Simplified Testing of the Bond Strength of Adhesives Used for Bonded Anchors

The analysis presented in this paper is focused on problems of bond strength as an overall bond quality parameter of industrial adhesives for structural anchoring. In the first part, the problem of bond strength as the most important parameter influencing the final anchor resistance to tension load is described. Further in the text, a new methodology of simplified testing of the strength parameters of adhesives is described. Special test specimens made from steel are repeatedly used in this methodology. Additionally, results of these tests on some new recipes for adhesive are presented. Especially, epoxy resins with special fillers, such as carbon fibres, carbon nanotubes or graphene, were tested. The use of these adhesives in temperatures close to zero degrees Celsius was also tested.     

Bond Strength of Soft Liners to Fiber‐Reinforced Denture‐Base Resin

Purpose: This study evaluated bond strengths of four soft liners to fiber‐reinforced (FR) and unreinforced poly methyl(methacrylate) (PMMA) denture‐base resin. Materials and Methods: The autopolymerized denture‐base resin Palapress Vario (Heraus Kulzer GmbH, Hanau, Germany) was used as the substrate (15 × 15 × 5 mm³). The test group consisted of substrates reinforced with porous PMMA preimpregnated unidirectional glass fibers (Stick [StickTech, Turku, Finland]) (PMMA + FR group), and the control group was unreinforced acrylic resin (PMMA group) (n = 80 per group). One of four soft liners (Ufi Gel SC [Voco, Cuxhaven, Germany], Sofreliner Tough [Tokuyama Dental Corporation, Tokyo, Japan], Vertex SoftSil 25 [Vertex‐Dental B.V., Zeist, The Netherlands], and Eversoft [Dentsply Austenal, York, PA]) was placed and cured between two substrates using a polyethylene ring (10 mm inner radius, 3 mm height). Tensile bond strength tests (crosshead speed = 10 mm/min) were performed, and the results were analyzed using analysis of variance followed by Tukey's test (p= 0.05). Fracture surfaces were categorized as adhesive or cohesive‐mixed modes, and failure types were statistically analyzed using chi‐square test. Results: FR did not affect the bond strength results significantly (p > 0.05) except for Ufi Gel SC. Significant differences in bond strength were found among the reline materials (p < 0.001). FR specimens showed a significantly higher number of cohesive‐mixed fractures compared to unreinforced specimens (p < 0.05), except for plasticized acrylic‐based reline material (Eversoft [Dentsply Austenal]), which showed fewer cohesive‐mixed failures with FR. Conclusions: The choice of appropriate reline material system with FR acrylic resin is important for the soft liner/denture‐base polymer bond. Glass FR did not have a decreasing effect on the bond strength, except for Ufi Gel SC.     

自锁托槽再粘结前处理对托槽脱落率影响的临床观察

目的：观察脱落自锁托槽喷砂处理后再粘结的脱落率。方法：选择使用自锁托槽矫治的正畸患者60例,随机分为两组,复诊时记录托槽初次脱落例数,记录时间为3个月,A组脱落托槽采用喷砂处理后再粘结,B组使用新托槽再粘结,记录3个月的再次脱落例数。结果：A组与B组初次、再次托槽脱落率均无统计学意义（P〉0.05）,再次脱落率明显高于初次粘结脱落率（P〈0.01）。结论：喷砂处理的脱落自锁托槽与新托槽再粘结的脱落率相当,可用于自锁托槽脱落后的再粘结。     

Bonding ability of 4-META self-etching primer used with 4-META/MMA-TBB resin to enamel and dentine: Primary vs permanent teeth

Objectives

The present study compared the efficacies of the self-etching Teeth Primer (TP: 4-META), and the etchants Red Activator (RA; 65% phosphoric acid) and Green Activator (GA; 10% citric acid with 3% ferric chloride), for bonding to enamel and dentine of human primary and permanent teeth, when used with 4-META/MMA-TBB resin (Bondfill SB).

Methods

Forty-eight non-carious primary canines and third molars were used. Eight groups were prepared: Group 1 (primary enamel with RA), Group 2 (permanent enamel with RA), Group 3 (primary enamel with TP), Group 4 (permanent enamel with TP), Group 5 (primary dentine with GA), Group 6 (permanent dentine with GA), Group 7 (primary dentine with TP) and Group 8 (permanent dentine with TP). Micro-tensile bond strengths (MTBS) were measured and analyzed statistically using ANOVAs and Tukey HSD tests at α = 0.05. Efficacy of etching/priming and the morphology of bonded interfaces were observed with SEM.

Results

Etching/priming efficacy of TP on enamel was low. The MTBS of Group 2 was significantly higher than the other groups (Groups 1, 3 and 4). For dentine, significant differences in MTBS were observed, in the order of Groups 6 > 8 > 7 = 5 (p < 0.05). The MTBSs of permanent dentine were significantly higher than primary dentine. For primary teeth, there was no significant difference in the MTBSs between enamel and dentine, irrespective of primer or etchant (p > 0.05).

Conclusion

TP primer/Bondfill SB may be used as an alternative to other adhesive/resin composite systems for bonding to enamel and dentine of primary teeth.     

Effect of saliva contamination on bond strength of resin luting cements to dentin

Objectives

This study examined the effect of saliva contamination on the microtensile bond strength (μTBS) of resin luting cements to dentin.

Methods

For RelyX ARC (ARC, 3M ESPE), dentin surfaces were etched with 32% phosphoric acid. The subgroups were: ARC-control (uncontaminated), ARC-I (saliva contamination, blot-dried), ARC-II (saliva contamination, rinse, blot-dried) and ARC-III (saliva contamination, rinse, re-etch, rinse, blot-dried). For Panavia F 2.0 (PF, Kuraray), the subgroups were: PF-control (uncontaminated), PF-I (saliva contamination, dried), PF-II (saliva contamination, rinse, dried), PF-III (primer, saliva contamination, dried), PF-IV (primer, saliva contamination, dried, primer re-applied) and PF-V (primer, saliva contamination, rinse, dried, primer re-applied). Composite blocks were luted onto dentin using the two cements. Bonded specimens were sectioned into 0.9 mm × 0.9 mm beams for μTBS testing. Representative fractured beams were prepared for fractographic analysis.

Results

For ARC, salivary contamination of etched dentin (ARC-I) significantly lowered bond strength (p = 0.001). Rinsing saliva off with water (ARC-II) restored bond strength to control level. Re-etching dentin surface after rinsing (ARC-III) resulted in the lowest bond strength (p < 0.001). For PF, salivary contamination of dentin before (PF-I) and after application of primer (PF-III and PF-IV) significantly lowered bond strength (p < 0.001). Rinsing saliva off with water and re-application of primer (PF-II and PF-V) improved bond strength.

Conclusion

Saliva contamination during luting deteriorated the bond quality of resin cements. Decontamination by rinsing with water was most effective in restoring the bond strength of RelyX ARC. Decontamination by water-rinsing and primer re-application after rinsing improved the bond strength of Panavia F 2.0.     

粘接界面处理对玻璃离子水门汀与复合树脂粘接强度的影响

目的 比较4种粘接剂对2种不同类型玻璃离子水门汀与复合树脂界面间粘接强度的影响.方法 选取传统型高强度玻璃离子FujiⅨ(F9)和树脂改良型玻璃离子FujiⅡLC(F2LC)为研究对象,将100个样本随机分为10组,每组10个样本,在样本中央制备窝洞后,随机选取5组样本,窝洞内置入F9,另外5组置入F2LC.样本界面分别采取不处理和4种不同类型的粘接剂,Clearfil SE Bond(SEB)、Clearfil S3 Bond(S3B)、Optibond Versa(OBV)及Single Bond 2(SB2)处理后,分别测定各组样本的剪切粘接强度.结果 OBV处理组的F9样本组获得最大的剪切粘结强度,未进行界面处理的F9样本组剪切粘结强度最小,其差异具有显著统计学意义.使用粘接剂处理后各组的粘接强度均显著增高.结论 粘接剂处理样本界面后显著提高玻璃离子与复合树脂间的粘接强度.自酸蚀粘接剂OBV使玻璃离子与复合树脂界面获得最大的粘接强度.     

Bonding strength between a hard chairside reline resin and a denture base material as influenced by surface treatment

Direct relining of dentures made with hard chairside reline resins is faster than laboratory-processed reline systems and the patient is not without the prosthesis for the time necessary to perform the laboratory procedures. However, a weak bond between the autopolymerizing acrylic reline resins and the denture base material has been observed. This study evaluated the effect of six different surface treatments on the bond strength between a hard chairside reline acrylic resin and a heat-cured acrylic resin. Specimens of the heat-cured acrylic resin were divided into seven groups. One of these groups remained intact. In the other groups, a 10-mm square section was removed from the centre of each specimen. The bonding surfaces were then treated with (i) methyl methacrylate monomer, (ii) isobutyl methacrylate monomer, (iii) chloroform, (iv) acetone, (v) experimental adhesive and (vi) no surface treatment -- control group. Kooliner acrylic resin was packed into the square sections and polymerized. The bonding strength was evaluated by a three-point loading test. The results were submitted to one-way analysis of variance (ANOVA) followed by a Tukey multiple range test at a 5% level of significance. No significant difference was found between the surface treatment with Lucitone 550 monomer or chloroform, but both were stronger than the majority of the other groups. The bond strength provided by all the surface treatments was lower than that of the intact heat-cured resin.     

Shear bond strength between light polymerized hard reline resin and denture base resin subjected to long term water immersion

Statement of the problemThe effect of long-term water immersion on the shear bond strength between denture base resin and Triad visible-light-polymerized (VLP) direct hard reline resin is not known.PurposeThe aim of this study was to investigate the bonding characteristics of Triad VLP direct hard reline resin to heat-polymerized denture base resin subjected to long-term water immersion.Material and methodsNinety circular disks, 15 mm in diameter and 3 mm thick, of denture base resin were polymerized from a gypsum mold. Sixty specimens were subjected to water immersion and 30 were stored at ambient room temperature for 4 months. Thirty water-immersed specimens were dried with gauze (group 1), while the other 30 water-immersed specimens were dried with a hair dryer (group 2). The dry specimens (n = 30) represented the control group (group 3). All specimens were air abraded and painted with bonding agent before packing Triad VLP direct hard-reline resin. Specimens in each group were subjected to thermal cycling for 50,000 cycles between 4 °C and 60 °C water baths with 1-min dwell time at each temperature. The bond strength at which the bond failed under stress was recorded using a universal testing machine. One-way ANOVA and Tukey post hoc comparison were applied to find significant differences between groups (α = 0.05).ResultsSignificant differences in mean shear bond strength among the specimens existed because of variable water content in the denture base resin (P < 0.05). Group 3 (dry) was higher than group 2 (desiccated), and the lowest was group 1 (saturated).ConclusionThe shear bond strength of Triad VLP direct hard reline resin to denture base resin depended on the water content in the denture base resin. The dry denture base resin demonstrated superior bond strength compared with the desiccated and water-saturated denture base resins.     

Influence of pH and F^- on Titanium-porcelain Bond Strength

Objective The aim of this study was to measure the influence of artificial saliva on the titanium-porcelain bond strength at different pH and fluoride concentration. Methods There were three groups of artificial saliva： pH2.7, pH7.0/F100ppm and pH2.7/F100ppm. The adhesion between titanium and porcelain was measured by the test of three-point flexure bond strength. SEM and EDX were used to investigate the bond mechanism. Results There was a remarkable decreasing of titanium-porcelain bond strength in group PH2.7/ F100ppm at 7d and 30d. The specimens in other groups had no significant differences compared with the control group. Conclusion In an acidified medium F has the tendency of decreasing the titanium-porcelain bond strength. But the patients with titanium-porcelain restorations needn＇t worry about the effect of F when using oral fluoride products, because the F in saliva will disappear within ld after common fluoride therapy and the effect of F on the titanium-porcelain bond strength will occur after ld.     

不同处理方法对瓷面与托槽粘结强度的影响

目的测定不同处理方法对瓷修复体与托槽抗剪强度的影响。方法制作金属烤瓷片,分甲、乙2组,甲组釉面作机械打磨,乙组不作处理。每组都用3种方法粘结托槽。粘结后冷热循环作抗剪强度测试,并记录托槽去除时的瓷崩情况。结果无论甲组或乙组,经酸蚀处理组的抗剪强度均显著高于非酸蚀组(P<0.05);甲组均高于乙组且具有显著性差异(P<0.05)。结论酸蚀处理是促进瓷和托槽粘结的可靠手段,机械打磨能提高其强度,偶联剂在本实验中作用不确定。