝沟封闭剂粘接,比较两组的粘接强度。结果 Kr:F激光处理组与酸蚀组粘接强度间无显著性差异(P>0.05)。结论 Kr:F准分子激光替代化学酸蚀法处理釉质表面具临床可行性和独特的优越性。