Comparison of shear bond strength relative to two testing devices

STATEMENT OF PROBLEM: Dentin adhesives are characterized on the basis of their bond strength to dentin; however, great variation exists within the same material depending on the testing apparatus. To realistically compare bond strengths, the testing mechanisms must be the same. PURPOSE: The purpose of this investigation was to use 2 testing devices to evaluate the shear bond strength of 3 single-bottle adhesives with their multistep counterparts. MATERIAL AND METHODS: The occlusal surfaces of 120 freshly extracted third molars were ground to expose the dentin and polished with 600-grit silicon carbide paper. Three single-bottle, (Optibond Solo Plus, 3M Single Bond, and Excite) and 3 multistep adhesives (Optibond FL, 3M MultiPurpose Plus, and Syntac) were each used to bond a composite cylinder (made from a 2.379 +/-.001-mm diameter by 4-mm-high mold) of Tetric Ceram to 20 teeth. The specimens were stored in 100% humidity for 24 hours. The shear bond strength at failure was measured in kilograms and converted to megapascals for each material, using a knife (conventional method) and an Ultradent testing device on a universal testing machine (Instron) at a loading rate of 0.5 mm/min. A 2-way analysis of variance (ANOVA) test was performed comparing the 2 testing devices and the materials at P<.05. Where significant, a 1-way ANOVA test was conducted among the materials for each test group, and a Tukey multiple comparison test was used to determine significant differences among the materials tested (P<.05). An independent Student t test at P<.05 was used to determine significance between testing devices. RESULTS: The results showed that Optibond Solo Plus (26.85 +/- 8.76 MPa), Optibond FL (25.40 +/- 4.44 MPa), 3M Single Bond (28.12 +/- 5.01 MPa), and 3M MultiPurpose Plus (34.40 +/- 7.90 MPa) had significantly higher bond strengths when tested with the Ultradent testing device. The mean values for Excite (19.47 +/- 6.17 MPa) and Syntac (20.20 +/- 7.07 MPa) were also higher with the Ultradent testing device, but the difference was not significant. CONCLUSION: Within the limitations of this study, all bonding agents tested resulted in higher mean shear bond strengths when tested with the Ultradent testing device compared with the unrestricted knife. The single-step bonding agents exhibited mean bond strengths comparable to their multistep counterparts.     

Effects of dentin disinfectants on the shear bond strength of all-ceramics to dentin

This study investigated the effect of dentin disinfectants on the shear bond strength of all-ceramic restorations luted with two different dual-polymerizing systems to dentin. Dentin disinfectants chlorhexidine gluconate-based Concepsis and benzalkonium chloride-based Tubulicid Red were applied in combination with Variolink 2 and Resilute. The buccal surfaces of non-carious extracted human premolars were flattened to expose dentin and subsequently polished with 600-grit wet silicon carbide paper. Each dual-polymerizing luting system had two test groups and a control group. Dentin from the test groups was first treated with dentin disinfectants, then the all-ceramic restorations were luted with dual polymerizing systems. The dentin without disinfectant application and ceramic restoration was used as a control. After the all-ceramic samples were luted to all treated surfaces, the specimens were thermocycled and tested for shear bond strength until failure. Analysis of the fractured dentin surfaces was performed using Optical Microscope-Nikon ECLIPSE ME 600 (Nikon Co, Tokyo, Japan) at between 10x and 1000x magnifications and the images were analyzed with Image Analyzer LUCIA 4.21 (Nikon Co). The data were analyzed with one-way ANOVA and Duncan test at a significance level of p<0.05. Application of the two dentin disinfectants increased the shear bond strength of both the Variolink 2 and Resilute systems, but this increase was statistically significant only in Tubulicid Red treated specimens (p<0.05). Surface analysis showed that all the specimens showed the adhesive failure mode between the dentin and composite luting agent interface.     

树脂类粘接剂对全瓷与牙本质之间粘接强度的影响

目的比较3种不同粘接剂对3种全瓷材料与牙本质之间抗剪切粘接强度的影响。方法样本为热压铸造陶瓷组、氧化铝渗透陶瓷组和氧化锆切削陶瓷组,每组各18片,各组再随机分为A、B、C3个小组,每小组6片。将收集的离体恒磨牙打磨至牙本质浅层,分别采用树脂类粘接剂RelyXTM ARC、PanaviaTMF以及Rely XTM Unicem与3种全瓷片粘接。所有试件均置于37℃人工唾液,24h后测试54个试件的抗剪切强度。结果热压铸造陶瓷组与氧化锆切削陶瓷组均为RelyXTM Unicem抗剪切粘接强度最高,而氧化铝渗透陶瓷组PanaviaTM F抗剪切粘接强度最高。结论对于3种不同全瓷材料,临床上可根据全瓷修复体的种类选择适当的粘接剂系统。     

2种耐湿性托槽粘结体系粘结强度的比较研究

目的比较3M Transbond MIP处理液+3M Transbond PLUS变色光固化粘结剂与GC Ortho LC光固化树脂加强型玻璃离子2种粘结体系的粘结强度。方法收集因正畸治疗而拔除的上颌前磨牙80颗,按照随机化原则分成8组,每组10颗。将2种粘结体系分别在干燥、水分污染、唾液污染和血液污染的条件下完成托槽粘结,用电子万能试验机测试剪切强度,并在显微镜下用ARI指数评价各组牙齿表面残余的粘结剂。结果在剪切强度测试中,第1组与第5组比较,第2组与第6组比较,第3组与第7组比较,P>0.05,均无统计学差异;第4组与第8组比较,P<0.01,有统计学差异。ARI评分结果提示两者在干燥、水分污染及唾液污染环境下的ARI平均分值无统计学差异,但在血液污染的条件下,GC Ortho LC的ARI值明显降低。结论 3M Transbond MIP处理液+3M Transbond PLUS变色光固化粘结剂与GC Ortho LC光固化树脂加强型玻璃离子在干燥、水分污染及唾液污染的环境下,粘结强度无明显差异,在血液污染的条件下,推荐使用3M Transbond MIP粘结体系。     

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。     

Influence of cross-head speed in orthodontic bond strength testing.

OBJECTIVE: The aim of this study was to investigate the influence of cross-head speed on debonding force of orthodontic brackets. METHODS: One hundred and twenty extracted permanent bovine mandibular incisors were randomly divided into 4 groups of 30 specimens each. Teeth were bonded with stainless steel orthodontic brackets. Enamel surfaces were etched with 37% phosphoric acid for 30 seconds and bonded with a composite adhesive. Debonding force measurements were performed with a universal testing machine Zwicki Z 2.5 (Zwick, Germany). Cross-head speeds of the four groups were: 0.1 mm s-1 (group A), 0.5 mm s-1 (group B), 1.0 mm s-1 (group C), 5.0 mm s-1 (group D). RESULTS: Mean debonding force measurements were as follows: 215.35 (39.09) N (group A), 231.79 (48.62) N (group B), 236.64 (39.26) N (group C), 224.95 (34.67) N (group D). Analysis of variance indicated that there were no significant differences in debonding forces between the groups investigated. The adhesive remnant index showed a median value of 2.0 for all groups. SIGNIFICANCE: Cross-head speed variation between 0.1 and 5 mm min-1 does not seem to influence debonding force measurements or failure mode of brackets bonded to enamel with a composite adhesive.     

An optimized synthetic substrate for orthodontic bond strength testing

OBJECTIVE: The purpose of this study was to investigate the suitability of different synthetic calcium phosphate based substrates as a biomimetic enamel surface model for orthodontic bond strength testing. METHODS: Carbonated apatite, amorphous calcium phosphate and commercial hydroxyapatite specimens were prepared as substrates for orthodontic bond strength testing. Carbonated apatite specimens were prepared by pressing, sintering and treatment with NaF. The shear bond strength was measured with a universal testing machine. RESULTS: Hydroxyapatite, amorphous and cold pressed carbonated hydroxyapatite exhibited fractures within the substrate after debonding. Mean bond strength values for carbonated hydroxyapatite were 7.38 (1.75) MPa for specimens pressed at 300 degrees C and 9.55 (2.23) MPa for specimens pressed at 300 degrees C and then sintered at 600 degrees C. An additional NaF treatment after sintering resulted in lower bond strength measurements of on average 6.52 (1.03) MPa. SIGNIFICANCE: Hot pressed and sintered carbonated hydroxyapatite showed acceptable shear bond strength values and may represent a suitable biomimetic model for orthodontic bond strength testing.     

Comparison of shear bond strength of two self-etch primer/adhesive systems

Orthodontic brackets adhesive systems use three different agents, an enamel conditioner, a primer solution, and an adhesive resin. A unique characteristic of some new bonding systems is that they combine the conditioning, priming, and adhesive agents into a single application. The purpose of this study was to assess and compare the effects of using one-step and two-step self-etch primer/adhesive systems on the shear bond strength of orthodontic brackets. The brackets were bonded to extracted human molars according to one of two protocols. Group I (control): a two-step self-etch acidic primer/adhesive system was used, Transbond Plus was applied to the enamel surface as suggested by the manufacturer. The brackets were bonded with Transbond XT and light cured for 20 seconds. Group II: a one-step self-etch, self-adhesive resin cement system, Maxcem, was applied directly to the bracket. The self-etch primer/adhesive is made of two components that mix automatically during application. The brackets were then light cured for 20 seconds. The mean shear bond strength of the two-step acid-etch primer/adhesive was 5.9 +/- 2.7 Mpa and the mean for the one-step system was 3.1 +/- 1.7 MPa. The in vitro findings of this study indicated that the shear bond strengths (t = 3.79) of the two adhesive systems were significantly different (P = .001). One-step adhesive systems could potentially be advantageous for orthodontic purposes if their bond strength can be improved.     

Effect of veneering method on the fracture and bond strength of bilayered zirconia restorations

This study evaluated the fracture strength and microtensile bond strength of a new computer-aided design (CAD) veneering method for zirconia frameworks. A new CAD/computer-assisted manufacture system was used to fabricate a resin replica of the esthetic ceramic required to veneer a zirconia framework. The replicas were processed using press-on technology. Identical manually layered zirconia specimens served as a control (n = 18; alpha = .05). Statistical analysis revealed that the fracture strength (442.8 +/- 25 N) and microtensile bond strength (26.6 +/- 2 MPa) of CAD-veneered zirconia were significantly higher (P < .001) compared to the control (346 +/- 24 N and 15.1 +/- 1 MPa, respectively). CAD veneering is a reliable method for veneering zirconia frameworks.     

测试微拉伸粘接强度的影响因素

微拉伸作为釉质和牙本质粘接剂粘接强度测试的主要方法已被广泛应用,其测试强度与粘接剂的临床应用效果有潜在的相关性。通过微拉伸粘接强度的测试可以了解粘接剂的粘接性能,指导临床应用。牙齿的来源、部位、储存媒介,以及样本粘接面积的大小、样本的几何形态、样本切割速度等因素均会影响微拉伸测试结果。本文就微拉伸样本制备前、制备过程中以及测试结果评价中所产生的影响因素等作一综述。     

Influence of force location in orthodontic shear bond strength testing.

OBJECTIVE: The purpose of the present study was to analyze the influence of debonding force location in shear bond strength testing of orthodontic brackets in vitro. METHODS: Ninety extracted permanent bovine mandibular incisors were randomly divided into 3 groups of 30 specimens each. Teeth were bonded with stainless steel orthodontic brackets. Enamel surfaces were etched with 37% phosphoric acid for 30s and bonded with a composite adhesive. Debonding force measurements were performed with a universal testing machine. Location of the debonding force was: bracket base (group A), ligature groove (group B), occlusal bracket wings (group C). RESULTS: Mean shear bond strength measurements were as follows: 22.70(4.23)MPa (group A), 11.52(2.74)MPa (group B), 9.44(2.96)MPa (group C). Analysis of variance indicated that there were significant differences in shear bond strength. Post-hoc Tukey tests showed that bond strength measurements of group A were significantly different from those of groups B and C. The adhesive remnant index also showed significant differences and ranged from a mean of 1.53 in group A to a mean of 2.10 in group C. SIGNIFICANCE: Debonding force location had a significant influence on shear bond strength measurements and bond failure pattern, indicating that this parameter needs to be taken into consideration for interstudy comparison of in vitro results.     

试样夹具对微拉伸黏结强度测定的影响

目的：评价试样夹具对微拉仲黏结强度测定的影响。方法：将12个离体人磨牙的黯面釉质切除，暴露牙本质并以600^#水砂纸打磨表面，然后将牙齿分为4组，每组3个牙。在牙本质表面分别应用下面4种黏结剂：Prime＆Bond NT（ Dentsply）, Contax（ DMG）, Adper Prompt （3M/ESPE）及 Clearfil S^3 Bond（Kuraray） ，光照固化后在黏结剂上分层堆塑制作复合树脂冠。浸37℃水24h后，顺牙齿长轴分别从近远中向及颊舌向切割牙齿，制备截面为0．8mm。的条状树脂-牙本质黏结试样．将每组黏结试样的一半黏固到无导向杆的夹具A上，另一半黏固到有导向杆的夹具B上，然后在拉力试验机上以1．0mm／min的速度测定拉伸黏结强度。结果：在夹具A上测定的拉伸黏结强度均显著小于在夹具B上的测定值（P〈0．01），夹具A上的试样在测定过程中出现明显弯曲现象，而且多数试样的断裂模式为混合破坏及复合树脂内聚破坏，而夹具B测定的试样绝大多数为黏结破坏。结论：无导向杆的夹具在测定拉伸黏结强度时存在明显弯曲现象，其测定值不能准确反映试样的拉仲黏结强度，而有导向杆的夹具测定的拉伸黏结强度能准确反映试样的拉伸黏结强度。     

Comparison of in vivo and in vitro shear bond strength.

Much of the research into composite adhesives suggests that these materials will deteriorate in the oral environment, but most of these claims are made on the basis of extrapolation from in vitro experiments; relatively little in vivo research has been conducted into the mechanical properties of composite adhesives. For this study, we recruited 20 volunteers to wear removable appliances containing orthodontic brackets bonded to enamel slabs for 12 weeks. Each appliance carried 3 brackets bonded with Transbond (3M Unitek UK; Bradford, United Kingdom) and 3 brackets bonded with Heliosit (Ivoclar-Vivadent; Leicester, United Kingdom). The bond strengths were tested at intervals of 4, 8, and 12 weeks. Control specimens were stored in sterile water at 37 degrees C and were debonded at the same time intervals. Transbond specimens debonded after 4 weeks in vivo had significantly (P <.05) lower bond strengths (9.78 megapascals [MPa]) than did the controls (14.34 MPa). In vivo, specimens bonded with Heliosit had significantly (P <.05) lower bond strengths after 4 weeks (8.16 MPa vs 10.96 MPa) and 8 weeks (9.96 MPa vs 13.61 MPa) than did the controls. These results indicate differences between bond strength testing in vitro and in vivo. Further research is required into the effects of the oral environment on bond strength.     

Comparison of Gluma bond strength to primary vs. permanent teeth

The purpose of this study was to measure the shear bond strength of Gluma/Lumifor (Gluma and Lumifor--Columbus Dental, St. Louis, MO) to the occlusal dentin of primary first and second molars, permanent first and second molars and premolars. The data were examined for differences using a one-way analysis of variance and Duncan's Multiple Range test. The shear bond strength, (kc/cm2, x +/- SEM) to primary molars was 85.6 +/- 13.7, to permanent molars was 110.1 +/- 9.3, and to premolars was 124.0 +/- 9.3. Gluma/Lumifor provides moderately good bonding to dentin. The bond strengths of Gluma/Lumifor to primary molars was statistically significantly lower than to permanent teeth.     

Shear bond strength of two resin adhesives for acid-etched metal prostheses

This study compared the shear bond strength of Panavia EX and Comspan Opaque adhesive resins with electrolytically etched or sandblasted Rexillium III or Litecast B metals bonded to extracted teeth. An analysis of variance revealed that there is no difference in bonding strength among etched or sandblasted Rexillium III metal with either Panavia EX or Comspan Opaque resins. With Litecast B metal, sandblasting produced a greater bond strength than etching with Panavia Ex resin (38.19 MPa sandblasted; 30.53 MPa etched). Conversely, Comspan Opaque resin had a value of 30.10 MPa etched and 15.40 MPa sandblasted. The etched Rexillium III and Panavia EX resins recorded a greater bond strength (38.38 MPa) than Comspan Opaque resin (27.83 MPa) or sandblasted Rexillium III metal (Rexillium III 34.74 MPa; Comspan Opaque 20.39 MPa) and Litecast B metal (Panavia EX 38.19 MPa; Comspan Opaque 15.40 MPa). Eighty percent of the failures occurred at the cement-metal interface with both cements.