Experimental Investigation of the Influence of the Bond Conditions on the Shear Bond Strength between Steel and Self-Compacting Concrete Using Push-Out Tests

2012 ◽  
Vol 525-526 ◽  
pp. 205-208 ◽  
Author(s):  
Peter Helincks ◽  
Wouter de Corte ◽  
Jan Klusák ◽  
Veerle Boel ◽  
Geert de Schutter

Steel-concrete joints are often provided with welded shear studs. However, stress concentrations are induced in the structure due to the welding. Moreover, a reduction in toughness and ductility of the steel and a decreased fatigue endurance of the construction is observed. In this paper the shear bond strength between steel and ultra-high performance concrete (UHPC) without mechanical shear connectors is evaluated through push-out tests. The test samples consist of two sandblasted steel plates with a thickness of 10 mm and a concrete core. The connection between steel and concrete is obtained by a 2-component epoxy resin. Test samples with a smooth adhesive layer are compared with those with an epoxy layer, which is applied with a toothed paddle and/or gritted with small aggregates. In this research, specimens prepared with river gravel, crushed stone, and steel grit are compared and also two different epoxy resins are used. During the tests, the ultimate shear force is recorded as well as the slip between steel and concrete. All test specimens exhibited a concrete-adhesive or concrete failure. Furthermore, test results show that the use of a more fluid epoxy resin improves the anchorage of the gritted aggregates in the adhesive layer, resulting in higher shear bond stresses. No significant difference is found between specimens, gritted with river gravel or crushed stone. Applying the adhesive layer with the toothed paddle in horizontal direction slightly improves the bond behaviour. Finally, the experimental results of the test members with a smooth epoxy layer without gritted aggregates, provide test data for a fracture mechanics approach, which uses a 2D numerical model of the test specimen, composed of steel, epoxy resin, and concrete.

2020 ◽  
Vol 10 (7) ◽  
pp. 2535
Author(s):  
Hyoung-Sik Kim ◽  
Song-Yi Yang ◽  
Eun Ha Choi ◽  
Kwang-Mahn Kim ◽  
Jae-Sung Kwon

The purpose of the study was to evaluate the adhesion between dental core resin and epoxy resin-based fiber post after treatment with non-thermal atmospheric pressure plasma (NTAPP) and compare with conventional methods of epoxy resin-based fiber post treatments. Contact angle was measured on the surface of epoxy resin before and after NTAPP treatment and X-ray photoelectron spectroscopy was used to analyze the surface chemistry. Finally, two shear bond strength tests were carried out; shear bond strength between core resin and epoxy resin for comparison between NTAPP treated and untreated sample, and push-out shear bond strength between core resin and NTAPP treated commercially available epoxy resin-based fiber post for comparison between NTAPP treated samples with conventionally treated samples. Contact angle on the surface of epoxy resin generally decreased with increasing NTAPP treatment time with presence of surface chemical changes. Also, there was significantly higher shear bond strength and push-out shear bond strength between epoxy resin and core resin for NTAPP treated epoxy resin, even to the conventionally treated epoxy resin-based fiber post with hydrofluoric acid or silane. In conclusion, new technology of NTAPP has potential for application on the epoxy resin-based fiber post to improve endodontic restoration success rate.


2017 ◽  
Vol 05 (02) ◽  
pp. 084-089
Author(s):  
Alisha Dhingra ◽  
Ashu Gupta ◽  
Anshu Minocha ◽  
Nayantara Sen

Abstract Aim: The aim of this study was to compare the reversal of shear bond strength of composite to bleached enamel immediately after bleaching followed by application of various antioxidant solutions. Material and Methods: Seventy central incisors were divided into seven groups. Groups I and II served as unbleached and bleached controls respectively. Groups III, IV, V, VI and VII served as the experimental groups and were subjected to 37.5% hydrogen peroxide bleaching followed by 10 min application of 10% sodium ascorbate, 25% alpha-tocopherol, 6.5% grape seed extract, 5% lycopene and 5% green tea extract respectively. Following composite bonding, shear bond strength was determined and the results were analyzed using ANOVA followed by Post Hoc Multiple Comparisons test. Results: The bond strength values for Group I (positive control) were maximum and significantly different than all the other groups except Grape seed extract group (Group V). When compared to Group II (bleached control), all the groups showed significantly higher bond strength. Significant difference in the bond strength values were seen between Group III (10% sodium ascorbate) and Group V. Also values for Group V were significantly different from Group VI (5% lycopene). All the other values showed insignificantly different results. Conclusion: All the antioxidant solutions improved the shear bond strength values after bleaching but only Grape seed extract application reversed the values to the non bleached levels. Lycopene was least effective. Other antioxidants showed comparable results.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3550
Author(s):  
Aerin Choi ◽  
Kyung-Hyeon Yoo ◽  
Seog-Young Yoon ◽  
Bong-Soo Park ◽  
In-Ryoung Kim ◽  
...  

Self-adhesive resins (SARs) contain adhesives, which simplify the procedures of resin application, and primers, which provide sufficient bonding ability. In this study, mesoporous bioactive glass nanoparticles (MBN) were added to a SAR to easily improve the physical properties and remineralization ability. The experimental resins comprised 1%, 3%, and 5% MBN mixed in Ortho Connect Flow (GC Corp, Tokyo, Japan). As the MBN content in the SAR increased, the microhardness increased, and a statistically significant difference was observed between the cases of 1% and 5% MBN addition. Shear bond strength increased for 1% and 3% MBN samples and decreased for 5% MBN. The addition of MBN indicated a statistically significant antibacterial effect on both gram-negative and gram-positive bacteria. The anti-demineralization experiment showed that the remineralization length increased with the MBN content of the sample. Through the above results, we found that SAR containing MBN has antibacterial and remineralization effects. Thus, by adding MBN to the SAR, we investigated the possibility of orthodontic resin development, wherein the strength is enhanced and the drawbacks of the conventional SAR addressed.


2014 ◽  
Vol 08 (04) ◽  
pp. 498-503 ◽  
Author(s):  
Lucas da Fonseca Roberti Garcia ◽  
Hebert Luis Rossetto ◽  
Fernanda de Carvalho Panzeri Pires-de-Souza

ABSTRACT Objective: To evaluate the shear bond strength of a novel calcium aluminate-based cement, EndoBinder (EB), to dentine in comparison with Grey and White Mineral Trioxide Aggregate (MTA). Materials and Methods: Root canal hemi-sections obtained from 30 extracted molar teeth were embedded in self-polymerized acrylic resin and were grounded wet in order to obtain a flat dentine surface. Next, the roots were randomly assigned into three groups (n = 10), according to the cement used, as follows: EB: EndoBinder; WMTA: White MTA and GMTA: Grey MTA. The shear bond strength test was performed using a Universal Testing Machine (0.5 mm/min) and the data were submitted to statistical analysis (1-way ANOVA and Tukey tests, P < 0.05). Results: EB presented the highest shear bond strength values; however, there was no statistically significant difference in comparison with GMTA (P > 0.05). WMTA presented the lowest mean values, which were significant in comparison with EB (P < 0.05). Conclusions: The novel calcium aluminate-based cement presented higher shear bond strength than WMTA, and should be considered as a promising alternative in endodontic therapy.


2004 ◽  
Vol 12 (3) ◽  
pp. 200-204 ◽  
Author(s):  
Gisele Maria Correr ◽  
Angela S. Caldo-Teixeira ◽  
Roberta Caroline Bruschi Alonso ◽  
Regina Maria Puppin-Rontani ◽  
Mário Alexandre Coelho Sinhoreti ◽  
...  

The aim of this study was to evaluate the effect of saliva contamination (SCT) and re-etching time (RET) on the shear bond strength (SBS) of the Fluroshield sealant. Forty-five extracted third molars were sectioned and flattened until reach an enamel surface area. Then, all samples were etched for 30 sec with 35% phosphoric acid and then they were distributed into 9 groups (n=10) according to SCT and RET (seconds), respectively: G1- control (no SCT and no RET); G2- 30s and 0s; G3- 60s and 0s; G4-30s and 2s; G5- 30s and 5s; G6- 30s and 15s; G7-60s and 2s; G8- 60s and 5s; G9- 60s and 15s. The sealant was applied according to the manufacturer's instructions. The samples were stored in distilled water at 37ºC for 72h and subjected to the SBS test. The results indicated that there was no statistically significant difference between the groups (p>0.05). However, it could be noticed that: 1- the longer the SCT, the lower the SBS values; 2 - the longer the RET, the higher the SBS values. It could be concluded that there was a tendency to the shortest SCT (30s) associated to the longest RET (5 and 15s) to reach similar SBS values for the control group.


2013 ◽  
Vol 1 (2) ◽  
pp. 175
Author(s):  
Bernardo Urbanetto Peres ◽  
Felipe Weidenbach Degrazzia ◽  
Renésio Armindo Ghers ◽  
Fabíola Rossato Arrais ◽  
Vilmar Antonio Ferrazzo

PURPOSE: To evaluate the shear bond strength (SBS) of metallic brackets bonded with Transbond Plus Self-Etching Primer (TPSEP) and Transbond Plus Color Change (TPCC) under contamination with a mixture of saliva and blood. MATERIALS AND METHODS: 42 human premolars were randomly divided into 2 groups (n=21). Group 1 (G1) were bonded under no contamination, and Group 2 (G2) was contaminated with saliva/blood before bonding. Both groups were bonded according to the manufacturer’s instructions and were cleaned with pumice before bonding. The shear bond strength (SBS) tests were performed after 24 hours in distilled water at 37°C and after thermocycling. RESULTS: Both groups showed a homogeneous distribution in the Levene’s test (p>0.05). The main shear bond strength value of G1 was 8.89 MPa with a standard deviation of 2.27; the value for G2 was 6.00 MPa with a standard deviation of 2.62 MPa. There was a significant difference between G1 and G2 (t-student test p<0.05). IRA scores indicated that the main value was IRA 0, and no significant difference (α=0.05) was found between the groups. CONCLUSION: Contamination of blood mixed with saliva significantly decreases the shear bond strength, but even so, the performance is clinically acceptable.


2014 ◽  
Vol 15 (6) ◽  
pp. 688-692 ◽  
Author(s):  
Sukumaran Anil ◽  
Farouk Ahmed Hussein ◽  
Mohammed Ibrahim Hashem ◽  
Elna P Chalisserry

ABSTRACT Objective The purpose of the current in-vivo study was to assess the effect of using 0.12% chlorhexidine (CHX) mouth rinse, before bonding, on shear bond strength of polycarbonate brackets bonded with composite adhesive. Subjects and methods Eighteen orthodontic patients with a mean age 21.41 ± 1.2 years, who were scheduled to have 2 or more first premolars extracted, were included in this study. Patients were referred for an oral prophylaxis program which included, in part, the use of a mouth rinse. Patients were divided into 2 groups, a test group of 9 patients who used 0.12% CHX gluconate mouth rinse twice daily and a control group of 9 patients who used a mouth rinse without CHX, but with same color. After 1 week, polycarbonate brackets were bonded to first premolars with Transbond XT composite adhesive. Premolars were extracted after 28 days and tested for shear bond strength on a universal testing machine. Student's t-test was used to compare shear bond strengths of both groups. Results No statistically significant difference was found in bond strengths’ values between both groups. The test group (with CHX) has mean shear bond strength of 14.21 ± 2.42 MPa whereas the control group (without CHX) revealed a mean strength of 14.52 ± 2.31 MPa. Conclusion The use of 0.12% CHX mouth rinse, for one week before bonding, did not affect the shear bond strength of polycarbonate brackets bonded with Transbond composite. Furthermore, these brackets showed clinically acceptable bond strength. How to cite this article Hussein FA, Hashem MI, Chalisserry EP, Anil S. The Impact of Chlorhexidine Mouth Rinse on the Bond Strength of Polycarbonate Orthodontic Brackets. J Contemp Dent Pract 2014;15(6):688-692.


2016 ◽  
Vol 17 (12) ◽  
pp. 997-1002 ◽  
Author(s):  
Fahad I Alkhudhairy ◽  
Zeeshan H Ahmad

ABSTRACT Introduction Various bulk-fill materials depending on their composition, viscosity, and flow ability have different physical and mechanical properties. The aim of this in vitro study was to determine and compare the shear bond strength and microleakage properties of activa restorative with other bulk-fill restorative materials surefil (SDR), Biodentine, ever X posterior. Materials and methods Forty permanent premolars were selected for shear bond strength, and 20 permanent premolars were selected with class II cavities on mesial and distal side for microleakage. Universal testing device was used to assess the shear bond strength. Microleakage was checked using dye penetration method under a stereomicroscope. Mean and standard deviation values were calculated from the recorded values. Intergroup comparison was done by one-way analysis of variance (ANOVA) followed by pairwise comparison using Tukey honestly significant difference (HSD) post hoc test. Results The mean shear bond strength was highest for SDR surefil followed by Ever X posterior, Bioactive restorative, and Biodentine respectively. In this study, SDR (surefil) showed better shear bond strength and better microleakage properties compared with the other test materials (F = 186.7157, p < 0.05). Conclusion The result of this study showed that flowable and fiber-reinforced composites have better shear bond strength and microleakage properties. Clinical significance Flowable bulk-fill composite resins can be used as dentin substitutes because of its superior properties. How to cite this article Alkhudhairy FI, Ahmad ZH. Comparison of Shear Bond Strength and Microleakage of Various Bulk-fill Bioactive Dentin substitutes: An in vitro study. J Contemp Dent Pract 2016;17(12):997-1002.


2020 ◽  
Vol 27 (3) ◽  
Author(s):  
Esma Saricam ◽  
◽  
Neslihan Bulak ◽  
Esra Özyurt ◽  
Suat Özcan ◽  
...  

Eliminating microorganisms in the root canal system is important for the success of regenerative endodontics. Objective: This study evaluated the effects of different antibiotic pastes used for regenerative endodontic procedures on dentin microhardness and the push-out bond strength of mineral trioxide aggregate (MTA) to root canal dentin. Methods: Sixty-four maxillary central incisors were instrumented and randomly divided into the following four groups (n = 16) for medicament treatment: triple antibiotic paste, amoxicillin+clavulanic acid, cefaclor, and control (no dressing). After 21 days, two root segments were obtained by sectioning the roots horizontally for push-out and microhardness evaluations. MTA was placed into the root canal of the sectioned segment for the push-out test. In the microhardness evaluation, three indentations were made at 500 and 1,000 μm from the canal lumen. The arithmetic mean was then calculated for each distance. ANOVA with post hoc Scheffe test and t test were used for the statistical analyses. The significance level was set at p < 0.05. Results: No significant difference was found between the groups in terms of push-out bond strength (p > 0.05). Cefaclor and amoxicillin+clavulanic acid reduced the microhardness values of the dentin at 500 μm (p < 0.05) while cefaclor had the lowest value at 1,000 μm (p < 0.05). Conclusion: Cefaclor reduced the microhardness value more than the other medicaments did at a depth of 1,000 μm. The pastes provided similar adhesion of MTA.


Author(s):  
Mattapudi Basavaiah Babu ◽  
T. B. V. G. Raju ◽  
N. Mahendra Varma ◽  
Gowtam Dev Dondapati ◽  
Srivalli Podili ◽  
...  

Aim: To evaluate the impact of environmental pH on intra-radicular dentin push-out bond strengths of MTA, MTA HP, and Biodentine. Materials and Methodology: Freshly extracted human mandibular single-rooted premolars or maxillary anterior incisors that were either intact or contained only small carious lesions were selected.120 mid root dentins is horizontally divided into 1.0 mm thick slices and divided into 3 MTA, MTA HP, BIODENTINE groups. The compressive load is applied at a speed of 0.5 mm/min by exerting a downward pressure on the outer surface of MTA using a 1.00 mm diameter cylindrical stainless-steel plunger. Maximum load to MTA was reported in newtons at the time of dislodgement and converted to megapascals. The 1-way analysis of variance test was used to compare the push-out bond strength of the groups with the same storage time (4 or 34 days), followed by the pair-wise comparison of the Tukey post hoc test. The Student's t-test was used to evaluate 3-group means. At P = .005, the degree of significance was set. Thus the clinical importance of the present study states that considering several factors like microhardness, composition by products, particle sizes and the environmental pH plays a critical role in selection of root end filling material. Results: There was significant difference between groups (P = .001) after 4 days of PBS and Acid condition, where Bio dentine had significantly the highest bond strength. Conclusion: The strength of MTA HP, BIODENTINE, MTA materials at dentine interface increases over 30 days in the storage of PBS solution at pH 7.4, after an initial acid challenge by acetic acid of pH 5.4, which decreases initial bond strength.


Sign in / Sign up

Export Citation Format

Share Document