2种不同粘接水门汀对树脂类冠修复材料和全瓷托槽剪切粘接力的影响

目的 评价两种不同粘接水门汀对树脂类冠修复材料和全瓷托槽剪切粘接力的影响。方法 选用2种水门汀Transbond XT和RelyX Ultimate,将上颌前磨牙全瓷托槽Inspire Ice与4种树脂类冠修复材料粘接。试件冷热循环5 000次后测量断裂载荷（N）,并观察破坏形态。结果 单因素方差分析结果F=4.52（P＜0.001）,显示粘接条件对陶瓷托槽和树脂类冠修复材料的剪切粘接力影响具有统计学意义。其中Lava Ultimate+Transbond XT组和Lava Ultimate+ RelyX Ultimate+托槽喷砂组分别为（325.10±135.54）N和（304.71±35.71）N,较其他组高,Lava Ultimate+ Transbond XT+托槽喷砂组最低,为（118.12±57.58）N。结论 树脂基陶瓷材料Lava Ultimate和全瓷托槽的剪切粘接力较暂时冠修复材料高。全瓷托槽未喷砂时,正畸全瓷托槽粘接水门汀Transbond XT和修复用水门汀RelyX Ultimate的粘接力未见明显区别,喷砂后全瓷托槽失去固位小球,RelyX Ultimate有更高的粘接力。     

不同正畸粘接系统在托槽再粘接中的应用评价

目的：检测使用不同正畸粘接系统再粘接托槽对其剪切粘接强度的影响,以探讨提高临床再粘接效率的方法。方法：选择60颗正畸减数的恒双尖牙,依据不同粘接系统随机分为3组：津京釉质粘接剂（A组）、TransbondXT光固化粘接系统（B组）及Transbond自酸蚀粘接系统（C组）。所有样本均先用津京釉质粘接剂粘接托槽,24h后去除托槽重新粘接新托槽,测量3组托槽再粘接的剪切强度及粘接剂残留指数（AdhesiveRemnantIndex,ARI）。结果：3组托槽再粘接剪切强度分别为（8．615±2．460）MPa、（8．807±1．801）MPa及（8．144±3．023）MPa,组间剪切强度差异无显著性;ARI评分表明：C组牙面上残留的粘接剂明显少于其他两组。结论：采用自酸蚀粘接系统再粘接托槽的剪切强度与其它两种粘接系统相当,并且去除托槽后牙面残留粘接剂较少。     

预置粘接剂托槽的抗剪切强度

目的本研究目的是检测预置粘接剂(Adhesive Precoated,APC)托槽粘接后的抗剪切强度,并与传统的正畸托槽粘接后的抗剪切强度进行对比研究。材料与方法研究中使用50个离体前磨牙,随机分为5组,每组10个样本。按照相应的步骤在牙釉质是粘接托槽。组1:先进行釉质酸蚀,然后用光固化树脂粘接剂(Transbond XT)粘接金属托槽;组2:先进行釉质酸蚀,然后粘接 APC 托槽;组3:釉质表面使用自酸蚀偶联剂,然后用光固化树脂粘接剂粘接金属托槽;组4:釉质表面使用自酸蚀偶联剂,然后粘接 APC 托槽;组5:先进行釉质酸蚀,然后用化学固化树脂粘接剂(Unite)粘接金属托槽。用材料力学实验机对托槽施加剪切力,检测每组样本的抗剪切强度和粘接材料残留指数(ARI)。结果每组的平均抗剪切强度分别为组1:11.37±6.62兆帕(MPa);组2:11.08±4.63兆帕;组3:11.62±6.88兆帕;组4:10.96±5.94兆帕;组5:14.41±6.34兆帕。方差分析表明,5组之间的粘接强度的差异没有显著的统计学意义(P>0.05)。结论预置粘接剂托槽可以有足够的粘接强度供临床使用。     

紫外线照射对正畸粘接剂去除后牙面颜色影响的研究

目的 研究紫外线照射条件下,酸蚀时间及粘接剂的固化形式对正畸粘接剂去除后牙面颜色稳定性的影响.方法 筛选色度为A3.5的前磨牙30颗,随机均分为5组,设一对照组,其它4组中前二组用37%磷酸分别酸蚀15秒、30秒后用Unite~（Tm）粘接剂（3M）粘接托槽,另外三组用37%磷酸分别酸蚀15秒、30秒后用Transbond XT粘接剂（3M）粘接托槽.恒温水浴48小时后去除托槽及残留粘接剂,紫外线照射72小时,实验前后进行比色.结果 除对照组外,其它各组的色差均大于3.3;除酸蚀15秒光固化粘接刺组外,其它各组与对照组色差差异均有统计学意义（P＜0.05）;粘接剂的固化形式及酸蚀时间对色差的影响均有统计学意义（P＜0.05）.结论 在紫外线照射条件下,粘接剂的固化形式及酸蚀时间均会影响正畸粘接剂去除后牙面颜色的稳定性,使其发生临床可识别的颜色改变,其中酸蚀15秒使用光固化粘接剂进行粘接后的牙面颜色改变最小.     

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。     

3种酸蚀、粘接方法粘接托槽后釉质粘接剂界面的超微形态观察

目的研究不同粘接材料、不同酸蚀方法粘接正畸金属托槽后釉质粘接剂界面纵切面的超微形态。方法选择正畸拔除的健康前磨牙72颗,随机分成3组,每组24颗。A组用体积分数37%的磷酸酸蚀30 s,京津釉质粘接剂粘接金属托槽;B组用体积分数37%的磷酸酸蚀30 s,Transbond光固化粘接剂粘接托槽;C组用自酸蚀处理液加压涂抹3 s,Transbond光固化粘接剂粘接托槽。高倍立体显微镜及扫描电镜观察3组牙釉质粘接剂界面纵切面的形态。结果 A组界面紧密而均匀,粘接剂固化后形成的颗粒较大,颗粒之间间隙明显。B组界面紧密均匀,粘接剂固化后的颗粒较小而均匀,颗粒间结合紧密。C组界面疏松不均匀,树脂突少而细,有时可见较明显的裂隙。结论不同酸蚀、粘接方法牙釉质粘接剂界面的结合情况不同,磷酸酸蚀组釉质表面与粘接剂间形成的树脂突较均匀而密合,而自酸蚀组多处存在较大的裂隙,提示酸蚀方法可能是影响微渗漏的主要原因。     

3种无托槽隐形矫治器附件粘接方法的比较研究

目的 比较全酸蚀粘接剂、自酸蚀粘接剂和树脂加强型玻璃离子水门汀3种材料粘接无托槽隐形矫治器附件的操作时间和临床效果。方法 将采用无托槽隐形矫治器矫治的30例错牙合畸形患者（附件156个）随机分为3组,每组10例。A组采用3M Adper Single Bond 2全酸蚀粘接剂和3M Z350纳米充填树脂粘接附件,B组采用3M Adper Easy One自酸蚀粘接剂和3M Z350纳米充填树脂粘接附件,C组直接采用GC Fuji Ortho LC树脂加强型玻璃离子水门汀粘接附件。记录每个附件的操作时间,评价粘接时、治疗1个月和6个月时3组附件的失败情况。结果 C组附件的操作时间较A、B组短（P<0.01）。3组附件之间的粘接失败率无统计学差异（P>0.05）,同一组内不同时间的粘接失败率也无统计学差异（P>0.05）。结论 3种材料粘接附件的稳定性均能达到满意的效果,但树脂加强型玻璃离子水门汀操作简便,更适宜临床推广。     

两种正畸粘接系统对金属和陶瓷托槽粘接强度的影响

目的:评价传统正畸粘接系统和自酸蚀粘接系统分别对金属托槽和陶瓷托槽的粘接强度。方法:将100颗人前磨牙均分为4组:金属托槽/传统粘接系统组(1组)、金属托槽/自酸蚀粘接系统组(2组)、陶瓷托槽/传统粘接系统组(3组)、陶瓷托槽/自酸蚀粘接系统组(4组),使用Transbond XT树脂糊剂将托槽粘接在牙面上,测量各组的抗剪切粘接强度,并评价其剩余粘接剂指数,对结果进行单因素方差分析。结果:统计学分析表明金属托槽的抗剪切粘接强度高于陶瓷托槽,其差异具有统计学意义(P<0.05);1组和2组平均抗剪切粘接强度的差异无统计学意义(P>0.05),3组和4组间的差异也无统计学意义(P>0.05);各组剩余粘接剂指数的差异无统计学意义(P>0.05),但各组的粘接强度与剩余粘接剂指数有平行相关性(P<0.05)。结论:金属托槽的粘接强度高于陶瓷托槽;自酸蚀粘接系统与传统粘接系统都可满足正畸临床粘接托槽的需求;大部分样本的粘接失败发生在托槽/粘接剂界面或粘接剂内部破坏,表明牙釉质受损的几率较低,且粘接强度和剩余粘接剂指数之间存在统计学相关性。     

2种粘接剂粘接托槽首次脱落率的临床评价

目的比较树脂类Grengloo粘接剂和玻璃离子类GC Fuji LC粘接剂粘接托槽的首次脱落率。方法固定正畸病例96例,采用自身对照法在口内左右侧随机使用Grengloo和GC粘接剂粘接托槽,记录托槽首次脱落情况。结果两种粘接剂托槽的总体首次脱落率Grengloo组高于GC组,差异有统计学意义（χ2=11.269,P=0.001）。组内比较：Grengloo组（χ2=76.816,P〈0.001）和GC组（χ2=48.538,P〈0.001）上颌、下颌颊面管脱落率的差异均有统计学意义,下颌均高于上颌;Grengloo组（χ2=11.045,P=0.010）、GC组（χ2=4.485,P=0.034）下颌前磨牙脱落率均高于上颌前磨牙,差异有统计学意义。组间比较：下颌颊面管脱落率GC组低于Grengloo组,差异有统计学意义（χ2=9.757,P=0.002）。其他组内组间比较差异均无统计学意义。结论下牙托槽的粘接脱落率较上牙高,尤其在磨牙区;GC与Grengloo粘接剂都能够满足临床粘接需要,GC粘接剂尤其适合后牙区托槽粘接。     

正畸托槽去除时粘接剂残留模式的体外研究

目的：本研究只对金属托槽、树脂托槽分别应用3种不同粘接剂粘接,正畸托槽去除时粘接剂残留的模式进行体外研究。方法：收集因正畸需要而拔除的新鲜双尖牙120颗,随机等分为6组,用国产双尖牙方丝弓树脂托槽和国产方丝弓金属托槽分别应用3种不同粘接剂模拟临床应用的实验条件下粘接,并做组别标记,1KN电液疲劳实验机进行托槽去除。在实体显微镜下观察ARI记分情况,对正畸托槽去除时粘接剂残留模式进行体外研究。结果：树脂托槽组中和金属托槽组中3组粘接剂去粘接后,ARI记分均无显著性差异（P〉0.05）,但同种粘接剂金属托槽与树脂托槽ARI记分有显著性差异（P〈0.05）。结论：去粘接时金属托槽留在牙面的粘接剂少,树脂托槽留在牙面的粘接剂多。说明树脂托槽与粘接剂之间的粘接强度有待进一步加强。     

An in vitro comparison of the shear bond strength of a resin-reinforced glass ionomer cement and a composite adhesive for bonding orthodontic brackets

The shear bond strength (SBS) of a light-cured, resin-reinforced glass ionomer and a composite adhesive in combination with a self-etching primer was compared after different setting times to evaluate when orthodontic wires could be placed. Additionally, the fracture site after debonding was assessed using the Adhesive Remnant Index (ARI). Eighty freshly extracted human premolars were used. Twenty teeth were randomly assigned to each of four groups: (1) brackets bonded with Transbond XT with a Transbond Plus etching primer and debonded within 5 minutes; (2) brackets bonded with Fuji Ortho LC and debonded within 5 minutes; (3) brackets bonded as for group 1 and debonded within 15 minutes; (4) brackets bonded as for group 2 and debonded within 15 minutes. The SBS of each sample was determined with an Instron machine. The mean SBS were, respectively: (1) 8.8 +/- 2 MPa; (2) 6.6 +/- 2.5 MPa; (3) 11 +/- 1.6 MPa and (4) 9.6 +/- 1.6 MPa. Interpolating the cumulative fracture probability by means of a Weibull analysis, the 10 per cent probabilities of fracture for the groups were found to be attained for shear stresses of 6.1, 3.1, 8.3 and 7.1 MPa, respectively. Chi-square testing of the ARI scores revealed that the nature of the remnant did not vary significantly with time, but the type of bonding material could generally be distinguished in leaving more or less than 10 per cent of bonding material on the tooth. After debonding, the Transbond system was likely to leave adhesive on at least 10 per cent of the bonded area of the tooth. The present findings indicate that brackets bonded with either Transbond XT in combination with Transbond Plus etching primer and Fuji Ortho LC had adequate bond strength at 5 minutes and were even stronger 15 minutes after initial bonding.     

Bond strengths of orthodontic brackets to restorative resin composite surfaces

In orthodontic practice, it is not uncommon to bond brackets to resin composite restorations. With this in mind, this study was designed to compare first the shear/peel strengths of metal, ceramic and polycarbonate brackets bonded to microfilled resin composite (RC), using either a light-cured resin-modified glass ionomer cement (Fuji Ortho LC), a chemical-cured composite (System 1+) or a light-cured composite adhesive (Transbond XT); and then to examine the effects of thermocycling on the shear/peel strengths of these systems. Four different brackets were used: two stainless steel (Victory and Optimesh), one ceramic (Transcend 6000) and one polycarbonate (Spirit MB). Seventy-two specimens of each bracket were divided into three groups for bonding with one of the three adhesives. Half the specimens from each group were also thermocycled. Mean shear/peel bond strengths were found to be significantly different for the four different brackets, although not influenced by the three adhesives used within each group. All groups were found to have clinically-acceptable mean bond strengths, except for Spirit MB-System 1+. After thermocycling, both Optimesh-Transbond XT and Victory-System 1+ groups showed superior mean bond strengths (26.8 and 24.4 MPa, respectively) when compared with all other groups (p < 0.05). Applying the Weibull survival analysis for groups utilising Victory, Transcend 6000 and Spirit MB brackets, those with 90 per cent or greater probabilities of survival included Victory-System 1+, Transcend 6000-Fuji Ortho LC, Victory-Fuji Ortho LC and Spirit MB-Transbond XT groups. In all groups, bond failure was mainly (64 per cent) cohesive within the RC restorative surface. The thermocycled Spirit MB-Transbond XT group had the highest frequency of undamaged RC failure interfaces. Despite the focus of this study being on bond strength and the potential for surface damage, it was noted that these properties should always be considered alongside other factors such as the strength of the bracket itself, friction within the bracket slot, patients' wishes, cost of the materials and the presenting malocclusion.     

New protective polish effects on shear bond strength of brackets

One of the solutions for the problem of white spot lesions has been the application of a polymer coating to the labial enamel surface. The aim of this study is to find out whether the liquid polish BisCover affects the bond strength of brackets bonded with a light-cured system (Transbond XT) and a no-mix system (Unite). Standard stainless steel premolar brackets were bonded to 100 permanent human premolars randomly divided into five equal groups. Two different enamel surface conditions were studied: dry and varnished with BisCover. For each enamel surface condition, two orthodontic adhesive systems were used: a light-cured system (Transbond XT) and a no-mix system (Unite). All teeth were conditioned with 37% phosphoric acid for 30 seconds, followed by thorough washing and drying. The teeth in groups 1 and 2 were bonded with Transbond XT and Unite, respectively. For groups 3, 4, and 5, a thin layer of BisCover was applied to the etched enamel with a brush and light cured for 15 seconds. In group 3, a thin layer of Transbond XT primer was applied, whereas in group 5, no additional primer was used on BisCover. In groups 3 and 5, the brackets were bonded with Transbond XT adhesive resin. Group 4 was bonded with no-mix Unite. Shear forces were applied to the samples by a Zwick Universal test machine, and bond strengths measured in megapascals. The results revealed that shear bond strengths of the groups did not differ significantly from each other.     

Effect of bonding material, etching time and silane on the bond strength of metallic orthodontic brackets to ceramic

The purpose of this study was to evaluate the bond strength of metallic orthodontic brackets to feldspathic ceramic with different etching times, bonding materials and with or without silane application. Cylinders of feldspathic ceramic were etched with 10% hydrofluoric acid for 20 or 60 s. For each etching time, half of the cylinders received two layers of silane. Metallic brackets were bonded to the cylinders using Transbond XT (3M Unitek) or Fuji Ortho LC (GC). Light-activation was carried out with total exposure time of 40 s using UltraLume 5. Shear bond strength testing was performed after 24 h storage. Data were submitted to three-way ANOVA and Tukey's test (α=0.05). The adhesive remnant index (ARI) was used to evaluate the amount of adhesive remaining on the ceramic surface at ×8 magnification. Specimens etched for 60 s had significantly higher bond strength compared with 20 s. The application of silane was efficient in increasing the shear bond strength between ceramic and both fixed materials. Transbond XT showed significantly higher (p<0.05) bond strength than Fuji Orth LC. There was a predominance of ARI score 0 (clean ceramic failure surface) for all groups, with an increase in scores 1, 2 and 3 (adhesive material increasingly present on ceramic failure aspect) for the 60-s etching time. In conclusion, 60-s etching time, silane and Transbond XT improved significantly the shear bond strength of brackets to ceramic.     

Influence of Adhesives and Methods of Enamel Pretreatment on the Shear Bond Strength of Orthodontic Brackets

Aim

The objective of present study was to examine influence of adhesives and methods of enamel pretreatment on the shear bond strength (SBS) of orthodontic brackets. The adhesives used were resin-reinforced glass ionomer cements-GIC (Fuji Ortho LC) and composite resin (Transbond XT).

Material and Methods

The experimental sample consisted of 80 extracted human first premolars. The sample was divided into four equal groups, and the metal brackets were bonded with different enamel pretreatments by using two adhesives: group A-10% polyacrylic acid; Fuji Ortho LC, group B–37% phosphoric acid; Fuji Ortho LC, group C–self etching primer; Transbond XT, group D–37% phosphoric acid, primer; Transbond XT. SBS of brackets was measured. After debonding of brackets, the adhesive remnant index (ARI) was evaluated.

Results

After the statistical analysis of the collected data was performed (ANOVA; Sheffe post-hoc test), the results showed that significantly lower SBS of the group B was found in relation to the groups C (p=0.031) and D (p=0.026). The results of ARI were similar in all testing groups and it was not possible to determine any statistically significant difference of the ARI (Chi- square test) between all four experimental groups.

Conclusion

The conclusion is that the use of composite resins material with appropriate enamel pretreatment according to manufacturer’s recommendation is the “gold standard” for brackets bonding for fixed orthodontic appliances.Key words: orthodontic brackets, shear strength, adhesive, enamel preparation     

A comparison of the shear bond strength of a resin cement and two orthodontic resin adhesive systems

The object of this study was to compare the shear bond strength and the quantity of adhesive remaining on the tooth after the debonding of brackets bonded with two light-cured orthodontic resin adhesive systems (Transbond XT and Light-Bond) and a dual-cured resin cement (RelyX Unicem). Seventy-five premolars were divided into three groups. In each group, brackets were bonded with one of the adhesives according to the manufacturer's instructions. Shear bond strength was measured using a universal test machine at a crosshead speed of one mm/min, and adhesive remnant was quantified using image analysis equipment. Our results showed that the resin cement produced significantly lower bond strength than the two orthodontic resin adhesive systems. It was also observed that the bond strength produced by Light-Bond was significantly greater than that of Transbond XT. RelyX left significantly less remnant adhesive than Transbond XT and Light-Bond. Between the two orthodontic systems, Light-Bond left significantly less adhesive on the tooth than Transbond XT.     

Enamel demineralization adjacent to orthodontic brackets bonded with hybrid glass ionomer cements: An in vitro study

Enamel demineralization is recognized as a possible side effect of bonding orthodontic brackets with composite resins. Fluoride-releasing restorative materials have been shown to inhibit tooth demineralization. The purpose of this study was to evaluate two fluoride-releasing hybrid glass ionomer bonding agents for inhibition of enamel demineralization surrounding orthodontic brackets under two experimental conditions. This in vitro study used 72 extracted human premolars. Twenty-four teeth were bonded with Advance resionomer, 24 were bonded with Fuji Ortho LC hybrid glass ionomer and 24 were bonded with Transbond XT composite resin as the control. The teeth were cycled in an artificial caries challenge three times daily for 30 days. Half of the teeth in each group were brushed twice daily with a fluoridated dentifrice, and the other half were not brushed. Demineralization of enamel surrounding orthodontic brackets was evaluated with polarized light microscopy. Enamel lesions were photographed under maximum illumination. Images were projected, and demineralized areas were traced. Both average depth and area were measured with a sonic digitizer. Analysis of variance (P < .0001) and Duncan’s test (P < .05) indicated significant differences in depth and area of demineralized enamel such that lesion size was: Transbond XT no brush > Transbond XT brush > Advance no brush = Advance brush = Fuji Ortho LC no brush = Fuji Ortho brush. The promising results of this in vitro study warrant further clinical investigation of hybrid glass ionomer adhesives as orthodontic bonding agents to minimize enamel demineralization. (Am J Orthod Dentofacial Orthop 1998;114:668-74)     

A self-conditioner for resin-modified glass ionomers in bonding orthodontic brackets

OBJECTIVE: To evaluate a new self-etch conditioner used with resin-modified glass ionomers (RMGIs) in bonding orthodontic brackets. MATERIALS AND METHODS: Sixty human molars were cleaned, mounted, and randomly divided into three groups. In group 1 (control), 20 orthodontic brackets were bonded to teeth using Transbond Plus Self-etching Primer; in group 2, 20 brackets were bonded using an RMGI with a 10% polyacrylic acid conditioner. In group 3, 20 brackets were bonded using Fuji Ortho LC with a new no-rinse self-conditioner for RMGIs. The same bracket type was used on all groups. The teeth were debonded in shear mode using a universal testing machine, and the amount of residual adhesive remaining on each tooth was evaluated. Analysis of variance was used to compare the shear bond strength (SBS), and the chi(2) test was used to compare the Adhesive Remnant Index (ARI) scores. RESULTS: There were no significant differences in the SBS (P = .556) between the groups. The mean SBS for Transbond Plus was 8.6 +/- 2.6 MPa, for Fuji Ortho LC using 10% polyacrylic acid 9.1 +/- 4.6 MPa, and for Fuji Ortho LC using GC Self-conditioner 9.9 +/- 4.1 MPa. The comparisons of the ARI scores between the three groups (chi(2) = 35.5) indicated that bracket failure mode was significantly different (P < .001), with more adhesive remaining on the teeth bonded using Transbond. Conclusions: The new self-etch conditioner can be used with an RMGI to successfully bond brackets. In addition, brackets bonded with Fuji Ortho LC resulted in less residual adhesive remaining on the teeth.     

Metallic brackets bonded with resin-reinforced glass ionomer cements under different enamel conditions

OBJECTIVE: To assess the shear bond strength of metallic orthodontic brackets bonded with either Fuji Ortho or Ortho Glass LC resin-reinforced glass ionomer cements to enamel surfaces under different conditions, namely, enamel without etching, enamel conditioned with 37% phosphoric acid and enamel conditioned with Transbond Plus Self Etching Primer (TPSEP). MATERIALS AND METHODS: One hundred and five bovine inferior incisors were divided into seven groups (n = 15). In group 1 (control) Transbond XT was used according to the manufacturer's recommendations. In groups 2, 3, and 4 all using Fuji Ortho LC, the brackets were bonded, respectively, to enamel nonetched, enamel etched with 37% phosphoric acid, and enamel etched with TPSEP. In groups 5, 6, and 7, the bonding was performed using Ortho Glass LC under the same enamel conditions observed in the other experimental groups. After 24 hours, shear bond strength tests were performed for all samples at a crosshead speed of 0.5 mm/min. RESULTS: The results (MPa) showed no statistically significant difference between groups 1, 3, and 4 (P > .05). However, such groups were statistically superior to the others (P < .05). No statistically significant difference was observed between groups 2, 6, and 7 (P > .05). Group 5 showed the lowest shear strength value, which was also statistically inferior to the other groups (P < .05). CONCLUSIONS: Regardless of the enamel treatment, Fuji Ortho LC yielded shear strength values superior to those from Ortho Glass LC.     

An in vivo investigation into the use of resin-modified glass poly(alkenote) cements as orthodontic bonding agents.

The aim of this study was to investigate the in vivo bonding of orthodontic brackets using two resin-modified glass poly(alkenoate) cements and to compare them with a conventional light-cured diacrylate bonding agent. Twenty consecutive patients attending for bond up appointments took part in this randomized cross-mouth control study. Alternate quadrants were bonded with either Fuji Ortho LC or 3 M Multi-Cure. Transbond [Adhesive Pre-Coated Brackets (APC)] acted as the control in the other quadrants. Failed brackets were rebonded with the same material. Bond failure rates were collected over a 1-year period. The bond failure rates over 1 year were 7.2 per cent for Transbond (APC), 5.9 per cent for 3 M Multi-Cure, and 5.8 per cent for Fuji Ortho LC. Statistically, there was no significant difference between the bond failure rates of the materials and there was no effect of time. This clinical investigation confirmed the suitability of the resin-modified glass poly(alkenoate) cements under test as orthodontic bonding agents.