Effect of self-etching primer and adhesive formulations on the shear bond strength of orthodontic brackets.

PURPOSE: Despite many published articles on the bond strength of self-etching primers and adhesives in the restorative dentistry literature, there have been relatively few laboratory studies of the bond strength of new orthodontic materials, and, in most of these published studies, investigators used various methodologic approaches during different stages of the in vitro testing procedures. The aim of this study was to compare the shear bond strength of 4 self-etching primer and adhesive formulations, a nonrinse conditioner and acetone adhesive system, and a conventional system. MATERIAL: The self-etching products tested were Prompt L-Pop (3M ESPE, Seefeld, Germany), Clearfil SE Bond (Kuraray Dental, Osaka, Japan), FL Bond (Shofu Dental, Kyoto, Japan), and One-Up Bond F (Tokuyama, Tokyo, Japan); the nonrinse conditioner and acetone-based adhesive system was NRC and Prime&Bond NT (Dentsply International, Konstanz, Germany); the conventional acid-etch and bond system was Transbond XT (3M Unitek, Monrovia, Calif). Brackets were bonded to intact bovine mandibular incisors (n = 7 per group) according to each manufacturer's recommendations. The specimens were first stored in deionized water at 37 degrees C for 24 hours and then subjected to thermal cycling in deionized water at 5 degrees C +/- 2 degrees C to 55 degrees C +/- 2 degrees C for 1000 cycles. To facilitate degradation of bonds, the specimens were further stored in distilled water for 6 weeks before debonding procedures. RESULTS: The shear bond strengths of the 5 experimental groups were all significantly lower (P < .05) than that of the control group (Prompt L-Pop, 1.72 +/- 0.13 MPa; Clearfil SE Bond, 1.75 +/- 0.19 MPa; FL Bond, 1.71 +/- 0.22 MPa; One-Up Bond F, 1.77 +/- 0.14 MPa; control, 10.5 +/- 0.86 MPa) but not different from one another (P > .05). CONCLUSIONS: The tested self-etching primer and adhesive systems produced bond strength values much lower than that of the control product. Clinically, these products might not be suitable for orthodontic bracket bonding in terms of the shear bond strength achieved after thermal cycling and water storage.     

Evaluation of an antimicrobial and fluoride-releasing self-etching primer on the shear bond strength of orthodontic brackets

The enhanced risk of dental caries is one negative side-effect of fixed appliances. A new antimicrobial and fluoride-releasing self-etching bonding system (Clearfil Protect Bond) has been introduced in restorative dentistry and clinical studies have already shown the potential for this primer to be used clinically with effective antiplaque properties. Therefore, this in vitro study was conducted in order to evaluate the new primer in comparison with a conventional bonding preparation. One hundred and twenty extracted human teeth were randomly divided into three groups of 40 specimens each (20 incisors, 20 premolars). In group 1 a conventional bonding procedure was used (etching, Transbond XT), in group 2 the new primer was used according to the manufacturer's recommendations when bonding to intact enamel, while in group 3 the new primer was used without prior etching. Shear bond strength (SBS) was measured with a universal testing machine and the adhesive remaining after debonding was determined using an optical microscope at x10 magnification. The adhesive remnant index was used in order to assess the mode of failure. No enamel fractures were detected in any of the specimens. In all groups acceptable bond strengths were observed. The only statistically significant difference (P = 0.004) was found for the incisors in group 2, which showed the highest mean SBS (17.46 MPa). Considering the acceptable bond strength and the mode of failure, use of the new primer without prior etching is recommended in patients with fixed appliances. Further in vivo studies will be carried out in order to evaluate clinical performance.     

自酸蚀偶联剂不同作用时间对托槽与牙面剪切粘接强度影响的研究

目的测量自酸蚀偶联剂不同作用时间下托槽与牙面间剪切粘接强度,以探讨正畸临床上运用自酸蚀偶联剂粘接托槽的最佳作用时间.方法选择48颗正畸减数的恒双尖牙,随机分为四组,自酸蚀偶联剂作用时间分别为5秒、15秒、30秒和60秒.所有样本均用光固化粘接剂粘接托槽.半小时后测量四组的剪切粘接强度(Shear bond strength,SBS)及粘接剂残留指数(Adhesive remnant index,ARI),并通过扫描电子显微镜观察树脂-牙釉质界面形态学改变.结果四组托槽与牙面平均剪切粘接强度范围5.1609 Mpa～5.5146 Mpa,组间剪切粘接强度无显著性差异(p＞0.05);ARI评分表明自酸蚀偶联剂作用时间为60秒时,牙面上残留的粘接剂明显多于其他三组;电镜观察结果显示随着自酸蚀偶联剂作用时间的延长,树脂突的形态更规则,结构更致密.结论自酸蚀偶联剂作用时间在5～60秒范围内较厂家推荐时间延长或缩短均不会影响其剪切粘接强度.     

Effect of antimicrobial monomer-containing adhesive on shear bond strength of orthodontic brackets

A new antibacterial and fluoride-releasing bonding system consists of a self-etching primer that contains an antibacterial monomer and a bonding agent that contains sodium fluoride. This study was to determine the effect of using this new adhesive on the shear bond strength of orthodontic brackets. Forty molar teeth were randomly divided into two groups. Group 1 consisted of 20 teeth that were etched for 15 seconds with 35% phosphoric acid, washed with a water spray for 10 seconds, and dried to a chalky white appearance, and the sealant was applied to the etched surface. The precoated brackets were placed on the teeth and light cured. Group 2 consisted of 20 teeth that were etched with 35% phosphoric acid for 15 seconds as suggested by the manufacturer when bonding to intact enamel. The teeth were washed with a water spray for 10 seconds and dried to a chalky white appearance, and the primer containing antibacterial monomer was applied to the etched surface, left for 20 seconds, and sprayed with a mild airstream. The adhesive was applied to each tooth, and the precoated bracket was placed and light cured. There were no significant differences (P = .220) in the shear bond strengths of the two groups. The mean shear bond strength for the antibacterial fluoride-releasing adhesive was 11.7 +/- 5.6 MPa and for the control was 9.6 +/- 5.0 MPa. The use of an antibacterial fluoride-releasing adhesive system did not affect the shear bond strength of the orthodontic brackets within the first half hour after initial bonding.     

Effects of self-etching primer on shear bond strength of orthodontic brackets at different debond times

OBJECTIVE: To evaluate the effect of a self-etching primer on shear bond strengths (SBS) at the different debond times of 5, 15, 30, and 60 minutes and 24 hours. MATERIALS AND METHODS: Brackets were bonded to human premolars with different etching protocols. In the control group (conventional method [CM]) teeth were etched with 37% phosphoric acid. In the study group, a self-etching primer (SEP; Transbond Plus Self Etching Primer; 3M Unitek, Monrovia, Calif) was applied as recommended by the manufacturer. Brackets were bonded with light-cure adhesive paste (Transbond XT; 3M Unitek) and light-cured for 20 seconds in both groups. The shear bond test was performed at the different debond times of 5, 15, 30 and 60 minutes and 24 hours. RESULTS: Lowest SBS was attained with a debond time of 5 minutes for the CM group (9.51 MPa) and the SEP group (8.97 MPa). Highest SBS was obtained with a debond time of 24 hours for the CM group (16.82 MPa) and the SEP group (19.11 MPa). Statistically significant differences between the two groups were not observed for debond times of 5, 15, 30, or 60 minutes. However, the SBS values obtained at 24 hours were significantly different (P < .001). CONCLUSIONS: Adequate SBS was obtained with self-etching primer during the first 60 minutes (5, 15, 30 and 60 minutes) when compared with the conventional method. It is reliable to load the bracket 5 minutes after bonding using self-etching primer (Transbond Plus) with the light-cure adhesive (Transbond XT).     

Effect of a self-etching primer on shear bond strength of adhesive precoated brackets in vivo

The aim of this study was to evaluate the influence of a self-etching primer (SEP) (Transbond Plus SEP, 3M Unitek, Monrovia, Calif) on shear bond strength of adhesive uncoated and precoated Victory brackets (3M Unitek). The sample group consisted of 23 patients, with four premolars each, equally divided in four different groups. Brackets were bonded in vivo by the same operator using a split-mouth random technique: group 1, 37% phosphoric acid + primer + composite + conventional Victory bracket; group 2, 37% phosphoric acid + primer + precoated Victory bracket; group 3, SEP + composite + conventional bracket; group 4, SEP + precoated bracket. After 30 days, premolars were extracted for orthodontic reasons and a Universal Instron Machine was used to apply an occlusal shear force directly to the enamel-bracket interface at a speed of 0.5 mm/min. The groups were compared using two-way analysis of variance. Mean results and standard deviation for the groups were: group 1 = 11.60 +/- 2.65 Mpa, group 2 = 9.79 +/- 2.71 Mpa, group 3 = 10.75 +/- 2.67 Mpa, and group 4 = 10.31+/- 2.70 Mpa. No difference was observed between the conventional etching and primer or SEP (P = .948). However, significant differences in bond strength were present between the uncoated and precoated brackets (P = .032). Considering the values required to withstand normal orthodontic forces (8-9 Mpa), it could be concluded that the SEP combined with adhesive precoated brackets showed adequate shear bond strength and may be suitable for clinical use.     

Effect of a self-etch primer/adhesive on the shear bond strength of orthodontic brackets

Conventional adhesive systems use 3 different agents (an enamel conditioner, a primer solution, and an adhesive resin) during the bonding of orthodontic brackets to enamel. A unique characteristic of some new bonding systems in operative dentistry is that they combine the conditioning and priming agents into a single product. Combining conditioning and priming saves time and should be more cost-effective to the clinician and, indirectly, to the patient. The purpose of this study was to determine the effects of the use of a self-etch primer on the shear bond strength of orthodontic brackets and on the bracket/adhesive failure mode. Brackets were bonded to extracted human teeth according to 1 of 2 protocols. In the control group, teeth were etched with 37% phosphoric acid. After the sealant was applied, the brackets were bonded with Transbond XT (3M Unitek, Monrovia, Calif) and light cured for 20 seconds. In the experimental group, a self-etch acidic primer (ESPE Dental AG, Seefeld, Germany) was placed on the enamel for 15 seconds and gently evaporated with air, as suggested by the manufacturer. The brackets were then bonded with Transbond XT as in the first group. The present in vitro findings indicate that the use of a self-etch primer to bond orthodontic brackets to the enamel surface resulted in a significantly (P = .004) lower, but clinically acceptable, shear bond force (mean, 7.1 +/- 4.4 MPa) as compared with the control group (mean, 10.4 +/- 2.8 MPa). The comparison of the adhesive remnant index scores indicated that there was significantly (P = .006) more residual adhesive remaining on the teeth that were treated with the new self-etch primer than on those teeth that were bonded with the use of the conventional adhesive system.     

Effect of saliva contamiination on the shear bond strength of orthodontic brackets bonded with a self-etching primer

This study evaluates the effect of saliva contamination at different stages of the bonding brackets procedure using the self-etching primer Adper Prompt L-Pop (3M ESPE, Minneapolis, Minn) and the resin orthodontic adhesive system Transbond XT (3M). A total of 70 brackets were bonded to human extracted premolars, which were divided into four groups: group 1, uncontaminated (control); group 2, saliva application before priming; group 3, saliva application after priming; and group 4, saliva application before and after priming. Shear bond strength was measured with a universal test machine. The adhesive remnant on the tooth after debonding was determined using image analysis equipment. Significant differences were only observed between group 1 (12.42 +/- 3.27) and groups 2 (9.93 +/- 4.50) and 4 (9.59 +/- 2.92) (P < .05). Concerning the adhesive remnant, no significant differences were found between the groups evaluated (P > .05).     

唾液污染对运用自酸蚀粘接系统托槽/牙面剪切强度的影响

目的 :评价唾液污染对运用自酸蚀粘接系统托槽 /牙面剪切强度的影响。方法 :根据牙面不同污染情况分为 4组 :A组 :牙面清洁干燥 ;B组 :牙面在涂布酸性封闭剂之前受唾液污染 ;C组 :牙面在涂布封闭剂之后受唾液污染 ;D组 :牙面在封闭剂涂布前后均受唾液污染。所有样本均用光固化粘接剂 (TransbondXT 3M )粘接托槽。粘接 0 .5h后比较 4组的剪切强度及粘接剂残留指数 (ARI)。结果 :4组剪切强度存在显著性差异 (F =11.89,P <0 .0 5 )。D组剪切强度 (4 .62 86± 1.6883MPa)明显低于A组 (8.75 48± 1.915 3MPa) ,B组 (7.895 1± 1.9692MPa)和C组 (6.90 10± 1.5 162MPa)。B组和C组虽有所下降 ,但仍在临床可接受范围之内。 4组粘接剂残留指数比较无显著性差异。结论 :即使在轻微污染的环境中 (牙面在封闭剂涂布之前或之后受唾液污染 ) ,自酸蚀封闭剂也能进行有效的粘接。     

Thermocycling effects on shear bond strength of a self-etching primer

OBJECTIVE: To determine the effects of thermocycling on shear bond strengths (SBSs) of a self-etching primer (SEP) after 0, 2000, and 5000 thermal cycles. MATERIALS AND METHODS: Brackets were bonded to bovine incisors with two etching protocols. In the control group (conventional method) teeth were etched with 37% phosphoric acid. In the experimental group, an SEP (Transbond Plus) was applied as recommended by the manufacturer. Brackets were bonded with light-cure adhesive paste (Transbond XT) and light cured for 20 seconds in both groups. The SBSs were measured after water storage at 37 degrees C for 24 hours, after 2000 and 5000 cycles of thermocycling between 5 degrees C and 55 degrees C. Bond failure location was determined with the Adhesive Remnant Index (ARI). RESULTS: In the control group, SBSs did not show any significant differences among 0, 2000, and 5000 thermal cycles. However, in group SEP, SBSs decreased with 2000 and 5000 thermal cycles, and these decreases were significantly different from no thermocyling (P < .001). A significant difference was observed between ARI scores of the control group with 5000 thermal cycles and group SEP with no thermal cycles (P < .003). In addition, a significant difference was found between group SEP with no thermocycling and with 5000 thermal cycles (P < .003). CONCLUSION: The results of this study indicate that the SEP (Transbond Plus) provides clinically acceptable bond strength values compared with the conventional method after thermocycling.     

Effect of primer precuring on the shear bond strength of orthodontic brackets

Two adhesive systems, Transbond APC II (3M Unitek, Monrovia, Calif) and Quick Cure (Reliance Orthodontic Products, Itasca, Ill), were used to determine the efficacy of precuring the liquid resin primer phase of the systems to increase shear bond strength. One hundred sixty bovine incisors were divided into groups of 20 specimens. In 1 group, the primer was cured before placement of the bracket with the filled adhesive material, and, in the other group, the primer was not precured. The shear-peel bond strength was tested with a testing machine at 30 minutes and 24 hours. No statistically significant difference in bond strength was found between the groups that had or had not been precured. More adhesive remained on the teeth with the Transbond when the primer was not precured. There is no advantage or disadvantage in bracket bond strength by precuring the primer before placing the bracket and filled component of the adhesive.     

Shear bond strength of orthodontic brackets bonded with self-etching primers

PURPOSE: To evaluate the effectiveness of two self-etching primers for bonding brackets in comparison with the conventional acid-etch technique. METHODS: The brackets were bonded to extracted human premolars using the resin orthodontic adhesive system, Transbond XT. This procedure was carried out in accordance with one of the following three protocols of enamel conditioning: (1) 37% phosphoric acid etching, (2) Transbond Plus Self Etching Primer (TSEP), and (3) Adper Prompt L-Pop (Adper PLP). Shear bond strength was measured with a universal test machine. The adhesive remnant on the tooth after debonding was quantified using image analysis equipment. Scanning electron microscopy (SEM) was used to observe the effects of conditioning of each product on the enamel. RESULTS: No significant differences were observed in bond strengths of the three groups evaluated (P> 0.05). Self-etching primers left significantly less adhesive on the tooth than the conventional acid-etch technique and, among them, Adper PLP left significantly less adhesive than TSEP (P< 0.017). SEM observations showed that the etching effect of self-etching primers approximated to the etching effect of phosphoric acid.     

Effect of thermal cycling on shear bond strength with different types of self-etching primer for bonding orthodontic brackets using a MMA-based resin

The purpose of this study was to determine the bonding durability when orthodontic bracket was bonded to human enamel using a MMA-based resin (Multibond) with two types of commercially available self-etching primer - Multibond and Megabond. Multibond primer contained a polymerization initiator, but Megabond primer did not. No significant differences in shear bond strength were observed between Multibond and Megabond primers after immersion in water at 37 degrees C for 24 hours (before thermal cycling). Multibond primer produced no significant decrease in shear bond strength after 2000 and 5000 thermo-cycles between 5 degrees C and 55 degrees C. On the contrary, Megabond primer showed significant decrease in shear bond strength after thermal cycling. The present study suggested that if Multibond resin were to be used for bonding orthodontic brackets, difference in self-etching primer's components would influence shear bond strength after thermal cycling.     

一种新型自酸蚀剂对托槽粘结强度的影响

目的 :探讨一种新型自酸蚀剂对托槽粘结强度的影响。方法 :收集人离体前磨牙 10 5个 ,随机分成 7组。 1组 :3 5 %磷酸酸蚀 3 0s ,去离子水冲洗 ,吹干 ;涂粘结剂 ,TransbondXT光固化复合树脂粘贴托槽。 2组、3组和 4组分别在涂自酸蚀剂 3s内、2min和 15min后粘贴托槽。 5组涂自酸蚀剂后 ,再涂一层唾液粘贴托槽 ;6组依次涂唾液、自酸蚀剂后粘贴托槽 ;7组涂唾液、自酸蚀剂、唾液后粘贴托槽。所有试件均于常温去离子水内放置2 4h ,测试抗剪切强度 ,观察断面形态。结果 :4组的抗剪切强度最高。 5组和 7组的抗剪切强度显著低于其它组。断面形态观察 ,结果显示抗剪切强度高的组别在托槽与复合树脂之间发生断裂 ;抗剪切强度低的组别在牙齿与复合树脂之间发生断裂。结论 :该自酸蚀剂能获得与磷酸酸蚀相同的粘结强度 ,且发生断裂不受操作时间的影响 ,但在操作时间内应防止唾液污染。     

Effect of a fluoride-releasing self-etch acidic primer on the shear bond strength of orthodontic brackets

Conventional adhesive systems use three different agents--an enamel conditioner, a primer solution, and an adhesive resin--during the bonding of orthodontic brackets to enamel. A unique characteristic of some new bonding systems in operative dentistry is that they combine the conditioning and priming agents into a single application. Combining conditioning and priming saves time and should be more cost-effective to the clinician and indirectly to the patient. The purpose of this study was to assess and compare the effects of self-etching primers, including a fluoride-releasing primer, on the shear bond strength of orthodontic brackets. The brackets were bonded to extracted human teeth according to one of four protocols. In group 1 (control), teeth were etched with 37% phosphoric acid; after the sealant was applied, the brackets were bonded with Transbond XT (3M Unitek, Monrovia, Calif) and light cured for 20 seconds. In group 2, a self-etch acidic primer (3M ESPE, St Paul, Minn) was applied as suggested by the manufacturer, and the brackets were then bonded with Transbond XT as in the first group. In group 3, an experimental self-etch primer EXL #547 (3M ESPE) was applied to the teeth as suggested by the manufacturer, and the brackets were then bonded as in groups 1 and 2. In group 4, a fluoride-releasing self-etch primer, One-Up Bond F (J. Mortia, USA Inc. Irvine, Calif) that also has a novel dye-sensitized photo polymerization initiator system was applied as suggested by the manufacturer, and the brackets were then bonded as in the other groups. The present in vitro findings indicated that the shear bond strengths of the four groups were significantly different (P = .001). Duncan multiple range tests indicated that One-Up Bond F (mean +/- SD strength, 5.1+/-2.5 MPa) and Prompt L-Pop (strength, 7.1+/-4.4 MPa) had significantly lower shear bond strengths than both the EXL #547 self-etch primer (strength, 9.7+/-3.7 MPa) or the phosphoric acid etch and the conventional adhesive system (strength, 10.4+/-2.8 MPa).