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Sample records for validate bonded composite

  1. Development and validation of bonded composite doubler repairs for commercial aircraft.

    Energy Technology Data Exchange (ETDEWEB)

    Roach, Dennis Patrick; Rackow, Kirk A.

    2007-07-01

    A typical aircraft can experience over 2,000 fatigue cycles (cabin pressurizations) and even greater flight hours in a single year. An unavoidable by-product of aircraft use is that crack, impact, and corrosion flaws develop throughout the aircraft's skin and substructure elements. Economic barriers to the purchase of new aircraft have placed even greater demands on efficient and safe repair methods. The use of bonded composite doublers offers the airframe manufacturers and aircraft maintenance facilities a cost effective method to safely extend the lives of their aircraft. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is now possible to bond a single Boron-Epoxy composite doubler to the damaged structure. The FAA's Airworthiness Assurance Center at Sandia National Labs (AANC), Boeing, and Federal Express completed a pilot program to validate and introduce composite doubler repair technology to the U.S. commercial aircraft industry. This project focused on repair of DC-10 fuselage structure and its primary goal was to demonstrate routine use of this repair technology using niche applications that streamline the design-to-installation process. As composite doubler repairs gradually appear in the commercial aircraft arena, successful flight operation data is being accumulated. These commercial aircraft repairs are not only demonstrating the engineering and economic advantages of composite doubler technology but they are also establishing the ability of commercial maintenance depots to safely adopt this repair technique. This report presents the array of engineering activities that were completed in order to make this technology available for widespread commercial aircraft use. Focused laboratory testing was conducted to compliment the field data and to address specific issues regarding damage tolerance and flaw growth in composite doubler repairs. Fatigue and strength tests were performed on a simulated wing

  2. Full-Scale Structural and NDI Validation Tests of Bonded Composite Doublers for Commercial Aircraft Applications

    Energy Technology Data Exchange (ETDEWEB)

    Roach, D.; Walkington, P.

    1999-02-01

    Composite doublers, or repair patches, provide an innovative repair technique which can enhance the way aircraft are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is possible to bond a single Boron-Epoxy composite doubler to the damaged structure. Most of the concerns surrounding composite doubler technology pertain to long-term survivability, especially in the presence of non-optimum installations, and the validation of appropriate inspection procedures. This report focuses on a series of full-scale structural and nondestructive inspection (NDI) tests that were conducted to investigate the performance of Boron-Epoxy composite doublers. Full-scale tests were conducted on fuselage panels cut from retired aircraft. These full-scale tests studied stress reductions, crack mitigation, and load transfer capabilities of composite doublers using simulated flight conditions of cabin pressure and axial stress. Also, structures which modeled key aspects of aircraft structure repairs were subjected to extreme tension, shear and bending loads to examine the composite laminate's resistance to disbond and delamination flaws. Several of the structures were loaded to failure in order to determine doubler design margins. Nondestructive inspections were conducted throughout the test series in order to validate appropriate techniques on actual aircraft structure. The test results showed that a properly designed and installed composite doubler is able to enhance fatigue life, transfer load away from damaged structure, and avoid the introduction of new stress risers (i.e. eliminate global reduction in the fatigue life of the structure). Comparisons with test data obtained prior to the doubler installation revealed that stresses in the parent material can be reduced 30%--60% through the use of the composite doubler. Tests to failure demonstrated that the bondline is able to transfer plastic strains into the doubler and that

  3. Effect of moist bonding on composite/enamel bond strength.

    Science.gov (United States)

    Moll, Karlheinz; Gärtner, Thomas; Haller, Bernd

    2002-04-01

    To evaluate the effect of moist bonding on shear bond strength of resin-based composite to enamel using different adhesive systems. Six restorative systems were selected for this study: OptiBond FL/Prodigy, Solid Bond/Charisma F, Syntac Single Component/Tetric, Prime&Bond 2.1/Spectrum TPH, Single Bond/Z100, Etch&Prime 3.0/Degufill Mineral. Flat enamel surfaces were ground on the buccal and lingual aspects of 80 extracted human molars. OptiBond FL and Solid Bond were tested with and without primer application. Prior to application of the adhesives, the enamel was either carefully dried with compressed air (dry bonding) or blot dried with a cotton pellet (moist bonding). Shear bond strength was determined with a universal testing machine after 24-hour storage in 0.9% NaCl at 37 degrees C. Moist bonding did not significantly affect shear bond strength to enamel of the adhesives tested except for Solid Bond without primer application. Primer contamination of the etched enamel did not significantly influence bond strength, neither in the dry bonding nor in the moist bonding group. Of all adhesives tested in both groups, the highest mean bond strength was observed with Prime&Bond 2.1 and the lowest with Etch&Prime 3.0.

  4. Analysis of "Kiss" Bonds Between Composite Laminates

    Science.gov (United States)

    Poveromo, Scott L.; Earthman, James C.

    2014-06-01

    One of the leading challenges to designing lightweight, cost-effective bonded structures is to detect low shear strength "kiss" bonds where no other defects such as voids and cracks exist. To develop a nondestructive testing method that is sensitive to kiss bonds, standards need to be fabricated with known strength values. In the current work, we attempt to create kiss bonds in between carbon fiber composite laminates that have been bonded with epoxy film adhesive and epoxy paste adhesive. Based on ultrasonic testing, when creating true kiss bonds using film adhesives, a complete disbond could not be avoided because of thermally induced stresses during the high-temperature cure. However, further work demonstrated that kiss bonds can be formed using room-temperature curable epoxy paste adhesives by creating an amine blush on the epoxy surface or applying a release agent on the bonding surfaces.

  5. Interlaminar toughness of fusion bonded thermoplastic composites

    NARCIS (Netherlands)

    Sacchetti, Francisco R.

    2017-01-01

    Thermoplastic composites are of increasing interest to the aerospace industry. The melt-processability of the thermoplastic matrix allows for fast manufacturing and assembling techniques, such as thermoforming and fusion bonding, which are also highly suitable for process automation. Fusion bonding

  6. Combining resin composite bonding and enamel microabrasion.

    Science.gov (United States)

    Croll, T P

    1996-10-01

    Some teeth can best be treated by a combination of enamel microabrasion and resin composite bonding. This article outlines a protocol for treating patients with such teeth and documents one case, showing 5-year results.

  7. Graphene composites containing chemically bonded metal oxides

    Indian Academy of Sciences (India)

    Abstract. Composites of graphene involving chemically bonded nano films of metal oxides have been prepared by reacting graphene containing surface oxygen functionalities with metal halide vapours followed by exposure to water vapour. The composites have been characterized by electron microscopy, atomic force ...

  8. Test method to assess interface adhesion in composite bonding

    OpenAIRE

    Teixeira de Freitas, S.; Sinke, J

    2015-01-01

    This paper introduces a new type of peel tests dedicated to composite bonding: Composite Peel Tests. This test is inspired on the standard floating roller peel test widely used for metal bonding. The aim of this study is to investigate the potential of the Composite Peel Test to assess interface adhesion in composite bonded structures. To this end, peel tests were performed with nine different types of adhesives and at two environmental temperatures, room temperature and +80°C. The results we...

  9. Progressive Damage Analysis of Bonded Composite Joints

    Science.gov (United States)

    Leone, Frank A., Jr.; Girolamo, Donato; Davila, Carlos G.

    2012-01-01

    The present work is related to the development and application of progressive damage modeling techniques to bonded joint technology. The joint designs studied in this work include a conventional composite splice joint and a NASA-patented durable redundant joint. Both designs involve honeycomb sandwich structures with carbon/epoxy facesheets joined using adhesively bonded doublers.Progressive damage modeling allows for the prediction of the initiation and evolution of damage within a structure. For structures that include multiple material systems, such as the joint designs under consideration, the number of potential failure mechanisms that must be accounted for drastically increases the complexity of the analyses. Potential failure mechanisms include fiber fracture, intraply matrix cracking, delamination, core crushing, adhesive failure, and their interactions. The bonded joints were modeled using highly parametric, explicitly solved finite element models, with damage modeling implemented via custom user-written subroutines. Each ply was discretely meshed using three-dimensional solid elements. Layers of cohesive elements were included between each ply to account for the possibility of delaminations and were used to model the adhesive layers forming the joint. Good correlation with experimental results was achieved both in terms of load-displacement history and the predicted failure mechanism(s).

  10. Test method to assess interface adhesion in composite bonding

    NARCIS (Netherlands)

    Teixeira de Freitas, S.; Sinke, J.

    2015-01-01

    This paper introduces a new type of peel tests dedicated to composite bonding: Composite Peel Tests. This test is inspired on the standard floating roller peel test widely used for metal bonding. The aim of this study is to investigate the potential of the Composite Peel Test to assess interface

  11. Effect of Biofilm on the Repair Bond Strengths of Composites

    NARCIS (Netherlands)

    Rinastiti, M.; Ozcan, M.; Siswomihardjo, W.; Busscher, H. J.; van der Mei, H. C.

    2010-01-01

    Composite restorations degrade during wear, but it is unknown how wear affects the composite surface and influences composite-to-composite bonding in minimally invasive repair. Here, it is hypothesized that in vitro exposure of composites to oral biofilm yields clinically relevant degradation of

  12. Non destructive evaluation of adhesively bonded carbon fiber reinforced composite lap joints with varied bond quality

    Science.gov (United States)

    Vijayakumar, R. L.; Bhat, M. R.; Murthy, C. R. L.

    2012-05-01

    Structural adhesive bonding is widely used to execute assemblies in automobile and aerospace structures. The quality and reliability of these bonded joints must be ensured during service. In this context non destructive evaluation of these bonded structures play an important role. Evaluation of adhesively bonded composite single lap shear joints has been attempted through experimental approach. Series of tests, non-destructive as well as destructive were performed on different sets of carbon fiber reinforced polymer (CFRP) composite lap joint specimens with varied bond quality. Details of the experimental investigations carried out and the outcome are presented in this paper.

  13. Strength and sorption properties of cement-bonded composites ...

    African Journals Online (AJOL)

    Strength and sorption properties of cement-bonded composites produced from eucalyptus ( Eucalyptus tereticornis SM.) veneer waste. ... applications where sound absorption is important. Keywords: Eucalyptus, Veneer waste, Cement composite, Strength, dimensional stability. Journal of Applied Science, Engineering and ...

  14. Drastic Improvements in Bonding of Fiber Reinforced Multifunctional Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Achievement of a dramatic increase in the bond strength in the composite/adhesive interfaces of existing fiber reinforced polymer (FRP) composite material joints and...

  15. Drastic Improvements in Bonding of Fiber Reinforced Multifunctional Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Achievement of a dramatic increase in the bond strength in the adhesive and composite/adhesive interfaces of existing fiber reinforced composite material joints and...

  16. Effect of bond thickness on fracture and fatigue strength of adhesively bonded composite joints

    Science.gov (United States)

    Mall, S.; Ramamurthy, G.

    1989-01-01

    An experimental investigation of composite to composite bonded joints was undertaken to study the effect of bond thickness on debond growth rate under cyclic loading and critical strain energy release rate under static loading. Double cantilever beam specimens of graphite/epoxy adherends bonded with EC 3445 were tested under mode I loading. A different behavior of fracture and fatigue strength was observed with variation of bondline thickness.

  17. Properties of composite materials used for bracket bonding.

    Science.gov (United States)

    Gama, Ana Caroline Silva; Moraes, André Guaraci de Vito; Yamasaki, Lilyan Cardoso; Loguercio, Alessandro Dourado; Carvalho, Ceci Nunes; Bauer, José

    2013-01-01

    The purpose of this study was to evaluate in vitro the shear bond strength to enamel, flexural strength, flexural modulus, and contraction stress of one orthodontic composite and two flowable composites. Orthodontic brackets were bonded to 45 human maxillary premolars with the composites Transbond XT, Filtek Z-350 flow and Opallis flow and tested for shear bond strength. For measurement of flexural strength and flexural modulus, specimens were fabricated and tested under flexion. For the contraction stress test, cylindrical specimens were tested and an extensometer determined the height of the specimens. The data were subjected to one-way ANOVA and Tukey's test (α=0.05). The shear bond strength values were significantly lower (p0.05) while the flexural modulus was significantly higher (plight-activated orthodontic composite material presented higher flexural modulus and shear bond strength and lower contraction stress than both flowable composites.

  18. Bond Strength of Composite Resin to Pulp Capping Biomaterials after Application of Three Different Bonding Systems

    Directory of Open Access Journals (Sweden)

    Zahra Jaberi-Ansari

    2013-08-01

    Full Text Available Background and aims. Bonding of composite resin filling materials to pulp protecting agents produces an adhesive joint which is important for the quality of filling as well as success of restoration. We aimed to assess the bond strength of composite resin to three pulp capping biomaterials: Pro Root mineral trioxide aggregate (PMTA, Root MTA (RMTA and calcium enriched mixture (CEM cement, using three bonding systems [a total-etch (Single Bond and two self-etch systems (Protect bond and SE Bond]. Materials and methods. Ninety acrylic molds, each containing a 6×2-mm hole, were divided into 3 groups and filled with PMTA, RMTA and CEM cements. The samples in each experimental group were then randomly divided into 3 subgroups; Single Bond, Protect Bond and SE Bond bonding systems were applied to the tested materials. Cylindrical forms of composite resin (Z100, 2×2 mm were placed onto the samples and cured. Shear bond strength values were measured for 9 subgroups using a universal testing machine. Data were analyzed using two-way ANOVA. Results. The average shear bond strengths of Z100 composite resin after application of Single Bond, Protect Bond and SE Bond systems were as follows; PMTA: 5.1±2.42, 4.56±1.96 and 4.52±1.7; RMTA: 4.71±1.77, 4.31±0.56 and 4.79±1.88; and CEM cement: 4.75±1.1, 4.54±1.59 and 4.64±1.78 MPa, respectively. The type of pulp capping material, bonding system and their interacting effects did not have a significant effect on the bond strengths of composite resin to pulp capping biomaterials. Conclusion. Within the limitations of this in vitro study, bond strength of composite resin to two types of MTA as well as CEM cement were similar following application of the total-etch or self-etch bonding systems.

  19. Spot-Bonding and Full-Bonding Techniques for Fiber Reinforced Composite (FRC) and Metallic Retainers

    Science.gov (United States)

    Gandini, Paola; Tessera, Paola; Vallittu, Pekka K.; Lassila, Lippo; Sfondrini, Maria Francesca

    2017-01-01

    Fiber reinforced Composite (FRC) retainers have been introduced as an aesthetic alternative to conventional metallic splints, but present high rigidity. The purpose of the present investigation was to evaluate bending and fracture loads of FRC splints bonded with conventional full-coverage of the FRC with a composite compared with an experimental bonding technique with a partial (spot-) resin composite cover. Stainless steel rectangular flat, stainless steel round, and FRC retainers were tested at 0.2 and 0.3 mm deflections and at a maximum load. Both at 0.2 and 0.3 mm deflections, the lowest load required to bend the retainer was recorded for spot-bonded stainless steel flat and round wires and for spot-bonded FRCs, and no significant differences were identified among them. Higher force levels were reported for full-bonded metallic flat and round splints and the highest loads were recorded for full-bonded FRCs. At the maximum load, no significant differences were reported among spot- and full-bonded metallic splints and spot-bonded FRCs. The highest loads were reported for full bonded FRCs. The significant decrease in the rigidity of spot-bonded FRC splints if compared with full-bonded retainers suggests further tests in order to propose this technique for clinical use, as they allow physiologic tooth movement, thus presumably reducing the risk of ankylosis. PMID:28976936

  20. Effect of Bonding Application Time on Bond Strength of Composite Resin to Glass Ionomer Cement

    Directory of Open Access Journals (Sweden)

    Narges Panahandeh

    2016-08-01

    Full Text Available Objectives: This experimental study evaluated the effect of bonding application time on the microshear bond strength of composite resin to different types of glass ionomer cements (GICs.Materials and Methods: One-hundred and sixty specimens (two conventional and two resin-modified GICs were prepared and divided into 16 groups. The surface of all specimens was prepared using two different bonding systems (Frog and Stea at three different times. After setting, the composite resin (Z100 was placed over the GICs. The specimens were then stored in distilled water for 24 hours (37oC and exposed to microshear stresses at a crosshead speed of 1 mm/min. The results were analyzed using three-way ANOVA and Tukey’s test (P˂0.05.Results: In conventional GICs, bond strength was affected by the type of bonding system at different times, and bond strength was significantly higher in the Fuji II group compared to Riva Self Cure group. In the Riva Self Cure group, bond strength was significantly affected by time; whereas, the type of bonding system failed to exert a significant effect on bond strength. There was no significant correlation between the type of bonding system and the two brands of resin-modified GICs. Bond strength was not affected by the type of bonding agent; however, among the two brands of resin-modified GICs, Fuji II LC yielded a significantly stronger bond.Conclusion: It appears that the type of bonding agent does not affect the microshear bond strength, and the bonding application time affects the microshear bond strength in Riva Self Cure GICs.

  1. Are Bonding Agents being Effective on the Shear Bond Strength of Orthodontic Brackets Bonded to the Composite?

    Directory of Open Access Journals (Sweden)

    Fahimeh Farzanegan

    2014-06-01

    Full Text Available Introduction: One of the clinical problems in orthodontics is the bonding of brackets tocomposite restorations. The aim of this study was to evaluate the shear bondstrength of brackets bonded to composite restorations using Excite. Methods:Forty brackets were bonded to composite surfaces, which were embedded inacrylic resin. One of the following four protocols was employed for surfacepreparation of the composite: group 1 37% phosphoric acid for 60 seconds, group2 roughening with a diamond bur plus 37% phosphoric acid for 60 seconds, group3 37% phosphoric acid for 60 seconds and the applying Excite®, group4 roughening with diamond bur plus 37% phosphoric acid for 60 seconds andapplying Excite®. Maxillary central brackets were bonded onto thecomposite prepared samples with Transbond XT. Shear Bond Strength (SBS wasmeasured by a universal testing machine. The ANOVA and Tukey test was utilizedfor data analysis. Results: There was a significant difference betweenthe four groups (P

  2. Shear bond strength of self-etching bonding systems in combination with various composites used for repairing aged composites.

    Science.gov (United States)

    Teixeira, Erica C; Bayne, Stephen C; Thompson, Jeffrey Y; Ritter, Andre V; Swift, Edward J

    2005-01-01

    Repair of worn, broken or discolored composite restorations can be accomplished using new composite material and dentin bonding systems. The purpose of this study was to investigate the effectiveness of self-etching adhesive systems for composite re-bonding procedures onto different composite substrates that had been aged for 6 years prior to testing. Two hundred cylinders (4 mm x 5 mm) of composite were fabricated using 4 hybrid composites [AeliteFil (Bisco), Prodigy (SDS Kerr), TPH (Dentsply Caulk), and Z100 (3M ESPE)] following manufacturers' directions and stored for 6 years in 1% NaCl solution. After aging, each specimen was wet polished through 600-grit SiC and randomly assigned to a self-etching bonding system (Adper Prompt L-Pop/Z100 [3M ESPE]; Tyrian One-Step Plus/AeliteFil [Bisco]; OptiBond Solo Plus SE/Prodigy [SDS Kerr], Xeno III/TPH [Dentsply Caulk]) or a total-etch control (Prime&Bond NT/TPH [Dentsply Caulk]) (n = 10 per group). Shear bond strengths (SBS) for repairs were evaluated after 48 h (crosshead speed = 0.5 mm/min) and were compared by two-way ANOVA (p = 0.05) with Tukey post-hoc tests. Significant differences (p bonding systems), but the interaction was not significant. SBS for bonding systems were from highest to lowest: (1) Prime&Bond NT, (2) OptiBond Solo Plus SE, (3) Adper Prompt L-Pop, (4) Xeno III, (5) Tyrian One-Step Plus. SBS of the repair systems to Z100 were significantly lower than those to the other composite substrates. Self-etching systems can be used to repair aged composite, but the efficacy of repair of aged composite is system dependent.

  3. Two-year composite/dentin bond stability.

    Science.gov (United States)

    Meiers, J C; Young, D

    2001-06-01

    To examine the composite-to-dentin shear bond strengths over 2 yrs of three chemically different single bottle dentin adhesives: water-based Syntac Single Component (SSC); acetone-based Prime & Bond 2.1 (PB), and; ethanol-based and filled OptiBond Solo (OS). Extracted human molars stored in 0.2% sodium azide were randomly assigned to each of three dentin bond groups for testing at 5 time periods (n=15). The crowns of the teeth were sectioned to expose occlusal dentin and the roots embedded in acrylic. The dentin was etched with 37% H3PO4 for 20 s, rinsed and dentin adhesives applied per manufacturers' instructions. A column of Z-100 composite was bonded to the treated dentin surface and light cured. Teeth were stored in distilled water at 37 degrees C and thermocycled for 1,000 cycles between 5 degrees C and 55 degrees C and tested in shear at 24 hrs (baseline), 6, 12, 18 and 24 months. Mean +/- SD shear bond strengths (SBS) were determined. ANOVA at a significance level of Pstability of resin-based composite to dentin bond strengths from single bond adhesives is questionable because after 2 yrs, bond strengths for two of the three tested dentin adhesives, OptiBond Solo and Syntac Single Component, were significantly lower than initial strengths.

  4. Composite Bonding to Stainless Steel Crowns Using a New Universal Bonding and Single-Bottle Systems

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Hattan

    2013-01-01

    Full Text Available Aim. The aim of this study is to evaluate the shear bond strength of nanocomposite to stainless steel crowns using a new universal bonding system. Material and Methods. Eighty (80 stainless steel crowns (SSCs were divided into four groups (20 each. Packable nanocomposite was bonded to the lingual surface of the crowns in the following methods: Group A without adhesive (control group, Group B using a new universal adhesive system (Scotchbond Universal Adhesive, 3M ESPE, Seefeld, Germany, and Group C and Group D using two different brands of single-bottle adhesive systems. Shear bond strengths were calculated and the types of failure also were recorded. Results. The shear strength of Group B was significantly greater than that of other groups. No significant differences were found between the shear bond strengths of Groups C and D. The control group had significantly lower shear bond strength ( to composite than the groups that utilized bonding agents. Conclusion. Composites bonding to stainless steel crowns using the new universal bonding agent (Scotchbond Universal Adhesive, 3M ESPE, Seefeld, Germany show significantly greater shear bond strengths and fewer adhesive failures when compared to traditional single-bottle systems.

  5. Characterization of Dentine to Assess Bond Strength of Dental Composites

    Science.gov (United States)

    Liaqat, Saad; Aljabo, Anas; Khan, Muhammad Adnan; Ben Nuba, Hesham; Bozec, Laurent; Ashley, Paul; Young, Anne

    2015-01-01

    This study was performed to develop alternating dentine adhesion models that could help in the evaluation of a self-bonding dental composite. For this purpose dentine from human and ivory was characterized chemically and microscopically before and after acid etching using Raman and SEM. Mechanical properties of dentine were determined using 3 point bend test. Composite bonding to dentine, with and without use of acid pre-treatment and/or the adhesive, were assessed using a shear bond test. Furthermore, micro gap formation after restoration of 3 mm diameter cavities in dentine was assessed by SEM. Initial hydroxyapatite level in ivory was half that in human dentine. Surface hydroxyapatites decreased by approximately half with every 23 s of acid etch. The human dentine strength (56 MPa) was approximately double that of ivory, while the modulus was almost comparable to that of ivory. With adhesive use, average shear bond strengths were 30 and 26 MPa with and without acid etching. With no adhesive, average bond strength was 6 MPa for conventional composites. This, however, increased to 14 MPa with a commercial flowable “self–bonding” composite or upon addition of low levels of an acidic monomer to the experimental composite. The acidic monomer additionally reduced micro-gap formation with the experimental composite. Improved bonding and mechanical properties should reduce composite failures due to recurrent caries or fracture respectively.

  6. Characterization of Dentine to Assess Bond Strength of Dental Composites

    Directory of Open Access Journals (Sweden)

    Saad Liaqat

    2015-04-01

    Full Text Available This study was performed to develop alternating dentine adhesion models that could help in the evaluation of a self-bonding dental composite. For this purpose dentine from human and ivory was characterized chemically and microscopically before and after acid etching using Raman and SEM. Mechanical properties of dentine were determined using 3 point bend test. Composite bonding to dentine, with and without use of acid pre-treatment and/or the adhesive, were assessed using a shear bond test. Furthermore, micro gap formation after restoration of 3 mm diameter cavities in dentine was assessed by SEM. Initial hydroxyapatite level in ivory was half that in human dentine. Surface hydroxyapatites decreased by approximately half with every 23 s of acid etch. The human dentine strength (56 MPa was approximately double that of ivory, while the modulus was almost comparable to that of ivory. With adhesive use, average shear bond strengths were 30 and 26 MPa with and without acid etching. With no adhesive, average bond strength was 6 MPa for conventional composites. This, however, increased to 14 MPa with a commercial flowable “self–bonding” composite or upon addition of low levels of an acidic monomer to the experimental composite. The acidic monomer additionally reduced micro-gap formation with the experimental composite. Improved bonding and mechanical properties should reduce composite failures due to recurrent caries or fracture respectively.

  7. Effect of simulated pulpal pressure on composite bond strength to ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... adhesive system was used. Key words: Bond strength, laser treatment, pulpal pressure, resin composite. INTRODUCTION. Adhesive techniques have expanded the range of possi- bilities for operative and esthetic dentistry (Kato and. Nakabayashi, 1998). Bonding to enamel is a relatively simple procedure ...

  8. Neutron imaging inspections of composite honeycomb adhesive bonds

    Energy Technology Data Exchange (ETDEWEB)

    Hungler, P.C., E-mail: paul.hungler@rmc.ca [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, 13 General Crerar Cres, Kingston, Ontario, K7K 7B4 (Canada); Bennett, L.G.I.; Lewis, W.J. [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, 13 General Crerar Cres, Kingston, Ontario, K7K 7B4 (Canada); Schulz, M.; Schillinger, B. [FRM-II, Technische Universitaet Muenchen (Germany)

    2011-09-21

    Numerous commercial and military aircraft, including the Canadian Forces CF188 Hornet, use composite honeycomb structures in the design of their flight control surfaces (FCS). These structures provide excellent strength to weight ratios, but are often susceptible to degradation from moisture ingress. Once inside the honeycomb structure moisture causes the structural adhesive bonds to weaken, which can lead to complete failure of the FCS in flight. There are two critical structural adhesive bonds: the node bond and the filet bond. The node bond is integral to the honeycomb portion of the composite core and is located between the honeycomb cells. The filet bond is the adhesive bond located between the skin and the core. In order to asses overall structural degradation and develop repair procedures, it is important to determine the degree of degradation in each type of bond. Neutron radiography and tomography of the adhesive bonds was conducted at the Royal Military College (RMC) and FRM-II. Honeycomb samples were manufactured from FCS with in-service water ingress. The radiographs and tomograms provided important information about the degree of degradation in the core as well as about which adhesive bonds are more susceptible. The information obtained from this study will help to develop repair techniques and assess the flight worthiness of FCS.

  9. Inspection of bonded composites using selectively excited ultrasonic modes

    Science.gov (United States)

    Krauss, Gordon Gustav

    Improved methods of nondestructive testing (NDT) of multi-layered composites are vital for fundamental research in composites fabrication and performance. Fast, accurate NDT methods can also be used to predict catastrophic in-use failure and to reduce costly rejects during the manufacture of composite parts. Commercial normal incidence inspection techniques have generally yielded reliable detection of large areas of delamination and damage. They fail, however, to detect defects within thin bonded regions, such as disbonds, debonds, kissing bonds, and porosity. We have developed and studied a nondestructive testing technique designed to be sensitive to flaws in the bond area of adhesively bonded anisotropic materials. The technique utilizes specific ultrasonic modes which are selected through a priori modeling of the composite as a single anisotropic elastic layer. The displacement and stress profiles of the modes within the fluid loaded layer are evaluated. A propagating mode that is predicted to be highly sensitive to the bond area is then utilized in the inspection. The inspection is carried out with an apparatus designed and constructed to excite and detect the selected ultrasonic mode. The apparatus uses transducers oriented at the theoretically optimal incident angle to excite the desired mode, using a tone burst between 0.5 and 10.0 MHz. We monitor with a second transducer changes in the amplitude of the leaky component of the mode propagating in the plate. By using this apparatus we have experimentally distinguished changes in the bond areas of adhesively bonded aluminum plates and carbon-epoxy composite plates of unidirectional and quasi-isotropic lay-up, The radiated leaky wave amplitudes from poorly bonded plates were less than 50% of those from corresponding well bonded plates. We observed no significant changes in the amplitudes of normal incidence pulse-echo signals for these specimens. These results demonstrate that selective mode excitation can

  10. Shear strength of dentin and dentin bonded composites.

    Science.gov (United States)

    Mondragon, E; Söderholm, K J

    2001-01-01

    The objective of this study was to compare the shear strength of dentin with the shear strength of dentin bonded composites, and to determine how variables such as composite strength and blade width used during shear testing influence shear strength values. Dentin test samples (n = 36) were made by milling the anatomical molar crowns to a shape similar to a composite rod bonded to a flat dentin surface. Dentin bonding was accomplished by bonding composites to flat dentin surfaces (n = 72) using Scotchbond MP and Z100 (n = 36) or Silux Plus (n = 36) composites. Shear testing was conducted using a guillotine-like device with a flat blade embracing half the dentin or composite cylinders. The blade thickness was either 0.25, 0.5, 0.75, 1.0, 1.25, or 1.50 mm. Six samples per material and blade thickness were tested. In addition to the above study, the bond strength of Z100 (n = 6) and Silux (n = 6) bonded with Scotchbond MP and tested with an orthodontic edgewire loop were also tested and compared with the bond strength of the Z100 and Silux samples tested with the 0.5 thick blade. All shear testing was done at a load rate of 0.5 mm/min. The results were analyzed using ANOVA and Duncan's multiple range test. The shear strength values when tested with the blades were: dentin = 39.7 +/- 13.0 MPa, Z100 = 29.3 +/- 7.2 MPa, and Silux = 21.1 +/- 4.9 MPa; each group had significantly different values (p bonding agent is significantly lower than the shear strength of dentin. The shear strength depends on testing method (blade vs loop) and composite material.

  11. Inspection for kissing bonds in composite materials using vibration measurements

    Science.gov (United States)

    Adams, Douglas E.; Sharp, Nathan D.; Myrent, Noah; Sterkenburg, Ronald

    2011-04-01

    Improper bonding of composite structures can result in close contact cracks under compressive stresses, called kissing bonds. These bond defects are very difficult to detect using conventional inspection techniques such as tap testing or local ultrasonic scanning and can lead to local propagation of damage if the structure is subjected to crack opening stresses. A method is investigated for identifying kissing bonds in composite material repairs based on vibration measurements. A damage feature of the kissing bond is extracted from the response of the input-output measurement that is a function of the structural path. This path exhibits local decoupling associated with the close contact cracks. Experimental vibration measurements from sandwich composite materials are presented along with the results of the damage detection algorithm for the healthy sections of the material and the kissing bond sections. A vibration based inspection technique could increase the ability to detect kissing bonds in composite material repairs while decreasing inspection time. Benefits of this method of identification over conventional techniques include its robust, objective damage detection methodology and the reduced requirement for specimen preparation and surface texture when compared to ultrasonic scanning.

  12. Comparison of Shear Bond Strength between Composite Resin and Porcelain Using Different Bonding Systems

    Directory of Open Access Journals (Sweden)

    E.Yassini

    2005-03-01

    Full Text Available Statement of Problem: Ceramics as in ceramo-metallic and all ceramic tooth restorations have grown popular owing to their high tissue compatibility and esthetic advantages. Such restorations have the capability to deliver valuable services over a long period of time; however, failures under intraoral conditions are not unanticipated.Purpose: The purpose of this in-vitro study was to investigate the shear bond strength of composite resin to porcelain using different bonding system materials.Materials and Methods: In this experimental study forty porcelain blocks were prepared and randomly divided into four equal groups. The porcelain surfaces were then etched with HF for 2 minutes, washed with water for 2 minutes and treated with a silane layer. The silane treated porcelain surfaces were left for one minute and then the specimens were bonded to composite resin as follow:Group 1 (control group, hybrid composite Z100 was applied and light cured from four directions for 20 seconds. Group 2, flowable composite was applied and light cured for 20 seconds. Group 3, unfilled resin was used and photo cured for 20 seconds. Group 4,(Dentin bonding agent adhesive resin was used followed by 20 seconds photo curing.Hybrid composite resin Z100 was subsequently applied on all porcelain surfaces of groups 2, 3 and 4, and light cured for 20 seconds from four directions. Specimens were then subjected to thermocycling 1000 times. Shear bond strength was determined by a Universal testing machine. The data obtained was subjected to a one-way ANOVA test.Results: The results indicate that there is a statistically significant difference between adhesive group and the other three groups of hybrid, flowable and unfilled resin (P<0.05.Conclusion: The results from this study showed that the shear bond strength of composite resin to porcelain was significantly higher for porcelain bonded surfaces using a dentin bonding agent than that of other materials tested.

  13. Repair Bond Strength of Aged Resin Composite after Different Surface and Bonding Treatments

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    Michael Wendler

    2016-07-01

    Full Text Available The aim of this study was to compare the effect of different mechanical surface treatments and chemical bonding protocols on the tensile bond strength (TBS of aged composite. Bar specimens were produced using a nanohybrid resin composite and aged in distilled water for 30 days. Different surface treatments (diamond bur, phosphoric acid, silane, and sandblasting with Al2O3 or CoJet Sand, as well as bonding protocols (Primer/Adhesive were used prior to application of the repair composite. TBS of the specimens was measured and the results were analyzed using analysis of variance (ANOVA and the Student–Newman–Keuls test (α = 0.05. Mechanically treated surfaces were characterized under SEM and by profilometry. The effect of water aging on the degree of conversion was measured by means of FTIR-ATR spectroscopy. An important increase in the degree of conversion was observed after aging. No significant differences in TBS were observed among the mechanical surface treatments, despite variations in surface roughness profiles. Phosphoric acid etching significantly improved repair bond strength values. The cohesive TBS of the material was only reached using resin bonding agents. Application of an intermediate bonding system plays a key role in achieving reliable repair bond strengths, whereas the kind of mechanical surface treatment appears to play a secondary role.

  14. Effect of thickness of bonded composite resin on compressive strength

    NARCIS (Netherlands)

    Hamburger, J.T.; Opdam, N.J.; Bronkhorst, E.M.; Roeters, J.; Huysmans, M.C.

    2014-01-01

    OBJECTIVE: The aim of this study was to investigate the compressive strength of composites with different physical properties bonded as a restoration to dentin in layers of varying thicknesses. METHODS: Four types of direct composite materials: a midway-filled (Tetric EvoCeram); a compact-filled

  15. Weak bond detection in composites using highly nonlinear solitary waves

    Science.gov (United States)

    Singhal, Taru; Kim, Eunho; Kim, Tae-Yeon; Yang, Jinkyu

    2017-05-01

    We experimentally investigate a diagnostic technique for identifying a weak bond in composites using highly nonlinear solitary waves (HNSWs). We set up a one-dimensional chain of granular crystals, consisting of spherical particles with nonlinear interactions, to generate HNSWs. These solitary wave packets are transmitted into an inspection area of composites by making a direct contact with the chain. We demonstrate that a strong type of solitary waves injected to the weak bond area can break the weak bond of laminates, thereby causing delamination. Then, to identify the creation of the delamination, we transmit a weak type of solitary waves by employing the same apparatus, and measure the solitary waves reflected from the specimens. By analyzing these reflected solitary waves, we differentiate the weak bond samples with the pristine bond ones in an efficient and fast manner. The diagnostic results based on the proposed method are compared with the strength and energy release rate at bond interfaces, which are measured via standard testing methods such as three point bending and end notched flexure tests. This study shows the potential of solitary wave-based detection of weak bonds for hot spot monitoring of composite-based structures.

  16. Comparison of the microtensile bond strength of different composite core materials and bonding systems to a fiber post (DT Light

    Directory of Open Access Journals (Sweden)

    Lelya Sadighpour

    2013-10-01

    Full Text Available   Background and Aims: Retention and stability of the post and core system is the key factor for success of final restoration . The aim of this study was to evaluate the microtensile bond strength of the different composite core materials and bonding systems to a fiber post.   Materials and Methods: To evaluate the bond strength of the composite resins to a fiber post ( DT light post 60 posts were divided into six groups : group A: Heliomolar Flow + Seal Bond, group B: Heliomolar Flow + SE Bond , group C: Valux Plus + Seal Bond , group D: Valux Plus + SE Bond , group E: Corecem + Seal Bond, group F: Corecem + SE Bond. All samples were thermocycled for 5000 cycles (5-55 0C and cut into four bars for the microtensile bond strength test. Failure modes were identified using a stereomicroscope. Data were analysed using One-way ANOVA and Tukey HSD post hoc test (P<0.05.   Results: The interaction between composite resin materials and bonding systems were positive. The conventional hybrid composite (Valux Plus had significantly higher bond strength compared with the core specific flowable composite (Corecem when Seal Bond was applied as bonding agent (P<0.05. However, when SE Bond was utilized hybrid composite demonstrated significantly lower bond strength than that of other two groups (P<0.05.   Conclusion: The performance of a particular composite is affected by the bonding system that is applied. A single composite resin may have different bond strength when combined with different bonding system.

  17. Automotive crashworthiness of adhesively bonded carbon fiber polymer composite structures

    Science.gov (United States)

    Jacob, George Chennakattu

    In passenger vehicles, the ability to absorb impact energy and be survivable for the occupant is called the "crashworthiness" of the structure. The ACC (Automotive Composite Consortium) has been and continues to be very interested in investigating the use of fiber-reinforced composites as crash energy absorbers. It would have been ideal if the composite structure to be used as a crash energy absorber were manufactured as an integral, monolithic component, but limitations in the present day manufacturing technology necessitate the presence of joints in composite structures. While many scientists have investigated the energy absorption characteristics in various fiber reinforced composite materials, there is no literature available on the energy absorption and crushing characteristics of these materials when they are used in a bonded structure. The influence of having a bonded joint within the crush zone of a composite structure has not been adequately characterized in the past. After reviewing the existing literature and based on our own work done in automotive crashworthiness studies it can be concluded that investigating the strain rate dependence of fiber reinforced polymer composites and bonded structures made from them are also very important since the amount of energy they absorb and their performance properties vary with loading rate. The above is the last stage in crashworthiness research, where in one would like to determine how best fiber composite structures can be bonded together in the pursuit of designing the most crashworthy adhesively bonded automotive composite structure. Hence, a comprehensive experimental methodology to analyze and design adhesively bonded automotive composite structures made of carbon fiber polymer composites to sustain axial, off-axis and lateral crash/impact loads is developed and strain rate effects on the crashworthiness of these bonded carbon fiber composite structures are studied. The experimental results from this work are

  18. Initial and fatigue bond strengths of nanofilled and conventional composite bonding adhesives.

    Science.gov (United States)

    BenGassem, Afnan A; Georgiou, George; Jones, Steven Peter

    2013-06-01

    To compare the initial and fatigue shear bond strengths of a nanofilled adhesive with a conventional light-cured adhesive in an ex vivo laboratory study. Fifty hydroxyapatite discs were prepared by cold pressing. Using a standardized bonding protocol, 100 Victory series upper left central incisor brackets were bonded to discs with Transbond™ Supreme LV nanofilled composite resin and 100 brackets were bonded to discs with Transbond XT. Fifty brackets from each group were subjected to cyclic loading (5000 cycles at 2 Hz) at 50% of the mean bond strength in a Dartec Series HC10 Testing Machine. Initial (unfatigued) and fatigued bond strengths were determined by applying a shear force at the bracket/substrate interface using a custom-made metal jig in an Instron Universal Testing Machine. RESULTS AND STATISTICAL ANALYSIS: One-way analysis of variance showed that Transbond Supreme LV exhibited higher initial mean bond strength than Transbond XT (P = 0·001). No statistically significant difference was found between the fatigue bond strengths of Transbond Supreme LV and Transbond XT (P = 0·323). Two-way analysis of variance demonstrated statistically significant differences when the effect of the composite resin (P = 0·013) and fatigue (P = 0·017) were considered individually. However, when considered in combination there was no statistical significance (P = 0·09). Kaplan-Meier survival analysis showed superior survival of unfatigued brackets with Transbond Supreme LV, but there was no significant difference between the adhesives after fatiguing. The initial bond strength of Transbond Supreme LV was significantly higher than Transbond XT, while the fatigue bond strengths of both resins were comparable. Overall, Transbond Supreme LV demonstrated superior survival under loading than Transbond XT. However, while this was statistically significant for the initial loading, it was not significant after fatiguing. Although these laboratory findings are

  19. Quantitative Percussion Diagnostics For Evaluating Bond Integrity Between Composite Laminates

    Science.gov (United States)

    Poveromo, Scott Leonard

    Conventional nondestructive testing (NDT) techniques used to detect defects in composites are not able to determine intact bond integrity within a composite structure and are costly to use on large and complex shaped surfaces. To overcome current NDT limitations, a new technology was utilized based on quantitative percussion diagnostics (QPD) to better quantify bond quality in fiber reinforced composite materials. Experimental results indicate that this technology is capable of detecting 'kiss' bonds (very low adhesive shear strength), caused by the application of release agents on the bonding surfaces, between flat composite laminates bonded together with epoxy adhesive. Specifically, the local value of the loss coefficient determined from quantitative percussion testing was found to be significantly greater for a release coated panel compared to that for a well bonded sample. Also, the local value of the probe force or force returned to the probe after impact was observed to be lower for the release coated panels. The increase in loss coefficient and decrease in probe force are thought to be due to greater internal friction during the percussion event for poorly bonded specimens. NDT standards were also fabricated by varying the cure parameters of an epoxy film adhesive. Results from QPD for the variable cure NDT standards and lap shear strength measurements taken of mechanical test specimens were compared and analyzed. Finally, experimental results have been compared to a finite element analysis to understand the visco-elastic behavior of the laminates during percussion testing. This comparison shows how a lower quality bond leads to a reduction in the percussion force by biasing strain in the percussion tested side of the panel.

  20. Microshear bond strength between restorative composites and resin cements

    OpenAIRE

    Rubens Nazareno GARCIA; Góes,Mário Fernando de; Giannini,Marcelo

    2008-01-01

    Introduction and objective: The techniques of adhesive cementationhave been widely used in dental restoration. The purpose of this studywas to evaluate the microshear bond strength between restorativecomposites and resin cements. Material and methods: Twenty composites blocks were prepared in order to obtain a flat surface, using 600-grid sandpaper. The samples were randomly divided in four groups(n=15) according to the experimental groups: [1] Z250 block + Single Bond + cylinder of RelyX ARC...

  1. Evaluation of Shear Bond Strength of Orthodontic Brackets Bonded with Nano-filled Composites

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    Mohammad Sadegh Ahmad Akhoundi

    2013-01-01

    Full Text Available Objectives: The purpose of this study was to evaluate the shear bond strength (SBS of orthodontic brackets bonded with two types of nano-composites in comparison to a conventional orthodontic composite. Materials and Methods: Sixty extracted human first premolars were randomly divided into 3 groups each containing 20 teeth. In group I, a conventional orthodontic composite (Transbond XT was used to bond the brackets, while two nano-composites (Filtek TM Supreme XT and AELITE Aesthetic Enamel were used in groups II and III respectively. The teeth were stored in distilled water at 37°C for 24 hours, thermocycled in distilled water and debonded with a universal testing machine at a crosshead speed of 1 mm/min. The adhesive remnant index (ARI was also evaluated using a stereomicroscope. Results: AELITE Aesthetic Enamel nano-composite revealed a SBS value of 8.44±2.09 MPa, which was higher than Transbond XT (6.91± 2.13 and Filtek TM Supreme XT (6.04± 2.01. Statistical analysis revealed a significant difference between groups II and III (P 0.05. Evaluation of ARI showed that Transbond XT left fewer adhesive remains on teeth after debonding. Conclusion: Results of this study indicate that the aforementioned nano-composites can be successfully used for bonding orthodontic brackets.

  2. ADHESIVE SYSTEM AFFECTS REPAIR BOND STRENGTH OF RESIN COMPOSITE

    Directory of Open Access Journals (Sweden)

    Özgür IRMAK

    2017-10-01

    Full Text Available Purpose: This study evaluated the effects of different adhesive systems on repair bond strength of aged resin composites. Materials and Methods: Ninety composite discs were built and half of them were subjected to thermal aging. Aged and non-aged specimens were repaired with resin composite using three different adhesive systems; a two-step self-etch adhesive, a two-step total-etch adhesive and a one-step self-etch adhesive; then they were subjected to shear forces. Data were analyzed statistically. Results: Adhesive type and aging significantly affected the repair bond strengths (p<0.0001. No statistical difference was found in aged composite groups repaired with two-step self- etch or two-step total-etch adhesive. One-step self-etch adhesive showed lower bond strength values in aged composite repair (p<0.0001. Conclusion: In the repair of aged resin composite, two-step self-etch and two-step total-etch adhesives exhibited higher shear bond strength values than that of one-step self-etch adhesive.

  3. Immediate bonding effectiveness of contemporary composite cements to dentin.

    Science.gov (United States)

    Sarr, Mouhamed; Mine, Atsushi; De Munck, Jan; Cardoso, Marcio Vivan; Kane, Abdoul Wakhabe; Vreven, José; Van Meerbeek, Bart; Van Landuyt, Kirsten L

    2010-10-01

    The objective of this study was to compare the one-week bonding effectiveness of nine contemporary composite cements used to lute ceramic to dentin and to determine an appropriate processing method for pretesting failures. The microtensile bond strengths (µTBS) of different luting agents including five self-adhesive cements (Unicem, 3 M ESPE; Maxcem, Kerr; Monocem, Shofu; G-Cem, GC; and Multilink Sprint, Ivoclar-Vivadent), two self-etch cements (Panavia F2.0 and Clearfil Esthetic Cement, Kuraray), and two etch-and-rinse cements (Calibra, Dentsply, and Variolink II, Ivoclar-Vivadent) were measured using a standardized protocol. As control, a two-step self-etch adhesive combined with a restorative composite (Clearfil SE+Clearfil APX, Kuraray) were included as luting material. Depending on the processing of the pretesting failures, two groups of cements could be distinguished: (1) those with low bond strength and many pretesting failures and (2) those with relatively high bond strength and few pretesting failures. Nevertheless, the control luting procedure involving a self-etch adhesive combined with a restorative composite presented with a significantly higher µTBS. The µTBS was clearly product-dependent rather than being dependent on the actual adhesive approach. Fracture analysis indicated that failure usually occurred at the dentin-cement interface especially for the cements with low bond strength and many pretesting failures. Depending on the cement system, an adequate immediate ceramic-to-dentin bond strength can be obtained, even with self-adhesive cements that do not use a separate dental adhesive. Yet, the self-etch adhesive Clearfil SE combined with the restorative composite revealed a superior bonding performance and should therefore be preferred in clinical situations where the restoration transmits light sufficiently.

  4. Comparison of the shear bond strength of orthodontic brackets bonded using silorane base and metacrylate base composite

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    Abdolrahim Davari

    2015-07-01

    Full Text Available Background and Aims: Orthodontic bracket failure during treatment is a common problem. With the introduction of low shrinkage composites the question is that whether: this sufficient has coefficient bond strength for bonding bracket during orthodontic treatment. The aim of this study was to compare the shear bond strength (SBS of silorane-based and metacrylate-based composites to metal brackets.   Materials and Methods: 30 human premolar teeth were collected and divided into 2 groups. In group 1, 15 orthodontic brackets were bonded using silorane-based composite, in group 2, 15 orthodontic brackets were bonded using metacrylate-based composite. The shear bond strength of each specimen was determined in an Instron machine. Amount of residual adhesive remaining on each tooth was evaluated using a stereomicroscope. Data were analyzed using T-test to compare the shear bond strength between groups and LSD method to compare the Adhesive Remnant Index (ARI scores.   Results: There was significant difference in the SBS between the test groups (P<0.001. The mean bond strength of bonding brackets to silorane-based composite was (42.42 ± 7.03 MPa, and the mean bond strength of bonding brackets metacrylate-based composite was (21.08±2.97 MPa. No significant difference in the ART was found between groups (P=0.66.   Conclusion: Silorane-based composite provided higher bond strength to orthodontic metal brackets.

  5. Nonlinear Analysis of Bonded Composite Single-LAP Joints

    Science.gov (United States)

    Oterkus, E.; Barut, A.; Madenci, E.; Smeltzer, S. S.; Ambur, D. R.

    2004-01-01

    This study presents a semi-analytical solution method to analyze the geometrically nonlinear response of bonded composite single-lap joints with tapered adherend edges under uniaxial tension. The solution method provides the transverse shear and normal stresses in the adhesive and in-plane stress resultants and bending moments in the adherends. The method utilizes the principle of virtual work in conjunction with von Karman s nonlinear plate theory to model the adherends and the shear lag model to represent the kinematics of the thin adhesive layer between the adherends. Furthermore, the method accounts for the bilinear elastic material behavior of the adhesive while maintaining a linear stress-strain relationship in the adherends. In order to account for the stiffness changes due to thickness variation of the adherends along the tapered edges, their in-plane and bending stiffness matrices are varied as a function of thickness along the tapered region. The combination of these complexities results in a system of nonlinear governing equilibrium equations. This approach represents a computationally efficient alternative to finite element method. Comparisons are made with corresponding results obtained from finite-element analysis. The results confirm the validity of the solution method. The numerical results present the effects of taper angle, adherend overlap length, and the bilinear adhesive material on the stress fields in the adherends, as well as the adhesive, of a single-lap joint

  6. Prediction of fracture toughness and durability of adhesively bonded composite joints with undesirable bonding conditions

    Science.gov (United States)

    Musaramthota, Vishal

    Advanced composite materials have enabled the conventional aircraft structures to reduce weight, improve fuel efficiency and offer superior mechanical properties. In the past, materials such as aluminum, steel or titanium have been used to manufacture aircraft structures for support of heavy loads. Within the last decade or so, demand for advanced composite materials have been emerging that offer significant advantages over the traditional metallic materials. Of particular interest in the recent years, there has been an upsurge in scientific significance in the usage of adhesively bonded composite joints (ABCJ's). ABCJ's negate the introduction of stress risers that are associated with riveting or other classical techniques. In today's aircraft transportation market, there is a push to increase structural efficiency by promoting adhesive bonding to primary joining of aircraft structures. This research is focused on the issues associated with the durability and related failures in bonded composite joints that continue to be a critical hindrance to the universal acceptance of ABCJ's. Of particular interest are the short term strength, contamination and long term durability of ABCJ's. One of the factors that influence bond performance is contamination and in this study the influence of contamination on composite-adhesive bond quality was investigated through the development of a repeatable and scalable surface contamination procedure. Results showed an increase in the contaminant coverage area decreases the overall bond strength significantly. A direct correlation between the contaminant coverage area and the fracture toughness of the bonded joint was established. Another factor that influences bond performance during an aircraft's service life is its long term strength upon exposure to harsh environmental conditions or when subjected to severe mechanical loading. A test procedure was successfully developed in order to evaluate durability of ABCJ's comprising severe

  7. Evaluation of adhesively bonded composites by nondestructive techniques

    Science.gov (United States)

    Malinowski, Paweł H.; Ecault, Romain; Wandowski, Tomasz; Ostachowicz, Wiesław M.

    2017-04-01

    Composite materials are commonly used in many branches of industry. One method to join or repair CFRP parts is by the use adhesive bonding. There is a search of effective methods for pre-bond assessment of bonded parts and post-bond inspection. Research reported here focuses on post-bond inspection of bonded CFRP plates. In this paper we reported results of two methods. We used noncontact ultrasonic testing (UT) technique as reference method. Ultrasonic testing was made in an immersion tank using phased-array probes. The second method was the electromechanical impedance (EMI). A piezoelectric sensors were surface mounted on each of the samples. Due to piezoelectric effect the electrical response of the sensor is related to mechanical response of the structure to which the sensors is bonded to. Measurements were conducted using HIOKI Impedance Analyzer IM3570. In order to perform a detailed study three samples of each kind were tested. There were three reference samples. The samples with modified adhesive bonds had three levels of severity, so there were three samples with each level of modification. The ultrasonic testing was focused on C-scan analysis taking into consideration the amplitude and time of flight (TOF). Two probes were used, one with 5 MHz frequency, second with 10 MHz. The EMI spectra were gathered up to 5 MHz and they were processed with signal processing algorithms in order to extract differences between reference samples and samples with modified bonds. The UT results provided relevant information about the investigated samples, while the EMI showed sensitivity to the level of adhesive bond modification.

  8. Bond strength of composite resin to enamel: assessment of two ethanol wet-bonding techniques.

    Directory of Open Access Journals (Sweden)

    Maryam Khoroushi

    2014-04-01

    Full Text Available Ethanol wet-bonding (EWB technique has been stated to decrease degradation of resin-dentin bond. This study evaluated the effect of two EWB techniques on composite resin-to-enamel bond strength.Silicon carbide papers were used to produce flat enamel surfaces on the buccal faces of forty-five molars. OptiBond FL (OFL adhesive was applied on enamel surfaces in three groups of 15 namely: Enamel surface and OFL (control;Protocol 1 of the EWB technique: absolute ethanol was applied to water-saturated acid-etched enamel surfaces for 1 minute before the application of ethanol-solvated hydrophobic adhesive resin of OFL 3 times;Protocol 2: progressive ethanol replacement; water was gradually removed from the enamel matrix using ascending ethanol concentrations before OFL application. Composite build-ups were made and the specimens were stored for 24 hours at 37°C and 100% relative humidity. Shear bond strength test was performed using a universal testing machine at 1 mm/min crosshead speed. Fracture patterns were evaluated microscopically. Data were analyzed with one-way ANOVA and Fisher's exact test (α=0.05.There were no significant differences in bond strength between the groups (P=0.73. However, regarding failure patterns, the highest cohesive enamel fractures were recorded in groups 2 and 3.In this study, although both methods of EWB did not influence immediate bond strength of composite resin to enamel, the majority of failure patterns occurred cohesively in enamel.

  9. Laser Surface Preparation for Adhesive Bonding of Aerospace Structural Composites

    Science.gov (United States)

    Belcher, M. A.; Wohl, C. J.; Hopkins, J. W.; Connell, J. W.

    2010-01-01

    Adhesive bonds are critical to the integrity of built-up structures. Disbonds can often be detected but the strength of adhesion between surfaces in contact is not obtainable without destructive testing. Typically the number one problem in a bonded structure is surface contamination, and by extension, surface preparation. Standard surface preparation techniques, including grit blasting, manual abrasion, and peel ply, are not ideal because of variations in their application. Etching of carbon fiber reinforced plastic (CFRP) panels using a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser appears to be a highly precise and promising way to both clean a composite surface prior to bonding and provide a bond-promoting patterned surface akin to peel ply without the inherent drawbacks from the same (i.e., debris and curvature). CFRP surfaces prepared using laser patterns conducive to adhesive bonding were compared to typical pre-bonding surface treatments through optical microscopy, contact angle goniometry, and post-bonding mechanical testing.

  10. Influence of the temperature on the composites' fusion bonding quality

    Science.gov (United States)

    Harkous, Ali; Jurkowski, Tomasz; Bailleul, Jean-Luc; Le Corre, Steven

    2017-10-01

    Thermoplastic composite parts are increasingly used to replace metal pieces in automotive field due to their mechanical properties, chemical properties and recycling potential [1]. To assemble and give them new mechanical functions, fusion bonding is often used. It is a type of welding carried out at a higher temperature than the fusion one [2]. The mechanical quality of the final adhesion depends on the process parameters like pressure, temperature and cycle time [3]. These parameters depend on two phenomena at the origin of the bonding formation: intimate contact [4] and reptation and healing [5]. In this study, we analyze the influence of the temperature on the bonding quality, disregarding in this first steps the pressure influence. For that, two polyamide composite parts are welded using a specific setup. Then, they undergo a mechanical test of peeling in order to quantify the adhesion quality.

  11. Bond strength of resin composite to differently conditioned amalgam

    NARCIS (Netherlands)

    Ozcan, M; Vallittu, PK; Huysmans, MC; Kalk, W; Vahlberg, T

    Bulk fracture of teeth, where a part of the amalgam restoration and/or the cusp is fractured, is a common clinical problem. The aim of this study was to evaluate the effect of different surface conditioning methods on the shear bond strength of a hybrid resin composite to fresh amalgam. Amalgams (N

  12. Amalgam stained dentin: a proper substrate for bonding resin composite?

    NARCIS (Netherlands)

    Scholtanus, J.D.

    2016-01-01

    Nowadays the use of dental amalgam is mostly abandoned and substituted by tooth colored resin composites that can be bonded to teeth tissues by adhesive techniques. The aim of this thesis was to find out whether dark stained dentin, as often observed after removal of amalgam restorations and

  13. Adhesively bonded single lap joint of composites

    Directory of Open Access Journals (Sweden)

    Peter Alvarado Prieto

    2013-09-01

    Full Text Available A study of single lap joints of composite materials with and without attachments is presented. Failure of this type of joint is caused by the high peel stress in a perpendicular direction presented in the geometric singularity. It is shown that the joint strength is affected by factors such as surface preparation, the adhesive curing process and cleaning. The two configurations, with and without attachments, are compared. It is shown that the single lap joint with attachment has a higher strength than the joint without attachments when no fillet is left on the geometrical singularity. However, because of the low increase in joint strength and the complexity of manufacturing, the choice of type of joint is left to the manufacturer's judgment.

  14. Bond durability of self-adhesive composite cements to dentine.

    Science.gov (United States)

    Suyama, Yuji; de Munck, Jan; Cardoso, Marcio Vivan; Yamada, Toshimoto; Van Meerbeek, Bart

    2013-10-01

    Clinically, the most easy-to-use composite cements are the so-called self-adhesive composite cements (SAC's). Hardly any data is however today available on the long-term bonding effectiveness of such luting composites. The purpose of this study was to evaluate the bond durability of different composite cements used to lute feldspathic ceramic blocks onto dentine. Four SAC's (Clearfil SA Cement, Kuraray; G-CEM, GC; SmartCem2, Dentsply; Unicem 3M ESPE), one 'self-etch' (Clearfil Esthetic Cement, Kuraray) and one 'etch-and-rinse' (Variolink ll, Ivoclar-Vivadent) multi-step composite cement were used to lute feldspathic ceramic blocks (Vita Mark II, Vita) onto dentine surfaces. Teeth were distributed randomly in 24 experimental groups according to two different surface-preparation techniques ('SMEAR-COVERED' versus 'SMEAR-FREE') and storage conditions ('IMMEDIATE' versus 'AGED'). Failure patterns were evaluated with a stereomicroscope, and afterwards imaged using Feg-SEM. Two additional specimens were processed for cement-dentine interfacial analysis using TEM. A linear mixed effects statistical model revealed significant differences for the variables 'composite cement', 'surface preparation' and 'ageing'. All self-adhesive composite cements, except Unicem (3M ESPE), did bond less favourably to fractured dentine. TEM revealed an ultra-structurally different interaction of the composite cements with 'SMEAR-COVERED' and 'SMEAR-FREE' dentine. All SAC's suffered most when luted to 'SMEAR-FREE' (fractured) dentine, fortunately of no clinical relevance and most likely due to enhanced water sorption through the open tubules. When luted to 'SMEAR-COVERED' dentine, all SACs appeared equally effective and durable as the 'etch-and-rinse' and 'self-etch' multi-step composite cements. Solely the SAC SmartCem2 (Dentsply) appeared clearly less favourable and consistent. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. ADHESIVE SYSTEM AFFECTS REPAIR BOND STRENGTH OF RESIN COMPOSITE

    OpenAIRE

    IRMAK, Özgür; Özge ÇELIKSÖZ; Begüm YILMAZ; Batu Can YAMAN

    2017-01-01

    Purpose: This study evaluated the effects of different adhesive systems on repair bond strength of aged resin composites. Materials and Methods: Ninety composite discs were built and half of them were subjected to thermal aging. Aged and non-aged specimens were repaired with resin composite using three different adhesive systems; a two-step self-etch adhesive, a two-step total-etch adhesive and a one-step self-etch adhesive; then they were subjected to shear forces. Data were analyzed stat...

  16. Effect of physicochemical aging conditions on the composite-composite repair bond strength

    NARCIS (Netherlands)

    Brendeke, Johannes; Ozcan, Mutlu

    2007-01-01

    Purpose: This study evaluated the effect of different physicochemical aging methods and surface conditioning techniques on the repair bond strength of composite. It was hypothesized that the aging conditions would decrease the repair bond strength and surface conditioning methods would perform

  17. The effects of internal tooth bleaching regimens on composite-to-composite bond strength.

    Science.gov (United States)

    Ferrari, Raphael; Attin, Thomas; Wegehaupt, Florian J; Stawarczyk, Bogna; Tauböck, Tobias T

    2012-12-01

    The authors conducted an in vitro study to investigate the influence of several internal bleaching regimens on the composite-to-composite shear bond strength of a dental core buildup material. The authors fabricated 72 specimens from a resin-based composite core buildup and assigned them randomly to six groups (four experimental and two control groups) (n = 12 per group), according to the following bleaching agents: sodium perborate mixed with distilled water (SP/W); sodium perborate mixed with 3 percent hydrogen peroxide (SP/HP-3); sodium perborate mixed with 30 percent hydrogen peroxide (SP/HP-30); 35 percent hydrogen peroxide (HP-35). After the 12-day bleaching procedures, the authors applied a calcium hydroxide dressing for two weeks. The two control groups consisted of unbleached specimens that either did not receive (C1) or did receive (C2) the calcium hydroxide dressing. The authors cleaned and silanized the resin-based composite specimens and coated them with an intermediate adhesive resin before applying fresh composite material. They measured composite surface roughness and shear bond strength and performed statistical analyses of the data. Unbleached specimens in groups C1 and C2 exhibited significantly lower composite-to-composite bond strength and significantly lower surface roughness than did specimens in groups SP/W and SP/HP-3. Bond strength in group HP-35 was significantly lower than that in group SP/W. Internal bleaching regimens that involve the use of sodium perborate mixed with water or 3 percent hydrogen peroxide might increase the composite-to-composite interfacial bond strength. None of the internal bleaching regimens in this study had an adverse effect on the composite-to-composite interfacial bond strength.

  18. Shear bond strength of composite resin to high performance polymer PEKK according to surface treatments and bonding materials.

    Science.gov (United States)

    Lee, Ki-Sun; Shin, Myoung-Sik; Lee, Jeong-Yol; Ryu, Jae-Jun; Shin, Sang-Wan

    2017-10-01

    The object of the present study was to evaluate the shear bonding strength of composite to PEKK by applying several methods of surface treatment associated with various bonding materials. One hundred and fifty PEKK specimens were assigned randomly to fifteen groups (n = 10) with the combination of three different surface treatments (95% sulfuric acid etching, airborne abrasion with 50 µm alumina, and airborne abrasion with 110 µm silica-coating alumina) and five different bonding materials (Luxatemp Glaze & Bond, Visio.link, All-Bond Universal, Single Bond Universal, and Monobond Plus with Heliobond). After surface treatment, surface roughness and contact angles were examined. Topography modifications after surface treatment were assessed with scanning electron microscopy. Resin composite was mounted on each specimen and then subjected to shear bond strength (SBS) test. SBS data were analyzed statistically using two-way ANOVA, and post-hoc Tukey's test (P<.05). Regardless of bonding materials, mechanical surface treatment groups yielded significantly higher shear bonding strength values than chemical surface treatment groups. Unlike other adhesives, MDP and silane containing self-etching universal adhesive (Single Bond Universal) showed an effective shear bonding strength regardless of surface treatment method. Mechanical surface treatment behaves better in terms of PEKK bonding. In addition, self-etching universal adhesive (Single Bond Universal) can be an alternative bonding material to PEKK irrespective of surface treatment method.

  19. Effect of mode of polymerization of bonding agent on shear bond strength of autocured resin composite luting cements.

    Science.gov (United States)

    Dong, Cecilia C S; McComb, Dorothy; Anderson, James D; Tam, Laura E

    2003-04-01

    There have been anecdotal reports of low bond strength with autocured resin composite materials, particularly when light-cured bonding agents that combine primer and adhesive in a 1-bottle preparation are used. The objective of this study was to determine if the mode of polymerization of the bonding agent influences the strength of the attachment of autocured resin composite luting cements to dentin. The shear bond strength of 2 resin luting cements, Calibra and RelyX ARC, polymerized by autocuring, in combination with 4 different bonding agents, Scotchbond Multipurpose Plus, Prime & Bond NT, IntegraBond and Single Bond, polymerized to bovine dentin by light-curing, autocuring or dual-curing, was determined. The pH of each bonding agent and its components was measured. Two-way analysis of variance was used to test the effect of cement and adhesive on shear bond strength. For each bonding agent, the adhesive variable combined the factors product brand and mode of polymerization. With significant interaction among the above variables, the least square means of the 16 combinations of resin cement and adhesive were compared. There was no consistent relationship between shear bond strength and mode of polymerization of the bonding agent. Significant differences in bond strength were specific to the proprietary brand of bonding agent. The pH of the bonding agent depends on the manufacturer's formulation, and low pH may contribute to low bond strength. The low in vitro bond strength occurring with some combinations of bonding agent and resin cement could be clinically significant.

  20. Defect assessment of bonded joints of composite tubes using shearography

    Science.gov (United States)

    Willemann, Daniel P.; Fantin, Analucia; Albertazzi Gonçalves, Armando, Jr.

    2010-09-01

    Composite materials tubes are being used in various industrial segments, including the oil and gas industry1. The union between adjacent composite tubes is often accomplished through adhesives, and thus the inspection for flaws in adhesive-bonded joints becomes crucial. In this context, tubes and elbows made of epoxy resin reinforced with glass fiber were assembled with adhesive in the Quick-Lock® 1 configuration forming loops (spools). During the assemblage of these loops, artificial defects (areas without adhesive or disbondings) were inserted in its joints to evaluate the capability of failure detection by shearography. This paper presents and discusses results obtained with shearography. Shearography demonstrated great potential for application in the adhesive-bonded joints inspection, as it detected all defects artificially inserted and also real defects present in the loops joints.

  1. Effect of Intermediate Agents and Preheated Composites on Repair Bond Strength of Silorane-Based Composites

    Directory of Open Access Journals (Sweden)

    Fereshteh Shafiei

    2016-05-01

    Full Text Available Objectives: Repairing composite restorations is a challenging procedure especially when two different types of composites are used. This study aimed to compare the repair strength of silorane-based composite (SC (Filtek P90 with that of preheated SC, methacrylate composite (MC(Z250, flowable MC (Filtek Supreme Plus and different adhesive/composite combinations.Materials and Methods: Eighty-four SC specimens were fabricated and randomly divided into seven groups (G. In the control group (G7, SC was bonded immediately to SC. The other specimens were water-aged for two months and were then roughened, etched and repaired with the following materials: G1 Silorane Adhesive Bond (SAB/SC;G2 Preheated SC; G3 SAB/MC; G4 Adper Single Bond (SB/MC; G5 Flowable MC/MC; G6 Preheated MC. After water storage and thermocycling, the repaired specimens were subjected to shear bond strength testing. The data were analyzed using ANOVA and Tukey’s test.Results: Preheated SC and MC, flowable MC and SAB/SC resulted in bond strength comparable to that of the control group. Preheated SC showed significantly higher bond strength when compared to SAB/MC (P=0.04 and SB/MC (P<0.001. Bond strength of SB/MC was significantly lower than that of the other groups (P<0.05, except for SAB/SC and SAB/MC.Conclusion: All repairing materials except for SB/MC resulted in bond strength values comparable to that of the control group. Repair with preheated SC yielded the highest bond strength. 

  2. Damage tolerance assessment of bonded composite doubler repairs for commercial aircraft applications

    Energy Technology Data Exchange (ETDEWEB)

    Roach, D.

    1998-08-01

    The Federal Aviation Administration has sponsored a project at its Airworthiness Assurance NDI Validation Center (AANC) to validate the use of bonded composite doublers on commercial aircraft. A specific application was chosen in order to provide a proof-of-concept driving force behind this test and analysis project. However, the data stemming from this study serves as a comprehensive evaluation of bonded composite doublers for general use. The associated documentation package provides guidance regarding the design, analysis, installation, damage tolerance, and nondestructive inspection of these doublers. This report describes a series of fatigue and strength tests which were conducted to study the damage tolerance of Boron-Epoxy composite doublers. Tension-tension fatigue and ultimate strength tests attempted to grow engineered flaws in coupons with composite doublers bonded to aluminum skin. An array of design parameters, including various flaw scenarios, the effects of surface impact, and other off-design conditions, were studied. The structural tests were used to: (1) assess the potential for interply delaminations and disbonds between the aluminum and the laminate, and (2) determine the load transfer and crack mitigation capabilities of composite doublers in the presence of severe defects. A series of specimens were subjected to ultimate tension tests in order to determine strength values and failure modes. It was demonstrated that even in the presence of extensive damage in the original structure (cracks, material loss) and in spite of non-optimum installations (adhesive disbonds), the composite doubler allowed the structure to survive more than 144,000 cycles of fatigue loading. Installation flaws in the composite laminate did not propagate over 216,000 fatigue cycles. Furthermore, the added impediments of impact--severe enough to deform the parent aluminum skin--and hot-wet exposure did not effect the doubler`s performance. Since the tests were conducting

  3. Immediate repair bond strengths of microhybrid, nanohybrid and nanofilled composites after different surface treatments

    NARCIS (Netherlands)

    Rinastiti, Margareta; Siswomihardjo, Widowati; Busscher, Henk J.; Ozcan, Mutlu

    Objectives: To evaluate immediate repair bond strengths and failure types of resin composites with and without surface conditioning and characterize the interacting composite surfaces by their surface composition and roughness. Methods: Microhybrid, nanohybrid and nanofilled resin composites were

  4. Bending Properties of Fiber-Reinforced Composites Retainers Bonded with Spot-Composite Coverage

    Directory of Open Access Journals (Sweden)

    Maria Francesca Sfondrini

    2017-01-01

    Full Text Available Orthodontic and periodontal splints are prepared with round or flat metallic wires. As these devices cannot be used in patients with allergy to metals or with aesthetic demands, fiber-reinforced composite (FRC retainers have been introduced. Stiffness of FRC materials could reduce physiologic tooth movement. In order to lower rigidity of conventional FRC retainers, a modified construction technique that provided a partial (spot composite coverage of the fiber has been tested and compared with metallic splints and full-bonded FRCs. Flat (Bond-a-Braid, Reliance Orthodontic Products and round (Penta-one 0155, Masel Orthodontics stainless steel splints, conventional FRC splints, and experimental spot-bonded FRC retainers (Everstick Ortho, StickTech were investigated. The strength to bend the retainers at 0.1 mm deflection and at maximum load was measured with a modified Frasaco model. No significant differences were reported among load values of stainless steel wires and experimental spot-bonded FRC retainers at 0.1 mm deflection. Higher strength values were recoded for conventional full-bonded FRCs. At maximum load no significant differences were reported between metallic splints (flat and round and experimental spot-bonded FRCs, and no significant differences were reported between spot- and full-bonded FRC splints. These results encourage further tests in order to evaluate clinical applications of experimental spot-bonded FRC retainers.

  5. Preliminary Validation of Composite Material Constitutive Characterization

    Science.gov (United States)

    John G. Michopoulos; Athanasios lliopoulos; John C. Hermanson; Adrian C. Orifici; Rodney S. Thomson

    2012-01-01

    This paper is describing the preliminary results of an effort to validate a methodology developed for composite material constitutive characterization. This methodology involves using massive amounts of data produced from multiaxially tested coupons via a 6-DoF robotic system called NRL66.3 developed at the Naval Research Laboratory. The testing is followed by...

  6. Shear bond strength of new self-adhesive flowable composite resins.

    Science.gov (United States)

    Wajdowicz, Michael N; Vandewalle, Kraig S; Means, Mark T

    2012-01-01

    Recently, new self-adhesive flowable composite resin systems have been introduced to the market. These new composite resin systems reportedly bond to dentin and enamel without the application of an adhesive bonding agent. The purpose of this study was to evaluate the shear bond strength to enamel of two new self-adhesive flowable composites with and without the use of an etch-and-rinse bonding agent. The new self-adhesive flowable composites had significantly lower bond strengths to enamel compared to a traditional adhesively bonded flowable composite. Both self-adhesive flowable composites had a significant increase in bond strength to enamel with the use of a phosphoric acid-etch and adhesive bonding agent.

  7. Numerical Characterization of a Composite Bonded Wing-Box

    Science.gov (United States)

    Smeltzer, Stanley S., III; Lovejoy, Andrew E.; Satyanarayana, Arunkumar

    2008-01-01

    The development of composite wing structures has focused on the use of mechanical fasteners to join heavily-loaded areas, while bonded joints have been used only for select locations. The focus of this paper is the examination of the adhesive layer in a generic bonded wing box that represents a "fastenerless" or unitized structure in order to characterize the general behavior and failure mechanisms. A global/local approach was applied to study the response of the adhesive layer using a global shell model and a local shell/solid model. The wing box was analyzed under load to represent a high-g up-bending condition such that the strains in the composite sandwich face sheets are comparable to an expected design allowable. The global/local analysis indicates that at these wing load levels the strains in the adhesive layer are well within the adhesive's elastic region, such that yielding would not be expected in the adhesive layer. The global/local methodology appears to be a promising approach to evaluate the structural integrity of the adhesively bonded structures.

  8. Bonding agensi za kompozitna raketna goriva / Bonding agents for composite rocket propellants

    Directory of Open Access Journals (Sweden)

    Mirjana Petrić

    2003-01-01

    Full Text Available U radu je analiziran uticaj bonding agensd na mehaničke karakteristike i viskozitet kompozitnih raketnih goriva na bazi hidroksiterminiranog polibutadiena i toluendiizocijanata, odnosno izoforondiizocijanata. Komparirana je efikasnost bonding agensd (BA različite strukture trietilentetramina (TET, tris-(2-metil aziridinil fosfin oksida (MAPO i N,N-di (2-hidroksietil-4,4-dimetilhidantoina (DHE. Efikasnost delovanja bonding agensa utvrdenaje na osnovu parametara dobijenih iz testa jednoosnog zatezanja uzoraka (σm - zatezna čvrstoća pri maksimalnoj sili, εm relativno izduženje pri maksimalnoj sili i εp - relativno izduženje pri prekidu. Mehaničke karakteristike merene su u temperaturskom području od -50°C do 50°C. Analiziran je uticaj BA na brzinu promene viskoziteta goriva. / The paper analyzes the effects of bonding agents on mechanical properties and viscosity of composite rocket propellants based on hydroxiterminated polybutadiene and toluendiizocyanate, i.e. izophorondiizocyanate. The efficiency of bonding agents (BA of different structure has been compared including triethylentetramine (TET, tris-(2-methyl azyrinidile phosphine oxide (MAPO and N, N-di (2-hydroxiethyl-4,4-dimethylhydantoine (DHE. The BA efficiency has been determined on the basis of parameters obtained by uniaxial tensile tests (σm - tensile strength at maximum force, εm - relative allongation at maximum force and εp - relative allongation at fracture. The mechanical properties have been measured at the temperature range from -50°C to 50°C. The BA effects on propellant viscosity change rates have been analyzed.

  9. Chemical composition, crystal structure, and their relationships with the intrinsic properties of spinel-type crystals based on bond valences.

    Science.gov (United States)

    Liu, Xiao; Wang, Hao; Lavina, Barbara; Tu, Bingtian; Wang, Weimin; Fu, Zhengyi

    2014-06-16

    Spinel-type crystals may possess complex and versatile chemical composition and crystal structure, which leads to difficulty in constructing relationships among the chemical composition, crystal structure, and intrinsic properties. In this work, we develop new empirical methods based on bond valences to estimate the intrinsic properties, namely, compressibility and thermal expansion of complex spinel-type crystals. The composition-weighted average of bond force constants in tetrahedral and octahedral coordination polyhedra is derived as a function of the composition-weighted average of bond valences, which can be calculated according to the experimental chemical composition and crystal structural parameters. We discuss the coupled effects of tetrahedral and octahedral frameworks on the aforementioned intrinsic properties. The bulk modulus could be quantitatively calculated from the composition-weighted average of bond force constants in tetrahedral and octahedral coordination polyhedra. In contrast, a quantitative estimation of the thermal expansion coefficient could be obtained from the composition-weighted average of bond force constants in octahedral coordination polyhedra. These empirical methods have been validated by the results obtained for a new complex quaternary spinel-type oxynitride Mg0.268Al2.577O3.733N0.267 as well as MgAl2O4 and Al2.85O3.45N0.55 from the literature. Further, these empirical methods have the potential to be extensively applied in other types of complex crystals.

  10. Validity of bond strength tests: A critical review: Part I

    Science.gov (United States)

    Sirisha, Kantheti; Rambabu, Tankonda; Shankar, Yalavarthi Ravi; Ravikumar, Pabbati

    2014-01-01

    Adhesive systems are selected based on their bond strengths achieved while testing in laboratories. These bond strengths can predict the longevity of a restoration to some extent. There were several discrepancies in the reported bond strengths. To critically review the reliability of macro-bond strength tests used to evaluate resin-tooth interface. Relevant literature published between January 1983 and May 2013 was collected from PubMed database, Google scholar, and hand-searched journals of Conservative Dentistry, Endodontics and Dental materials. Variables that influence the test outcome are categorized into substrate-related factors, factors related to specimen properties, preparation of specimens, and test methodology. Impact of these variables on the test outcome is critically analyzed. There is lack of a standard format for reporting the bond strength tests, which could lead to misinterpretation of the data and bonding abilities of adhesives. PMID:25125840

  11. Effect of different adhesion strategies on bond strength of resin composite to composite-dentin complex.

    Science.gov (United States)

    Özcan, M; Pekkan, G

    2013-01-01

    Service life of discolored and abraded resin composite restorations could be prolonged by repair or relayering actions. Composite-composite adhesion can be achieved successfully using some surface conditioning methods, but the most effective adhesion protocol for relayering is not known when the composite restorations are surrounded with dentin. This study evaluated the effect of three adhesion strategies on the bond strength of resin composite to the composite-dentin complex. Intact maxillary central incisors (N=72, n=8 per subgroup) were collected and the coronal parts of the teeth were embedded in autopolymerized poly(methyl tfr54methacrylate) surrounded by a polyvinyl chloride cylinder. Cylindrical cavities (diameter: 2.6 mm; depth: 2 mm) were opened in the middle of the labial surfaces of the teeth using a standard diamond bur, and the specimens were randomly divided into three groups. Two types of resin composite, namely microhybrid (Quadrant Anterior Shine; AS) and nanohybrid (Grandio; G), were photo-polymerized incrementally in the cavities according to each manufacturer's recommendations. The composite-enamel surfaces were ground finished to 1200-grit silicone carbide paper until the dentin was exposed. The surfaces of the substrate composites and the surrounding dentin were conditioned according to one of the following adhesion protocols: protocol 1: acid-etching (dentin) + silica coating (composite) + silanization (composite) + primer (dentin) + bonding agent (dentin + composite); protocol 2: silica coating (composite) + acid-etching (dentin) + silanization (composite) + primer (dentin) + bonding agent (dentin + composite); and protocol 3: acid-etching (dentin) + primer (dentin) + silanization (composite) + bonding agent (dentin + composite). Applied primer and bonding agents were the corresponding materials of the composite manufacturer. Silica coating (CoJet sand, 30 μm) was achieved using a chairside air-abrasion device (distance: 10 mm; duration

  12. Anisotropic thermal conductivity in epoxy-bonded magnetocaloric composites

    Science.gov (United States)

    Weise, Bruno; Sellschopp, Kai; Bierdel, Marius; Funk, Alexander; Bobeth, Manfred; Krautz, Maria; Waske, Anja

    2016-09-01

    Thermal management is one of the crucial issues in the development of magnetocaloric refrigeration technology for application. In order to ensure optimal exploitation of the materials "primary" properties, such as entropy change and temperature lift, thermal properties (and other "secondary" properties) play an important role. In magnetocaloric composites, which show an increased cycling stability in comparison to their bulk counterparts, thermal properties are strongly determined by the geometric arrangement of the corresponding components. In the first part of this paper, the inner structure of a polymer-bonded La(Fe, Co, Si)13-composite was studied by X-ray computed tomography. Based on this 3D data, a numerical study along all three spatial directions revealed anisotropic thermal conductivity of the composite: Due to the preparation process, the long-axis of the magnetocaloric particles is aligned along the xy plane which is why the in-plane thermal conductivity is larger than the thermal conductivity along the z-axis. Further, the study is expanded to a second aspect devoted to the influence of particle distribution and alignment within the polymer matrix. Based on an equivalent ellipsoids model to describe the inner structure of the composite, numerical simulation of the thermal conductivity in different particle arrangements and orientation distributions were performed. This paper evaluates the possibilities of microstructural design for inducing and adjusting anisotropic thermal conductivity in magnetocaloric composites.

  13. Effect of Sandblasting on Shear Bond Strength Composite Resin Veneer

    Directory of Open Access Journals (Sweden)

    Octarina Octarina

    2013-07-01

    Full Text Available Attachment between restoration and enamel surface in indirect resin composite veneer restoration (IRCV is obtained using multi-step (MS resin cement. Recently, a one step self-adhesive dual-cured resin cement (SADRC was introduced. Objective: To determine the effect of sandblasting on shear bond strength (SBS of IRCV to enamel using MS resin cement and SADRC. Methods: Forty specimens of buccal surface of enamel human were light-cured in Solidilite chamber and were divided into two groups: IRCV without sandblasting (n=20 and with sandblasting for 10 seconds (n=20 and then bonded to enamel using MS (n=10 and SADRC (n=10, respectively. After 24h SBS of specimens were tested using a Universal Testing Machine. Data were analyzed statistically by one-way ANOVA. Results: The average SBS value of IRCV without SB and bonded with MS was 18.95+7.80MPa and MS with SB was 19.30+ SB (4.85+2.12MPa and SADRC with SB (9.57+3.45MPa(p<0.05. Conclusion: increased SBS VIRK to enamel using MS resin cement than SADRC.  

  14. Bonding of glass ceramic and indirect composite to non-aged and aged resin composite.

    Science.gov (United States)

    Gresnigt, Marco; Özcan, Mutlu; Muis, Maarten; Kalk, Warner

    2012-02-01

    Since adhesion of the restorative materials to pre-polymerized or aged resin composites presents a challenge to the clinicians, existing restorations are often removed and remade prior to cementation of fixed dental prostheses (FDPs). This study evaluated bond strength of non-aged and aged resin composite to an indirect resin composite and pressed glass ceramic using two resin cements. Disk-shaped specimens (diameter: 3.5, thickness: 3 mm) (N = 160) produced from a microhybrid resin composite (Quadrant Anterior Shine) were randomly divided into eight groups. While half of the specimens were kept dry at 37°C for 24 h, the other half was aged by means of thermocycling (6000 times, 5°C to 55°C). The non-aged and aged resin composites were bonded to a highly filled indirect composite (Estenia) and a pressed glass ceramic (IPS Empress II) using either a photopolymerizing (Variolink Veneer) or a dual-polymerizing (Panavia F2.0) resin cement. While cementation surfaces of both the direct and indirect composite materials were silica coated (30 µm SiO2, CoJet-Sand) and silanized (ESPE-Sil), ceramic surfaces were conditioned with hydrofluoric acid (20 s), neutralized, and silanized prior to cementation. All specimens were cemented under a load of 750 g. Shear force was applied to the adhesive interface in a universal testing machine (1 mm/min). Failure types of the specimens were identified after debonding. Significant effects of aging (p cement type (p cements showed no significant difference (p > 0.05). Both indirect composite (24.3 ± 5.1 MPa) and glass ceramic in combination with Variolink (22 ± 9 MPa) showed the highest results on non-aged composites, but were not significantly different from one another (p > 0.05). On the aged composites, indirect composite and glass ceramic showed no significant difference in bond strength within each material group (p > 0.05), with both Panavia (17.2 ± 6 and 15 ± 5.5 MPa, respectively) and Variolink (19 ± 8, 12.8 ± 5.3 MPa

  15. Bonding of Glass Ceramic and Indirect Composite to Non-aged and Aged Resin Composite

    NARCIS (Netherlands)

    Gresnigt, Marco; Ozcan, Mutlu; Muis, Maarten; Kalk, Warner

    2012-01-01

    Purpose: Since adhesion of the restorative materials to pre-polymerized or aged resin composites presents a challenge to the clinicians, existing restorations are often removed and remade prior to cementation of fixed dental prostheses (FDPs). This study evaluated bond strength of non-aged and aged

  16. Bond strength durability of direct and indirect composite systems following surface conditioning for repair

    NARCIS (Netherlands)

    Passos, Sheila Pestana; Ozcan, Mutlu; Vanderlei, Aleska Dias; Leite, Fabiola Pessoa Pereira; Kimpara, Estevao Tomomitsu; Bottino, Marco Antonio

    2007-01-01

    Purpose: This study evaluated the effect of surface conditioning methods and thermocycling on the bond strength between a resin composite and an indirect composite system in order to test the repair bond strength. Materials and Methods: Eighteen blocks (5 x 5 x 4 mm) of indirect resin composite

  17. Adhesive Characterization and Progressive Damage Analysis of Bonded Composite Joints

    Science.gov (United States)

    Girolamo, Donato; Davila, Carlos G.; Leone, Frank A.; Lin, Shih-Yung

    2014-01-01

    The results of an experimental/numerical campaign aimed to develop progressive damage analysis (PDA) tools for predicting the strength of a composite bonded joint under tensile loads are presented. The PDA is based on continuum damage mechanics (CDM) to account for intralaminar damage, and cohesive laws to account for interlaminar and adhesive damage. The adhesive response is characterized using standard fracture specimens and digital image correlation (DIC). The displacement fields measured by DIC are used to calculate the J-integrals, from which the associated cohesive laws of the structural adhesive can be derived. A finite element model of a sandwich conventional splice joint (CSJ) under tensile loads was developed. The simulations indicate that the model is capable of predicting the interactions of damage modes that lead to the failure of the joint.

  18. Retention of Resin Composite CAM Crowns Following Different Bonding Protocols

    Science.gov (United States)

    Nejat, Amir Hossein

    Objectives: Resin composite CAM materials offer more efficient milling, however, there is a high incidence of clinical debonding when this material is used for full-coverage crowns. The aim of the present study is to evaluate the effect of different surface treat-ments and primers on the crown retention of a new resin composite CAM material. Methods: 120 molars were prepared with a 24 degree taper, 1.5mm height, and axial walls in dentin. Surface area was measured by digital microscopy and preparations were scanned with an intraoral scanner. Crowns were milled from an experimental com-posite material with 4mm occlusal height. Teeth were randomly allocated to 12 groups (n= 10) based on the possible combinations of three surface treatments (Control, Alumina air abrasion [50mum Al2O3 at 0.28MPa], Hydrofluoric acid etch [5% HF acid for 20 sec]), silane application (with or without Kerr Silane), and adhesive application (with or without Optibond XTR adhesive). Optibond XTR adhesive was applied to the tooth preparations and crowns were bonded with MaxCem Elite. Crowns were fatigued for 100,000 cycles at 100N in water. Crowns were debonded in tension in a universal testing machine at 1mm/min. Crown retention strength (maximum load/area of preparation) was analyzed using a three-way ANOVA with Tukey's post-hoc tests. Results: Surface treatment, silane and adhesive applications independently affect the retention force (pResin composite crowns should be alumina particle abraded and coated with silane and adhesive.

  19. Shear Bond Strength between Fiber-Reinforced Composite and Veneering Resin Composites with Various Adhesive Resin Systems.

    Science.gov (United States)

    AlJehani, Yousef A; Baskaradoss, Jagan K; Geevarghese, Amrita; AlShehry, Marey A; Vallittu, Pekka K

    2016-07-01

    The aim of this research was to evaluate the shear bond strength of different laboratory resin composites bonded to a fiber-reinforced composite substrate with some intermediate adhesive resins. Mounted test specimens of a bidirectional continuous fiber-reinforced substrate (StickNet) were randomly assigned to three equal groups. Three types of commercially available veneering resin composites - BelleGlass®, Sinfony®, and GC Gradia® were bonded to these specimens using four different adhesive resins. Half the specimens per group were stored for 24 hours; the remaining were stored for 30 days. There were 10 specimens in the test group (n). The shear bond strengths were calculated and expressed in MPa. Data were analyzed statistically, and variations in bond strength within each group were additionally evaluated by calculating the Weibull modulus. Shear bond values of those composites are influenced by the different bonding resins and different indirect composites. There was a significant difference in the shear bond strengths using different types of adhesive resins (p = 0.02) and using different veneering composites (p veneering composite to bidirectional continuous fiber-reinforced substrate is influenced by the brand of the adhesive resin and veneering composite. © 2015 by the American College of Prosthodontists.

  20. A New Material Model for 2D FE Analysis of Adhesively Bonded Composite Joints

    Directory of Open Access Journals (Sweden)

    Libin ZHAO

    2014-12-01

    Full Text Available Effective and convenient stress analysis techniques play important roles in the analysis and design of adhesively bonded composite joints. A new material model is presented at the level of composite ply according to the orthotropic elastic mechanics theory and plane strain assumption. The model proposed has the potential to reserve nature properties of laminates with ply-to-ply modeling. The equivalent engineering constants in the model are obtained only by the material properties of unidirectional composites. Based on commercial FE software ABAQUS, a 2D FE model of a single-lap adhesively bonded joint was established conveniently by using the new model without complex modeling process and much professional knowledge. Stress distributions in adhesive were compared with the numerical results by Tsai and Morton and interlaminar stresses between adhesive and adherents were compared with the results from a detailed 3D FE analysis. Good agreements in both cases verify the validity of the proposed model. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.5960

  1. Comparative evaluation of shear bond strength of composite resin bonded to acid etched or Nd:Yag lased enamel

    Directory of Open Access Journals (Sweden)

    Mridula Goswami

    2011-01-01

    Full Text Available Aims: In vitro evaluation of the shear bond strength of composite resin bonded to enamel which is pretreated using acid etchant or pulsed Nd:YAG. Qualitative morphological changes in enamel surfaces were observed under a scanning electron microscope (SEM. Materials and Methods: 60 extracted human teeth were divided in two groups of 30 each (Groups A and B. In Group A, prepared surface of enamel was etched using 35% phosphoric acid (Scotchbond, 3M. In Group B, enamel was surface treated by a surgical Nd:YAG laser beam (Medilas 4060 Fibertom at 0.8 W, 10 Hz, for 10 s with 80 mJ/pulse power. Bonding agent (single bond dental adhesive, 3M was applied over the test areas on 20 samples of Groups A and B each, and light cured. Composite resin (Z 100, 3M was applied onto the test areas as a 3 mm diameter cylinder, and light cured. The samples were tested for shear bond strength. Remaining 10 samples from each group were observed under SEM for morphological changes. Results: The mean shear bond strength was 20.00 MPa (΁ 1.93 and 13.28 MPa (΁1.97 for Group A and B, respectively. The difference in mean values was statistically significant between Groups A and B (P<0.001. Under SEM, Group A showed typical honeycomb appearance and Group B showed bubble-like cavities. Conclusions: In enamel, acid etch technique showed higher shear bond strength.

  2. Comparison of Shear Bond Strength of Composite to Stainless Steel Crowns Using Two Mechanical Surface Treatments and Two Bonding Systems.

    Science.gov (United States)

    Ghadimi, Sara; Heidari, Alireza; Sarlak, Hamid

    2016-01-01

    This study aimed to compare the shear bond strength (SBS) of composite to stainless steel crowns (SSC) using two mechanical surface treatments (MSTs) and two bonding systems. Eighty-four SSCs were divided into six groups of 14; Group1: No MST+Scotchbond Universal adhesive (N+U), Group 2: Surface roughening by a diamond bur+Scotchbond Universal adhesive (R+U), Group 3: Sandblasting+Scotchbond Universal adhesive (S+U), Group 4: No MST+Alloy Primer+Clearfil SE Primer and Bond (N+A), Group 5: Surface roughening by a diamond bur+Alloy Primer+Clearfil SE Primer and Bond (R+A), Group 6: Sandblasting+Alloy Primer+Clearfil SE Primer and Bond (S+A). After MST and bonding procedure, composite cylinders were bonded to the lingual surface of SSCs, then the SBS of composite to SSCs was measured using a universal testing machine following thermocycling. The SBS of groups R+U and S+U was significantly higher than that of group N+U. No significant difference was noted in SBS of groups R+U and S+U. The SBS of group S+A was significantly higher than that of groups N+A and R+A. No significant difference was noted in the SBS of groups N+A and R+A (P>0.05). In Scotchbond Universal adhesive groups, sandblasting and surface roughening by diamond bur significantly increased the SBS of composite to SSCs compared to no MST. In Alloy Primer groups, sandblasting significantly increased the SBS of composite to SSC compared to surface roughening with diamond bur and no MST.

  3. Comparison of Shear Bond Strength of Composite to Stainless Steel Crowns Using Two Mechanical Surface Treatments and Two Bonding Systems

    Directory of Open Access Journals (Sweden)

    Sara Ghadimi

    2016-08-01

    Full Text Available Objectives: This study aimed to compare the shear bond strength (SBS of composite to stainless steel crowns (SSC using two mechanical surface treatments (MSTs and two bonding systems.Materials and Methods: Eighty-four SSCs were divided into six groups of 14; Group1: No MST+Scotchbond Universal adhesive (N+U, Group 2: Surface roughening by a diamond bur+Scotchbond Universal adhesive (R+U, Group 3: Sandblasting+Scotchbond Universal adhesive (S+U, Group 4: No MST+Alloy Primer+Clearfil SE Primer and Bond (N+A, Group 5: Surface roughening by a diamond bur+Alloy Primer+Clearfil SE Primer and Bond (R+A, Group 6: Sandblasting+Alloy Primer+Clearfil SE Primer and Bond (S+A. After MST and bonding procedure, composite cylinders were bonded to the lingual surface of SSCs, then the SBS of composite to SSCs was measured using a universal testing machine following thermocycling.Results: The SBS of groups R+U and S+U was significantly higher than that of group N+U. No significant difference was noted in SBS of groups R+U and S+U. The SBS of group S+A was significantly higher than that of groups N+A and R+A. No significant difference was noted in the SBS of groups N+A and R+A (P>0.05.Conclusions: In Scotchbond Universal adhesive groups, sandblasting and surface roughening by diamond bur significantly increased the SBS of composite to SSCs compared to no MST. In Alloy Primer groups, sandblasting significantly increased the SBS of composite to SSC compared to surface roughening with diamond bur and no MST.

  4. Effect of universal adhesive etching modes on bond strength to dual-polymerizing composite resins.

    Science.gov (United States)

    Michaud, Pierre-Luc; Brown, Matthew

    2017-09-26

    Information is lacking as to the effect on bond strength of the etching modes of universal adhesives when they are used to bond dual-polymerizing composite resins to dentin. The purpose of this in vitro study was to investigate the bonding of dual-polymerizing foundation composite resins to dentin when universal bonding agents are used in self-etch or etch-and-rinse modes. Sixty caries-free, extracted third molar teeth were sectioned transversely in the apical third of the crown and allocated to 12 groups (n=5). Three different bonding agents (Scotchbond Universal, OptiBond XTR, All-Bond Universal) were used to bond 2 different dual-polymerizing composite resins (CompCore AF or CoreFlo DC) to dentin, using 2 different etching approaches (etch-and-rinse or self-etch). The specimens were sectioned into sticks (1×1×8 mm) with a precision saw. The bond strength of the specimens was tested under microtensile force at a crosshead speed of 0.5 mm/min. The data were analyzed using a 3-way ANOVA, a Games-Howell post hoc comparisons model, and Student t tests with Bonferroni corrections (α=.05). In the overall model, the composite resin used had no effect on bond strength (P=.830). The etching protocol by itself also did not have a significant effect (P=.059), although a trend was present. The bonding agent, however, did have an effect (PUniversal (PUniversal (PUniversal was used, whereas with All-Bond Universal, an etch-and-rinse protocol, provided higher bond strength. When universal bonding agents were used to secure dual-polymerizing composite resins to dentin, no single etching protocol is better than another. Depending on which bonding agent is being used, one etching mode may perform better. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  5. Bonded carbon or ceramic fiber composite filter vent for radioactive waste

    Science.gov (United States)

    Brassell, Gilbert W.; Brugger, Ronald P.

    1985-02-19

    Carbon bonded carbon fiber composites as well as ceramic or carbon bonded ceramic fiber composites are very useful as filters which can separate particulate matter from gas streams entraining the same. These filters have particular application to the filtering of radioactive particles, e.g., they can act as vents for containers of radioactive waste material.

  6. Evaluation of Peel Ply Surface Preparation of Composite Surfaces for Secondary Bonding

    Science.gov (United States)

    2013-09-01

    bonding, which include mechanical abrasion , chemical treatments, cleaning, and inspection. The success or failure of a peel ply to create a...Evaluation of Peel Ply Surface Preparation of Composite Surfaces for Secondary Bonding by Jared M. Gardner, James P. Wolbert, Larry R. Holmes...Evaluation of Peel Ply Surface Preparation of Composite Surfaces for Secondary Bonding Jared M. Gardner, James P. Wolbert, Larry R

  7. Microleakage of Class II Combined Amalgam-Composite Restorations Using Different Composites and Bonding Agents

    Directory of Open Access Journals (Sweden)

    F. Sharafeddin

    2008-09-01

    Full Text Available Objective: The purpose of the present study was to assess the microleakage of composite restorations with and without a cervical amalgam base and to compare the results of dif-ferent composites and bonding agents.Materials and Methods: One hundred and twenty mesio-occlusal (MO and disto-occlusal (DO Class II cavities were prepared on sixty extracted permanent premolar teeth. The teeth were randomly divided into four groups of 30 and restored as follows:In group A, the mesio-occlusal cavity (MO, Scotchbond multi purpose plus + Z250 and in the disto-occlusal (DO cavity, Prompt-L-Pop + Z250 were applied. As for group B, in the MO and DO cavities, Clearfil SE Bond + Clearfil APX, and varnish + amalgam (In box + Clearfil SE Bond + Clearfil APX were used respectivelywhile in group C; the teeth were restored with amalgam and varnish mesio-occlusally and with amalgam only disto-occlusally. As for group D, varnish + amalgam (in box + Scotchbond multi purpose plus + Z250 were applied mesio-occlusally and Varnish + Amalgam (in box + Prompt–L–Pop + Z250 disto-occlusally.Marginal leakage was assessed by the degree of dye penetration into various sections of the restored teeth. Chi-square and Fisher's exact tests were used for data analysis.Results: Microleakage in gingival margin was more than that in occlusal margin (P<0.05 and microleakage of combined amalgam-composite restorations was significantly lower than that of conventional composite and amalgam restorations.Conclusion: Marginal microleakage decreased by using amalgam at the base of the box in Class II composite restorations.

  8. Bonding between CAD/CAM resin and resin composite cements dependent on bonding agents: three different in vitro test methods.

    Science.gov (United States)

    Gilbert, Simona; Keul, Christine; Roos, Malgorzata; Edelhoff, Daniel; Stawarczyk, Bogna

    2016-03-01

    The aim of this study was to assess the bonding properties between CAD/CAM resin and three resin composite cements combined with different bonding agents using three test methods. Four hundred twenty CAD/CAM resin substrates were fabricated and divided into three test methods (shear bond strength (SBS, n = 180), tensile bond strength (TBS, n = 180) and work of adhesion (WA, n = 60)), further into four pretreatment methods (VP connect (VP), visio.link (VL), Clearfil Ceramic Primer (CP) and no pretreatment (CG)) and three cements (RelyX ARC, Variolink II and Clearfil SA Cement). Each subgroup contained 15 specimens. SBS and TBS were measured after 24 h H2O/37 °C + 5000 thermal-cycles (5/55 °C) and failure types were assessed. WA was determined for pretreated CAD/CAM resin and non-polymerized resin composite cements. Data were analysed with Mann-Whitney U, Kruskal-Wallis H, Chi(2) and Spearman's Rho tests. Within SBS and TBS tests, CGs and groups pretreated with CP (regardless of resin composite cements), and VP pretreated with Clearfil SA Cement showed no bond. However, CG combined with RelyX ARC showed a TBS of 5.6 ± 1.3 MPa. In general, highest bond strength was observed for groups treated with VL. CG and groups pretreated using VL showed lower WA than the groups treated with VP or CP. Measured TBS values were higher than SBS ones. In general, SBS and TBS showed similar trends for the ranges of the values for the groups. WA results were not comparable with SBS/TBS results and admitted, therefore, no conclusions on it. For a clinical use of XHIP-CAD/CAM resin, the bond surface should be additionally pretreated with visio.link as bonding agent.

  9. Effect of indirect composite treatment microtensile bond strength of self-adhesive resin cements.

    Science.gov (United States)

    Fuentes, María-Victoria; Escribano, Nuria; Baracco, Bruno; Romero, Martin; Ceballos, Laura

    2016-02-01

    No specific indications about the pre-treatment of indirect composite restorations is provided by the manufacturers of most self-adhesive resin cements. The potential effect of silane treatment to the bond strength of the complete tooth/indirect restoration complex is not available.The aim of this study was to determine the contribution of different surface treatments on microtensile bond strength of composite overlays to dentin using several self-adhesive resin cements and a total-etch one. Composite overlays were fabricated and bonding surfaces were airborne-particle abraded and randomly assigned to two different surface treatments: no treatment or silane application (RelyX Ceramic Primer) followed by an adhesive (Adper Scotchbond 1 XT). Composite overlays were luted to flat dentin surfaces using the following self-adhesive resin cements: RelyX Unicem, G-Cem, Speedcem, Maxcem Elite or Smartcem2, and the total-etch resin cement RelyX ARC. After 24 h, bonded specimens were cut into sticks 1 mm thick and stressed in tension until failure. Two-way ANOVA and SNK tests were applied at α=0.05. Bond strength values were significantly influenced by the resin cement used (pcement applied and surface treatment did not significantly affect dentin bond strength (p>0.05). All self-adhesive resin cements showed lower bond strength values than the total-etch RelyX ARC. Among self-adhesive resin cements, RelyX Unicem and G-Cem attained statistically higher bond strength values. Smartcem2 and Maxcem Elite exhibited 80-90% of pre-test failures. The silane and adhesive application after indirect resin composite sandblasting did not improve the bond strength of dentin-composite overlay complex. Selection of the resin cement seems to be a more relevant factor when bonding indirect composites to dentin than its surface treatment. Bond strength, self-adhesive cement, silane, dentin, indirect composite.

  10. Methodology for optimal configuration in structural health monitoring of composite bonded joints

    Science.gov (United States)

    Quaegebeur, N.; Micheau, P.; Masson, P.; Castaings, M.

    2012-10-01

    In this study, a structural health monitoring (SHM) strategy is proposed in order to detect disbonds in a composite lap-joint. The structure under study is composed of a carbon fiber reinforced polymer (CFRP) bonded to a titanium plate and artificial disbonds are simulated by inserting Teflon tapes of various dimensions within the joint. In situ inspection is ensured by piezoceramics bonded to the structure to generate and measure guided waves. Theoretical propagation and through-thickness stress distribution are first studied in order to determine damage sensitivity with respect to the mode and frequency of the generated guided wave. The optimal configuration of the system in terms of piezoceramic size, shape and inter-unit spacing is then validated using finite element modeling (FEM) in 3D. Experimental assessment of propagation characteristics is conducted using laser Doppler vibrometer (LDV) in order to justify theoretical and numerical assumptions and pitch-catch measurements are then performed to validate the efficient detection of the damage and accurate estimation of its size.

  11. Composite Bonding to Stainless Steel Crowns Using a New Universal Bonding and Single-Bottle Systems

    OpenAIRE

    Hattan, Mohammad Ali; Pani, Sharat Chandra; AlOmari, Mohammad

    2013-01-01

    Aim. The aim of this study is to evaluate the shear bond strength of nanocomposite to stainless steel crowns using a new universal bonding system. Material and Methods. Eighty (80) stainless steel crowns (SSCs) were divided into four groups (20 each). Packable nanocomposite was bonded to the lingual surface of the crowns in the following methods: Group A without adhesive (control group), Group B using a new universal adhesive system (Scotchbond Universal Adhesive, 3M ESPE, Seefeld, Germany), ...

  12. GPM GROUND VALIDATION COMPOSITE SATELLITE OVERPASSES GCPEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation Composite Satellite Overpasses GCPEx dataset provides satellite overpasses from the Special Sensor Microwave Imager/Sounder (SSMIS)...

  13. The Effects of Cavity Preparation and Composite Resin on Bond Strength and Stress Distribution Using the Microtensile Bond Test.

    Science.gov (United States)

    Braga, Ssl; Oliveira, Lrs; Rodrigues, R B; Bicalho, A A; Novais, V R; Armstrong, S; Soares, C J

    2017-10-04

    To evaluate the effect of flowable bulk-fill or conventional composite resin on bond strength and stress distribution in flat or mesio-occlusal-distal (MOD) cavity preparations using the microtensile bond strength (μTBS) test. Forty human molars were divided into two groups and received either standardized MOD or flat cavity preparations. Restorations were made using the conventional composite resin Z350 (Filtek Z350XT, 3M-ESPE, St Paul, MN, USA) or flowable bulk-fill (FBF) composite resin (Filtek Bulk Fill Flowable, 3M-ESPE). Postgel shrinkage was measured using the strain gauge technique (n=10). The Z350 buildup was made in two increments of 2.0 mm, and the FBF was made in a single increment of 4.0 mm. Six rectangular sticks were obtained for each tooth, and each section was used for μTBS testing at 1.0 mm/min. Polymerization shrinkage was modeled using postgel shrinkage data. The μTBS data were analyzed statistically using a two-way analysis of variance (ANOVA), and the postgel shrinkage data were analyzed using a one-way ANOVA with Tukey post hoc test. The failure modes were analyzed using a chi-square test (α=0.05). Our results show that both the type of cavity preparation and the composite resin used affect the bond strength and stress distribution. The Z350 composite resin had a higher postgel shrinkage than the FBF composite resin. The μTBS of the MOD preparation was influenced by the type of composite resin used. Irrespective of composite resin, flat cavity preparations resulted in higher μTBS than MOD preparations (pcomposite resin had a similar μTBS relative to Z350 composite resin. However, in MOD-prepared cavities, those with FBF composite resin had higher μTBS values than those with Z350 composite resin. Adhesive failure was prevalent for all tested groups. The MOD preparation resulted in higher shrinkage stress than the flat preparation, irrespective of composite resin. For MOD-prepared cavities, FBF composite resin resulted in lower stress

  14. Microtensile Bond Strength of New Ceramic/Polymer Materials Repaired with Composite Resin

    Science.gov (United States)

    2015-06-30

    34Microtensile Bond Strength of New Ceramic/Polymer Materials Repaired with Composite Resin " 7. Intended publication/meeting: General Dentistry 8...Strength of New Ceramic/Polymer Materials Repaired with Composite Resin Maj Stephen S. Potter APPROVED: Lt Col Clifton W. Bailey I Col Villa l...Microtensile Bond Strength of New Ceramic/Polymer Materials Repaired with Composite Resin Abstract The new millable ceramic/polymer block materials

  15. Composite bonding to stainless steel crowns using a new universal bonding and single-bottle systems.

    Science.gov (United States)

    Hattan, Mohammad Ali; Pani, Sharat Chandra; Alomari, Mohammad

    2013-01-01

    Aim. The aim of this study is to evaluate the shear bond strength of nanocomposite to stainless steel crowns using a new universal bonding system. Material and Methods. Eighty (80) stainless steel crowns (SSCs) were divided into four groups (20 each). Packable nanocomposite was bonded to the lingual surface of the crowns in the following methods: Group A without adhesive (control group), Group B using a new universal adhesive system (Scotchbond Universal Adhesive, 3M ESPE, Seefeld, Germany), and Group C and Group D using two different brands of single-bottle adhesive systems. Shear bond strengths were calculated and the types of failure also were recorded. Results. The shear strength of Group B was significantly greater than that of other groups. No significant differences were found between the shear bond strengths of Groups C and D. The control group had significantly lower shear bond strength (P stainless steel crowns using the new universal bonding agent (Scotchbond Universal Adhesive, 3M ESPE, Seefeld, Germany) show significantly greater shear bond strengths and fewer adhesive failures when compared to traditional single-bottle systems.

  16. Shear bond strength between alumina substrate and prosthodontic resin composites with various adhesive resin systems.

    Science.gov (United States)

    AlJehani, Yousef A; Baskaradoss, Jagan K; Geevarghese, Amrita; AlShehry, Marey A; Vallittu, Pekka K

    2015-05-02

    With the increase in demand for cosmetics and esthetics, resin composite restorations and all-ceramic restorations have become an important treatment alternative. Taking into consideration the large number of prosthodontic and adhesive resins currently available, the strength and durability of these materials needs to be evaluated. This laboratory study presents the shear bond strengths of a range of veneering resin composites bonded to all-ceramic core material using different adhesive resins. Alumina ceramic specimens (Techceram Ltd, Shipley, UK) were assigned to three groups. Three types of commercially available prosthodontic resin composites [BelleGlass®, (BG, Kerr, CA, USA), Sinfony® (SF, 3 M ESPE, Dental Products, Germany), and GC Gradia® (GCG, GC Corp, Tokyo, Japan)] were bonded to the alumina substrate using four different adhesive resins. Half the specimens per group (N = 40) were stored dry for 24 hours, the remaining were stored for 30 days in water. The bonding strength, so-called shear bond strengths between composite resin and alumina substrate were measured. Data were analysed statistically and variations in bond strength within each group were additionally evaluated by calculating the Weibull modulus. Bond strengths were influenced by the brand of prosthodontic resin composites. Shear bond strengths of material combinations varied from 24.17 ± 3.72-10.15 ± 3.69 MPa and 21.20 ± 4.64-7.50 ± 4.22 at 24 h and 30 days, respectively. BG resin composite compared with the other resin composites provided the strongest bond with alumina substrate (p < 0.01). SF resin composite was found to have a lower bond strength than the other composites. The Weibull moduli were highest for BG, which was bonded by using Optibond Solo Plus adhesive resin at 24 h and 30 days. There was no effect of storage time and adhesive brand on bond strength. Within the limitations of this study, the shear bond strengths of composite resins to alumina substrate are related to

  17. Effect of simulated pulpal pressure on composite bond strength to ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... Bonding to dentin with adhesive systems is affected by the tubular fluid flow induced by pulpal pressure. The aim of this study was to evaluate the effect of simulated pulpal pressure on the microtensile bond strength of an adhesive to dentin surface prepared by laser irradiation. Crowns of twenty human ...

  18. Effect of simulated pulpal pressure on composite bond strength to ...

    African Journals Online (AJOL)

    Bonding to dentin with adhesive systems is affected by the tubular fluid flow induced by pulpal pressure. The aim of this study was to evaluate the effect of simulated pulpal pressure on the microtensile bond strength of an adhesive to dentin surface prepared by laser irradiation. Crowns of twenty human extracted third ...

  19. Delamination Arrestment in Bonded-Bolted Composite Structures by Fasteners

    Science.gov (United States)

    Cheung, Chi Ho Eric

    Laminated composites have exceptional in-plane strengths and fatigue properties. However, they are susceptible to the interlaminar mode of failure, namely disbond and delamination. This failure mode challenges the edges of structural interface, such as the skin-stringer flange and run-out, where interlaminar tension, shear, and opening moment are concentrated. The fasteners provide a substantiation path for the FAA damage tolerance requirement for composite bonded joints (FAR 23.573). A comprehensive understanding of delamination arrestment by fasteners was developed. The fastener provides crack arrest capability by three main mechanisms: 1) mode I suppression, 2) crack-face friction, and 3) fastener joint shear stiffness. The fastener mechanically closes the crack tip, suppressing mode I fracture and forcing the crack to propagate in pure mode II with higher fracture toughness. Fastener preload generates significant friction force on the cracked surfaces which reduces crack-tip forces and moments. The fastener shear joint provides an alternate load path around the crack tip that becomes more effective as crack length increases. The three mechanisms work in concert to provide various degrees of crack arrestment and retardation capability. A novel test technique was developed to quantify the delamination arrestment capability by fasteners under in-plane dominated loading, i.e. mode II propagation. The test results show that the fastener is highly capable of delamination arrestment and retardation. The test also demonstrates that fastener installation preload, which is directly related to crack-face friction, is an important factor in delamination arrestment. A computationally efficient analytical method was developed to capture the behavior and efficacy of delamination arrestment by fasteners. The solution method is based on the principle of minimum potential energy and beam-column modeling of the delaminating structure. The fastener flexibility approach is used to

  20. Micro-tensile bond strength of solely self-cured composite cement onto dentin

    OpenAIRE

    Suzuki, Thais Yumi Umeda; Santos, PH; de Munck, Jan; Van Meerbeek, Bart

    2016-01-01

    To evaluate bonding effectiveness of a new experimental composite cement to dentin in terms of microtensile bond strength (μTBS) after 1week (‘immediate’) and 6month (‘aged’) artificial aging. Flat ground dentin of 32 human molars was prepared using 600-grit SiC paper. Selfmade composite blocks (Clearfil AP-X,Kuraray Noritake) were bonded to flat dentin surfaces using 4 composite cements: Exp. HPC100 (Kuraray Noritake), Multilink (Ivoclar Vivadent), RelyX Unicem 2 and RelyX Ultimate ...

  1. Bond strength and cement-tooth interfacial characterization of self-adhesive composite cements.

    Science.gov (United States)

    Temel, U Burak; Van Ende, Annelies; Van Meerbeek, Bart; Ermis, R Banu

    2017-08-01

    (1) To determine the microtensile bond strength (µTBS) of self-adhesive (SA) composite cements to unetched/etched enamel and dentin, and (2) to characterize the cements' interaction with tooth tissue. 51 composite blocks were bonded to smear layer-covered enamel and dentin (three teeth per group). Four SA composite cements (Clearfil SA, G-CEM, RelyX Unicem, SmartCem2), and three multi-step composite cements, two used following an etch-and-rinse (E&R) approach (RelyX ARC, Variolink II 'E&R') and one used following a self-etch (SE) approach (Variolink II ' SE') were investigated. The cement-tooth specimens were perpendicularly sectioned into micro-specimens (1.0 × 1.0 mm) in order to measure the µTBS. The data were statistically analyzed by ANOVA followed by Tukey HSD (Pcomposite cements were applied to dentin free of a smear layer, regular and long resin tags were formed. No significant differences in bonding effectiveness were recorded for the self-adhesive composite cements when bonded to unetched/etched enamel and to dentin. Multi-step etch-and-rinse composite cements showed a better bonding effectiveness to enamel, although this could be approximated by the self-adhesive composite cements when enamel was acid-etched beforehand. On dentin, however, the bond strength of the etch-and-rinse composite cement RelyX ARC was superior.

  2. Effect of thermocycling and surface treatment on repair bond strength of composite.

    Science.gov (United States)

    Kiomarsi, Nazanin; Saburian, Pardis; Chiniforush, Nasim; Karazifard, Mohammad-Javd; Hashemikamangar, Sedighe-Sadat

    2017-08-01

    Repair of composite restorations is a conservative method that can increase the longevity and durability of restorations while preserving the tooth structure. Achieving a suitable bond between the old and new composite is difficult. To overcome this problem, some methods have been recommended to increase the repair bond strength of composite.This study aimed to assess the effect of aging by thermocycling (5,000 and 10,000 cycles) and mechanical surface treatments (Er,Cr:YSGG laser and bur) on repair shear bond strength of composite resin. Totally, 120 composite blocks measuring 6x4x4 mm were fabricated of Filtek Z250 composite and were randomly divided into three groups (n=40) based on initial aging protocol: (a) no aging: storage in distilled water at 37°C for 24 hours, (b) 5,000 thermal cycles, (c) 10,000 thermal cycles. Each group was then randomly divided into two subgroups (n=20) based on mechanical surface treatment (laser and bur). The laser and bur-prepared surfaces were silanized and Adper Single Bond 2 was then applied. The repair composite was bonded to surfaces. Half of the samples in each subgroup (n=10) were subjected to 5,000 thermal cycles to assess durability of bond. The remaining half were stored in distilled water at 37°C for 24 hours and all samples were then subjected to shear bond strength testing in a universal testing machine with a crosshead speed of 1mm/min. Data (in megapascals) were subjected to one-way ANOVA and Tukey's test (P=0.05). Mode of failure was determined under a stereomicroscope. Bur preparation significantly improved the bond strength compared to laser (Pcomposite (Pcomposite and surface preparation by bur provides a higher bond strength compared to laser. Key words:Thermocycling, Composite, Repair, Laser.

  3. Developing and validating a chemical bonding instrument for Korean high school students

    Science.gov (United States)

    Jang, Nak Han

    The major purpose of this study was to develop a reliable and valid instrument designed to collect and investigate on Korean high school students' understanding about concepts regarding chemical bonding. The Chemical Bonding Diagnostic Test (CBDT) was developed by the procedure by previously relevant researches (Treagust, 1985; Peterson, 1986; Tan, 1994). The final instrument consisted of 15 two-tier items. The reliability coefficient (Cronbach alpha) for the whole test was 0.74. Also, the range of values for the discrimination index was from 0.38 to 0.90 and the overall average difficulty index was 0.38. The test was administered to 716 science declared students in Korean high school. The 37 common misconceptions on chemical bonding were identified through analysis of the items from the CBDT. The grade 11 students had slightly more misconceptions than the grade 12 students for ionic bonding, covalent bonding, and hydrogen bonding while the grade 12 students had more misconceptions about octet rule and hydrogen bonding than the grade 11 students. From the analysis of ANCOVA, there was no significant difference in grades, and between grade levels and gender on the mean score of CBDT. However, there was a significant difference in gender and a significant interaction between grade levels and chemistry preference. In conclusion, Korean high school students had the most common misconception about the electron configuration on ionic bonding and the water density on hydrogen bonding. Korean students' understanding about the chemical bonding was dependent on the interaction between grade levels and the chemistry preference. Consequently, grade 12 chemistry-preferred students had the highest mean scores among student groups concerned by this study.

  4. Effect of desensitizer application on shear bond strength of composite resin to bleached enamel

    Directory of Open Access Journals (Sweden)

    Maryam Khoroushi

    2013-01-01

    Full Text Available Objective: Tooth sensitivity is common after vital tooth bleaching. The aim of this study is to evaluate the effect of a desensitizing agent on shear bond strength of composite resin to bleached enamel; and determine whether a delay of one or two weeks in bonding procedure is sufficient subsequent to bleaching/desensitizer regimen. Materials and Methods: Buccal enamel surfaces of ninety-six human sound molars were prepared and divided into eight groups. The surfaces of specimens in Group 1 as negative control group were bonded by composite resin using the single bond adhesive. Specimens in Groups 2-4 were bleached with an at-home bleaching agent (Daywhite ACP. Relief ACP desensitizing gel alone was applied in Group 5. In Groups 6-8, specimens were bleached same as in Group 2 and relief ACP desensitizing gel was applied same as inGroup 5 subsequent to each bleaching session. Composite cylinders were bonded after 24 h, 7 days and 14 days in Groups 2-4, respectively, and also in Groups 6-8, respectively. The shear bond strengths of the cylinders were tested and data was analyzed using two-way ANOVA and Tukey test (α = 0.05. Results: The results showed that bleaching and bleaching/desensitizer regimens significantly reduced the bond strength of composite resin to enamel. However, desensitizer alone did not reduce bond strength. No statistically significant differences were found between bleaching and bleaching/desensitizer regarding bond strength. Conclusion: Bleaching or bleaching/desensitizer treatment significantly decreases bond strength of composite resin to enamel. In both regimens, adhesive bonding is recommended after two weeks.

  5. Microtensile bond strength of bulk-fill restorative composites to dentin.

    Science.gov (United States)

    Mandava, Jyothi; Vegesna, Divya-Prasanna; Ravi, Ravichandra; Boddeda, Mohan-Rao; Uppalapati, Lakshman-Varma; Ghazanfaruddin, M D

    2017-08-01

    To facilitate the easier placement of direct resin composite in deeper cavities, bulk fill composites have been introduced. The Mechanical stability of fillings in stress bearing areas restored with bulk-fill resin composites is still open to question, since long term clinical studies are not available so far. Thus, the objective of the study was to evaluate and compare the microtensile bond strength of three bulk-fill restorative composites with a nanohybrid composite. Class I cavities were prepared on sixty extracted mandibular molars. Teeth were divided into 4 groups (n= 15 each) and in group I, the prepared cavities were restored with nanohybrid (Filtek Z250 XT) restorative composite in an incremental manner. In group II, III and IV, the bulk-fill composites (Filtek, Tetric EvoCeram, X-tra fil bulk-fill restoratives) were placed as a 4 mm single increment and light cured. The restored teeth were subjected to thermocycling and bond strength testing was done using instron testing machine. The mode of failure was assessed by scanning electron microscope (SEM). The bond strength values obtained in megapascals (MPa) were subjected to statistical analysis, using SPSS/PC version 20 software.One-way ANOVA was used for groupwise comparison of the bond strength. Tukey's Post Hoc test was used for pairwise comparisons among the groups. The highest mean bond strength was achieved with Filtek bulk-fill restorative showing statistically significant difference with Tetric EvoCeram bulk-fill ( p composites. Adhesive failures are mostly observed with X-tra fil bulk fill composites, whereas mixed failures are more common with other bulk fill composites. Bulk-fill composites exhibited adequate bond strength to dentin and can be considered as restorative material of choice in posterior stress bearing areas. Key words: Bond strength, Bulk-fill restoratives, Configuration factor, Polymerization shrinkage.

  6. Damage prognosis of adhesively-bonded joints in laminated composite structural components of unmanned aerial vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, Charles R [Los Alamos National Laboratory; Gobbato, Maurizio [UCSD; Conte, Joel [UCSD; Kosmatke, John [UCSD; Oliver, Joseph A [UCSD

    2009-01-01

    The extensive use of lightweight advanced composite materials in unmanned aerial vehicles (UAVs) drastically increases the sensitivity to both fatigue- and impact-induced damage of their critical structural components (e.g., wings and tail stabilizers) during service life. The spar-to-skin adhesive joints are considered one of the most fatigue sensitive subcomponents of a lightweight UAV composite wing with damage progressively evolving from the wing root. This paper presents a comprehensive probabilistic methodology for predicting the remaining service life of adhesively-bonded joints in laminated composite structural components of UAVs. Non-destructive evaluation techniques and Bayesian inference are used to (i) assess the current state of damage of the system and, (ii) update the probability distribution of the damage extent at various locations. A probabilistic model for future loads and a mechanics-based damage model are then used to stochastically propagate damage through the joint. Combined local (e.g., exceedance of a critical damage size) and global (e.g.. flutter instability) failure criteria are finally used to compute the probability of component failure at future times. The applicability and the partial validation of the proposed methodology are then briefly discussed by analyzing the debonding propagation, along a pre-defined adhesive interface, in a simply supported laminated composite beam with solid rectangular cross section, subjected to a concentrated load applied at mid-span. A specially developed Eliler-Bernoulli beam finite element with interlaminar slip along the damageable interface is used in combination with a cohesive zone model to study the fatigue-induced degradation in the adhesive material. The preliminary numerical results presented are promising for the future validation of the methodology.

  7. Bond strength of composite to astringent-contaminated dentin using self-etching adhesives.

    Science.gov (United States)

    O'Keefe, Kathy L; Pinzon, Lilliam M; Rivera, Babette; Powers, John M

    2005-06-01

    To determine the effects of contamination by ferric sulfate and aluminum chloride astringents on the bond strength of composite bonded to superficial dentin using self-etching adhesives. Freshly extracted human teeth were ground to expose superficial dentin and polished to 600 grit. One of three self-etching adhesive systems and restorative composites were bonded to the specimens, with contamination by one of three astringents and five surface conditions (no contamination, moist dentin control; contaminant, air, adhesive; contaminant, water rinse, air, adhesive; contaminant, water rinse, glycolic acid scrub, rinse, adhesive; contaminant, water rinse, chlorhexadine scrub, rinse, adhesive). Composite was bonded to the surfaces in the shape of an inverted, truncated cone (n = 5, 180 specimens total). Specimens were stored in water at 37 degrees C for 24 hours, then de-bonded in tension with a testing machine at a crosshead speed of 0.5 mm/minute. Tensile bond strengths (MPa) were calculated. Means (SD) were compared using analysis of variance. Significant differences (Fisher's PLSD) were found among all variables. SE and ABF had the highest control values, but were affected most by astringent contamination. Ferric sulfate reduced bond strengths the greatest in most cases, and aluminum chloride putty reduced bond strengths the least. Chlorhexadine rinse was most effective in restoring bond strength values.

  8. Bond Characteristics of Macro Polypropylene Fiber in Cementitious Composites Containing Nanosilica and Styrene Butadiene Latex Polymer

    Directory of Open Access Journals (Sweden)

    Jae-Woong Han

    2015-01-01

    Full Text Available This study evaluated the bond properties of polypropylene (PP fiber in plain cementitious composites (PCCs and styrene butadiene latex polymer cementitious composites (LCCs at different nanosilica contents. The bond tests were evaluated according to JCI SF-8, in which the contents of nanosilica in the cement were 0, 2, 4, 6, 8, and 10 wt%, based on cement weight. The addition of nanosilica significantly affected the bond properties between macro PP fiber and cementitious composites. For PCCs, the addition of 0–2 wt% nanosilica enhanced bond strength and interface toughness, whereas the addition of 4 wt% or more reduced bond strength and interface toughness. The bond strength and interfacial toughness of LCCs also increased with the addition of up to 6% nanosilica. The analysis of the relative bond strength showed that the addition of nanosilica affects the bond properties of both PCC and LCC. This result was confirmed via microstructural analysis of the macro PP fiber surface after the bond tests, which revealed an increase in scratches due to frictional forces and fiber tearing.

  9. Bond strength of resin composite to light activated bleached enamel

    African Journals Online (AJOL)

    2015-09-02

    , resin bonding, tooth bleaching. Date of Acceptance: ... The energy absorbed from the light accelerates the oxidation–reduction reaction.[12]. Bleaching treatment is frequently recommended before porcelain restorations or ...

  10. Convergent validity of the short-EMBU and the parental bonding instrument (PBI) : Dutch findings

    NARCIS (Netherlands)

    Arrindell, W.A.; Engebretsen, A.A

    2000-01-01

    Using a large sample of Spanish students (N = 796), Livianos-Aldana and Rojo-Moreno (1999) found poor evidence of convergent validity of the homologous dimensions that underlie the EMBU and the Parental Bonding Instrument. The Spanish findings however are neither in line with previous ones that were

  11. Contamination and Surface Preparation Effects on Composite Bonding

    Science.gov (United States)

    Kutscha, Eileen O.; Vahey, Paul G.; Belcher, Marcus A.; VanVoast, Peter J.; Grace, William B.; Blohowiak, Kay Y.; Palmieri, Frank L.; Connell, John W.

    2017-01-01

    Results presented here demonstrate the effect of several prebond surface contaminants (hydrocarbon, machining fluid, latex, silicone, peel ply residue, release film) on bond quality, as measured by fracture toughness and failure modes of carbon fiber reinforced epoxy substrates bonded in secondary and co-bond configurations with paste and film adhesives. Additionally, the capability of various prebond surface property measurement tools to detect contaminants and potentially predict subsequent bond performance of three different adhesives is also shown. Surface measurement methods included water contact angle, Dyne solution wettability, optically stimulated electron emission spectroscopy, surface free energy, inverse gas chromatography, and Fourier transform infrared spectroscopy with chemometrics analysis. Information will also be provided on the effectiveness of mechanical and energetic surface treatments to recover a bondable surface after contamination. The benefits and drawbacks of the various surface analysis tools to detect contaminants and evaluate prebond surfaces after surface treatment were assessed as well as their ability to correlate to bond performance. Surface analysis tools were also evaluated for their potential use as in-line quality control of adhesive bonding parameters in the manufacturing environment.

  12. Effect of Curing Mode on Shear Bond Strength of Self-Adhesive Cement to Composite Blocks

    National Research Council Canada - National Science Library

    Jin-Young Kim; Ga-Young Cho; Byoung-Duck Roh; Yooseok Shin

    2016-01-01

    .... The purpose of this study was to evaluate the shear bond strength and fracture pattern of indirect CAD/CAM composite blocks cemented with two self-etch adhesive cements with different curing modes...

  13. Bonding performance of self-adhesive flowable composites to enamel, dentin and a nano-hybrid composite.

    Science.gov (United States)

    Peterson, Jana; Rizk, Marta; Hoch, Monika; Wiegand, Annette

    2017-12-14

    This study aimed to analyze bond strengths of self-adhesive flowable composites on enamel, dentin and nano-hybrid composite. Enamel, dentin and nano-hybrid composite (Venus Diamond, Heraeus Kulzer, Germany) specimens were prepared. Three self-adhesive composites (Constic, DMG, Germany; Fusio Liquid Dentin, Pentron Clinical, USA; Vertise Flow, Kerr Dental, Italy) or a conventional flowable composite (Venus Diamond Flow, Heraeus Kulzer, Germany, etch&rinse technique) were applied to enamel and dentin. Nano-hybrid composite specimens were initially aged by thermal cycling (5000 cycles, 5-55 °C). Surfaces were left untreated or pretreated by mechanical roughening, Al2O3 air abrasion or silica coating/silanization. In half of the composite specimens, an adhesive (Optibond FL, Kerr Dental, Italy) was used prior to the application of the flowable composites. Following thermal cycling (5000 cycles, 5-55 °C) of all specimens, shear bond strengths (SBS) and failure modes were analyzed (each subgroup n = 16). Statistical analysis was performed by ANOVAs/Bonferroni post hoc tests, Weibull statistics and χ 2-tests (p composites on enamel and dentin were significantly lower (enamel: composite (enamel: 13.0 ± 5.1, dentin: 11.2 ± 6.3), and merely adhesive failures could be observed. On the nano-hybrid composite, SBS were significantly related to the pretreatment. Adhesive application improved SBS of the conventional, but not of the self-adhesive composites. The self-adhesive composite groups showed less cohesive failures than the reference group; the occurence of cohesive failures increased after surface pretreatment. Bonding of self-adhesive flowable composites to enamel and dentin is lower than bonding to a nano-hybrid composite.

  14. Bond strength of a composite resin to glass ionomer cements using different adhesive systems

    Directory of Open Access Journals (Sweden)

    Ana Carolina de Oliveira BECCI

    2017-08-01

    Full Text Available Abstract Introduction Glass ionomer cements are often used as a base or cavity lining prior to restorative material. Objective To evaluate the bond strength of a composite resin to different glass ionomer cements, when using a two-step conventional and self-etching adhesive systems. Material and method Three glass ionomer cements (Ketac Molar Easymix, Vitremer and Vitrebond, the composite resin Filtek Z350 XT and the adhesive systems Adper Single Bond 2, Clearfil SE Bond and Adper Easy One were used. As negative control, resin was bonded to cement without using an adhesive system. Holes (4 mm diameter, 2 mm deep prepared in acrilic bloks were filled with the glass ionomer cements (n=12/group. On the surface, an area of 1mm in diameter was delimited, the adhesive system was applied, and a specimen of composite resin with 1 mm height was made. After 24 hours storage (37 °C and 100% humidity, the microshear test was performed. Data were analyzed using two-way ANOVA and Tukey test for comparison between groups (α=0.05. Result The adhesive systems significantly improved the bond strenght of composite resin to glass ionomer cements (p≤0.001. There was no significant difference in bond strength when self-etching adhesive systems were compared with the simplified etch-and-rinse adhesive, except for Vitrebond where Clearfil SE Bond determined higher bond strength when compared to Adper Single Bond 2 (p=0.003. Conclusion Self-etching adhesive systems are a good option for establishing the bond between the composite resin and the glass ionomer cement.

  15. Resin bond to indirect composite and new ceramic/polymer materials: a review of the literature.

    Science.gov (United States)

    Spitznagel, Frank A; Horvath, Sebastian D; Guess, Petra C; Blatz, Markus B

    2014-01-01

    Resin bonding is essential for clinical longevity of indirect restorations. Especially in light of the increasing popularity of computer-aided design/computer-aided manufacturing-fabricated indirect restorations, there is a need to assess optimal bonding protocols for new ceramic/polymer materials and indirect composites. The aim of this article was to review and assess the current scientific evidence on the resin bond to indirect composite and new ceramic/polymer materials. An electronic PubMed database search was conducted from 1966 to September 2013 for in vitro studies pertaining the resin bond to indirect composite and new ceramic/polymer materials. The search revealed 198 titles. Full-text screening was carried out for 43 studies, yielding 18 relevant articles that complied with inclusion criteria. No relevant studies could be identified regarding new ceramic/polymer materials. Most common surface treatments are aluminum-oxide air-abrasion, silane treatment, and hydrofluoric acid-etching for indirect composite restoration. Self-adhesive cements achieve lower bond strengths in comparison with etch-and-rinse systems. Thermocycling has a greater impact on bonding behavior than water storage. Air-particle abrasion and additional silane treatment should be applied to enhance the resin bond to laboratory-processed composites. However, there is an urgent need for in vitro studies that evaluate the bond strength to new ceramic/polymer materials. This article reviews the available dental literature on resin bond of laboratory composites and gives scientifically based guidance for their successful placement. Furthermore, this review demonstrated that future research for new ceramic/polymer materials is required. © 2014 Wiley Periodicals, Inc.

  16. Comparison of bond strength of composite and acrylic teeth to heat-cured and

    Directory of Open Access Journals (Sweden)

    Amirjan A

    2011-02-01

    Full Text Available "nBackground and Aims: Failure of bonding between artificial teeth and denture base material is a considerable problem for patients who wear dentures. Because of the cost of denture repair and the expensive price of foreign artificial teeth, this study was designed to compare the bond strength of composite and acrylic artificial teeth with heat-cured and auto-polymerized denture base resins."nMaterials and Methods: In this experimental and in vitro study, two type of acrylic resin (heat-cured: Selectaplus H/ Trevalon, Dentsply and auto-polymerized: Rapid Repair, Dentsply and four artificial teeth (acrylic Marjan New, composite Glamour teeth which both of them are Iranian and Ivoclar acrylic and composite teeth were used. Therefore, 8 groups of 14 specimens each were evaluated. A shear bond strenghth test in a Universal Testing Machine was used. Data were analyzed using the 2-way ANOVA test."nResults: The bond strengths of acrylic teeth (Marjan New and Ivoclar to heat-cured resin were similar (P=0.632 and statistically higher than those of composite teeth (Glamour and Ivoclar. Acrylic teeth (Marjan New and Ivoclar and Glamour teeth had similar bond strength to auto-polymerized resin, which showed the highest bond strength values. Ivoclar composite teeth showed significantly the lowest bond strength (P<0.05. All acrylic teeth had the highest mean bond strengths to heat-cured resin which were significantly different from that of "nauto-polymerized resin (P<0.05. However, the bond strengths of all composite teeth to both denture base resins were not significantly different (P>0.05."nConclusion: Based on the results of this study, the type of denture base material and artificial tooth may influence the failure load.

  17. The bond of different post materials to a resin composite cement and a resin composite core material.

    Science.gov (United States)

    Stewardson, D; Shortall, A; Marquis, P

    2012-01-01

    To investigate the bond of endodontic post materials, with and without grit blasting, to a resin composite cement and a core material using push-out bond strength tests. Fiber-reinforced composite (FRC) posts containing carbon (C) or glass (A) fiber and a steel (S) post were cemented into cylinders of polymerized restorative composite without surface treatment (as controls) and after grit blasting for 8, 16, and 32 seconds. Additional steel post samples were sputter-coated with gold before cementation to prevent chemical interaction with the cement. Cylindrical composite cores were bonded to other samples. After sectioning into discs, bond strengths were determined using push-out testing. Profilometry and electron microscopy were used to assess the effect of grit blasting on surface topography. Mean (standard deviation) bond strength values (MPa) for untreated posts to resin cement were 8.41 (2.80) for C, 9.61(1.88) for A, and 19.90 (3.61) for S. Prolonged grit blasting increased bond strength for FRC posts but produced only a minimal increase for S. After 32 seconds, mean values were 20.65 (4.91) for C, 20.41 (2.93) for A, and 22.97 (2.87) for S. Gold-coated steel samples produced the lowest bond strength value, 7.84 (1.40). Mean bond strengths for untreated posts bonded to composite cores were 6.19 (0.95) for C, 13.22 (1.61) for A, and 8.82 (1.18) for S, and after 32 seconds of grit blasting the values were 17.30 (2.02) for C, 26.47 (3.09) for A, and 20.61 (2.67) for S. FRC materials recorded higher roughness values before and after grit blasting than S. With prolonged grit blasting, roughness increased for A and C, but not for S. There was no evidence of significant bonding to untreated FRC posts, but significant bonding occurred between untreated steel posts and the resin cement. Increases in the roughness of FRC samples were material dependent and roughening significantly increased bond strength values (p<0.05). Surface roughening of the tested FRC posts is

  18. Effect of surface conditioning methods on the microtensile bond strength of resin composite to composite after aging conditions

    NARCIS (Netherlands)

    Ozcan, Mutlu; Barbosa, Silvia Helena; Melo, Renata Marques; Galhano, Graziela Avila Prado; Bottino, Marco Antonio

    2007-01-01

    Objectives. This study evaluated the effect of two different surface conditioning methods on the repair bond strength of a bis-GMA-adduct/bis-EMA/TEGDMA based resin composite after three aging conditions. Methods. Thirty-six composite resin blocks (Esthet X, Dentsply) were prepared (5 mm x 6 mm x 6

  19. Reaction-bonded Si3N4 and SiC matrix composites

    Science.gov (United States)

    Bhatt, Ramakrishna T.; Behrendt, Donald R.

    1992-01-01

    A development status evaluation is presented for the reaction-bonded SiC- and Si3N4-matrix types of fiber-reinforced ceramic-matrix composite (FRCMC). A variety of reaction-bonding methods are being pursued for FRCMC fabrication: CVI, CVD, directed metal oxidation, and self-propagating high-temperature synthesis. Due to their high specific modulus and strength, toughness, and fabricability, reaction-bonded FRCMC are important candidate materials for such heat-engine components as combustor liners, nozzles, and turbine and stator blading. The improvement of long-term oxidative stability in these composites is a major goal of current research.

  20. The Effect of Different Disinfecting Agents on Bond Strength of Resin Composites

    Directory of Open Access Journals (Sweden)

    Ahmed Mohammed Hassan

    2014-01-01

    Full Text Available Objective. The aim of this study was to evaluate the effect of different disinfectant agents on bond strength of two types of resin composite materials. Methods. A total of 80 sound posterior teeth were used. They were divided into four groups (n=20 according to the dentin surface pretreatment (no treatment, chlorhexidine gluconate 2%, sodium hypochlorite 4%, and EDTA 19%. Each group was divided into two subgroups according to the type of adhesive (prime and bond 2.1 and Adper easy one. Each subgroup was further divided into two subgroups according to the type of resin composite (TPH spectrum and Tetric EvoCeram. Shear bond strength between dentin and resin composite was measured using Universal Testing Machine. Data collected were statistically analyzed by t-test and one-way ANOVA followed by Tukey’s post hoc test. Results. It was found that dentin treated with EDTA recorded the highest shear bond strength values followed by sodium hypochlorite and then chlorhexidine groups while the control group showed the lowest shear bond strength. Conclusions. The surface treatment of dentin before bonding application has a great effect on shear bond strength between resin composite and dentin surface.

  1. The effect of a dentin desensitizer on the shear bond strength of composite to dentin using three different bonding agents: An in vitro study.

    Science.gov (United States)

    Mushtaq, Eeshan Arub; Mathai, Vijay; Nair, Rajesh Sasidharan; Angelo, JeyaBalaji Mano Christaine

    2017-01-01

    The effect of dentin desensitizer Systemp on the shear bond strength of composite resin to dentin using three different bonding agents, i.e., Prime & Bond NT, Xeno V(+), and Futurabond DC were evaluated. Sixty recently extracted human premolars were divided into six groups of ten teeth each. The superficial dentin was etched with 37% phosphoric acid. In Groups I, II, and III, Prime & Bond NT, Xeno V(+), and Futurabond DC, respectively, were applied to dentin and composite placed. Following application of dentin desensitizer Systemp in Groups IV, V, and VI, Prime & Bond NT, Xeno V(+), and Futurabond DC, respectively, were applied to dentin and composite placed. The shear bond strength was evaluated. Data obtained were statistically analyzed using one-way analysis of variance, post hoc, and Dunnett's test. Following application of dentin desensitizer Systemp, mean shear bond strength increased when Prime & Bond NT bonding agent was used while it decreased for Xeno V(+) and Futurabond DC bonding agents. Within the limitations of this in vitro study, it was observed that following application of dentin desensitizer Systemp, mean shear bond strength may increase or decrease depending on the bonding agents used.

  2. Effect of mineral trioxide aggregate surface treatments on morphology and bond strength to composite resin.

    Science.gov (United States)

    Shin, Joo-Hee; Jang, Ji-Hyun; Park, Sang Hyuk; Kim, Euiseong

    2014-08-01

    The aim of this study was to evaluate the micromorphologic changes that accompany different surface treatments on mineral trioxide aggregate (MTA) and their effect on the bond strength to the composite resin with 4 adhesive systems. Three types of MTA cement, ProRoot MTA (WMTA) (Dentsply, Tulsa, OK), MTA Angelus (AMTA) (Angelus, Londrina, PR, Brazil), and Endocem MTA (EMTA) (Maruchi, Wonju, Korea), were prepared and stored for a week to encourage setting. Surface treatment was performed using phosphoric acid or self-etch primer, and an untreated MTA surface was prepared as a control. The surface changes were observed using scanning electron microscopy. MTA surfaces were bonded with 4 adhesive systems, including Scotchbond Multipurpose (3M ESPE, St Paul, MN), Single Bond 2 (3M ESPE), Clearfil SE BOND (Kuraray, Osaka, Japan), and AdheSE One F (Ivoclar Vivadent, Schaan, Liechtenstein), to evaluate the adhesive effectiveness of MTA followed by composite resin restoration. The shear bond strength of the polymerized specimens was tested. For WMTA and AMTA, untreated surfaces showed an irregular crystalline plate with clusters of globular aggregate particles. For EMTA, the untreated surface presented a reticular matrix with acicular crystals. After surface treatment, superficial crystalline structures were eroded regardless of the MTA cement and adhesive system used. WMTA bonded significantly more strongly than AMTA and EMTA, regardless of the adhesive system used. In the WMTA and AMTA groups, AdheSE One F showed the highest bond strength to the composite. For EMTA, no significant differences were found across adhesive systems. Acidic treatment of the MTA surface affected the micromorphology and the bond strength to the composite. Within the limitations of this study, using a 1-step self-etch adhesive system might result in a strong bond to WMTA when the composite resin restoration is required over MTA cement. Copyright © 2014 American Association of Endodontists

  3. Effect of surface treatments on the bond strength between composite resin and acrylic resin denture teeth.

    Science.gov (United States)

    Vergani, C E; Machado, A L; Giampaolo, E T; Pavarina, A C

    2000-01-01

    This investigation studied the effects of 3 surface treatments on the shear bond strength of a light-activated composite resin bonded to acrylic resin denture teeth. The occlusal surfaces of 30 acrylic resin denture teeth were ground flat with up to 400-grit silicon carbide paper. Three different surface treatments were evaluated: (1) the flat ground surfaces were primed with methyl methacrylate (MMA) monomer for 180 seconds; (2) light-cured adhesive resin was applied and light polymerized according to the manufacturer's instructions; and (3) treatment 1 followed by treatment 2. The composite resin was packed on the prepared surfaces using a split mold. The interface between tooth and composite was loaded at a cross-head speed of 0.5 mm/min until failure. Analysis of variance indicated significant differences between the surface treatments. Results of mean comparisons using Tukey's test showed that significantly higher shear bond strengths were developed by bonding composite resin to the surfaces that were previously treated with MMA and then with the bonding agent when compared to the other treatments. Combined surface treatment of MMA monomer followed by application of light-cured adhesive resin provided the highest shear bond strength between composite resin and acrylic resin denture teeth.

  4. Development and Validation of a Constitutive Model for Dental Composites during the Curing Process

    Science.gov (United States)

    Wickham Kolstad, Lauren

    Debonding is a critical failure of a dental composites used for dental restorations. Debonding of dental composites can be determined by comparing the shrinkage stress of to the debonding strength of the adhesive that bonds it to the tooth surface. It is difficult to measure shrinkage stress experimentally. In this study, finite element analysis is used to predict the stress in the composite during cure. A new constitutive law is presented that will allow composite developers to evaluate composite shrinkage stress at early stages in the material development. Shrinkage stress and shrinkage strain experimental data were gathered for three dental resins, Z250, Z350, and P90. Experimental data were used to develop a constitutive model for the Young's modulus as a function of time of the dental composite during cure. A Maxwell model, spring and dashpot in series, was used to simulate the composite. The compliance of the shrinkage stress device was also taken into account by including a spring in series with the Maxwell model. A coefficient of thermal expansion was also determined for internal loading of the composite by dividing shrinkage strain by time. Three FEA models are presented. A spring-disk model validates that the constitutive law is self-consistent. A quarter cuspal deflection model uses separate experimental data to verify that the constitutive law is valid. Finally, an axisymmetric tooth model is used to predict interfacial stresses in the composite. These stresses are compared to the debonding strength to check if the composite debonds. The new constitutive model accurately predicted cuspal deflection data. Predictions for interfacial bond stress in the tooth model compare favorably with debonding characteristics observed in practice for dental resins.

  5. In-vitro comparison of the effect of different bonding strategies on the micro-shear bond strength of a silorane-based composite resin to dentin

    Science.gov (United States)

    Samimi, Pouran; Alizadeh, Vahid; Fathpour, Kamyar; Mazaheri, Hamid; Mortazavi, Vajihosadat

    2016-01-01

    Background: The current study evaluated the micro-shear bond strengths of a new low-shrinkage composite resin to dentin. Materials and Methods: In this in-vitro study, 70 extracted premolars were assigned to one of seven groups (n = 10): Group 1: OptiBond Solo Plus (Opt; Kerr); Group 2: SE Bond (SE; Kuraray); Group 3: Silorane System Adhesive (SSA; 3M ESPE); Group 4: OptiBond Solo Plus + LS Bond (Opt LS); Group 5: SE Bond + LS Bond (SE LS); Group 6: OptiBond Solo Plus (Opt Po); and Group 7: SE Bond (SE Po). Occlusal dentin was exposed and restored with Filtek LS (3M ESPE) in groups 1 to 5 and Point 4 (Kerr) in groups 6 and 7. After thermocycling (1000 cycles at 5/55΀C), micro-shear bond test was carried out to measure the bond strengths. The results were submitted to analysis of variance and post hoc Tukeytests (P bonding agents (P = 0.06) and between composite resin and bonding agents (P = 0.894). Because P value of bonding agents was near the significance level, one-way ANOVA was used separately between the two composite groups. This analysis showed significant differences between silorane composite resin groups (P = 0.045) and Tukey test showed a significant difference between Groups 4 and 5 (P = 0.03). Conclusion: The application of total-etch and self-etch methacrylate-based adhesives with and without use of a hydrophobic resin coating resulted in acceptable bond strengths. PMID:27076826

  6. Analysis of Delamination Arrest Fasteners in Bolted-Bonded Composite Structures

    Science.gov (United States)

    Liu, Wenjing

    Delamination is one of the most critical damages in carbon fiber composites, which are being employed in primary aircraft structures. One common solution to prevent a delamination from propagating is to install fasteners, clamping the laminate together and partially arresting the delamination. In this thesis, the effectiveness of multiple fasteners installed in series to arrest the mixed-mode interlaminar failure in composite structures is investigated analytically. An accurate finite element model for predicting delamination propagation behavior of bolted-bonded structures was developed and validated by experimental test data. The finite element results showed that the presence of fasteners can slow down propagation of the crack by compressing the lamina together and transferring load via Mode II shear engagement of the fastener. Compared to the single-fastener case, damage tolerance of the structure was improved by the inclusion of the second fastener. Additionally, if the tensile modulus of the lamina is not high enough, laminate failure would occur before the delamination past the second fastener. Parametric studies were also performed to evaluate the influences of friction and laminate stiffness, fastener stiffness, fastener spacing and specimen width. Numerical results were discussed and a conclusion on the effectiveness of delamination arrest was drawn.

  7. Bond strength of self-adhesive resin cements to composite submitted to different surface pretreatments

    Directory of Open Access Journals (Sweden)

    Victor Hugo dos Santos

    2014-02-01

    Full Text Available Objectives Extensively destroyed teeth are commonly restored with composite resin before cavity preparation for indirect restorations. The longevity of the restoration can be related to the proper bonding of the resin cement to the composite. This study aimed to evaluate the microshear bond strength of two self-adhesive resin cements to composite resin. Materials and Methods Composite discs were subject to one of six different surface pretreatments: none (control, 35% phosphoric acid etching for 30 seconds (PA, application of silane (silane, PA + silane, PA + adhesive, or PA + silane + adhesive (n = 6. A silicone mold containing a cylindrical orifice (1 mm2 diameter was placed over the composite resin. RelyX Unicem (3M ESPE or BisCem (Bisco Inc. self-adhesive resin cement was inserted into the orifices and light-cured. Self-adhesive cement cylinders were submitted to shear loading. Data were analyzed by two-way ANOVA and Tukey's test (p < 0.05. Results Independent of the cement used, the PA + Silane + Adhesive group showed higher microshear bond strength than those of the PA and PA + Silane groups. There was no difference among the other treatments. Unicem presented higher bond strength than BisCem for all experimental conditions. Conclusions Pretreatments of the composite resin surface might have an effect on the bond strength of self-adhesive resin cements to this substrate.

  8. Effect Aging Conditions on the Repair Bond Strength of a Microhybrid and a Nanohybrid Resin Composite

    NARCIS (Netherlands)

    Ozcan, Mutlu; Cura, Cenk; Brendeke, Johannes

    2010-01-01

    Purpose This study evaluated the effect of different aging methods on the repair bond strength and failure types of a microhybrid and a nanohybrid composite Materials and Methods Disk shaped microhybrid (Quadrant Anterior Shine-QA) and nanohybrid (Tetric EvoCeram TE) resin composite specimens (N =

  9. Bond Strength of Composite to Dentin using Resin-Modified Glass Ionomers as Bonding Agents

    Science.gov (United States)

    2016-03-02

    Vitremer (3M/ ESPE ) is a RMGI restorative material . The RMGis were applied to the dentinal surface in a thin layer. Clearfil SE Bond was applied to the...DEPARTMENT OF THE AIR FORCE 59TH MEDICAL WING (AETC) LACKLAND AIR FORCE BASE TEXAS MEMORANDUMFORSGVT ATTN: SSGT FJRAS ZAKO/KRAIG VANDEWALLE FROM...the designated wing POC. 4. Congratulations, and thank you for your efforts and time. Your contributions are vital to the medica l mission. We look

  10. Determining Composite Validity Coefficients for Army Jobs and Job Families

    National Research Council Canada - National Science Library

    Zeidner, Joseph

    2002-01-01

    ...) is to compute composite validity coefficients. using criterion data derived from the 1987 - 1989 Skill Qualifications Test program, for the 7-test ASVAB for 150, 17, and 9 job family structures...

  11. Evaluation of the shear bond strength of the Orthobond composite under different conditions

    Directory of Open Access Journals (Sweden)

    Antônio Carlos de Oliveira Ruellas

    2008-01-01

    Full Text Available Objective: Evaluate the shear bond strength of metal brackets bonded with Orthobond composite (Dental Morelli Ltda, Sorocaba, Brazil under different enamel surface conditions. Methods: Ninety bovine mandibular permanent incisors were divided into six groups (n = 15. In Group 1 (control and Group 2 the bonding procedures were performed by using Transbond XT (3M Unitek, Monrovia, USA and Orthobond (Dental Morelli Ltda, Sorocaba, Brazil composites,respectively, according to the manufacturer’s recommendations. In the other groups brackets were bonded with Orthobond composite (Dental Morelli Ltda, Sorocaba, Brazil as follows: Group 3 – dental surface conditioned with Transbond Plus Self-Etching Primer (3M Unitek, Monrovia, USA; Group 4 – bonding procedure without application of Orthoprimer (Dental Morelli Ltda, Sorocaba, Brazil; Group 5 - Eagle Bond applied on saliva/blood-contaminated dental surface; and Group 6 – use of homogenized Orthobond (Dental Morelli Ltda, Sorocaba, Brazil. After bonding the brackets, all the samples were submitted to shear bond strength tests by means of an Emic Universal Testing Machine at a crosshead speed of 0.5 mm/min. The results obtained in mega Pascal (MPa were submitted to the analysis of variance (ANOVA and then to the Tukey test. Results: The results in mega Pascal showed statistically significant differences between Groups 1 and 2 (p= 0.041, 1 and 5 (p=0.000 and between 4 and 5 (p=0.016. The ARI (Adhesive Remnant Index scores showed evidence of a higher number of fractures at the bracket/composite interface. Conclusion: In all tested situations the Orthobond (Dental Morelli Ltda, Sorocaba, Brazil was shown to be apt for bracket bonding.

  12. Effect of newer antioxidants on the bond strength of composite on bleached enamel

    Directory of Open Access Journals (Sweden)

    M Manoharan

    2016-01-01

    Full Text Available Aim: The study aims to evaluate the effect of the application of two antioxidants on the bond strength of composite resin to bleached enamel. Materials and Methods: Eighty enamel surfaces were obtained from forty human extracted premolars. Specimens were randomly divided into four groups (n = 20. Group 1: No bleaching (control; Group 2a: Bleaching with 15% carbamide peroxide gel; Group 2b: Bleaching, followed by application of 10% sodium ascorbate gel; Group 2c: Bleaching, followed by application of 5% proanthocyanidin agent. Surfaces were etched followed by application of total etch bonding system, and composite resin cylinders were bonded. Specimens were tested for shear bond strength. Statistical Analysis Used: One-way analysis of variance was used for multiple group comparison and post hoc Tukey′s test for individual group-wise comparison. Results: Significantly higher shear bond strength values were observed in Group 2c and 2b as compared with Group 1 and 2a (P < 0.05. Among the antioxidants, Group 2c showed significantly higher shear bond strength values than Group 2b (P < 0.05. Conclusion: It can be concluded that the use of antioxidant before bonding procedures on bleached enamel completely neutralizes the deleterious effects of bleaching and increases the bond strength significantly.

  13. Standard Guide for Acousto-Ultrasonic Assessment of Composites, Laminates, and Bonded Joints

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This guide explains the rationale and basic technology for the acousto-ultrasonic (AU) method. Guidelines are given for nondestructive evaluation (NDE) of flaws and physical characteristics that influence the mechanical properties and relative strength of composite structures (for example, filament-wound pressure vessels), adhesive bonds (for example, joints between metal plates), and interlaminar and fiber/matrix bonds in man-made composites and natural composites (for example, wood products). 1.2 This guide covers technical details and rules that must be observed to ensure reliable and reproducible quantitative AU assessments of laminates, composites, and bonded structures. The underlying principles, prototype apparatus, instrumentation, standardization, examination methods, and data analysis for such assessments are covered. Limitations of the AU method and guidelines for taking advantage of its capabilities are cited. 1.3 The objective of AU is to assess subtle flaws and associated strength variations...

  14. Finite Element Analysis of Quantitative Percussion Diagnostics for Evaluating the Strength of Bonds Between Composite Laminates

    Science.gov (United States)

    Poveromo, Scott; Malcolm, Doug; Earthman, James

    Conventional nondestructive (NDT) techniques used to detect defects in composites are not able to determine intact bond integrity within a composite structure and are costly to use on large and complex shaped surfaces. To overcome current NDT limitations, a new technology was adopted based on quantitative percussion diagnostics (QPD) to better quantify bond quality in fiber reinforced composite materials. Results indicate that this technology is capable of detecting weak (`kiss') bonds between flat composite laminates. Specifically, the local value of the probe force determined from quantitative percussion testing was predicted to be significantly lower for a laminate that contained a `kiss' bond compared to that for a well-bonded sample, which is in agreement with experimental findings. Experimental results were compared to a finite element analysis (FEA) using MSC PATRAN/NASTRAN to understand the visco-elastic behavior of the laminates during percussion testing. The dynamic FEA models were used to directly predict changes in the probe force, as well as effective stress distributions across the bonded panels as a function of time.

  15. Adjusting the Chemical Bonding of SnO2 @CNT Composite for Enhanced Conversion Reaction Kinetics.

    Science.gov (United States)

    Cheng, Yayi; Huang, Jianfeng; Qi, Hui; Cao, Liyun; Yang, Jun; Xi, Qiao; Luo, Xiaomin; Yanagisawa, Kazumichi; Li, Jiayin

    2017-08-01

    Carbon nanotubes (CNTs) with excellent electron conductivity are widely used to improve the electrochemical performance of the SnO2 anode. However, the chemical bonding between SnO2 and CNTs is not clearly elucidated despite it may affect the lithiation/delithiation behavior greatly. In this work, an SnO2 @CNT composite with SnC and SnOC bonds as a linkage bridge is reported and the influence of the SnC and SnOC bonds on the lithium storage properties is revealed. It is found that the SnC bond can act as an ultrafast electron transfer path, facilitating the reversible conversion reaction between Sn and Li2 O to form SnO2 . Therefore, the SnO2 @CNT composite with more SnC bond shows high reversible capacity and nearly half capacity contributes from conversion reaction. It is opposite for the SnO2 @CNT composite with more SnOC bond that the electrons cannot be transferred directly to CNTs, resulting in depressed conversion reaction kinetics. Consequently, this work can provide new insight for exploration and design of metal oxide/carbon composite anode materials in lithium-ion battery. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. The comparative evaluation of fracture resistance and microleakage in bonded amalgam, amalgam, and composite resins in primary molars

    Directory of Open Access Journals (Sweden)

    H S Vanishree

    2015-01-01

    Conclusions: Bonded amalgam appears to be comparable to amalgam when microleakage is considered and to composite resin when fracture resistance is considered; hence, bonded amalgam can also be an alternative material to amalgam in primary molars.

  17. Microleakage of three self-etch bonding agents in class 5 composite cavities

    Directory of Open Access Journals (Sweden)

    Saeed Nemati Anaraki

    2016-07-01

    Full Text Available Background and Aims: Microleakage is one of the most common problems in bonding systems, which cause different clinical shortcomings such as post operative sensitivity, marginal discoloration and pulp necrosis that can decrease those using bonding systems. The aim of this study was to compare the microleakage of three self etch bonding agents (generation 6 and 7 in class 5 composite cavities. Materials and Methods: In this experimental study, 30 facial class 5 cavities were prepared in 30 human premolar teeth which were freshly extracted for orthodontic purposes. Cl V cavities were prepared in 2*3*2 mm dimensions. Occlusal margins were in enamel and gingival ones in cementum and randomly divided into 3 groups of 10 each. Then the cavities were treated by clearhil SE Bond (Kuraray, Japan, G Bond (GC, Japan, and Opti Bond Solo Plus (Kerr, USA, according to the manufacturers’ insductions. Then the cavities were filled using Z100 resin composite. The specimens were then immersed in a 50% AgNo solution for 24 hrs. Then, the teeth were cut buccolingually to be evaluated for dye penetration with stereomicroscope. Data were analyzed using Kruskal-Wallis test. Results: This study revealed that Opti bond solo plus had type1 microleakage (dye penetration up to 1/3 of cavity in 80% of specimen, and type 4 microleakage (along axial wall in 10%. Clearfil SE bond had no leakage in 50%, type1 in 40% and type 2 (up to 2/3 of cavity in 10%. But there was no significant difference in the microleakage at the gingival margins between 3 groups (P>0.05. Conclusion: Clearfil SE Bond and G bond could prevent microleakage more effectively than that of Opti Bond Solo Plus on the occlusal margins. However, no difference in the microleakage on the gingival surfaces was found.

  18. In vitro evaluation of the bond strength of composite resin foundation materials to dentin.

    Science.gov (United States)

    Al-Ansari, Asim; Al-Harbi, Fahad; Baba, Nadim Z

    2015-10-01

    Achieving adequate bonding of composite resin foundation materials to dentin can be a challenge. Bonding can be affected by the type of bonding material and method used. The purpose of this in vitro study was to test the bond strengths of selected dual-polymerizing composite resin foundation materials to dentin using light, chemical, or dual-polymerized adhesive systems. Eighty freshly extracted human third molars were sectioned vertically into mesial and distal halves and embedded in acrylic resin using a copper cylinder. Specimens were divided into 16 groups. Each group received a resin foundation that was bonded to dentin according to each manufacturer's instructions. All tested foundations were dual polymerized except Tetric Ceram, which was light polymerized. BisCore, Build-it, CompCore, CoreRestore, and FluoroCore resin foundation materials were bonded to dentin with the use of the corresponding adhesives in 3 different bonding methods: adhesive was light polymerized; adhesive was chemically polymerized; and adhesive was dual polymerized. Each specimen was seated in a custom shear test device, and a load was applied with the descending rod of the jig from a mechanical testing machine with a perpendicular force to the dentin-adhesive interface. Statistical analysis was performed using 2-way ANOVA and post hoc pairwise comparison with Tukey test when statistically significant differences were found (α=.05). Resin foundation materials bonded to dentin with light-polymerized adhesives produced significantly higher bond strengths than when bonded with chemically or dual-polymerized adhesives. No significant difference was found between the single-component and multiple-components adhesives used with Tetric Ceram and BisCore foundations (P=.083). However, BisCore used with All-Bond 2 adhesive (multiple components) produced significantly lower bond strengths than when used with One-Step (P=.024). Adhesive failure was the most common failure location. Cohesive

  19. A comparative effect of various surface chemical treatments on the resin composite-composite repair bond strength

    Directory of Open Access Journals (Sweden)

    Shaloo Gupta

    2015-01-01

    Full Text Available Aim: The aim of this in vitro study was an attempt to investigate the effect of different surface treatments on the bond strength between pre-existing composite and repair composite resin. Materials and Methods: Forty acrylic blocks were prepared in a cuboidal mould. In each block, a well of 5 mm diameter and 5 mm depth was prepared to retain the composite resin (Filtek™ Z350, 3M/ESPE. Aging of the composite discs was achieved by storing them in water at 37°C for 1 week, and after that were divided into 5 groups (n = 8 according to surface treatment: Group I- 37% phosphoric acid, Group II-10% hydrofluoric acid, Group III-30% citric acid, Group IV-7% maleic acid and Group V- Adhesive (no etchant. The etched surfaces were rinsed and dried followed by application of bonding agent (Adper™ Single Bond 2. 3M/ESPE. The repair composite was placed on aged composite, light-cured for 40 seconds and stored in water at 37°C for 1 week. Shear bond strength between the aged and the new composite resin was determined with a universal testing machine (crosshead speed of 0.5 mm/min. Statistical Analysis: The compressive shear strengths were compared for differences using ANOVA test followed by Tamhane′s T2 post hoc analysis. Results: The surface treatment with 10% hydrofluoric acid showed the maximum bond strength followed by 30% citric acid, 7% maleic acid and 37% phosphoric acid in decreasing order. Conclusion: The use of 10% hydrofluoric acid can be a good alternative for surface treatment in repair of composite resin restoration as compared to commonly used 37% orthophosphoric acid.

  20. Effect of Pre-heating on Microtensile Bond Strength of Composite Resin to Dentin.

    Directory of Open Access Journals (Sweden)

    Abdolrahim Davari

    2014-10-01

    Full Text Available Direct composite resin restorations are widely used and the impact of different storage temperatures on composites is not well understood. The purpose of this study was to evaluate the microtensile bond strength of composite to dentin after different pre-curing temperatures.Occlusal surfaces of 44 human molars were ground with diamond burs under water coolant and polished with 600 grit silicon carbide papers to obtain flat dentin surfaces. The dentin was etched with 37% phosphoric acid and bonded with Adper Single Bond 2 according to the manufacturer's instructions. The specimens were randomly divided into two groups (n=22 according to the composite resin applied: FiltekP60 and Filtek Z250. Each group included three subgroups of composite resin pre-curing temperatures (4°C, 23°C and 37°C. Composite resins were applied to the dentin surfaces in a plastic mold (8mm in diameter and 4mm in length incrementally and cured. Twenty-two composite-to-dentin hour-glass sticks with one mm(2 cross-sectional area per group were prepared. Microtensile bond strength measurements were made using a universal testing machine at a crosshead speed of one mm/min. For statistical analysis, t-test, one-way and two-way ANOVA were used. The level of significance was set at P<0.05.Filtek P60 pre-heated at 37ºC had significantly higher microtensile bond strength than Filtek Z250 under the same condition. The microtensile bond strengths were not significantly different at 4ºC, 23ºC and 37ºC subgroups of each composite resin group.Filtek P60 and Filtek Z250 did not have significantly different microtensile bond strengths at 4ºC and 23ºC but Filtek P60 had significantly higher microtensile bond strength at 37 ºC. Composite and temperature interactions had significant effects on the bond strength.

  1. Investigation of the interfacial bonding in composite propellants. 1,3,5-Trisubstituted isocyanurates as universal bonding agents

    Directory of Open Access Journals (Sweden)

    GORDANA S. USCUMLIC

    2006-05-01

    Full Text Available A series of 1,3,5-trisubstituted isocyanurates (substituents: CH2CH2OH, CH2CH=CH2 and CH2CH2COOH was synthesized according to a modified literature procedure. Experimental investigations included modification of the synthetic procedure in terms of the starting materials, solvents, temperature, isolation techniques, as well as purification and identification of the products. All the synthesized isocyanurates were identified by their melting point and FTIR, 1H NMR and UV spectroscopic data. Fourier transform infrared spectrophotometry was also used to study the interaction between ammonium perchlorate, hydroxyl terminated poly(butadiene, carboxyl terminated poly(butadiene, poly(butadiene-co-acrylonitrile, poly(propylene ether, cyclotrimethylenetrinitramine and the compounds synthesized in this work, which can serve as bonding agents. The results show that tris(2-hydroxyethylisocyanurate is a universal bonding agent for the ammonium perchlorate/carboxyl terminated poly(butadiene/cyclotrimethylenetrinitramine composite propellant system.

  2. Push-Out Bond Strength of Restorations with Bulk-Fill, Flow, and Conventional Resin Composites

    Directory of Open Access Journals (Sweden)

    Rodrigo Vieira Caixeta

    2015-01-01

    Full Text Available The aim of this study was to evaluate the bond strengths of composite restorations made with different filler amounts and resin composites that were photoactivated using a light-emitting diode (LED. Thirty bovine incisors were selected, and a conical cavity was prepared in the facial surface of each tooth. All preparations were etched with Scotchbond Etching Gel, the Adper Scotchbond Multipurpose Plus adhesive system was applied followed by photoactivation, and the cavities were filled with a single increment of Filtek Z350 XT, Filtek Z350 XT Flow, or bulk-fill X-tra fil resin composite (n = 10 followed by photoactivation. A push-out test to determine bond strength was conducted using a universal testing machine. Data (MPa were submitted to Student’s t-test at a 5% significance level. After the test, the fractured specimens were examined using an optical microscope under magnification (10x. Although all three composites demonstrated a high prevalence of adhesive failures, the bond strength values of the different resin composites photoactivated by LED showed that the X-tra fil resin composite had a lower bond strength than the Filtek Z350 XT and Filtek Z350 XT Flow resin composites.

  3. Effects of different surface treatments on the bond strength of glass fiber-reinforced composite root canal posts to composite core material

    Directory of Open Access Journals (Sweden)

    Murat Kurt

    2012-03-01

    Conclusion: Er:YAG laser treatments on the FRC post surface decreased the bond strength. Airborne-particle abrasion and HF acid etching are alternative methods for increasing bond strength of FRC posts to composite core material.

  4. Influence of proximal box elevation on bond strength of composite inlays.

    Science.gov (United States)

    Da Silva Gonçalves, Dayana; Cura, María; Ceballos, Laura; Fuentes, Mª Victoria

    2017-01-01

    The objective of the present study was to evaluate the influence of proximal box elevation on microtensile bond strength (mTBS) of composite inlays to the proximal box floor, using either a total-etch or a self-adhesive resin cement. Twenty-five human molars were selected, and a class II OM (inlay) cavity preparation was performed in each tooth. Cavities were randomly assigned into four experimental groups, according to the location of the proximal cervical margin (located 1 mm below cementoenamel junction (CEJ), or with proximal box elevation with composite resin) and the resin cement used for luting (a total-etch resin cement RelyX ARC or a self-adhesive resin cement G-Cem). After 1-week water storage, samples were subjected to mTBS test. Results were analyzed by Kruskal-Wallis and Mann-Whitney U tests (p box elevation improved the bond strength of composite inlays for both resin cements. However, only for G-Cem was this improvement statistically significant. The proximal box elevation improved the bond strength attained by G-Cem resin cement. For RelyX ARC, the position of the cervical margin did not affect composite inlays bond strength. Proximal box elevation does not decline bond strength of composite inlays to the proximal floor when a total-etch or a self-adhesive resin cement is used.

  5. Resistance of Bonded Composite Restorations on Fractures of Endodontically Treated Teeth

    Directory of Open Access Journals (Sweden)

    AR Daneshkazemi

    2005-01-01

    Full Text Available Introduction: This study was performed to evaluate the effect of dentine bonding agents and Glass Ionomer cement beneath composite restorations and its resistance on fractures of endodontically treated teeth. Material and Methods: Forty sound maxillary teeth were selected; ten of them for positive control, and on the rest, RCT and MOD cavity preparations were done with standard methods. Then, the teeth were divided to four groups: 1-Sound teeth for positive control. 2-Prepared without any restoration for negative control. 3-Prepared and restored with Vitrabond(3M, USA, Single bond(3M, USA and Z100(3M, USA resin composite. 4-Prepared and restored by Single bond and Z100 resin composite. Specimens were subjected to compressive load by Instron 8502 until fracture occurred. Results: Group 1 showed the highest resistance to compressive forces followed by group 4,3&2 respectively. ANOVA, t test and Chi-square tests indicated significant difference between all the groups. Conclusion: Use of dentine bonding agents and resin composite increases resistance of endodontically treated teeth to fractures more than teeth restored with sandwich of glass ionomer cements, dentine bonding agents and resin composite.

  6. Recent Trends in Surface Treatment Methods for Bonding Composite Cement to Zirconia: A Reveiw.

    Science.gov (United States)

    Khan, Aftab Ahmed; Al Kheraif, Abdul Aziz A; Jamaluddin, Syed; Elsharawy, Mohamad; Divakar, Darshan Devang

    To evaluate the in vitro studies conducted in the last six years on new zirconia materials to discover and explore current trends in bonding composite cement to zirconia substrate. An in-depth review of the in vitro studies performed between 2010 and 2016 was conducted, focusing on the current trends in surface conditioning methods for zirconia ceramic. PubMed was used for searching the literature. Resin composite bonding to zirconia, zirconia surface coating, and zirconia surface treatment method were the keywords used. Complete scientific articles were reviewed and evaluated for appropriateness. The literature survey showed a variety of surface treatment techniques comprising grit blasting (laboratory or chairside) with or without silica-coated alumina particles, the use of materials containing phosphate monomers, different silanes and primers, laser irradiation, Si vapor-phase deposition, and selective infiltration etching. The problem of composite cement bonding to zirconia has yet to be definitively solved. Nevertheless, the application of phosphate monomer on tribochemically silica-coated zirconia surfaces is currently the least complicated and most efficaceous means of bonding composite cement to zirconia. Selective infiltration etching seems to be a promising technique for establishing a durable bond between composite cement and zirconia, and should be studied further.

  7. Effect of dentin primer on shear bond strength of composite resin to moist and dry enamel.

    Science.gov (United States)

    Jain, P; Stewart, G P

    2000-01-01

    The etched enamel-composite resin bond is the most reliable bond known to us. Moisture and dentin primers are the two most important variables that can interfere with this bond. This study investigated the effect of dentin primer on bond strengths of composite resin to moist and dry enamel. One hundred freshly extracted molar teeth were used for shear bond strength testing. The teeth were mounted in phenolic rings with an approximal enamel surface exposed. The exposed enamel surface on each tooth was flattened using 320- 400- and 600-grit silicon carbide papers and etched using 34-38% phosphoric acid gel. The teeth were then divided into 10 groups (n = 10). Four groups were assigned to each of the two dentin bonding systems, Scotchbond Multi-Purpose and OptiBond FL. Two groups were assigned to the single-bottle bonding agent (Single Bond). Each bonding system was tested on moist and dry enamel. OptiBond FL and Scotchbond MP were tested with and without the use of primer. All samples were thermocycled and tested in shear. Fracture analysis was performed using a binocular microscope. For scanning electron microscopy, approximal samples of enamel (1 mm thick) were flattened, etched, and bonded with and without primer on moist and dry enamel. A 1 mm-thick layer of Z100 was bonded to the specimens, which were then immersed in 10% HCl for 24 hours to dissolve the enamel. The specimens were viewed under a scanning electron microscope. Results indicated that the use of primer on dry enamel did not significantly affect (P > 0.05) shear bond strengths for the two bonding systems, Scotchbond MP (primed 24.10 +/- 4.83 MPa, unprimed 29.57 +/- 7.49 MPa) and OptiBond FL (primed 26.82 +/- 4.44, unprimed 25.66 +/- 2.95). However, the use of primer was found to be essential on moist enamel to obtain acceptable bond strengths with both Scotchbond MP (primed 25.61 +/- 10.29 MPa, unprimed 3.26 +/- 0.95 MPa) and OptiBond FL (primed 30.28 +/- 3.49 MPa, unprimed 8.37 +/- 3.31 MPa

  8. “Evaluation of shear bond strength of a composite resin to white mineral trioxide aggregate with three different bonding systems”-An in vitro analysis

    Science.gov (United States)

    Patil, Anand C.

    2016-01-01

    Background Mineral trioxide aggregate (MTA) is a biomaterial that has been investigated for endodontic applications. With the increased use of MTA in pulp capping, pulpotomy, perforation repair, apexification and obturation, the material that would be placed over MTA as a final restoration is an important matter. As composite resins are one of the most widely used final restorative materials, this study was conducted to evaluate the shear bond strength of a composite resin to white mineral trioxide aggregate (WMTA) using three different bonding systems namely the two-step etch and rinse adhesive, the self-etching primer and the All-in-one system. Material and Methods Forty five specimens of white MTA (Angelus) were prepared and randomly divided into three groups of 15 specimens each depending on the bonding systems used respectively. In Group A, a Two-step etch and rinse adhesive or ‘total-etch adhesive’, Adper Single Bond 2 (3M/ESPE) and Filtek Z350 (3M ESPE, St Paul, MN) were placed over WMTA. In group B, a Two-step self-etching primer system, Clearfil SE Bond (Kuraray, Medical Inc) and Filtek Z350 were used. In Group C, an All-in-one system, G Bond (GC corporation, Tokyo, Japan) and Filtek Z350 were used. The shear bond strength was measured for all the specimens. The data obtained was subjected to One way Analysis of Variance (ANOVA) and Scheffe’s post hoc test. Results The results suggested that the Two-step etch and rinse adhesive when used to bond a composite resin to white MTA gave better bond strength values and the All-in-one exhibited the least bond strength values. Conclusions The placement of composite used with a Two-step etch and rinse adhesive over WMTA as a final restoration may be appropriate. Key words:Composite resins, dentin bonding agents, mineral trioxide aggregate, shear bond strength. PMID:27398177

  9. Comparison of shear bond strengths of conventional orthodontic composite and nano-ceramic restorative composite: An in vitro study

    Directory of Open Access Journals (Sweden)

    Namit Nagar

    2013-01-01

    Full Text Available Objectives: To compare the shear bond strength of a nano-ceramic restorative composite Ceram-X MonoTM♦, a restorative resin with the traditional orthodontic composite Transbond XTTM† and to evaluate the site of bond failure using Adhesive Remnant Index. Materials and Methods: Sixty extracted human premolars were divided into two groups of 30 each. Stainless steel brackets were bonded using Transbond XTTM† (Group I and Ceram-X MonoTM♦ (Group II according to manufacturer′s protocol. Shear bond strength was measured on Universal testing machine at crosshead speed of 1 mm/minute. Adhesive Remnant Index scores were assigned to debonded brackets of each group. Data was analyzed using unpaired ′t′ test and Chi square test. Results: The mean shear bond strength of Group I (Transbond XTTM† was 12.89 MPa ± 2.19 and that of Group II (Ceram-X MonoTM was 7.29 MPa ± 1.76. Unpaired ′t′ test revealed statistically significant differences amongst the shear bond strength of the samples measured. Chi-square test revealed statistically insignificant differences amongst the ARI scores of the samples measured. Conclusions: Ceram-X MonoTM♦ had a lesser mean shear bond strength when compared to Transbond XTTM† which was statistically significant difference. However, the mean shear bond of Ceram X Mono was within the clinically acceptable range for bonding. Ceram-X MonoTM† and Transbond XTTM† showed cohesive fracture of adhesive in 72.6% and 66.6% of the specimens, respectively.

  10. Long-term Bond Strength between Layering Indirect Composite Material and Zirconia Coated with Silicabased Ceramics.

    Science.gov (United States)

    Fushiki, Ryosuke; Komine, Futoshi; Honda, Junichi; Kamio, Shingo; Blatz, Markus B; Matsumura, Hideo

    2015-06-01

    This study evaluated the long-term shear bond strength between an indirect composite material and a zirconia framework coated with silica-based ceramics, taking the effect of different primers into account. A total of 165 airborne-particle abraded zirconia disks were subjected to one of three pretreatments: no pretreatment (ZR-AB), airborne-particle abrasion of zirconia coated with feldspathic porcelain (ZR-PO-AB), and 9.5% hydrofluoric acid etching of zirconia coated with feldspathic porcelain (ZR-PO-HF). An indirect composite material (Estenia C&B) was then bonded to the zirconia disks after they were treated with one of the following primers: Clearfil Photo Bond (CPB), Clearfil Photo Bond with Clearfil Porcelain Bond Activator (CPB + Activator), Estenia Opaque Primer (EOP), Porcelain Liner M Liquid B (PLB), or no priming (CON, control group). Shear bond strength was tested after 100,000 thermocycles, and the data were analyzed using the Steel-Dwass U-test (α = 0.05). For ZR-PO-AB and ZR-PO-HF specimens, bond strength was highest in the CPB+Activator group (25.8 MPa and 22.4 MPa, respectively). Bond strengths were significantly lower for ZR-AB specimens in the CON and PLB groups and for ZR-PO-AB specimens in the CON, CPB, and EOP groups. Combined application of a hydrophobic phosphate monomer (MDP) and silane coupling agent enhanced the long-term bond strength of indirect composite material to a zirconia coated with silica-based ceramics.

  11. The effect of bonding and surface sealant application on postoperative sensitivity from posterior composites

    OpenAIRE

    Tekce, Neslihan; Demirci, Mustafa; Gokturk, Sultan Aslıhan; Tuncer, Safa; Ozel, Emre; Pala, Kansad; Baydemir, Canan

    2015-01-01

    Purpose: The purpose of the study was to evaluate the postoperative sensitivity of posterior Class I composite restoration at short-term, restorated with two different all-in-one self-etch adhesives with or without surface sealant application. Materials and Methods: 44 restorations were inserted in 11 patients who required Class I restorations in their molars. Each patient received 4 restorations, thus four groups were formed; (1) G-Aenial Bond (GC, Japan); (2) Clearfil S3 Bond (Kuraray, Japa...

  12. Shear Bond Strength of Composite-Resin to Porcelain: Effect of Thermocycling

    Directory of Open Access Journals (Sweden)

    M. Khoroushi

    2007-03-01

    Full Text Available Objective: Different ceramic repair systems have been reported for fractured ceramics.However, limited information is available concerning the bond strength of these systems especially after thermocycling. The aim of this in-vitro study was to determinethe effect of thermocycling on the shear bond strength of composite-resin to feldspathic porcelain with and without silane pretreatment.Materials and Methods: In this experimental study, forty porcelain blocks were prepared and randomly divided into four groups (n=10. All porcelain surfaces were etched with 9.6% hydrofluoric acid, rinsed and air dried. In groups 1 and 3, silane pretreatment was applied using Adper Scotchbond Multipurpose Plus (ASMP.Smallparticlecomposite-resin was subsequently added on the ceramic surfaces, and lightcured.Specimens of groups 3 and 4 then subjected to 1000 thermal cycles. Shear bond strength was determined on a universal testing machine at a crosshead speed of 1mm/min. Two-way ANOVA test (α=0.05 was used to analyze the bond strength.Results: There were statistically significant differences between study groups (P<0.05.Thermocycling caused a decrease in the shear bond strength for both silanized and nonsilanized groups.Conclusion: According to the results of this study, shear bond strength after thermocycling reduced considerably in ASMP system. In addition, silane treatment of porcelain was critical for achieving durable bond strength between composite-resin and porcelain.

  13. Comparative study to evaluate shear bond strength of RMGIC to composite resin using different adhesive systems

    Science.gov (United States)

    Chandak, Manoj G.; Pattanaik, Navdheeraj; Das, Ayan

    2012-01-01

    Aim: The aim of the study is to compare and evaluate the role of new dental adhesives to bond composite to the resinmodified glass inomer cement (RMGIC). Materials and Methods: Thirty specimens were prepared on acrylic blocks, with wells prepared in it by drilling holes, to retain the RMGIC. The specimens were randomly divided into three groups of ten specimens each. In Group a thin layer of selfetch adhesive (3M ESPE) was applied between the RMGIC and the composite resin FILTEK P60 (3M SPE). In Group II, total etch adhesive (Adeper Scotch bond 2, 3M ESPE) was applied, and in Group III, there was no application of any adhesive between RMGIC and the composite resin. After curing all the specimens, the shear bond strength was measured using an Instron universal testing machine. Results: The results were drawn and tabulated using ANOVA-fishers and Dunnet D statistical tests.The maximum shear bond strength values were recorded in Group I specimens with self-etch adhesive showing a mean value of 2.74 when compared to the Group II adhesive (Total etch) showing a mean shear strength of value 1.89, where no adhesive was used, showed a minimum mean shear bond strength of 1.42. There was a great and significant difference between Group I and Group II (P value 0.05) whereas, both Group I and Group II showed a vast and significant difference from Group III (P value = 0–001). Conclusion: Hence, this present study concludes that application of self-etch adhesive (3M ESPE, U.S.A) in between RMGIC and composite resin increases the shear bond strength between RMGIC and the resin composites, as compared to the total-etch type adhesive (Adeper Scotch bond 2,3M ESPE, U.S.A) as well as without application of the adhesive agent. PMID:23293476

  14. Comparative study to evaluate shear bond strength of RMGIC to composite resin using different adhesive systems

    Directory of Open Access Journals (Sweden)

    Manoj G Chandak

    2012-01-01

    Full Text Available Aim: The aim of the study is to compare and evaluate the role of new dental adhesives to bond composite to the resinmodified glass inomer cement (RMGIC. Materials and Methods: Thirty specimens were prepared on acrylic blocks, with wells prepared in it by drilling holes, to retain the RMGIC. The specimens were randomly divided into three groups of ten specimens each. In Group a thin layer of selfetch adhesive (3M ESPE was applied between the RMGIC and the composite resin FILTEK P60 (3M SPE. In Group II, total etch adhesive (Adeper Scotch bond 2, 3M ESPE was applied, and in Group III, there was no application of any adhesive between RMGIC and the composite resin. After curing all the specimens, the shear bond strength was measured using an Instron universal testing machine. Results: The results were drawn and tabulated using ANOVA-fishers and Dunnet D statistical tests.The maximum shear bond strength values were recorded in Group I specimens with self-etch adhesive showing a mean value of 2.74 when compared to the Group II adhesive (Total etch showing a mean shear strength of value 1.89, where no adhesive was used, showed a minimum mean shear bond strength of 1.42. There was a great and significant difference between Group I and Group II (P value 0.05 whereas, both Group I and Group II showed a vast and significant difference from Group III (P value = 0-001. Conclusion: Hence, this present study concludes that application of self-etch adhesive (3M ESPE, U.S.A in between RMGIC and composite resin increases the shear bond strength between RMGIC and the resin composites, as compared to the total-etch type adhesive (Adeper Scotch bond 2,3M ESPE, U.S.A as well as without application of the adhesive agent.

  15. Efficacy of Experimental Hydrofluoric Acid (HF on Bond Strength and Microleakage of Composite-Porcelain Interface

    Directory of Open Access Journals (Sweden)

    Samaneh Mahvidyzadeh

    2012-09-01

    Full Text Available Background and Aims: The aim of this study was to evaluate the quality of an experimental hydrofluoric acid (HF for preparation of porcelain and to compare it with two commercial hydrofluoric acids in Iranian trademark. Materials and Methods: A- Evaluation of etch pattern of experimental HF using scanning electron microscope (SEM: 6 feldespathic discs were divided into 3 groups. Each group was etched with related HF (experimental, Ultradent and Kimia for 1 minute. SEM images were recorded at 3 magnifications. B- Bond strength test: 18 feldespathic discs were considered for each acidic group. Then the porcelain surfaces were etched and bonded to composite with unfilled resin. Consequently, the microshear test was done. C- Microleakage test: 54 discs were divided into 3 groups (n=18. Then the porcelain surfaces were etched and bonded to composite with unfilled resin and finally observed under stereomicroscope. The data were analyzed with one-way ANOVA and Smirnov tests. Results: SEM analysis showed no difference between groups in terms of etch pattern. Microshear bond strength values for experimental, Kimia, and Ultradent HF were 28.53 (±4.92, 28.21 (±6.61, and 26.14 (±7.61 MPa, respectively. There was no significant difference between the bond strength of test groups (P0.05. Conclusion: Quality of experimental HF in terms of etch pattern, microshear bond strength and microleakage of composite/porcelain interface was similar to that of two commercial hydrofluoric acids.

  16. Bio-inspired carbon nanotube-polymer composite yarns with hydrogen bond-mediated lateral interactions.

    Science.gov (United States)

    Beese, Allison M; Sarkar, Sourangsu; Nair, Arun; Naraghi, Mohammad; An, Zhi; Moravsky, Alexander; Loutfy, Raouf O; Buehler, Markus J; Nguyen, SonBinh T; Espinosa, Horacio D

    2013-04-23

    Polymer composite yarns containing a high loading of double-walled carbon nanotubes (DWNTs) have been developed in which the inherent acrylate-based organic coating on the surface of the DWNT bundles interacts strongly with poly(vinyl alcohol) (PVA) through an extensive hydrogen-bond network. This design takes advantage of a toughening mechanism seen in spider silk and collagen, which contain an abundance of hydrogen bonds that can break and reform, allowing for large deformation while maintaining structural stability. Similar to that observed in natural materials, unfolding of the polymeric matrix at large deformations increases ductility without sacrificing stiffness. As the PVA content in the composite increases, the stiffness and energy to failure of the composite also increases up to an optimal point, beyond which mechanical performance in tension decreases. Molecular dynamics (MD) simulations confirm this trend, showing the dominance of nonproductive hydrogen bonding between PVA molecules at high PVA contents, which lubricates the interface between DWNTs.

  17. Influence of curing rate of resin composite on the bond strength to dentin

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Asmussen, E; Peutzfeldt, A

    2007-01-01

    This study determined whether the strength with which resin composite bonds to dentin is influenced by variations in the curing rate of resin composites. Resin composites were bonded to the dentin of extracted human molars. Adhesive (AdheSE, Ivoclar Vivadent) was applied and cured (10 seconds...... @ 1000 mW/cm2) for all groups. A split Teflon mold was clamped to the treated dentin surface and filled with resin composite. The rate of cure was varied, using one of four LED-curing units of different power densities. The rate of cure was also varied using the continuous or pulse-delay mode...... of the four power densities was followed by a one-minute interval, after which light cure was completed (14, 29, 27 or 78 seconds), likewise, giving a total energy density of 16 J/cm2. The specimens produced for each of the eight curing protocols and two resin composites (Tetric EvoCeram, Ivoclar Vivadent...

  18. A dense and strong bonding collagen film for carbon/carbon composites

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Sheng; Li, Hejun, E-mail: lihejun@nwpu.edu.cn; Li, Kezhi; Lu, Jinhua; Zhang, Leilei

    2015-08-30

    Graphical abstract: - Highlights: • Significantly enhancement of biocompatibility on C/C composites by preparing a collagen film. • The dense and continuous collagen film had a strong bonding strength with C/C composites after dehydrathermal treatment (DHT) crosslink. • Numerous oxygen-containing functional groups formed on the surface of C/C composites without matrix damage. - Abstract: A strong bonding collagen film was successfully prepared on carbon/carbon (C/C) composites. The surface conditions of the modified C/C composites were detected by contact angle measurements, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and Raman spectra. The roughness, optical morphology, bonding strength and biocompatibility of collagen films at different pH values were detected by confocal laser scanning microscope (CLSM), universal test machine and cytology tests in vitro. After a 4-h modification in 30% H{sub 2}O{sub 2} solution at 100 °C, the contact angle on the surface of C/C composites was decreased from 92.3° to 65.3°. Large quantities of hydroxyl, carboxyl and carbonyl functional groups were formed on the surface of the modified C/C composites. Then a dense and continuous collagen film was prepared on the modified C/C substrate. Bonding strength between collagen film and C/C substrate was reached to 8 MPa level when the pH value of this collagen film was 2.5 after the preparing process. With 2-day dehydrathermal treatment (DHT) crosslinking at 105 °C, the bonding strength was increased to 12 MPa level. At last, the results of in vitro cytological test showed that this collagen film made a great improvement on the biocompatibility on C/C composites.

  19. Study of the damaging mechanisms of a carbon - carbon composite bonded to copper under thermomechanical loading; Etude des mecanismes d'endommagement d'un assemblage cuivre / composite carbone - carbone sous chargement thermomecanique

    Energy Technology Data Exchange (ETDEWEB)

    Moncel, L

    1999-06-15

    The purpose of this work is to understand and to identify the damaging mechanisms of Carbon-Carbon composite bonded to copper under thermomechanical loading. The study of the composite allowed the development of non-linear models. These ones have been introduced in the finite elements analysis code named CASTEM 2000. They have been validated according to a correlation between simulation and mechanical tests on multi-material samples. These tests have also permitted us to better understand the behaviour of the bonding between composite and copper (damaging and fracture modes for different temperatures) under shear and tensile loadings. The damaging mechanisms of the bond under thermomechanical loading have been studied and identified according to microscopic observations on mock-ups which have sustained thermal cycling tests: some cracks appear in the composite, near the bond between the composite and the copper. The correlation between numerical and experimental results have been improved because of the reliability of the composite modelization, the use of residual stresses and the results of the bond mechanical characterisation. (author)

  20. Laser Surface Preparation of Epoxy Composites for Secondary Bonding: Optimization of Ablation Depth

    Science.gov (United States)

    Palmieri, Frank L.; Hopkins, John; Wohl, Christopher J.; Lin, Yi; Connell, John W.; Belcher, Marcus A.; Blohowiak, Kay Y.

    2015-01-01

    Surface preparation has been identified as one of the most critical aspects of attaining predictable and reliable adhesive bonds. Energetic processes such as laser ablation or plasma treatment are amenable to automation and are easily monitored and adjusted for controlled surface preparation. A laser ablation process was developed to accurately remove a targeted depth of resin, approximately 0.1 to 20 micrometers, from a carbon fiber reinforced epoxy composite surface while simultaneously changing surface chemistry and creating micro-roughness. This work demonstrates the application of this process to prepare composite surfaces for bonding without exposing or damaging fibers on the surface. Composite panels were prepared in an autoclave and had a resin layer approximately 10 micrometers thick above the fiber reinforcement. These composite panels were laser surface treated using several conditions, fabricated into bonded panels and hygrothermally aged. Bond performance of aged, experimental specimens was compared with grit blast surface treated specimens using a modified double cantilever beam test that enabled accelerated saturation of the specimen with water. Comparison of bonded specimens will be used to determine how ablation depth may affect average fracture energies and failure modes.

  1. Influence of increment thickness on dentin bond strength and light transmission of composite base materials.

    Science.gov (United States)

    Omran, Tarek A; Garoushi, Sufyan; Abdulmajeed, Aous A; Lassila, Lippo V; Vallittu, Pekka K

    2017-06-01

    Bulk-fill resin composites (BFCs) are gaining popularity in restorative dentistry due to the reduced chair time and ease of application. This study aimed to evaluate the influence of increment thickness on dentin bond strength and light transmission of different BFCs and a new discontinuous fiber-reinforced composite. One hundred eighty extracted sound human molars were prepared for a shear bond strength (SBS) test. The teeth were divided into four groups (n = 45) according to the resin composite used: regular particulate filler resin composite: (1) G-ænial Anterior [GA] (control); bulk-fill resin composites: (2) Tetric EvoCeram Bulk Fill [TEBF] and (3) SDR; and discontinuous fiber-reinforced composite: (4) everX Posterior [EXP]. Each group was subdivided according to increment thickness (2, 4, and 6 mm). The irradiance power through the material of all groups/subgroups was quantified (MARC® Resin Calibrator; BlueLight Analytics Inc.). Data were analyzed using two-way ANOVA followed by Tukey's post hoc test. SBS and light irradiance decreased as the increment's height increased (p composite used. EXP presented the highest SBS in 2- and 4-mm-thick increments when compared to other composites, although the differences were not statistically significant (p > 0.05). Light irradiance mean values arranged in descending order were (p composites. Discontinuous fiber-reinforced composite showed the highest value of curing light transmission, which was also seen in improved bonding strength to the underlying dentin surface. Discontinuous fiber-reinforced composite can be applied safely in bulks of 4-mm increments same as other bulk-fill composites, although, in 2-mm thickness, the investigated composites showed better performance.

  2. Strengthening of Concrete Structures with cement based bonded composites

    DEFF Research Database (Denmark)

    Täljsten, Björn; Blanksvärd, Thomas

    2008-01-01

    Due to demands on higher loads, degradation, re-construction etc. there is a constant need for repair or strengthening of existing concrete structures. Many varying methods exist to strengthen concrete structures, one such commonly used technique utilizes surface epoxy bonded FRPs (Fibre Reinforced...... with improved working environment and better compatibility to the base concrete structure. This study gives an overview of different cement based systems, all with very promising results for structural upgrading. Studied parameters are structural retrofit for bending, shear and confinement. It is concluded...... that the use of carbon FRPs provides the highest strengthening effect and that the fibres should be imbedded into a matrix for enhanced utilisation of inherent strain capacity...

  3. Reliability Analysis for Adhesive Bonded Composite Stepped Lap Joints Loaded in Fatigue

    DEFF Research Database (Denmark)

    Kimiaeifar, Amin; Sørensen, John Dalsgaard; Lund, Erik

    2012-01-01

    This paper describes a probabilistic approach to calculate the reliability of adhesive bonded composite stepped lap joints loaded in fatigue using three- dimensional finite element analysis (FEA). A method for progressive damage modelling is used to assess fatigue damage accumulation and residual...... by the wind turbine standard IEC 61400-1. Finally, an approach for the assessment of the reliability of adhesive bonded composite stepped lap joints loaded in fatigue is presented. The introduced methodology can be applied in the same way to calculate the reliability level of wind turbine blade components...

  4. Processing and properties of FeAl-bonded composites

    Energy Technology Data Exchange (ETDEWEB)

    Schneibel, J.H.; Subramanian, R.; Alexander, K.B.; Becher, P.F. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1996-12-31

    Iron aluminides are thermodynamically compatible with a wide range of ceramics such as carbides, borides, oxides, and nitrides, which makes them suitable as the matrix in composites or cermets containing fine ceramic particulates. For ceramic contents varying from 30 to 60 vol.%, composites of Fe-40 at. % Al with WC, TiC, TiB{sub 2}, and ZrB{sub 2} were fabricated by conventional liquid phase sintering of powder mixtures. For ceramic contents from 70 to 85 vol.%, pressureless melt infiltration was found to be a more suitable processing technique. In FeAl-60 vol.% WC, flexure strengths of up to 1.8 GPa were obtained, even though processing defects consisting of small oxide clusters were present. Room temperature fracture toughnesses were determined by flexure testing of chevron-notched specimens. FeAl/WC and FeAl/TiC composites containing 60 vol.% carbide particles exhibited K{sub Q} values around 20 MPa m{sup 1/2}. Slow crack growth measurements carried out in water and in dry oxygen suggest a relatively small influence of water-vapor embrittlement. It appears therefore that the mechanical properties of iron aluminides in the form of fine ligaments are quite different from their bulk properties. Measurements of the oxidation resistance, dry wear resistance, and thermal expansion of iron aluminide composites suggest many potential applications for these new materials.

  5. Evaluation of shear bond strength of composite resin to nonprecious metal alloys with different surface treatments

    Directory of Open Access Journals (Sweden)

    Yassini E.

    2007-07-01

    Full Text Available Background and Aim: Replacing fractured ceramometal restorations may be the best treatment option, but it is costly. Many different bonding systems are currently available to repair the fractured ceramometal restorations. This study compared the shear bond strength of composite to a base metal alloy using 4 bonding systems.Materials and Methods: In this experimental in vitro study, fifty discs, casted in a Ni-Cr-Be base metal alloy (Silvercast, Fulldent,were ground with 120, 400 and 600 grit sandpaper and divided equally into 5 groups receiving 5 treatments for veneering. Conventional feldspathic porcelain (Ceramco2, Dentsply Ceramco was applied on control group (PFM or group1 and the remaining metal discs were air- abraded for 15 seconds with 50 mm aluminum oxide at 45 psi and washed for 5 seconds under tap water.Then the specimens were dried by compressed air and the  groups were treated with one of the bonding systems as follows: All-Bond 2 (AB, Ceramic Primer (CP, Metal Primer II (MP and Panavia F2 (PF. An opaque composite (Foundation opaque followed by a hybrid composite (Gradia Direct was placed on the treated metal surface and light cured separately. Specimens were stored in distilled water at 370C and thermocycled prior to shear strength testing. Fractured specimens were evaluated under a stereomicroscope. Statistical analysis was performed with one way ANOVA and Tukey HSD tests. P<0.05 was considered as the level of significance.Results: Mean shear bond strengths of the groups in MPa were as follows: PFM group 38.6±2, All-Bond 2 17.06±2.85, Ceramic Primer 14.72±1.2, Metal Primer II 19.04±2.2 and Panavia F2 21.37±2.1. PFM group exhibited the highest mean shear bond strength and Ceramic Primer showed the lowest. Tukey's HSD test revealed the mean bond strength of the PFM group to be significantly higher than the other groups (P<0.001. The data for the PF group was significantly higher than AB and CP groups (P<0.05 and the shear

  6. Influence of air-abrasion on zirconia ceramic bonding using an adhesive composite resin.

    Science.gov (United States)

    Yang, B; Barloi, A; Kern, M

    2010-01-01

    Air-abrasion as bonding conditioning method for zirconia ceramic might compromise the mechanical strength of zirconia restorations. The purpose of this study was to evaluate the influence of surface conditioning parameters, i.e., air-abrasion with reduced pressure or no air-abrasion and priming with adhesive primers on the long-term resin bond strength to zirconia ceramic. Zirconia ceramic disks were polished with 600 grit abrasive paper. Plexiglas tubes filled with composite resin were bonded with RelyX Unicem luting composite resin to the conditioned zirconia disks. Three surface conditions (unconditioned, air-born particle abrasion at 0.05 or 0.25 MPa) and four priming conditions (no priming, priming with Metal/Zirconia Primer, priming with Alloy Primer, priming with Clearfil Ceramic Primer) were tested. Sixteen specimens of each combination were bonded. Subgroups of eight bonded samples were stored in water either for 3 days or 150 days with 37,500 thermocycling. Tensile bond strengths (TBSs) were determined with a universal testing machine at a crosshead speed of 2mm/min. Without priming, RelyX Unicem showed durable bond strength to 0.25 MPa airborne-particle abraded ceramic. When combined with 10-methacryloyloxy-decyl dihydrogenphosphate containing primers, air-abrasion resulted in a durable TBS to zirconia ceramic even at a reduced abrasion pressure. However, combined with Metal/Zirconia Primer air-abrasion did not provide a durable TBS to zirconia ceramic. Using a self-adhesive luting resin composite (RelyX Unicem), air-abrasion at 0.25 MPa or the combination of low pressure air-abrasion and priming with MDP-containing primers seems to be useful to achieve durable long-term bonding to zirconia ceramic.

  7. Microleakage and Shear Bond Strength of Composite Restorations Under Cycling Conditions.

    Science.gov (United States)

    Zanatta, R F; Lungova, M; Borges, A B; Torres, Crg; Sydow, H-G; Wiegand, A

    The aim of this study was to evaluate microleakage and shear bond strength of composite restorations under different cycling conditions. Class V cavities were prepared in the buccal and lingual surfaces of 30 human molars (n=60). A further 60 molars were used to prepare flat enamel and dentin specimens (n=60 each). Cavities and specimens were divided into six groups and pretreated with an adhesive (self-etch/Clearfil SE Bond or etch-and-rinse/Optibond FL). Composite was inserted in the cavities or adhered to the specimens' surfaces, respectively, and submitted to cycling (control: no cycling; thermal cycling: 10,000 cycles, 5°C to 55°C; thermal/erosive cycling: thermal cycling plus storage in hydrochloric acid pH 2.1, 5 minutes, 6×/day, 8 days). Microleakage was quantified by stereomicroscopy in enamel and dentin margins after immersion in silver nitrate. Specimens were submitted to shear bond strength testing. Statistical analysis was done by two-way analysis of variance and Kruskal-Wallis tests (pcycling or thermal/erosive cycling. Erosive conditions increased microleakage compared with thermal cycling (significant only for Clearfil SE Bond). No significant differences were observed in dentin margins. Bond strength of enamel specimens was reduced by thermal cycling and thermal/erosive cycling when Clearfil SE Bond was used and only by thermal/erosive cycling when Optibond FL was used. No differences were observed among dentin specimens. Thermal/erosive cycling can adversely affect microleakage and shear bond strength of composite resin bonded to enamel.

  8. Bond strength between fiber posts and composite resin core: influence of temperature on silane coupling agents.

    Science.gov (United States)

    Novais, Veridiana Resende; Simamotos Júnior, Paulo Cézar; Rontani, Regina Maria Puppin; Correr-Sobrinho, Lourenço; Soares, Carlos José

    2012-01-01

    This study evaluated the effect of air drying temperature and different silane coupling agents on the bond strength between glass fiber posts and composite resin core. The post surface was cleaned with alcohol and treated with different silane coupling agents, being three prehydrolyzed silanes [Silano (Angelus), Prosil (FGM), RelyX Ceramic Primer (3M ESPE)] and one two-component silane [Silane Coupling Agent (Dentsply)]. Two post-silanization air drying temperatures, 23ºC and 60ºC, were applied. A cylindrical plastic matrix was placed around the silanized post and filled with composite resin. Each bonded post provided 7 slices for push-out testing. Each slice was loaded to failure under compression at a cross-head speed of 0.5 mm/min. Data were analyzed by two-way ANOVA and Scott-Knott tests (α=0.05). Dunnett's test was used to compare the mean of the control group with that of each experimental group. Scanning electron microscopy (SEM) was used to evaluate the interface of the fractured slices. For the 23ºC air drying temperature, the use of RelyX Ceramic Primer resulted in significantly lower bond strength than the other silane coupling agents, while the bond strength with Silane Coupling Agent was the highest of all groups. Only with Silane Coupling Agent, the bond strength for the 23ºC air drying temperature was significantly higher than that for 60ºC air drying. In conclusion, the use of warm air drying after silane application produced no increase in the bond strength between the fiber-reinforced composite post and the composite core. The two-component silane produced higher bond strength than all prehydrolyzed silanes when it was used with air drying at room temperature.

  9. [Effects of different surface conditioning agents on the bond strength of resin-opaque porcelain composite].

    Science.gov (United States)

    Liu, Wenjia; Fu, Jing; Liao, Shuang; Su, Naichuan; Wang, Hang; Liao, Yunmao

    2014-04-01

    The objective of this research is to evaluate the effects of different silane coupling agents on the bond strength between Ceramco3 opaque porcelain and indirect composite resin. Five groups of Co-Cr metal alloy substrates were fabricated according to manufacturer's instruction. The surface of metal alloy with a layer of dental opaque porcelain was heated by fire. After the surface of opaque porcelain was etched, five different surface treatments, i.e. RelyX Ceramic Primer (RCP), Porcelain Bond Activator and SE Bond Primer (mixed with a proportion of 1:1) (PBA), Shofu Porcelain Primer (SPP), SE bond primer (SEP), and no primer treatment (as a control group), were used to combine P60 and opaque porcelain along with resin cement. Shear bond strength of specimens was tested in a universal testing machine. The failure modes of specimens in all groups were observed and classified into four types. Selected specimens were subjected to scanning electron microscope and energy disperse spectroscopy to reveal the relief of the fracture surface and to confirm the failure mode of different types. The experimental results showed that the values of the tested items in all the tested groups were higher than that in the control group. Group PBA exhibited the highest value [(37.52 +/- 2.14) MPa] and this suggested a fact that all of the specimens in group PBA revealed combined failures (failure occurred in metal-porcelain combined surface and within opaque porcelain). Group SPP and RCP showed higher values than SEP (P porcelain or composite resin) while all the specimens in group SEP and control group revealed adhesive failures. Conclusions could be drawn that silane coupling agents could reinforce the bond strength of dental composite resin to metal-opaque porcelain substrate. The bond strength between dental composite resin and dental opaque porcelain could meet the clinical requirements.

  10. Microstructure characterization of erosion resistant coatings on carbon-bonded carbon fibre composites.

    Science.gov (United States)

    Moskalewicz, T; Smeacetto, F; Salvo, M; Boccaccini, A R; Czyrska-Filemonowicz, A

    2010-03-01

    The microstructure of as received and surface treated carbon-bonded carbon fibre composites has been examined by light microscopy, scanning and transmission electron microscopy. The microstructure of the as received material consists of a bonded together layered carbon fiber network, identified as graphitic carbon (hexagonal close packed). To improve the erosion resistance of the carbon-bonded carbon fibre composites composite, the SiC and silicate glass-ceramic coatings from the system SiO(2)-Al(2)O(3)-Y(2)O(3) were produced on carbon-bonded carbon fibre composites composites by a low-cost slurry technique. Transmission electron microscopy investigations of cross-section thin foils allowed for detailed analysis of the coatings microstructure. It was found that the SiC coating was consisting mainly of a nanocrystalline SiC (fcc). The multilayered glass-ceramic coating showed a complex microstructure consisting of an external SiO(2)-Al(2)O(3)-Y(2)O(3) layer and an intermediate nanocrystalline SiC layer. The SiO(2)-Al(2)O(3)-Y(2)O(3) layer was composed of SiO(2) (fcc), Y(2)Si(2)O(7) (op) and Al(4.644)Si(1.357)O(9.68) (op).

  11. Are nano-composites and nano-ionomers suitable for orthodontic bracket bonding?

    Science.gov (United States)

    Uysal, Tancan; Yagci, Ahmet; Uysal, Banu; Akdogan, Gülsen

    2010-02-01

    The aim of this study was to test nano-composite (Filtek Supreme Plus Universal) and a newly introduced nano-ionomer (Ketac N100 Light Curing Nano-Ionomer) restorative to determine their shear bond strength (SBS) and failure site locations in comparison with a conventional light-cure orthodontic bonding adhesive (Transbond XT). Sixty freshly extracted human maxillary premolar teeth were arbitrarily divided into three equal groups. The brackets were bonded to the teeth in each group with different composites, according to the manufacturers' instructions. The SBS values of the brackets were recorded in Megapascals (MPa) using a universal testing machine. Adhesive remnant index scores were determined after failure of the brackets. The data were analysed using analysis of variance, Tukey honestly significant difference, and chi-square tests. The results demonstrated that group 1 (Transbond XT, mean: 12.60 +/- 4.48 MPa) had a higher SBS than that of group 2 (nano-composite, mean: 8.33 +/- 5.16 MPa; P < 0.05) and group 3 (nano-ionomer, mean: 6.14 +/- 2.12 MPa; P < 0.001). No significant differences in debond locations were found among the three groups. Nano-composites and nano-ionomers may be suitable for bonding since they fulfil the previously suggested SBS ranges for clinical acceptability, but they are inferior to a conventional orthodontic composite.

  12. Effect of an Extra Hydrophobic Resin Layer on Repair Shear Bond Strength of a Silorane-Based Composite Resin

    Directory of Open Access Journals (Sweden)

    Narmin Mohammadi

    2016-08-01

    Full Text Available Objectives: Composite repair is a minimally invasive and conservative approach. This study aimed to evaluate the effect of an additional hydrophobic resin layer on the repair shear bond strength of a silorane-based composite repaired with silorane or methacrylate-based composite.Materials and Methods: Sixty bar-shaped composite blocks were fabricated and stored in saline for 72 hours. The surface of the samples were roughened by diamond burs and etched with phosphoric acid; then, they were randomly divided into three groups according to the repairing process: Group 1: Silorane composite-silorane bonding agent-silorane composite; group 2: Silorane composite-silorane bonding agent- hydrophobic resin-silorane composite, and group 3: Silorane composite-silorane bonding agent-hydrophobic resin methacrylate-based composite. Repairing composite blocks measured 2.5×2.5×5mm. After repairing, the samples were stored in saline for 24 hours and thermocycled for 1500 cycles. The repair bond strength was measured at a strain rate of 1mm/min. Twenty additional cylindrical composite blocks (diameter: 2.5mm, height: 6mm were also fabricated for measuring the cohesive strength of silorane-based composite. The data were analyzed using One-way ANOVA and the post hoc Tukey’s test (α=0.05.Results: Cohesive bond strength of silorane composite was significantly higher than the repair bond strengths in other groups (P<0.001. The repair bond strength of group 3 was significantly higher than that of group 1 (P=0.001.Conclusion: Application of an additional hydrophobic resin layer for repair of silorane-based composite with a methacrylate-based composite enhanced the repair shear bond strength.

  13. Supersonic Retropulsion Surface Preparation of Carbon Fiber Reinforced Epoxy Composites for Adhesive Bonding

    Science.gov (United States)

    Palmieri, Frank L.; Belcher, Marcus A.; Wohl, Christopher J.; Blohowiak, Kay Y.; Connell, John W.

    2013-01-01

    Surface preparation is widely recognized as a key step to producing robust and predictable bonds in a precise and reproducible manner. Standard surface preparation techniques, including grit blasting, manual abrasion, and peel ply, can lack precision and reproducibility, which can lead to variation in surface properties and subsequent bonding performance. The use of a laser to ablate composite surface resin can provide an efficient, precise, and reproducible means of preparing composite surfaces for adhesive bonding. Advantages include elimination of physical waste (i.e., grit media and sacrificial peel ply layers that ultimately require disposal), reduction in process variability due to increased precision (e.g. increased reproducibility), and automation of surface preparation, all of which improve reliability and process control. This paper describes a Nd:YAG laser surface preparation technique for composite substrates and the mechanical performance and failure modes of bonded laminates thus prepared. Additionally, bonded specimens were aged in a hot, wet environment for approximately one year and subsequently mechanically tested. The results of a one year hygrothermal aging study will be presented.

  14. The effect of silver nanoparticles on composite shear bond strength to dentin with different adhesion protocols

    Directory of Open Access Journals (Sweden)

    KOOHPEIMA Fatemeh

    Full Text Available Abstract In Dentistry, restorative materials and oral bacteria are believed to be responsible for restoration failure. To make long-lasting restorations, antibacterial agents should be made. Inorganic nanoparticles and their nano composites are applied as good antibacterial agents. Objective The purpose of this study was to investigate the effect of silver nanoparticles on composite shear bond strength using one etch and rinse and one self-etch adhesive systems. Material and Methods Silver nanoparticles were prepared. Transmission electron microscope and X-ray diffraction were used to characterize the structure of the particles. Nanoparticles were applied on exposed dentin and then different adhesives and composites were applied. All samples were tested by universal testing machine and shear bond strength was assesed. Results Particles with average diameter of about 20 nm and spherical shape were found. Moreover, it was shown that pretreatment by silver nanoparticles enhanced shear bond strength in both etch and rinse, and in self-etch adhesive systems (p≤0.05. Conclusions Considering the positive antibacterial effects of silver nanoparticles, using them is recommended in restorative dentistry. It seems that silver nanoparticles could have positive effects on bond strength of both etch-and-rinse and self-etch adhesive systems. The best results of silver nanoparticles have been achieved with Adper Single Bond and before acid etching.

  15. Bonding Effectiveness of Luting Composites to Different CAD/CAM Materials.

    Science.gov (United States)

    Peumans, Marleen; Valjakova, Emilija Bajraktarova; De Munck, Jan; Mishevska, Cece Bajraktarova; Van Meerbeek, Bart

    To evaluate the influence of different surface treatments of six novel CAD/CAM materials on the bonding effectiveness of two luting composites. Six different CAD/CAM materials were tested: four ceramics - Vita Mark II; IPS Empress CAD and IPS e.max CAD; Celtra Duo - one hybrid ceramic, Vita Enamic, and one composite CAD/CAM block, Lava Ultimate. A total of 60 blocks (10 per material) received various mechanical surface treatments: 1. 600-grit SiC paper; 2. sandblasting with 30-μm Al2O3; 3. tribochemical silica coating (CoJet). Subsequent chemical surface treatments involved either no further treatment (control), HF acid etching (HF), silanization (S, or HF acid etching followed by silanization (HF+S). Two specimens with the same surface treatment were bonded together using two dual-curing luting composites: Clearfil Esthetic Cement (self-etching) or Panavia SA Cement (self-adhesive). After 1 week of water storage, the microtensile bond strength of the sectioned microspecimens was measured and the failure mode was evaluated. The bonding performance of the six CAD/CAM materials was significantly influenced by surface treatment (linear mixed models, p CAD (p = 0.0115), and Lava Ultimate (p CAD/CAM materials: Vita Mark II and IPS Empress CAD: S, HF+S; Celtra Duo: HF, HF+S; IPS e.max CAD: HF+S; Vita Enamic: HF+S, S. For Lava Ultimate, the highest bond strengths were obtained with HF, S, HF+S. Failure analysis showed a relation between bond strength and failure type: more mixed failures were observed with higher bond strengths. Mainly adhesive failures were noticed if no further surface treatment was done. The percentage of adhesive failures was higher for CAD/CAM materials with higher flexural strength (Celtra Duo, IPS e.max CAD, and Lava Ultimate). The bond strength of luting composites to novel CAD/CAM materials is influenced by surface treatment. For each luting composite, an adhesive cementation protocol can be specified in order to obtain the highest bond to the

  16. Effect of three porcelain etchants type (HF-APF-PHA on porcelain- composite shear bond strength

    Directory of Open Access Journals (Sweden)

    Kermanshah H.

    2005-05-01

    Full Text Available Statement of Problem: Porcelain restorations are susceptible to fracture and a common method for repairing is the use of silane and composite on etched porcelain. Although HF is very effective in porcelain etching but has detrimental effects on tissues. Purpose: In this study, the effect of APF and PHA was compared with HF in porcelain etching. Also the role of silane, unfilled resin and dentin bonding in bond strength of composite- porcelain was evaluated. Methods and Materials: In this experimental in-vitro study, one-hundred twenty porcelain square blocks (552 mm were prepared and bonding surfaces of each sandblasted. Samples were divided into three groups. The first group (n=40 were etched with buffered HF 9.5% (Ultradent for 1 min., the second group (n=40 were etched with Iranian APF 1.23% (Kimia for 10 minutes and the third group (n=40 were etched with Iranian PHA 37% (Kimia for 1 min. Ultradent silane was applied on the surfaces of half of cases in each group. On the surfaces of half of silane-treated samples unfilled resin was applied and dentin bonding was used on the surfaces of the remaining. Samples without silane were treated in a similar manner. Composite cylinder with 4mm diameter and 2 mm height was bonded to porcelain. Specimens were stored in 37°C distilled water for 24 hours and subjected to 500 cycles. Shear bond strength was measured with an Instron machine and type of fracture was evaluated using a stereomicroscope. Results were analyzed using 3 way ANOVA, Kaplan- Maier and Tukey HSD tests. Results: Findings showed that PHA and APF roughened the porcelain surface without creating retentive micro undercuts but HF etches porcelain and creates retentive microundercuts. Ultradent silane had no significant effect on bond strength of porcelain- composite. Unfilled resin with Ultradent silane compared with dentin bonding with the same silane is more effective in bond strength of composite- porcelain. Conclusion: Based on

  17. Shear bond strength of composite resin to dentin after application of cavity disinfectants - SEM study

    Directory of Open Access Journals (Sweden)

    Vivek Sharma

    2011-01-01

    Full Text Available Aim: The aim was to evaluate the effect of different cavity disinfectants on dentin bond strengths of composite resin applied with two different adhesive systems. Materials and Methods: Two-hundred mandibular molars were sectioned parallel to the occlusal surface to expose dentin in the midcoronal one-third. The dentinal surfaces were polished with waterproof-polishing papers. The specimens were randomly divided into five groups of 40 teeth each as follows: group 1(control -- specimens were not treated with any cavity disinfectants. Groups 2--5 (experimental groups -- dentin surfaces were treated with the following cavity disinfectants, respectively; 2% chlorhexidine solution, 0.1% benzalkonium chloride-based disinfectant, 1% chlorhexidine gel, and an iodine potassium iodide/copper sulfate-based disinfectant. The specimens were then randomly divided into two subgroups including 20 teeth each to evaluate the effect of different bonding systems. Dentin bonding systems were applied to the dentin surfaces and the composite buildups were done. After the specimens were stored in an incubator for 24 hours, the shear bond strength was measured at a crosshead speed of 1 mm/min. The specimens were then statistically analyzed. Statistical Analysis Used: One way analysis of variance and Tukey-HSD tests were used. Results: There was no significant difference between chlorhexidine gel and control groups regardless of the type of the bonding agent used (P>0.05. On the other hand, pretreatment with benzalkonium chloride-based, iodine potassium iodide/copper sulfate-based disinfectants or chlorhexidine solutions had a negative effect on the shear bond strength of self-etching bonding systems. Conclusions: The findings of this study suggest that when benzalkonium chloride-based, iodine potassium iodide/copper sulfate-based disinfectants or chlorhexidine solutions are used as a cavity disinfectant, an etch-and-rinse bonding system should be preferred.

  18. An Experimental Investigation of Silicone-to-Metal Bond Strength in Composite Space Docking System Seals

    Science.gov (United States)

    Gaier, James R.; Siamidis, John; Larkin, Elizabeth M. G.

    2010-01-01

    The National Aeronautics and Space Administration (NASA) is currently developing a new universal docking mechanism for future space exploration missions called the Low Impact Docking System (LIDS). A candidate LIDS main interface seal design is a composite assembly of silicone elastomer seals vacuum molded into grooves in an electroless nickel plated aluminum retainer. The strength of the silicone-tometal bond is a critical consideration for the new system, especially due to the presence of small areas of disbond created during the molding process. In the work presented herein, seal-to-retainer bonds of subscale seal specimens with different sizes of intentional disbond were destructively tensile tested. Nominal specimens without intentional disbonds were also tested. Tension was applied either uniformly on the entire seal circumference or locally in one short circumferential length. Bond failure due to uniform tension produced a wide scatter of observable failure modes and measured load-displacement behaviors. Although the preferable failure mode for the seal-to-retainer bond is cohesive failure of the elastomer material, the dominant observed failure mode under the uniform loading condition was found to be the less desirable adhesive failure of the bond in question. The uniform tension case results did not show a correlation between disbond size and bond strength. Localized tension was found to produce failure either as immediate tearing of the elastomer material outside the bond region or as complete peel-out of the seal in one piece. The obtained results represent a valuable benchmark for comparison in the future between adhesion loads under various separation conditions and composite seal bond strength.

  19. Effect of preforming adherends on static and fatigue strength of bonded composite single-lap joints

    Science.gov (United States)

    Sawyer, J. W.

    1984-01-01

    An analytical and experimental investigation was conducted on bonded composite single-lap joints with the adherends performed to reduce the angle between the line of action of the applied in-plane force and the bondline. A classical closed-form solution was used to analyze the composite joints with various preform angles and overlap lengths. The adherends of the test specimens were preformed before bonding, during the layup and curing process. Static tests were conducted for preform angles of 0, 5, 10, and 15 deg and overlap lengths of 0.75, 1.75, 2.75, and 3.75 in. A limited fatigue study was conducted for specimens with a 2.75-in. overlap and a preform angle of 5 deg. Results of the analysis showed that preforming the adherends of bonded composite single-lap joints significantly reduced the shear and peel stress concentrations in the adhesive. Experimental results showed that preforming the adherends significantly increased their static and fatigue strength and thus increased the load level for which bonded composite single-lap joints can be designed.

  20. INVESTIGATION OF TITANIUM BONDED GRAPHITE FOAM COMPOSITES FOR MICRO ELECTRONIC MECHANICAL SYSTEMS (MEMS) APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Menchhofer, Paul A [ORNL; Bozorgi, Payam [ORNL

    2016-04-01

    PiMEMS Inc. (Santa Barbara, CA) in collaboration with ORNL investigated the use of Titanium Bonded Graphite Foam Composites (TBGC) for thermal mitigation in Micro Electronic Mechanical Systems (MEMS) applications. Also considered were potentially new additive manufacturing routes to producing novel high surface area micro features and diverse shaped heat transfer components for numerous lightweight MEMs applications.

  1. Bond strength durability of a resin composite on a reinforced ceramic using various repair systems

    NARCIS (Netherlands)

    Ozcan, Mutlu; Valandro, Luiz Felipe; Amaral, Regina; Leite, Fabiola; Bottino, Marco Antonio

    2009-01-01

    Objectives. This study compared the durability of repair bond strength of a resin composite to a reinforced ceramic after three repair systems. Methods. Alumina-reinforced feldspathic ceramic blocks (Vitadur-alpha(R)) (N=30) were randomly divided into three groups according to the repair method:

  2. The internal bond and shear strength of hardwood veneered particleboard composites

    Science.gov (United States)

    P. Chow; J.J. Janowiak; E.W. Price

    1986-01-01

    The effects of several accelerated aging tests and weather exposures on hardwood reconstituted structural composite panels were evaluated. The results indicated that the internal bond and shear by tension loading strength reductions of the panels were affected by the exposure test method. The ranking of the effects of various exposure tests on strength values in an...

  3. Phosphate-bonded ceramic–wood composites : R&D project overview and invitation to participate

    Science.gov (United States)

    Theodore L. Laufenberg; Matt Aro

    2004-01-01

    We are developing chemically bonded ceramic phosphate binders for the production of biofiber-based composite materials. These binders promise to have better processing and properties than some current cement and polymer resin binder systems. The ceramic phosphate binders (termed Ceramicrete), if used in place of cement and polymers, will significantly reduce the...

  4. Adhesive Properties of Bonded Orthodontic Retainers to Enamel : Stainless Steel Wire vs Fiber-reinforced Composites

    NARCIS (Netherlands)

    Foek, Dave Lie Sam; Krebs, Eliza; Sandham, John; Ozcan, Mutlu

    2009-01-01

    Purpose: The objectives of this study were to compare the bond strength of a stainless steel orthodontic wire vs various fiber-reinforced composites (FRC) used as orthodontic retainers on enamel, analyze the failure types after debonding, and investigate the influence of different application

  5. Bond and low cycle fatigue behavior of thermoset composite reinforcing for the concrete industry

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, B.

    1990-09-21

    This thesis encompasses two separate research projects. The first project, described in Chapter 2 was a project investigating the fatigue behavior of thermoset Fiber Composite (FC) sandwich wall ties. The second research project detailed in this thesis was a project studying the bond and tensile properties of FC rod and FC fibers.

  6. Repair of amalgam restorations with composite resin and bonded amalgam: a microleakage study.

    Science.gov (United States)

    Popoff, Daniela Araújo Veloso; Gonçalves, Fabiana Santos; Magalhães, Cláudia Silami; Moreira, Allyson Nogueira; Ferreira, Raquel Conceição; Mjör, Ivar A

    2011-01-01

    Total replacement is the most common technique for defective amalgam restorations, and it represents a major part of restorative dental treatment. Repair is an alternative option for amalgam restorations with localized defects. This study compared microleakage of amalgam restorations repaired by bonded amalgam or composite resin. Thirty extracted human pre-molars were prepared and restored with class I amalgam. A simulated defect was prepared that included the cavosurface margin on restorations, and the pre-molars were assigned to two treatment groups (n=15): In group 1, premolars were treated by composite resin (34% Tooth Conditioner Gel + Adper Single Bond 2 + Z100) and in group 2, premolars were repaired by bonded amalgam (34% Tooth Conditioner Gel + Prime and Bond 2.1 + Permite C). The teeth were immersed in a 50% silver nitrate solution, thermocycled, sectioned longitudinally and then observed by three examiners using a stereomicroscope. Microleakage was evaluated using a 0-4 scale for dye penetration, and data was analyzed by Kruskal Wallis and Dunn tests. Neither of the two methods eliminated microleakage completely. Composite resin was significantly the most effective for repair/tooth interface sealing (score 0 = 80.0%; P=0.0317). For the repair/restoration interface, composite resin was also statistically more effective as a sealant (score 0=66%; P=0.0005) when compared to the bonded amalgam technique (score 0=13%; P=0.0005). The use of adhesive systems significantly affected the ability to seal the repair/ tooth interface. However, at the level of the repair/restoration interface, the bonded amalgam technique may increase microleakage.

  7. Monomer priming of denture teeth and its effects on the bond strength of composite resin.

    Science.gov (United States)

    Perea, Leila; Matinlinna, Jukka P; Tolvanen, Mimmi; Lassila, Lippo V; Vallittu, Pekka K

    2014-08-01

    The bond strength of acrylic resin denture teeth used as pontics in fiber-reinforced composite fixed dental prostheses needs to be improved. The purpose of this study was to assess the influence of various chemical surface-conditioning monomers on the ridge-lap surface of acrylic resin denture teeth by determining the strength of their bonding to a composite resin and changes in surface hardness. Acrylic resin denture teeth of 2 different brands (Artic 8 and Vitapan Cuspiform) (n=120) were tested. Four monomer systems were used as surface primers (conditioning): a flowable composite resin, methylmethacrylate 99%, composite primer, and a photopolymerizable dimethacrylate resin. Five surface-conditioning exposure times were used: no conditioning, 1, 5, 15, and 60 minutes. Surface microhardness measurements were made after the application of the monomer systems. Shear bond strength tests were subsequently performed, followed by a new surface microhardness indentation after the application of the load. The evaluation of the changes on specimen surfaces was performed with a scanning electron microscope. The differences between the shear bond strength and the surface hardness were evaluated for statistical significance by using a 3-way ANOVA. Tooth brand, monomer used, exposure time, and their 2- and 3-way interactions had a significant effect on the shear bond strength and hardness before and after testing, except for the 3-way interaction effect on hardness before testing. The chemical pretreatment of the ridge-lap surface of acrylic resin denture teeth increased the shear bond strength and influenced the surface hardness. The monomer systems caused dissolution on the denture surfaces. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  8. Composite shear bond strength to dry and wet enamel with three self-etch adhesives

    Directory of Open Access Journals (Sweden)

    Shafiee F

    2006-01-01

    Full Text Available Background and Aim: The bonding mechanisms of self etching primers, based upon the simultaneous etching and priming of dentin, simplifies the bonding technique, but the efficiency of these systems is still controversial. This study compared the shear bond strength of three self etch adhesive systems in dry and wet conditions. Materials and Method: In this experimental study, 77 intact bovine lower incisors with flat 600 grit sanded enamel surface were fixed in acrylic molds and divided into 7 groups, of 11 teeth. The enamel surfaces were treated according to a special procedure as follows: Group 1: Prompt L-Pop (PLP in dry condition, Group 2: Prompt L-Pop in wet condition, Group 3: Clearfield SE Bond (CSEB in dry condition, Group 4: Clearfield SE Bond in wet condition, Group 5: iBond (iB in dry condition, Group 6: iBond in wet condition, Group 7: Margin Bond (Control in dry condition. Surfaces were air dried for ten seconds, or blot dried in wet condition. Composite resin was bonded on the enamel and built up by applying a cylindric teflon split mold (4 mm height 2mm diameter. After 24 hours storage in dionized water at room temperature, all specimens were thermocycled and shear bond test was employed by a universal testing machine (Instron with a cross-head speed of 1mm/min. The shear bond strength was recorded in MPa and data were analyzed with ANOVA and Scheffe statistical tests. P<0.05 was considered as statistically significant. The mode of failure was examined under a stereomicroscope. Results: 1- Shear bond strength of CSEB in dry condition (21.5 ± 4.8 MPa was significantly higher than PLP and iB groups (p<0.0001. 2- Shear bond strength of iB and PLP groups in dry condition (9.60 ± 2.2, 9.49 ± 3 MPa were significantly lower than CSEB and control (2.99 ± 5.1 MPa (P<0.0001. 3- There was no significant difference between PLP and iB groups in dry condition (P=1. 4- Shear bond strength of CSEB in wet condition (21.8 ± 3 MPa was

  9. Stickiness of dental resin composite materials to steel, dentin and bonded dentin.

    Science.gov (United States)

    Ertl, Kathrin; Graf, Alexandra; Watts, David; Schedle, Andreas

    2010-01-01

    Stickiness is a vital rheological parameter for the clinical handling behavior of unset resin composite restoratives. The aim of this study was to investigate the stickiness of three different resin composites at 23 degrees C and 37 degrees C tested on steel, dentin and dentin covered with different bonding agents. The stickiness instrument, used in this study consists of a vertical cylindrical stainless steel rod, with a flat circular end, and a platform with a cylindrical mold (diameter: 6.1mm, depth: 2.2mm). The test-material surface temperature and the speed of the rod can be modified. It moves slowly into the prepared mold which is filled with unset composite materials. The degree of stickiness is deducted from the height of the "elevation" the material forms when the plunger is withdrawn from the mold until the steelhead detaches itself from the composite. In this study, stickiness was tested directly to the steel plunger and to dentin slices (uncovered or covered with two different bonding agents) fixed to the plunger rod with a clamp. The coefficients of variation (CVs) were generally less than 0.10, indicating that the stickiness instrument offers an adequately reproducible way of testing stickiness. The tested composite materials varied significantly in stickiness. For all investigated materials a decrease of peak heights with increasing speed was found (for all three materials: pcomposites was higher on dentin than on steel and least on bonded dentin. The order of stickiness of composites was not affected by testing the stickiness on the different materials. This method allows the characterization of composite resin materials stickiness to steel, as equivalent to dental steel instruments, and to bonded dentin as equivalent to the tooth cavity after preparation. An ideal material should have a sufficient difference between stickiness on steel and dentin so that it remains in the cavity and is not pulled back by the steel instrument.

  10. An in vitro study to evaluate the effect of two ethanol-based and two acetone-based dental bonding agents on the bond strength of composite to enamel treated with 10% carbamide peroxide

    Directory of Open Access Journals (Sweden)

    Deepa Basavaraj Benni

    2014-01-01

    Full Text Available Background and Objective: Carbamide peroxide bleaching has been implicated in adversely affecting the bond strength of composite to enamel. The objective of this in vitro study was to evaluate the effect of ethanol-based (Clearfil S 3 bond, Kuraray, Adper Single bond 2, 3M ESPE dental products and acetone-based (Prime and Bond NT, Dentsply, One Step, Bisco bonding agents on the shear bond strength of composite to enamel treated with 10% carbamide peroxide bleaching agent. Materials and Methods: A total of 120 extracted human noncarious permanent incisors were randomly divided into two groups (control and experimental. Experimental group specimens were subjected to a bleaching regimen with a 10% carbamide peroxide bleaching system (Opalescence; Ultradent Products Inc, South Jordan, USA. Composite resin cylinders were bonded to the specimens using four bonding agents and shear bond strength was determined with universal testing machine. Results: There was no statistically significant difference in the shear bond strength between control and experimental groups with both ethanol-based (Clearfil S 3 Bond and Adper Single Bond 2 and acetone-based bonding agent (Prime and Bond NT and One Step. Interpretation and Conclusion: The adverse effect of bleaching on bonding composite to enamel can be reduced or eliminated by using either ethanol- or acetone-based bonding agent. Clinical Significances: Immediate bonding following bleaching procedure can be done using ethanol- or acetone-based bonding agent without compromising bond strength.

  11. An in vitro study to evaluate the effect of two ethanol-based and two acetone-based dental bonding agents on the bond strength of composite to enamel treated with 10% carbamide peroxide.

    Science.gov (United States)

    Benni, Deepa Basavaraj; Naik, Satyajith N; Subbareddy, V V

    2014-01-01

    Carbamide peroxide bleaching has been implicated in adversely affecting the bond strength of composite to enamel. The objective of this in vitro study was to evaluate the effect of ethanol-based (Clearfil S 3 bond, Kuraray, Adper Single bond 2, 3M ESPE dental products) and acetone-based (Prime and Bond NT, Dentsply, One Step, Bisco) bonding agents on the shear bond strength of composite to enamel treated with 10% carbamide peroxide bleaching agent. A total of 120 extracted human noncarious permanent incisors were randomly divided into two groups (control and experimental). Experimental group specimens were subjected to a bleaching regimen with a 10% carbamide peroxide bleaching system (Opalescence; Ultradent Products Inc, South Jordan, USA). Composite resin cylinders were bonded to the specimens using four bonding agents and shear bond strength was determined with universal testing machine. There was no statistically significant difference in the shear bond strength between control and experimental groups with both ethanol-based (Clearfil S 3 Bond and Adper Single Bond 2) and acetone-based bonding agent (Prime and Bond NT and One Step). The adverse effect of bleaching on bonding composite to enamel can be reduced or eliminated by using either ethanol- or acetone-based bonding agent. Clinical Significances: Immediate bonding following bleaching procedure can be done using ethanol- or acetone-based bonding agent without compromising bond strength.

  12. Repair bond strength of nanohybrid composite resins with a universal adhesive.

    Science.gov (United States)

    Altinci, Pinar; Mutluay, Murat; Tezvergil-Mutluay, Arzu

    2018-01-01

    Objective: To investigate the repair bond strength of fresh and aged nanohybrid and hybrid composite resins using a universal adhesive (UA). Materials and methods: Fresh and aged substrates were prepared using two nanohybrid (Venus Pearl, Heraus Kulzer; Filtek Supreme XTE, 3 M ESPE) and one hybrid (Z100, 3 M ESPE) composite resin, and randomly assigned to different surface treatments: (1) no treatment (control), (2) surface roughening with 320-grit (SR), (3) SR + UA (iBOND, Heraus Kulzer), (4) SR + Silane (Signum, Ceramic Bond I, Heraeus Kulzer) + UA, (5) SR + Sandblasting (CoJet, 3 M ESPE) + Silane + UA. After surface treatment, fresh composite resin was added to the substrates at 2 mm layer increments to a height of 5 mm, and light cured. Restored specimens were water-stored for 24 h and sectioned to obtain 1.0 × 1.0 mm beams (n = 12), and were either water-stored for 24 h at 37 °C, or water-stored for 24 h, and then thermocycled for 6000 cycles before microtensile bond strength (µTBS) testing. Data were analyzed with ANOVA and Tukey's HSD tests (p = .05). Results: Combined treatment of SR, sandblasting, silane and UA provided repair bond strength values comparable to the cohesive strength of each tested resin material (p composite resins upto 65% (p composite repair. Sandblasting and silane application slightly increases the repair strength for all substrate types.

  13. Evaluating the Microshear Bond Strength and Microleakage of Flowable Composites Containing Zinc Oxide Nano-particles

    Science.gov (United States)

    Teymoornezhad, Koorosh; Alaghehmand, Homayoun; Daryakenari, Ghazaleh; Khafri, Soraya; Tabari, Mitra

    2016-01-01

    Introduction Preventive resin restorations (PRR) are the conservative choice for the most common carious lesions in children. Thus, new age flowable resin composites with higher filler content are readily used. The aim of this study was to evaluate the microshear bond strength and microleakage of two flowable resin composites containing different percentages of nano zinc oxide (NZnO) particles, which have proven to have antimicrobial properties. Methods This experimental in-vitro study was carried out in the Dental Material Research Center of Babol University of Medical Sciences in 2015. One nanohybrid and one nanofill flowable resin composite were chosen and modified with the incorporation of 1% and 3% Wt NZnO particles. Six groups (n=10, 0%, 1%, and 3%) of resin composite sticks on dental enamel (2×2mm) were prepared to be placed in the microtensile tester. The microshear bond strength magnitude (MPa) was recorded at the point of failure. A class I box (3×0.8×1 mm) was prepared on 60 premolars and filled using the resin composites (6 groups, n=10). The specimens were immersed in a 5% basic fuschin solution and sectioned bucco-lingually to view the microleakage using a stereomicroscope. One-way ANOVA and Tukey tests for microshear and Wilcoxon and Kruskal–Wallis tests for microleakage were used to analyze the data in the IBM SPSS Statistics version 22 software. Results The bond strength of the 3% clearfill group significantly decreased while no significant change occurred in the bond strength in other groups. The Z-350 group had significantly lower microleakage as nanoparticles increased. No significant difference was observed in the clearfill group. Conclusion Up to 3% Wt incorporation of NZnO particles will not diversely alter the bond strength, but it will be beneficial in providing antimicrobial effects with lower microleakage rates. PMID:28070263

  14. The cryogenic bonding evaluation at the metallic-composite interface of a composite overwrapped pressure vessel with additional impact investigation

    Science.gov (United States)

    Clark, Eric A.

    A bonding evaluation that investigated the cryogenic tensile strength of several different adhesives/resins was performed. The test materials consisted of 606 aluminum test pieces adhered to a wet-wound graphite laminate in order to simulate the bond created at the liner-composite interface of an aluminum-lined composite overwrapped pressure vessel. It was found that for cryogenic applications, a flexible, low modulus resin system must be used. Additionally, the samples prepared with a thin layer of cured resin -- or prebond -- performed significantly better than those without. It was found that it is critical that the prebond surface must have sufficient surface roughness prior to the bonding application. Also, the aluminum test pieces that were prepared using a surface etchant slightly outperformed those that were prepared with a grit blast surface finish and performed significantly better than those that had been scored using sand paper to achieve the desired surface finish. An additional impact investigation studied the post impact tensile strength of composite rings in a cryogenic environment. The composite rings were filament wound with several combinations of graphite and aramid fibers and were prepared with different resin systems. The rings were subjected to varying levels of Charpy impact damage and then pulled to failure in tension. It was found that the addition of elastic aramid fibers with the carbon fibers mitigates the overall impact damage and drastically improves the post-impact strength of the structure in a cryogenic environment.

  15. Relationship between mechanical properties and bond durability of short fiber-reinforced resin composite with universal adhesive.

    Science.gov (United States)

    Tsujimoto, Akimasa; Barkmeier, Wayne W; Takamizawa, Toshiki; Watanabe, Hidehiko; Johnson, William W; Latta, Mark A; Miyazaki, Masashi

    2016-10-01

    The purpose of this study was to determine the relationship between mechanical properties and bond durability of short fiber-reinforced resin composite with universal adhesive. As controls, micro-hybrid and nano-hybrid resin composites were tested. The universal adhesives used were Scotchbond Universal, Adhese Universal, and G-Premio Bond. The fracture toughness and flexural properties of resin composites, and shear bond strength and shear fatigue strength of universal adhesive with resin composite using both total-etch and self-etch modes were determined. In the results, short fiber-reinforced resin composite showed significantly higher fracture toughness than did micro-hybrid and nano-hybrid resin composites. The flexural strength and modulus of short fiber-reinforced and nano-hybrid resin composites were significantly lower than were those of micro-hybrid resin composites. Regardless of etching mode, the shear bond strength of universal adhesives with short fiber-reinforced resin composite did not show any significant differences from micro-hybrid and nano-hybrid resin composites. The shear fatigue strength of universal adhesives with short fiber-reinforced resin composite and micro-hybrid resin composites were significantly higher than that of nano-hybrid resin composites. The results of this study suggest that the mechanical properties of short fiber-reinforced resin composite improve their bond durability with universal adhesive. © 2016 Eur J Oral Sci.

  16. Environmental Aging of Scotch-Weld(TradeMark) AF-555M Structural Adhesive in Composite to Composite Bonds

    Science.gov (United States)

    Hou, Tan-Hung; Miner, Gilda A.; Lowther, Sharon E.; Connell, John W.; Baughman, James M.

    2010-01-01

    Fiber reinforced resin matrix composites have found increased usage in recent years. Due to the lack of service history of these relatively new material systems, their long-term aging performance is not well established. In this study, adhesive bonds were prepared by the secondary bonding of Scotch-Weld(TradeMark) AF-555M between pre-cured adherends comprised of T800H/3900-2 uni-directional laminate. The adherends were co-cured with wet peel-ply for surface preparation. Each bond-line of single-lap-shear (SLS) specimen was measured to determine thickness and inspected visually for voids. A three-year environmental aging plan for the SLS specimens at 82 C and 85% relative humidity was initiated. SLS strengths were measured for both controls and aged specimens at room temperature and 82 C. The aging results of strength retention and failure modes to date are reported.

  17. Adhesive Bonding Techniques in Hybrid Structures Made from Fibre Reinforced Polymeric Composites and Concrete

    Directory of Open Access Journals (Sweden)

    Ruxandra Oltean

    2009-01-01

    Full Text Available Mechanical joining techniques are used in construction industry all over the world on a daily basis. A further method of joining has proven to be highly successful – adhesive bonding. Known for thousands of years, adhesive bonding has become as important as other joining techniques as a result of the pace of developments in recent years. In many areas, this bonding technology has become a key technology. Virtually, all solid materials can be connected with one another using adhesives. Although bonding fibre reinforced polymeric composites to the concrete substrate is a relatively simple technique, the proper installation of the fibre reinforced polymeric composites is essential to ensure the adequate performance of the hybrid system. Since the installation procedures differ from one system to another, appropriate specifications will be clearly presented. The paper will include requirements to provide a quality joint assembly, meaning the special pre-treatments of the concrete surface. The material to be bonded is cleaned and prepared so that adhesives can adhere better to them.

  18. The effect of silver nanoparticles on composite shear bond strength to dentin with different adhesion protocols.

    Science.gov (United States)

    Fatemeh, Koohpeima; Mohammad Javad, Mokhtari; Samaneh, Khalafi

    2017-01-01

    The purpose of this study was to investigate the effect of silver nanoparticles on composite shear bond strength using one etch and rinse and one self-etch adhesive systems. Silver nanoparticles were prepared. Transmission electron microscope and X-ray diffraction were used to characterize the structure of the particles. Nanoparticles were applied on exposed dentin and then different adhesives and composites were applied. All samples were tested by universal testing machine and shear bond strength was assesed. Particles with average diameter of about 20 nm and spherical shape were found. Moreover, it was shown that pretreatment by silver nanoparticles enhanced shear bond strength in both etch and rinse, and in self-etch adhesive systems (p≤0.05). Considering the positive antibacterial effects of silver nanoparticles, using them is recommended in restorative dentistry. It seems that silver nanoparticles could have positive effects on bond strength of both etch-and-rinse and self-etch adhesive systems. The best results of silver nanoparticles have been achieved with Adper Single Bond and before acid etching.

  19. Select aspects of FEM analysis for bonded joints of polymer composite materials

    Science.gov (United States)

    Rudawska, A.

    2015-07-01

    The paper presents selected aspects of modelling bonded joints of polymer composite materials by finite element method. The shear-loaded adhesive lap joints made of epoxy-graphite and epoxy-glass composite materials were investigated. The research objective was to determine correct modelling of adhesive layers using cohesive elements and of bonded joints for selected epoxy composite materials with different mechanical properties (e.g. Young's modulus) and geometrical dimensions, using, however, the same type of adhesive. The numerical analysis was performed based on experimental tests. A comparison is made between the distribution of reduced stress in the examined joint models according to the H-M- H hypothesis and that determined according to the maximum principal stress hypothesis. The finite elements analysis was performed in ABAQUS software and the traction-separation failure criterion was used for the damage onset and growth in the adhesive layer.

  20. Influence of different light curing units on the bond strength of indirect resin composite restorations

    Directory of Open Access Journals (Sweden)

    Veridiana Camilotti

    2008-06-01

    Full Text Available The aim of this study was to evaluate the influence of different light sources on the bond strength of indirect resin composite restorations cemented with a dual-cure resin cement. The superficial dentin of human third molars was exposed and acid-etched and an adhesive system was applied (Single Bond 2. Four-mm-thick indirect resin composite restorations (Gradia were fabricated and cemented using a dual-cure resin cement (Rely X. Four light sources were used to polymerize the cement: QTH - Optilux 401; LED1 - L.E.Demetron 1; LED2 - Optilight CL; and LED3 - Ultralume 5. The teeth were stored for 24 h and then sectioned, yielding stick-shaped specimens for each group with a bonded area of 1.0 mm². The specimens were then tested in a universal testing machine, at a crosshead speed of 1 mm/min. Data were analyzed using ANOVA. Bond strength mean values were: QTH: 22.5 (± 8.4; LED1: 22.7 (± 9.4; LED2: 21.4 (± 10.2; and LED3: 27.3 (± 13.8. No statistically significant difference was observed among the experimental groups. The bond strength values when the cement was polymerized using different LED lights were equivalent to the values when the QTH light was used. It can be concluded that the variety of light sources used in the present study did not influence the bond strength of indirect resin composite restorations cemented with a dual-cure resin cement.

  1. The effect of bonding and surface sealant application on postoperative sensitivity from posterior composites.

    Science.gov (United States)

    Tekce, Neslihan; Demirci, Mustafa; Gokturk, Sultan Aslıhan; Tuncer, Safa; Ozel, Emre; Pala, Kansad; Baydemir, Canan

    2015-01-01

    The purpose of the study was to evaluate the postoperative sensitivity of posterior Class I composite restoration at short-term, restorated with two different all-in-one self-etch adhesives with or without surface sealant application. 44 restorations were inserted in 11 patients who required Class I restorations in their molars. Each patient received 4 restorations, thus four groups were formed; (1) G-Aenial Bond (GC, Japan); (2) Clearfil S3 Bond (Kuraray, Japan); (3) G-Aenial Bond+Fortify Plus (Bisco, USA), (4) Clearfil S3 Bond+Fortify Plus. Sensitivity was evaluated at 24h, 7, 15, and 30 days using cold air, ice, and pressure stimuli using a visual analog scale. Comparisons of continuous variables between the sensitivity evaluations were performed using the Friedman's One-Way Analysis of Variance with repeated measures test (p0.05). The use of Clearfil S3 Bond resulted in almost the same level of postoperative sensitivity as did the use of G-Aenial Bond. The highest sensitivity scores were observed for the surface sealant applied teeth without any statistical significance (p>0.05). Self etch adhesives displayed postoperative sensitivity. The sensitivity scores slightly decreased at the end of 30 days (p>0.05). Surface sealant application did not result in a decrease in sensitivity scores for either dentin adhesives.

  2. THE EFFECT OF BONDING AND SURFACE SEALANT APPLICATION ON POSTOPERATIVE SENSITIVITY FROM POSTERIOR COMPOSITES

    Directory of Open Access Journals (Sweden)

    Neslihan TEKÇE

    2015-10-01

    Full Text Available Purpose: The purpose of the study was to evaluate the postoperative sensitivity of posterior Class I composite restoration at short-term, restorated with two different all-in-one self-etch adhesives with or without surface sealant application. Materials and Methods: 44 restorations were inserted in 11 patients who required Class I restorations in their molars. Each patient received 4 restorations, thus four groups were formed; (1 G-Aenial Bond (GC, Japan; (2 Clearfil S3 Bond (Kuraray, Japan; (3 G-Aenial Bond+Fortify Plus (Bisco, USA, (4 Clearfil S3 Bond+Fortify Plus. Sensitivity was evaluated at 24h, 7, 15, and 30 days using cold air, ice, and pressure stimuli using a visual analog scale. Comparisons of continuous variables between the sensitivity evaluations were performed using the Friedman’s One-Way Analysis of Variance with repeated measures test (p0.05. The use of Clearfil S3 Bond resulted in almost the same level of postoperative sensitivity as did the use of G-Aenial Bond. The highest sensitivity scores were observed for the surface sealant applied teeth without any statistical significance (p>0.05. Conclusions: Self etch adhesives displayed postoperative sensitivity. The sensitivity scores slightly decreased at the end of 30 days (p>0.05. Surface sealant application did not result in a decrease in sensitivity scores for either dentin adhesives.

  3. Shear test of composite bonded to dentin: Er:YAG laser versus dental handpiece preparations

    Science.gov (United States)

    Visuri, Steven R.; Gilbert, Jeremy L.; Walsh, Joseph T., Jr.; Wigdor, Harvey A.

    1995-05-01

    The erbium:YAG laser coupled with a cooling stream of water appears to be an effective means of removing dental hard tissues. However, before the procedure is deemed clinically viable, there are several important issues of safety and efficacy that need to be explored. In this study we investigated the surface that remains following laser ablation of dentin and compared the results to the use of a dental handpiece. Specifically, we studied the effect the laser radiation had on the bonding of composite to dentin. The crowns of extracted human molars were removed revealing the underlying dentin. An additional thickness of material was removed with either a dental handpiece or an Er:YAG laser by raster scanning the samples under a fixed handpiece or laser. Comparable surface roughnesses were achieved. A cylinder of composite was bonded onto the prepared surfaces following the manufacturer's directions. The dentin-composite bond was then shear stressed to failure on a universal testing apparatus and the maximum load recorded. Preliminary results indicated that laser irradiated samples had improved bond strengths. SEM photographs of the surfaces were also taken to compare the two methods of tooth preparation.

  4. Effect of desensitizing treatments on bond strength of resin composites to dentin - an in vitro study.

    Science.gov (United States)

    Makkar, Sameer; Goyal, Meenu; Kaushal, Ashih; Hegde, Vivek

    2014-09-01

    Hypersensitivity is a common clinical multietiological problem. Many desensitizing treatments are there to overcome hypersensitivity. The aim of this study was to evaluate the effect of different dentin-desensitizing treatments on the tensile bond strength of composite restoration. Twenty-four sound human molars were used. Enamel was wet abraded to expose flat dentin surfaces, polished with sandpaper. The specimens were then divided into three groups (n = 8) based on the type of dentin-desensitizing treatment given. The first group: G1 was the control group where no desensitizing agent was used. The second group: G2 was treated with desensitizing dentifrice containing a combination of potassium nitrate, triclosan, and sodium monoflorophosphate. The third group: G3 was treated with Er:YAG laser. Afterwards, the desensitized specimens were treated with one step self-etch adhesive according to manufacturer's instructions and composite microcylinders were packed. The specimens were then examined for tensile bond strength using universal tensile machine (KMI(TM) ). Statistical analysis of the data obtained revealed the mean values for the tensile bond strengths were 10.2613 MPa, 5.9400 MPa and 6.3575 MPa for groups 1, 2 and 3, respectively. These values were statistically significantly different between groups pretreated with laser or dentifrice as compared to control group. Dentifrice and Laser pre-treated dentin has lower tensile bond strength with resin composites as compared to dentin that is untreated.

  5. Pulse Current Assisted TLP Bonding of SiCP/Al Composites Sheet Using Powders Interlayer

    Directory of Open Access Journals (Sweden)

    WANG Bo

    2017-06-01

    Full Text Available The powders interlayer was applied for transient liquid phase (TLP bonding of SiCp/Al composites using pulse current heating. Pulse current got though the joint with powder interlayer and generated the effect of Joule heat and spark plasma sintering to achieve the TLP bonding of SiCp/Al composites sheet. The results show that there is the good TLP bonded joint without defects under the conditions of vacuum:1.39×103 Pa; Pulse current density: 115 A/mm2; holding time: 15-60 min; original pressure: 0.5 MPa. The results reveal the dense joint without pores composed of the Al-based solid solution, pure Ti zone, Al2Cu, and Al3Ti intermetallic phase. Furthermore, the thermal and isothermal effects of pulse current on in situ synthesis of TLP bonded joints of SiCp/Al composites using mixed Al-Cu-Ti powder interlayer are analyzed and discussed. According to microstructure of joint, pulse current promote to in situ form the intermetallic compound, which can provide higher mechanical properties of joint.

  6. Evaluation of flexural, diametral tensile, and shear bond strength of composite repairs.

    Science.gov (United States)

    Imbery, T A; Gray, T; DeLatour, F; Boxx, C; Best, A M; Moon, P C

    2014-01-01

    Repairing composite restorations may be a more conservative treatment than replacing the entire restoration. The objective of this in vitro study was to determine the best repair method by measuring flexural, diametral tensile, and shear bond strength of repaired composites in which the surfaces were treated with chemical primers (Add & Bond or Silane Bond Enhancer), a bonding agent (Optibond Solo Plus [OBSP]), or mechanical retention with a bonding agent. Filtek Supreme Ultra shade B1B was placed in special molds to fabricate specimens that served to test the flexural, diametral tensile, or shear strength of the inherent resin substrate. The same molds were modified to make specimens for testing repair strength of the resin. Repairs were made immediately or after aging in deionized water at 37°C for seven days. All repair sites were finished with coarse Sof-Lex discs to simulate finishing new restorations or partially removing aged restorations. Repair surfaces were treated with one of the following: 1) phosphoric-acid etching and OBSP; 2) Add & Bond; 3) phosphoric-acid etching, Silane Bond Enhancer, and OBSP; or 4) quarter round bur, phosphoric-acid etching, and OBSP. Specimens were placed back in the original molds to fabricate specimens for diametral tensile or flexural testing or in an Ultradent jig to make specimens for shear bond testing. Composite resin in shade B5B was polymerized against the treated surfaces to make repairs. Two negative control groups for the three testing methods consisted of specimens in which repairs were made immediately or after aging without any surface treatments. Controls and experimental repairs were aged (water 37°C, 24 hours) before flexural, diametral tensile, or shear testing in an Instron Universal testing machine at a crosshead speed of 0.5 mm/min. Experimental flexural repair strengths ranged from 26.4% to 88.6% of the inherent substrate strength. Diametral tensile repair strengths ranged from 40% to 80% of the inherent

  7. A study on the compatibility between one-bottle dentin adhesives and composite resins using micro-shear bond strength

    Directory of Open Access Journals (Sweden)

    Minju Song

    2015-02-01

    Full Text Available Objectives This study was performed to determine whether the combined use of one-bottle self-etch adhesives and composite resins from same manufacturers have better bond strengths than combinations of adhesive and resins from different manufacturers. Materials and Methods 25 experimental micro-shear bond test groups were made from combinations of five dentin adhesives and five composite resins with extracted human molars stored in saline for 24 hr. Testing was performed using the wire-loop method and a universal testing machine. Bond strength data was statistically analyzed using two way analysis of variance (ANOVA and Tukey's post hoc test. Results Two way ANOVA revealed significant differences for the factors of dentin adhesives and composite resins, and significant interaction effect (p < 0.001. All combinations with Xeno V (Dentsply De Trey and Clearfil S3 Bond (Kuraray Dental adhesives showed no significant differences in micro-shear bond strength, but other adhesives showed significant differences depending on the composite resin (p < 0.05. Contrary to the other adhesives, Xeno V and BondForce (Tokuyama Dental had higher bond strengths with the same manufacturer's composite resin than other manufacturer's composite resin. Conclusions Not all combinations of adhesive and composite resin by same manufacturers failed to show significantly higher bond strengths than mixed manufacturer combinations.

  8. Identification of parameters of cohesive elements for modeling of adhesively bonded joints of epoxy composites

    Directory of Open Access Journals (Sweden)

    Kottner R.

    2013-12-01

    Full Text Available Adhesively bonded joints can be numerically simulated using the cohesive crack model. The critical strain energy release rate and the critical opening displacement are the parameters which must be known when cohesive elements in MSC.Marc software are used. In this work, the parameters of two industrial adhesives Hunstman Araldite 2021 and Gurit Spabond 345 for bonding of epoxy composites are identified. Double Cantilever Beam (DCB and End Notched Flexure (ENF test data were used for the identification. The critical opening displacements were identified using an optimization algorithm where the tests and their numerical simulations were compared.

  9. Surface modifications and Nano-composite coatings to improve the bonding strength of titanium-porcelain

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Litong, E-mail: guolitong810104@163.com [China University of Mining and Technology, Xuzhou 221116 (China); ustralian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072 (Australia); Chen, Xiaoyuan; Liu, Xuemei; Feng, Wei [China University of Mining and Technology, Xuzhou 221116 (China); Li, Baoe [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Lin, Cheng; Tao, Xueyu; Qiang, Yinghuai [China University of Mining and Technology, Xuzhou 221116 (China)

    2016-04-01

    Surface modifications of Ti and nano-composite coatings were employed to simultaneously improve the surface roughness, corrosion resistance and chemical bonding between porclain-Ti. The specimens were studied by field-emission scanning electron microscopy, surface roughness, differential scanning calorimetry, Fourier transform infrared spectroscopy, corrosion resistance and bonding strength tests. The SEM results showed that hybrid structures with micro-stripes, nano-pores and nano-protuberances were prepared by surface modification of Ti, which significantly enhanced the surface roughness and corrosion resistance of Ti. Porous nano-composite coatings were synthesized on Ti anodized with pre-treatment in 40% HF acid. TiO{sub 2} nanoparticles were added into the hybrid coating to increase the solid phase content of the sols and avoid the formation of microcracks. With the TiO{sub 2} content increasing from 45 wt% to 60 wt%, the quantities of the microcracks on the coating surface gradually decreased. The optimal TiO{sub 2} content for the nanocomposite coatings is 60 wt% in this research. Compared to the uncoated group, the bonding strength of the coated groups showed a bonding strength improvement of 23.96%. The cytotoxicity of the 4# coating group was ranked as zero, which corresponds to non-cytotoxicity. - Highlights: • Surface roughness of Ti was increased by surface modification of Ti. • Corrosion resistance was enhanced by surface modification of Ti. • Porous nano-composite coatings were synthesized on Ti by sol–gel process. • TiO{sub 2} nanoparticles were added into the coating to avoid formation of cracks. • The nano-composite coatings increased the bonding strength of about 24%.

  10. Effect of components and surface treatments of fiber-reinforced composite posts on bond strength to composite resin.

    Science.gov (United States)

    Asakawa, Yuya; Takahashi, Hidekazu; Kobayashi, Masahiro; Iwasaki, Naohiko

    2013-10-01

    The aim of this study was to clarify the effect of the components and surface treatments of fiber-reinforced composite (FRC) posts on the durable bonding to core build-up resin evaluated using the pull-out and microtensile tests. Four types of experimental FRC posts, combinations of two types of matrix resins (polymethyl methacrylate and urethane dimethacrylate) and two types of fiberglass (E-glass and zirconia-containing glass) were examined. The FRC posts were subjected to one of three surface treatments (cleaned with ethanol, dichloromethane, or sandblasting). The bond strength between the FRC posts and core build-up resin were measured using the pull-out and microtensile tests before and after thermal cycling. The bond strengths obtained by each test before and after thermal cycling were statistically analyzed by three-way ANOVA and Tukey's multiple comparisons test (pposts by the pull-out test, but not by the microtensile test. Sandblasting was effective for both PMMA- and UDMA-based FRC posts, regardless of the test method. The bond strengths were influenced by the matrix resin of the FRC post and the surface treatment. The bond strengths of the pull-out test showed a similar tendency of those of the microtensile test, but the value obtained by these test were different. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. The effect of different surface treatments of stainless steel crown and different bonding agents on shear bond strength of direct composite resin veneer

    Directory of Open Access Journals (Sweden)

    Ajami B

    2007-01-01

    Full Text Available Background and Aim: Stainless steel crown (SSC is the most durable and reliable restoration for primary teeth with extensive caries but its metalic appearance has always been a matter of concern. With advances in restorative materials and metal bonding processes, composite veneer has enhanced esthetics of these crowns in clinic. The aim of this study was to evaluate the shear bond strength of SSC to composite resin using different surface treatments and adhesives. Materials and Methods: In this experimental study, 90 stainless steel crowns were selected. They were mounted in molds and divided into 3 groups of 30 each (S, E and F. In group S (sandblast, buccal surfaces were sandblasted for 5 seconds. In group E (etch acidic gel was applied for 5 minutes and in group F (fissure bur surface roughness was created by fissure diamond bur. Each group was divided into 3 subgroups (SB, AB, P based on different adhesives: Single Bond, All Bond2 and Panavia F. Composite was then bonded to specimens. Cases were incubated in 100% humidity at 37°C for 24 hours. Shear bond strength was measured by Zwick machine with crosshead speed of 0.5 mm/min. Data were analyzed by ANOVA test with p0.05 so the two variables were studied separately. No significant difference was observed in mean shear bond strength of composite among the three kinds of adhesives (P>0.05. Similar results were obtained regarding surface treatments (P>0.05. Conclusion: Based on the results of this study, treating the SSC surface with bur and using single bond adhesive and composite can be used successfully to obtain esthetic results in pediatric restorative treatments.

  12. Microtensile bond strength of composite resin to glass-infiltrated alumina composite conditioned with Er,Cr:YSGG laser.

    Science.gov (United States)

    Eduardo, Carlos de Paula; Bello-Silva, Marina Stella; Moretto, Simone Gonçalves; Cesar, Paulo Francisco; de Freitas, Patricia Moreira

    2012-01-01

    Tribochemical silica-coating is the recommended conditioning method for improving glass-infiltrated alumina composite adhesion to resin cement. High-intensity lasers have been considered as an alternative for this purpose. This study evaluated the morphological effects of Er,Cr:YSGG laser irradiation on aluminous ceramic, and verified the microtensile bond strength of composite resin to ceramic following silica coating or laser irradiation. In-Ceram Alumina ceramic blocks were polished, submitted to airborne particle abrasion (110 μm Al(2)O(3)), and conditioned with: (CG) tribochemical silica coating (110 μm SiO(2)) + silanization (control group); (L1-L10) Er,Cr:YSGG laser (2.78 μm, 20 Hz, 0.5 to 5.0 W) + silanization. Composite resin blocks were cemented to the ceramic blocks with resin cement. These sets were stored in 37°C distilled water (24 h), embedded in acrylic resin, and sectioned to produce bar specimens that were submitted to microtensile testing. Bond strength values (MPa) were statistically analyzed (α ≤0.05), and failure modes were determined. Additional ceramic blocks were conditioned for qualitative analysis of the topography under SEM. There were no significant differences among silicatization and laser treatments (p > 0.05). Microtensile bond strength ranged from 19.2 to 27.9 MPa, and coefficients of variation ranged from 30 to 55%. Mixed failure of adhesive interface was predominant in all groups (75-96%). No chromatic alteration, cracks or melting were observed after laser irradiation with all parameters tested. Surface conditioning of glass-infiltrated alumina composite with Er,Cr:YSGG laser should be considered an innovative alternative for promoting adhesion of ceramics to resin cement, since it resulted in similar bond strength values compared to the tribochemical treatment.

  13. An In vitro Evaluation of the Effect of Four Dentin Bonding System on the Bond Strength between Quartz Fiber Post and Composite Core.

    Science.gov (United States)

    Shirinzad, M; Ebadi, Sh; Shokripour, M; Darabi, Ma

    2014-03-01

    A strong bond of fiber post to resin core, as well as to dentin would critically ensure the durability of restorations in endodontically treated teeth. The purpose of this study was to evaluate the effect of etch-and-rinse dentin bonding systems on the bond strength between resin core and fiber post after application of 24% hydrogen peroxide.  24 fiber posts (RTD; St. Egèven, France) were treated with 24% hydrogen peroxide for 10 minutes. They were randomly divided into 4 groups (n=6) based on the bonding agent used: Group P: Prime&Bond, Group O: One Step, Group S: Single Bond and Group E: Excite. Each group was prepared according to the manufacturer's instructions. For all posts, a flowable composite core (ÆliteFlo; Bisco, USA) was built-up over the bonded area. Each specimen was sectioned to produce 2 sticks, 1mm in thickness and underwent microtensile bond strength (µTBS). Data were analyzed using one-way ANOVA at the 0.05 level. The fractured surfaces of all sticks were evaluated by stereomicroscope (× 20). Scanning electron microscopy(SEM) assessment of two sticks from each group was performed to evaluate the surface morphology. The means and SDs of µTBS were: Group P: 10.95±1.74; Group S: 10.25±2.39; Group E: 9.52±2.07; and Group O: 9.12±1.34. There was no statistically significant difference in bond strength means between the groups tested (p> 0.05).   The results of this study indicated the bonding agents used had no significant influence on the bond strength of fiber post to composite core.

  14. Comparative evaluation of shear bond strength of conventional composite resin and nanocomposite resin to sandblasted primary anterior stainless steel crown.

    Science.gov (United States)

    Khatri, A; Nandlal, B

    2007-01-01

    To evaluate and compare the shear bond strength of conventional composite resin and nanocomposite resin to sandblasted primary anterior stainless steel crown. The study samples consisted of 30 primary anterior stainless steel crowns (Unitek TM, size R4), embedded in resin blocks with crown, in test groups of 15 samples each. Mounting of the crown was done using resin block with one crown each. Sandblasting was done and the bonding agent Prime and Bond NT (Dentsply) was applied on the labial surface of the primary anterior sandblasted crown. The composite resin and nanocomposite resin were placed into the well of Teflon jig and bonded to Stainless Steel Crowns. The cured samples were placed in distilled water and stored in incubator at 37 degrees C for 48 hours. Shear bond strength was measured using universal testing machine (Hounsefield U.K. Model, with a capacity of 50 KN). Independent sample 't' test revealed a nonsignificant (P < 0.385) difference between mean shear bond strength values of conventional and nanocomposite group. The bond strength values revealed that nanocomposite had slightly higher mean shear bond strength (21.04 +/- 0.56) compared to conventional composite (20.78 +/- 0.60). It was found that conventional composite resin and nanocomposite resin had statistically similar mean shear bond strength, with nanocomposite having little more strength compared to conventional composite.

  15. Comparative evaluation of shear bond strength of conventional composite resin and nanocomposite resin to sandblasted primary anterior stainless steel crown

    Directory of Open Access Journals (Sweden)

    Khatri A

    2007-06-01

    Full Text Available To evaluate and compare the shear bond strength of conventional composite resin and nanocomposite resin to sandblasted primary anterior stainless steel crown. The study samples consisted of 30 primary anterior stainless steel crowns (Unitek TM , size R4, embedded in resin blocks with crown, in test groups of 15 samples each. Mounting of the crown was done using resin block with one crown each. Sandblasting was done and the bonding agent Prime and Bond NT (Dentsply was applied on the labial surface of the primary anterior sandblasted crown. The composite resin and nanocomposite resin were placed into the well of Teflon jig and bonded to Stainless Steel Crowns. The cured samples were placed in distilled water and stored in incubator at 37°C for 48 hours. Shear bond strength was measured using universal testing machine (Hounsefield U.K. Model, with a capacity of 50 KN. Independent sample ′t′ test revealed a nonsignificant ( P < 0.385 difference between mean shear bond strength values of conventional and nanocomposite group. The bond strength values revealed that nanocomposite had slightly higher mean shear bond strength (21.04 ± 0.56 compared to conventional composite (20.78 ± 0.60. It was found that conventional composite resin and nanocomposite resin had statistically similar mean shear bond strength, with nanocomposite having little more strength compared to conventional composite.

  16. Hydrogen bond induced nonmonotonic composition behavior of the glass transition in aqueous binary mixtures.

    Science.gov (United States)

    Sjöström, Johan; Mattsson, Johan; Bergman, Rikard; Swenson, Jan

    2011-08-25

    The glass transition temperature, T(g), of a binary mixture commonly varies monotonically between the T(g)s of its two components. However, mixtures of strongly associating liquids can instead exhibit a nonmonotonic T(g) variation. The origins of such nonideal mixing behavior have often been correlated with composition dependent structural variations. For binary mixtures between a hydrogen- (H-) bonded liquid and water, however, such behavior is generally not well understood. The ubiquity and importance of aqueous mixtures both in nature and in man-made applications stresses the needed for a better understanding. We here demonstrate nonmonotonic T(g) variations in binary mixtures of n-propylene glycol monomethyl ethers (nPGMEs) and water, where the composition dependent T(g) show maxima within an intermediate composition range. We show that these T(g) maxima correspond to crossovers in the composition dependence of the step amplitude in the isobaric heat capacity at T(g). We further demonstrate that the observed effects are caused by H-bond interactions involving the nPGME hydroxyl group. We can account for our obervations using a simple model based on two effects due to the added water: (i) an H-bond induced formation of effective relaxing entities and (ii) a plasticizing effect at high water contents. © 2011 American Chemical Society

  17. Effects of different cavity disinfectants on shear bond strength of a silorane-based resin composite.

    Science.gov (United States)

    Arslan, Soley; Yazici, A Ruya; Gorucu, Jale; Ertan, Atilla; Pala, Kansad; Ustun, Yakup; Antonson, Sibel A; Antonson, Donald E

    2011-07-01

    This in vitro study evaluated the effect of different cavity disinfection agents on bond strength of a silorane-based resin composite. Thirty-six caries-free human third mandibular molars sectioned in mesio-distal direction were mounted in acrylic resin with their flat dentin surfaces exposed. After the dentin surfaces were wet ground with # 600 silicon carbide paper, the teeth were randomly divided into 6 groups of 12 each according to the cavity disinfection agents; chlorhexidine (CHX); sodium hypochlorite (NaOCl), propolis, ozone, Er,Cr:YSGG laser and no treatment (control). After treatment of dentin surfaces with one of these cavity disinfection agents, Filtek Silorane adhesive system was applied. The silorane-based resin composite, Filtek Silorane was condensed into a mold and polymerized. After storage at 37°C for 24 hours, the specimens were tested in shear mode at a crosshead speed of 1.0 mm/minute. The results were analyzed by one-way ANOVA. No statistically significant difference was observed between the groups (p>0.05). The use of the tested cavity disinfection agents, chlorhexidine, sodium hypochlorite, propolis, ozone and Er,Cr:YSGG laser did not significantly affect the dentin bond strength of a silorane-based resin composite, filtek supreme. Cavity disinfectant applications did not affect the dentin bond strength of a silorane-based resin composite.

  18. Repair bond strength of dual-cured resin composite core buildup materials.

    Science.gov (United States)

    El-Deeb, Heba A; Ghalab, Radwa M; Elsayed Akah, Mai M; Mobarak, Enas H

    2016-03-01

    The reparability of dual-cured resin composite core buildup materials using a light-cured one following one week or three months storage, prior to repair was evaluated. Two different dual-cured resin composites; Cosmecore™ DC automix and Clearfil™ DC automix core buildup materials and a light-cured nanofilled resin composite; Filtek™ Z350 XT were used. Substrate specimens were prepared (n = 12/each substrate material) and stored in artificial saliva at 37 °C either for one week or three months. Afterward, all specimens were ground flat, etched using Scotchbond™ phosphoric acid etchant and received Single Bond Universal adhesive system according to the manufacturers' instructions. The light-cured nanofilled resin composite (Filtek™ Z350 XT) was used as a repair material buildup. To determine the cohesive strength of each solid substrate material, additional specimens from each core material (n = 12) were prepared and stored for the same periods. Five sticks (0.8 ± 0.01 mm(2)) were obtained from each specimen (30 sticks/group) for microtensile bond strength (μTBS) testing. Modes of failure were also determined. Two-way ANOVA revealed a significant effect for the core materials but not for the storage periods or their interaction. After one week, dual-cured resin composite core buildup materials (Cosmecore™ DC and Clearfil™ DC) achieved significantly higher repair μTBS than the light-cured nanofilled resin composite (Filtek™ Z350 XT). However, Clearfil™ DC revealed the highest value, then Cosmecore™ DC and Filtek™ Z350 XT, following storage for 3-month. Repair strength values recovered 64-86% of the cohesive strengths of solid substrate materials. The predominant mode of failure was the mixed type. Dual-cured resin composite core buildup materials revealed acceptable repair bond strength values even after 3-month storage.

  19. Comparison of Shear Bond Strength of Resin-Modified Glass Ionomer and Composite Resin to Three Pulp Capping Agents

    Directory of Open Access Journals (Sweden)

    Amir Ahmad Ajami

    2013-08-01

    Full Text Available Background and aims. Present study was designed to compare the bonding strength of resin-modified glass ionomer (RMGI and composite resin to mineral trioxide aggregate (MTA, MTA mixed with Na2HPO4 (NAMTA, and calciumenriched mixture (CEM. Materials and methods. Thirty specimens of each CEM, NAMTA, and MTA were prepared. Composite and RMGI restorations were then placed on the samples (15 samples in six subgroups. Shear bond strength was assessed using universal testing machine. Data were analyzed with two-way ANOVA and post-hoc Tukey test. To compare the bond strength in subgroups, one-away ANOVA was applied. Significance level was set at P 0.05. Conclusion. Regarding shear bond strength to the tested substrates, composite was shown to be superior to RMGI. The bond of resin composite to MTA was weaker than that to CEM and NAMTA.

  20. Differences in interfacial bond strengths of graphite fiber-epoxy resin composites

    Science.gov (United States)

    Needles, H. L.

    1985-01-01

    The effect of epoxy-size and degree of cure on the interfacial bonding of an epoxy-amine-graphite fiber composite system is examined. The role of the fiber-resin interface in determining the overall mechanical properties of composites is poorly understood. A good interfacial adhesive bond is required to achieve maximum stress transfer to the fibers in composites, but at the same time some form of energy absorbing interfacial interaction is needed to achieve high fracture toughening. The incompatibility of these two processes makes it important to understand the nature and basic factors involved at the fiber-resin interface as stress is applied. The mechanical properties including interlaminar shear values for graphite fiber-resin composites are low compared to glass and boron-resin composites. These differences have been attributed to poor fiber-matrix adhesion. Graphite fibers are commonly subjected to post-treatments including application of organic sizing in order to improve their compatibility with the resin matrix and to protect the fiber tow from damage during processing and lay-up. In such processes, sized graphite fiber tow is impregnated with epoxy resin and then layed-up i nto the appropriate configuration. Following an extended ambient temperature cure, the graphite-resin composite structure is cured at elevated temperature using a programmed temperature sequence to cure and then cool the product.

  1. Bond strength of selected composite resin-cements to zirconium-oxide ceramic

    Science.gov (United States)

    Fons-Font, Antonio; Amigó-Borrás, Vicente; Granell-Ruiz, María; Busquets-Mataix, David; Panadero, Rubén A.; Solá-Ruiz, Maria F.

    2013-01-01

    Objectives: The aim of this study was to evaluate bond strengths of zirconium-oxide (zirconia) ceramic and a selection of different composite resin cements. Study Design: 130 Lava TM cylinders were fabricated. The cylinders were sandblasted with 80 µm aluminium oxide or silica coated with CoJet Sand. Silane, and bonding agent and/or Clearfil Ceramic Primer were applied. One hundred thirty composite cement cylinders, comprising two dual-polymerizing (Variolink II and Panavia F) and two autopolymerizing (Rely X and Multilink) resins were bonded to the ceramic samples. A shear test was conducted, followed by an optical microscopy study to identify the location and type of failure, an electron microscopy study (SEM and TEM) and statistical analysis using the Kruskal-Wallis test for more than two independent samples and Mann-Whitney for two independent samples. Given the large number of combinations, Bonferroni correction was applied (α=0.001). Results: Dual-polymerizing cements provided better adhesion values (11.7 MPa) than the autopolymerizing (7.47 MPa) (p-value M-WAdhesive failure (separation of cement and ceramic) was produced at a lesser force than cohesive failure (fracture of cement) (p-value M-Wcement and the ceramic. Key words:Shear bond strength, silica coating, surface treatment, zirconia ceramics, phosphate monomer. PMID:22926485

  2. A study on the compatibility between one-bottle dentin adhesives and composite resins using micro-shear bond strength

    Science.gov (United States)

    2015-01-01

    Objectives This study was performed to determine whether the combined use of one-bottle self-etch adhesives and composite resins from same manufacturers have better bond strengths than combinations of adhesive and resins from different manufacturers. Materials and Methods 25 experimental micro-shear bond test groups were made from combinations of five dentin adhesives and five composite resins with extracted human molars stored in saline for 24 hr. Testing was performed using the wire-loop method and a universal testing machine. Bond strength data was statistically analyzed using two way analysis of variance (ANOVA) and Tukey's post hoc test. Results Two way ANOVA revealed significant differences for the factors of dentin adhesives and composite resins, and significant interaction effect (p Dental) adhesives showed no significant differences in micro-shear bond strength, but other adhesives showed significant differences depending on the composite resin (p adhesives, Xeno V and BondForce (Tokuyama Dental) had higher bond strengths with the same manufacturer's composite resin than other manufacturer's composite resin. Conclusions Not all combinations of adhesive and composite resin by same manufacturers failed to show significantly higher bond strengths than mixed manufacturer combinations. PMID:25671210

  3. A study on the compatibility between one-bottle dentin adhesives and composite resins using micro-shear bond strength.

    Science.gov (United States)

    Song, Minju; Shin, Yooseok; Park, Jeong-Won; Roh, Byoung-Duck

    2015-02-01

    This study was performed to determine whether the combined use of one-bottle self-etch adhesives and composite resins from same manufacturers have better bond strengths than combinations of adhesive and resins from different manufacturers. 25 experimental micro-shear bond test groups were made from combinations of five dentin adhesives and five composite resins with extracted human molars stored in saline for 24 hr. Testing was performed using the wire-loop method and a universal testing machine. Bond strength data was statistically analyzed using two way analysis of variance (ANOVA) and Tukey's post hoc test. Two way ANOVA revealed significant differences for the factors of dentin adhesives and composite resins, and significant interaction effect (p adhesives showed no significant differences in micro-shear bond strength, but other adhesives showed significant differences depending on the composite resin (p adhesives, Xeno V and BondForce (Tokuyama Dental) had higher bond strengths with the same manufacturer's composite resin than other manufacturer's composite resin. Not all combinations of adhesive and composite resin by same manufacturers failed to show significantly higher bond strengths than mixed manufacturer combinations.

  4. Effect of different surface treatments on the shear bond strength of nanofilled composite repairs

    Directory of Open Access Journals (Sweden)

    Ghazaleh Ahmadizenouz

    2016-03-01

    Full Text Available Background. Repairing aged composite resin is a challenging process. Many surface treatment options have been proposed to this end. This study evaluated the effect of different surface treatments on the shear bond strength (SBS of nano-filled composite resin repairs. Methods. Seventy-five cylindrical specimens of a Filtek Z350XT composite resin were fabricated and stored in 37°C distilled water for 24 hours. After thermocycling, the specimens were divided into 5 groups according to the following surface treatments: no treatment (group 1; air abrasion with 50-μm aluminum oxide particles (group 2; irradiation with Er:YAG laser beams (group 3; roughening with coarse-grit diamond bur + 35% phosphoric acid (group 4; and etching with 9% hydrofluoric acid for 120 s (group 5. Another group of Filtek Z350XT composite resin samples (4×6 mm was fabricated for the measurement of cohesive strength (group 6. A silane coupling agent and an adhesive system were applied after each surface treatment. The specimens were restored with the same composite resin and thermocycled again. A shearing force was applied to the interface in a universal testing machine. Data were analyzed using one-way ANOVA and post hoc Tukey tests (P < 0.05. Results. One-way ANOVA indicated significant differences between the groups (P < 0.05. SBS of controls was significantly lower than the other groups; differences between groups 2, 3, 4, 5 and 6 were not significant. Surface treatment with diamond bur + 35% phosphoric acid resulted in the highest bond strength. Conclusion. All the surface treatments used in this study improved the shear bond strength of nanofilled composite resin used.

  5. Effect of Setting Time on the Shear Bond Strength Between Biodentine and Composite

    Science.gov (United States)

    2015-06-01

    bonding systems are utilized the preparation must first undergo exposure to a phosphoric acid etchant, rinsing, and drying , before application of the...manufacturers claim less than 1% shrinkage (which is low for composite resin materials) (3M ESPE, St. Paul MN, USA). Though more investigation is...Scotchbond Universal Etchant, 32% phosphoric acid (3M ESPE) • Apply for 15 seconds • Rinse with water 15 seconds, dry with cotton pellet Scotchbond

  6. Bonded resin composite strip crowns for primary incisors: clinical tips for a successful outcome.

    Science.gov (United States)

    Kupietzky, Ari

    2002-01-01

    The bonded resin composite strip crown is perhaps the most esthetic of all the restorations available to the clinician for the treatment of severely decayed primary incisors. However, strip crowns are also the most technique-sensitive and may be difficult to place. The purpose of this step-by-step technique article is to present some simple clinical tips to assist the clinician in achieving an esthetic and superior outcome.

  7. The effect of plasticity to interlaminar fracture toughness of adhesive bond of composite

    Science.gov (United States)

    Pavelko, V.; Lapsa, K.; Pavlovskis, P.

    2017-10-01

    In this paper the effect of plasticity of an adhesive to interlaminar fracture toughness of adhesive bond of thin-walled layered composite is investigated. The characteristics of failure of low toughness adhesive layer were obtained using the double cantilever beam (DCB) sample. The main features of plasticity effect are obtained. The procedure of results use for strength analysis of structure with the plasticity affected adhesive joint is proposed.

  8. Bond Strength of Methacrylate-Based Composite to Dentin using a Silorane Adhesive

    Science.gov (United States)

    2013-06-06

    Paul, MN ) was recently introduced and differs from traditional methacrylate-based composites in that its ring-opening mechanism decreases...primer has been shown to be capable of dissolving calcium ions and binding to apatite surfaces and forming a distinct nano-interaction zone of 100...involved in dentin bonding. J Dent Res 2012;91:351-357. Filtek LS Technical Product Profile (PDF). 3M/ESPE, St. Paul, MN : accessed 28 April, 2012 at

  9. Effect of a New Surface Treatment Solution on the Bond Strength of Composite to Enamel

    Science.gov (United States)

    2016-06-01

    stored in 0.5% chloramine-T (Science Stuff, Austin, TX). The teeth were sectioned buccolingualy at the cemento- enamel junction to remove the root using...etching or the etch morphology achieved. The enamel hybrid layer is very important in etch-and-rinse adhesive systems because it allows resin to...Bond Strength of Composite to Enamel " is appropriately acknowledged and, beyond brief excerpts, is with the permission of the copyright owner

  10. Non-destructive Evaluation of Bonds Between Fiberglass Composite and Metal

    Science.gov (United States)

    Zhao, Selina; Sonta, Kestutis; Perey, Daniel F.; Cramer, K. E.; Berger, Libby

    2015-01-01

    To assess the integrity and reliability of an adhesive joint in an automotive composite component, several non-destructive evaluation (NDE) methodologies are correlated to lap shear bond strengths. A glass-fabric-reinforced composite structure was bonded to a metallic structure with a two-part epoxy adhesive. Samples were subsequently cut and tested in shear, and flaws were found in some areas. This study aims to develop a reliable and portable NDE system for service-level adhesive inspection in the automotive industry. The results of the experimental investigation using several NDE methods are presented and discussed. Fiberglass-to-metal bonding is the ideal configuration for NDE via thermography using excitation with induction heating, due to the conductive metal and non-conductive glass-fiber-reinforced composites. Excitation can be either by a research-grade induction heater of highly defined frequency and intensity, or by a service-level heater, such as would be used for sealing windshields in a body shop. The thermographs thus produced can be captured via a high-resolution infrared camera, with principal component analysis and 2D spatial Laplacian processing. Alternatively, the thermographs can be captured by low resolution thermochromic microencapsulated liquid crystal film imaging, which needs no post-processing and can be very inexpensive. These samples were also examined with phased-array ultrasound. The NDE methods are compared to the lap shear values and to each other for approximate cost, accuracy, and time and level of expertise needed.

  11. Influence of 10-MDP Adhesive System on Shear Bond Strength of Zirconia-Composite Interfaces

    Directory of Open Access Journals (Sweden)

    Philipp Cornelius Pott

    2015-09-01

    Full Text Available Introduction: This in-vitro study investigated the initial 24h bond strength between different composites and zirconia after application of four different adhesive systems. Methods: A total of 120 specimens of zirconia (InCoris, Sirona, Germany, Bernsheim were ground with a 165 µm grit rotating diamond disc. Thirty specimens were each additionally treated with Cimara Zircon “CZ” (VOCO GmbH, Germany, Cuxhaven, Futurabond U “FBU” (VOCO GmbH, Futurabond M+ “FBM” (VOCO GmbH or Futurabond M+ in combination with the DCA activator “FBMD” (VOCO GmbH. One of three different types of composites – BifixSE (“BS”, BifixQM (“BQ” or GrandioSO (“G” (VOCO GmbH – was bonded to ten specimens each in every group. Shear bond strength (SBS was determined in a universal testing machine. Statistical analysis was performed with ANOVA and the Tukey test. Results: FBM and FBMD gave higher SBS than CZ and FBU in combination with all tested composites. In comparison to FBU, FBM gave statistically significant increases in SBS with BifixSE (19.4±5.7 MPa (P

  12. Shear bond strength of a hot pressed Au-Pd-Pt alloy-porcelain dental composite.

    Science.gov (United States)

    Henriques, B; Soares, D; Silva, F S

    2011-11-01

    The purpose of this study was to evaluate the effect of hot pressing on the shear bond strength of a Au-Pt-Pd alloy-porcelain composite. Several metal-porcelain composites specimens were produced by two different routes: conventional porcelain fused to metal (PFM) and hot pressing. In the latter case, porcelain was hot pressed onto a polished surface (PPPS) as well as a roughened one (PPRS). Bond strength of all metal-porcelain composites were assessed by the means of a shear test performed in a universal test machine (crosshead speed: 0.5 mm/min) until fracture. Interfaces of fractured specimens as well as undestroyed interface specimens were examined with optical microscope, stereomicroscope, Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS). The data were analyzed using one-way ANOVA followed by Tuckey's test (pporcelain (p0.05). This study shows that it is possible to significantly improve metal-porcelain bond strength by applying an overpressure during porcelain firing. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Bonding and wear characteristics of a tri-n-butylborane initiated adhesive resin filled with pre-polymerized composite particles.

    Science.gov (United States)

    Naito, Koji

    2011-03-01

    This study evaluated the wear characteristics and bonding to silver-palladium-copper-gold (Ag-Pd-Cu-Au) alloy of an acrylic resin that was filled with pre-polymerized composite particles and initiated with tri-n-butylborane (TBB) derivative (Bondfill). Three methyl methacrylate (MMA)-based resins (Bondfill, Super-Bond, and Multi-Bond II) and a microfilled composite restorative material (Metafil C) were assessed. Disk specimens were cast from the alloy and were air-abraded with alumina. The disks were bonded with nine bonding systems selected from two priming and three luting agents. Shear bond strengths were measured before and after thermocycling. Bond strength varied from 2.2 MPa to 28.2 MPa. Three systems based on thione primers (Metaltite and V-Primer) and TBB-initiated resins (Bondfill and Super-Bond) had the highest bond strength after thermocycling (15.9-20.4 MPa). The toothbrush-dentifrice abrasion test showed that the Metafil C material was the most wear-resistant, followed by Bondfill and Super-Bond. In conclusion, Bondfill resin is an alternative to Super-Bond resin for luting metallic restorations and for restoring tooth defects. However, care is required in selecting appropriate clinical cases.

  14. Shear Bond Strength of Composite to Nd-YAG Lased Dentin with and without Dye

    Directory of Open Access Journals (Sweden)

    H. Kermanshah

    2004-06-01

    Full Text Available Statement of Problem: The achievement of a good and durable dentin/composite resin bond is an important task in restorative dentistry. The application of acid conditioners and dentin bonding agents is an accepted method to enhance this bond strength. Pretreating of dentin surface by laser irradiation seems to be a supplemental way to obtain better results,since lased dentin is more roughened and has a widest surface area to interact with acidconditioner.Purpose: In this study, the effect of dentin surface pretreating by Nd-YAG laser on dentin/composite shear bond strength was examined. Moreover, the effect of Chinese ink as a surface energy absorber on this value was investigated.Methods and Materials: Thirty-nine freshly extracted human teeth without dentinal caries were collected and their occlusal dentins were exposed using a diamond disk. The collected samples were divided into three identical groups. The dentin surface of the first group was lased by an Nd-YAG pulsed laser (100 mJ, 20 Hz through a 320 mm fiber optic in a swiping movement. In the second group, 10% solution of Chinese ink was applied on the dentinal surface before lasing. The samples of the third group were not lased at all. Thedentinal surface prepared by 35% phosphoric acid and Scotchbond MP primer and adhesive. Then, composite resin was cured on dentinal surface. After incubation, in water at 37°C for 24 hours, the samples were tested by Digital Tritest ELE machine.Results: The values of bond strength were 20.83±3.96 MPa, 17.83±3.63 MPa and 19.38±4.88 MPa for the lased, unlased and dye-enhanced groups, respectively. The results were not significant by ANOVA test (a=0.05. Although in the Weiboul modulus, the lased group offered better bond strength.Conclusion: Further studies are required to determine whether chemical as well as physical alterations to the dentin surface are induced by laser etching, and whether these influence the performance of the range of dentin

  15. Development of bonded composite doublers for the repair of oil recovery equipment.

    Energy Technology Data Exchange (ETDEWEB)

    Roach, David W.; Rackow, Kirk A.

    2005-06-01

    An unavoidable by-product of a metallic structure's use is the appearance of crack and corrosion flaws. Economic barriers to the replacement of these structures have created an aging infrastructure and placed even greater demands on efficient and safe repair methods. In the past decade, an advanced composite repair technology has made great strides in commercial aviation use. Extensive testing and analysis, through joint programs between the Sandia Labs FAA Airworthiness Assurance Center and the aviation industry, have proven that composite materials can be used to repair damaged aluminum structure. Successful pilot programs have produced flight performance history to establish the durability of bonded composite patches as a permanent repair on commercial aircraft structures. With this foundation in place, this effort is adapting bonded composite repair technology to civil structures. The use of bonded composite doublers has the potential to correct the difficulties associated with current repair techniques and the ability to be applied where there are no rehabilitation options. It promises to be cost-effective with minimal disruption to the users of the structure. This report concludes a study into the application of composite patches on thick steel structures typically used in mining operations. Extreme fatigue, temperature, erosive, and corrosive environments induce an array of equipment damage. The current weld repair techniques for these structures provide a fatigue life that is inferior to that of the original plate. Subsequent cracking must be revisited on a regular basis. The use of composite doublers, which do not have brittle fracture problems such as those inherent in welds, can help extend the structure's fatigue life and reduce the equipment downtime. Two of the main issues for adapting aircraft composite repairs to civil applications are developing an installation technique for carbon steel and accommodating large repairs on extremely thick

  16. Effects of surface preparation on the long-term durability of adhesively bonded composite joints

    Science.gov (United States)

    Bardis, Jason Dante

    The long-term durability of adhesively bonded composite joints is critical to modern aircraft structures, which are increasingly adopting bonding as an alternative option to mechanical fastening. The effects of the surface preparation of the adherends are critical, affecting initial strength, long-term durability, fracture toughness, and failure modes of bonded joints. In this study, several potential factors are evaluated, with focus on the following: (1) Effects of possible chemical contamination from release fabrics, release films, and peel plies during adherend cure. (2) Chemical and mechanical effects of abrasion on the fracture toughness and failure mode. (3) Characterization of paste and film adhesives. There are several standard test methods used to evaluate specimen fracture, but the majority concentrate on bonded metals and interlaminar composite fracture. Testing concentrated on mode I tests; a custom double cantilever beam specimen was devised and utilized, and two forms of a wedge crack test (traveling and static) were also used. Additionally, single lap shear tests were run to contrast the mode I tests. Non-destructive testing included X-ray photography of crack fronts, energy dispersive spectroscopy and X-ray photoelectron spectroscopy surface chemistry analyses, and scanning electron microscope imaging of prepared surfaces. All mode I test methods tended to be in agreement in the ranking of different surface preparation methods. Test results revealed that release agents deposited on adherend surfaces during their cure cycle prevented proper adhesion. While mechanical abrasion did improve their fracture toughness and lower their contamination greatly, the test values did not reach the levels of samples that were not contaminated before bonding, and the interfacial modes of failure did not always change to desirable modes.

  17. Effect of Different Surface Treatments on Microtensile Bond Strength of Composite Resin to Normal and Fluorotic Enamel after Microabrasion

    Directory of Open Access Journals (Sweden)

    Mahshid Mohammadi Basir

    2017-01-01

    Full Text Available Objectives: This study aimed to determine the effect of surface treatments such as tooth reduction and extending the etching time on microtensile bond strength (µTBS of composite resin to normal and fluorotic enamel after microabrasion. Materials and Methods: Fifty non-carious anterior teeth were classified into two groups of normal and fluorotic (n=25 using Thylstrup and Fejerskov index (TFI=4-6. Teeth in each group were treated with five modalities as follows and restored with OptiBond FL and Z350 composite resin: 1-Etching (30 seconds, bonding, filling (B; 2-Tooth reduction (0.3mm, etching, bonding, filling (R-B; 3-Microabrasion (120 seconds, etching, bonding, filling (M-B; 4- Microabrasion, tooth reduction, etching, bonding, filling (M-R-B; and 5- Microabrasion, etching (60 seconds, bonding, filling (M-2E-B. Ten experimental groups (n=5 were designed; 150 rectangular samples (10 in each group with a cross-sectional area of 1×1mm2 were prepared for µTBS test. Failure mode was determined under a stereomicroscope and one specimen was selected from each group for scanning electron microscopy (SEM analysis. Data were analyzed using two-way ANOVA and Tukey’s test.Results: The µTBS to normal enamel was higher than to fluorotic enamel in all groups except for group (R-B. The Maximum and minimum µTBS were noted in the group (normal, reduction, bonding and (fluorosed, microabrasion, bonding, respectively.  Tooth reduction increased µTBS more effectively than extended etching time after microabrasion. Conclusions: Fluorosis may reduce µTBS of composite resin to enamel. Microabrasion reduced the bond strength. Tooth reduction and extended etching time increased µTBS of composite resin to both normal and fluorotic enamel.Keywords: Fluorosis, Dental; Enamel Microabrasion; Dental Bonding; Composite Resins

  18. Comparison of Effect of C-Factor on Bond Strength to Human Dentin Using Different Composite Resin Materials.

    Science.gov (United States)

    Singh, Thakur Veerandar; Patil, Jaya Prakash; Raju, Rvs Chakradhar; Venigalla, Bhuvan Shome; Jyotsna, S V; Bhutani, Neha

    2015-08-01

    The study was planned to assess the use of low shrinkage composites for restoring cavities with high configuration factor (C-factor) which are subjected to high stresses. The aim of the study was to evaluate the effect of C- factor on tensile bond strength to human dentin using methacrylate based nanohybrid and low shrinkage silorane composite. In this study 40 non carious human molar teeth were selected and assigned into two main groups - cavity (Class I cavity with high C-factor) and flat group (flat surface with low C-factor). Two different composite materials- methacrylate based and silorane low shrinkage composite were used to restore the teeth. Dentin surface was treated, adhesive application was done and composite was applied as per manufacturer's instructions. Samples were stored in distilled water then subjected to tensile bond strength measurement using universal testing machine. Statistical analysis was done using Independent sample t-test. The mean bond strength in methacrylate based and silorane composite was significantly higher in flat preparation (Low C-factor) than cavity preparation. The mean bond strength in both cavity (High C-factor) and flat preparation(Low C-factor) was significantly higher in silorane than in conventional methacrylate based composite. The bond strength of composites to dentin is strongly influenced by C-factor and type of composite resin material used.

  19. Effect of flowable composite liner and glass ionomer liner on class II gingival marginal adaptation of direct composite restorations with different bonding strategies.

    Science.gov (United States)

    Aggarwal, Vivek; Singla, Mamta; Yadav, Suman; Yadav, Harish

    2014-05-01

    The purpose of the present study was to comparatively evaluate the effect of flowable composite resin liner and resin modified glass ionomer liner on gingival marginal adaptation of class II cavities restored using three bonding agents (Single Bond 3M ESPE, One Coat Self Etching Bond Coltene Whaledent; Adper Easy Bond Self-Etch Adhesive 3M ESPE) and respective composite resins, under cyclic loading. The marginal adaptation was evaluated in terms of 'continuous margin' (CM) at the gingival margin. Ninety class II cavities with margins extending 1mm below the cement-enamel junction were prepared in extracted mandibular third molars. The samples were divided into three groups: no liner placement; 0.5-1mm thick flowable resin liner placement (Filtek Z350 XT flowable resin) on gingival floor and; light cure glass ionomer (Ketac N100) liner. The groups were further subdivided into three sub-groups on the basis of the bonding agents used. Cavities were restored with composite resins (Z350 for Single Bond and Adper Easy Bond; and Synergy D6 Universal, for One Coat Self Etching Bond) in 2mm increments and the samples were mechanically loaded (60N, 1,50,000 cycles). Marginal adaptation was evaluated using a low vacuum scanning electron microscope. Statistical analysis was done with two way ANOVA with Holm-Sidak's correction for multiple comparisons. Placement of flowable composite liner significantly improved the CM values of Single Bond (78±11%) and One Coat Self Etching Bond (77±9%) compared with no liner group, but the values of CM of Adper Easy Bond were not improved (61±12%). Placement of glass ionomer liner significantly improved the values of CM in all the sub-groups (78±9%, 72±10% and 77±10% for Single Bond, One Coat Self Etching Bond & Adper Easy Bond respectively) compared with no liner group. Placement of liners improved the values of 'continuous margin' in the gingival floor of the proximal cavities restored with composite resins using different bonding

  20. Evaluation of Alternative Peel Ply Surface Preparation Methods of SC-15 Epoxy / Fiberglass Composite Surfaces for Secondary Bonding

    Science.gov (United States)

    2014-01-01

    The peel ply is removed prior to surface preparation methods for secondary bonding, which include mechanical abrasion , chemical treatments...Evaluation of Alternative Peel Ply Surface Preparation Methods of SC-15 Epoxy / Fiberglass Composite Surfaces for Secondary Bonding by Jared...originator. Army Research Laboratory Aberdeen Proving Ground, MD 21005-5069 ARL-TR-6781 January 2014 Evaluation of Alternative Peel Ply

  1. Dentin Bond Strength of Two One-Bottle Adhesives after Delayed Activation of Light-Cured Resin Composites

    Directory of Open Access Journals (Sweden)

    F. Shafiei

    2007-12-01

    Full Text Available Objective: Adverse surface interactions between one-bottle adhesives and chemical-cured composites may occur with delayed light activation of light-cured composites. The purpose of this study was to assess the Effects of delayed activation of light-cured compositeson shear bond strength of two one-bottle adhesives with different acidity to bovine dentin.Materials and Methods: Flat dentin surface was prepared on sixty-six bovine incisors using 600 grit carbide papers. Prime&Bond NT, and One-Step adhesives and resin composite were applied in six groups: 1 immediate curing of the composite, 2 the composite was left 2.5 minutes over the cured adhesive before light activation, 3 prior to delayed activation of the composite, the cured adhesive was covered with a layer of nonacidic hydrophobic porcelain bonding resin (Choice 2 and cured immediately. After thermocycling,shear bond strength (SBS test was performed using a universal testing machine at 1 mm/min crosshead speed. Data were analyzed with Friedmans two-way Non-parametric ANOVA.Results: The SBS of delayed activation of Prime&Bond was significantly lower than immediate activated (P<0.05. Decrease in the SBS of One-Step was not statistically significant after delayed activation. The SBS of delayed activation of Prime&Bond and One-Step with an additional resin layer was significantly higher than delayed activation (P<0.001.Conclusion: The bond strength of Prime&Bond might be compromised by the higher acidity of this adhesive during the 2.5 minutes delayed activation of light-cured composite.Addition of a layer of hydrophobic resin compensated the effect of delayed activation andimproved the bond strength.

  2. Bond strength durability of a resin composite on a reinforced ceramic using various repair systems.

    Science.gov (United States)

    Ozcan, Mutlu; Valandro, Luiz Felipe; Amaral, Regina; Leite, Fabiola; Bottino, Marco Antonio

    2009-12-01

    This study compared the durability of repair bond strength of a resin composite to a reinforced ceramic after three repair systems. Alumina-reinforced feldspathic ceramic blocks (Vitadur-alpha) (N=30) were randomly divided into three groups according to the repair method: PR-Porcelain Repair Kit (Bisco) [etching with 9.5% hydrofluoric acid+silanization+adhesive]; CJ-CoJet Repair Kit (3M ESPE) [(chairside silica coating with 30microm SiO(2)+silanization (ESPE)-Sil)+adhesive (Visio-Bond)]; CL-Clearfil Repair Kit [diamond surface roughening, etching with 40% H(3)PO(4)+Clearfil Porcelain Bond Activator+Clearfil SE Bond)]. Resin composite was photo-polymerized on each conditioned ceramic block. Non-trimmed beam specimens were produced for the microtensile bond strength (microTBS) tests. In order to study the hydrolytic durability of the repair methods, the beam specimens obtained from each block were randomly assigned to two conditions. Half of the specimens were tested either immediately after beam production (Dry) or after long-term water storage (37 degrees C, 150 days) followed by thermocyling (12,000 cycles, 5-55 degrees C) in a universal testing machine (1mm/min). Failure types were analyzed under an optical microscope and SEM. microTBS results were significantly affected by the repair method (p=0.0001) and the aging conditions (p=0.0001) (two-way ANOVA, Tukey's test). In dry testing conditions, PR method showed significantly higher (p<0.001) repair bond strength (19.8+/-3.8MPa) than those of CJ and CL (12.4+/-4.7 and 9.9+/-2.9, respectively). After long-term water storage and thermocycling, CJ revealed significantly higher results (14.5+/-3.1MPa) than those of PR (12.1+/-2.6MPa) (p<0.01) and CL (4.2+/-2.1MPa) (p<0.001). In all groups when tested in dry conditions, cohesive failure in the composite accompanied with adhesive failure at the interface (mixed failures), was frequently observed (76%, 80%, 65% for PR, CJ and CL, respectively). After aging conditions

  3. The effect of different adhesives and setting times on bond strength between Biodentine and composite.

    Science.gov (United States)

    Çolak, Hakan; Tokay, Uğur; Uzgur, Recep; Uzgur, Zeynep; Ercan, Ertuğrul; Hamidi, Mehmet M

    2016-05-18

    The aim of this study was to evaluate the effects of 3 different adhesives with different functional monomers, on the shear bond strength (SBS) of Biodentine®. Acrylic blocks (n = 90) were prepared and a 2-mm height x 4-mm diameter hole was opened in each block. Every hole was completely restored with Biodentine®. Before preparation of composite restorations over the Biodentine® (2-mm height x 2-mm diameter), 3 different adhesives (Etch-37 (37%) w/BAC by Bisco & Prime Bond N&T, Clearfil S3 Bond and Adper Prompt L-Pop) were applied. SBS was evaluated using a universal testing machine, and failure mode for each sample was recorded. The results were statistically analyzed using 2-way ANOVA and post hoc Tukey test. When the megapascal values of all groups were compared, although there was no statistically significant difference in the different setting times (p>0.05), statistically significant differences were observed among all adhesive groups (p<0.05). Moreover, the highest SBS values were observed in the Clearfil S3 Bond group. Clinical performance of Biodentine® may be affected by adhesive procedures and its setting time.

  4. Vibroacoustic Model Validation for a Curved Honeycomb Composite Panel

    Science.gov (United States)

    Buehrle, Ralph D.; Robinson, Jay H.; Grosveld, Ferdinand W.

    2001-01-01

    Finite element and boundary element models are developed to investigate the vibroacoustic response of a curved honeycomb composite sidewall panel. Results from vibroacoustic tests conducted in the NASA Langley Structural Acoustic Loads and Transmission facility are used to validate the numerical predictions. The sidewall panel is constructed from a flexible honeycomb core sandwiched between carbon fiber reinforced composite laminate face sheets. This type of construction is being used in the development of an all-composite aircraft fuselage. In contrast to conventional rib-stiffened aircraft fuselage structures, the composite panel has nominally uniform thickness resulting in a uniform distribution of mass and stiffness. Due to differences in the mass and stiffness distribution, the noise transmission mechanisms for the composite panel are expected to be substantially different from those of a conventional rib-stiffened structure. The development of accurate vibroacoustic models will aide in the understanding of the dominant noise transmission mechanisms and enable optimization studies to be performed that will determine the most beneficial noise control treatments. Finite element and boundary element models of the sidewall panel are described. Vibroacoustic response predictions are presented for forced vibration input and the results are compared with experimental data.

  5. Shear sensing in bonded composites with cantilever beam microsensors and dual-plane digital image correlation

    Science.gov (United States)

    Baur, Jeffery W.; Slinker, Keith; Kondash, Corey

    2017-04-01

    Understanding the shear strain, viscoelastic response, and onset of damage within bonded composites is critical to their design, processing, and reliability. This presentation will discuss the multidisciplinary research conducted which led to the conception, development, and demonstration of two methods for measuring the shear within a bonded joint - dualplane digital image correlation (DIC) and a micro-cantilever shear sensor. The dual plane DIC method was developed to measure the strain field on opposing sides of a transparent single-lap joint in order to spatially quantify the joint shear strain. The sensor consists of a single glass fiber cantilever beam with a radially-grown forest of carbon nanotubes (CNTs) within a capillary pore. When the fiber is deflected, the internal radial CNT array is compressed against an electrode within the pore and the corresponding decrease in electrical resistance is correlated with the external loading. When this small, simple, and low-cost sensor was integrated within a composite bonded joint and cycled in tension, the onset of damage prior to joint failure was observed. In a second sample configuration, both the dual plane DIC and the hair sensor detected viscoplastic changes in the strain of the sample in response to continued loading.

  6. Shear bond strength between veneering composite and PEEK after different surface modifications.

    Science.gov (United States)

    Rosentritt, Martin; Preis, Verena; Behr, Michael; Sereno, Nuno; Kolbeck, Carola

    2015-04-01

    This study aims to test the influence of different surface treatments and conditioning on the shear bond strength between polyetherketone (PEEK) and composite. Surfaces (570 plates) were used untreated, etched, air-particle abraded or activated with silica-modified alumina oxide. Surface roughness was determined after different treatments. Cylinders of composite were polymerized onto the surfaces. Eighteen different pre-treatment combinations were applied, partly combined with opaque application. Shear bond strength (SBS) was determined following ISO TR 11405. Baseline tests were performed 24 h after composite polymerization. For investigating the influence of storage and aging, the specimens were either stored in distilled water (37 °C, 90 days) or thermally cycled (12,000 cycles 5 °C/55 °C, distilled water). Means and standard deviations were calculated (statistics: one-way ANOVA/Bonferroni (α = 0.05)). Surface roughness varied between 0.04 ± 0.01 and 6.76 ± 1.11 μm. Only etching caused a significant (p < 0.001) increase. SBS strongly varied between 0.0 ± 0.0 and 23.2 ± 2.1 MPa. After thermal cycling (TC), nine of the investigated systems showed SBS higher than 5 MPa, varying from 8.8 ± 2.7 MPa (#7) to 19.4 ± 2.5 MPa (#4). After water storage, nine systems provided SBS higher than 5 MPa, seven even values higher than 10 MPa. Maximum SBS was 27.1 ± 3.1 MPa (#2) and lowest value was 5.4 ± 2.6 MPa (#4). Significant (p < 0.001) differences were found between the individual systems after 24 h, TC and after 90 days storage. For good bonding between PEEK and composite, cleaning and roughening is recommended. Surface conditioning prior to bonding seems essential. Combination with opaque revealed an increase in SBS. Successful bonding on PEEK surfaces can be achieved by surface roughening and subsequent surface activation with acetone- or phosphate-based methacrylate primers or tribochemical treatment.

  7. Evaluation of class V composite restorations microleakage in premolars with/without electric current while applying variant dentin bondings

    OpenAIRE

    Narges Dorri; Azita Kaviani; Ali Noori

    2014-01-01

      Background and Aims: The ability of composite restorations to prevent microleakage needs desirable bonding material for proper sealing . The purpose of this study was to evaluate class V composite restorations microleakage in premolars with/without electric current while applying variant dentin bonding in vitro.   Materials and Methods: 120 non-carious human premolars were used for this study and standardized class v cavities were prepared. The tooth roots were cut by discs at a distance of...

  8. A study on the compatibility between one-bottle dentin adhesives and composite resins using micro-shear bond strength

    OpenAIRE

    Minju Song; Yooseok Shin; Jeong-Won Park; Byoung-Duck Roh

    2015-01-01

    Objectives This study was performed to determine whether the combined use of one-bottle self-etch adhesives and composite resins from same manufacturers have better bond strengths than combinations of adhesive and resins from different manufacturers. Materials and Methods 25 experimental micro-shear bond test groups were made from combinations of five dentin adhesives and five composite resins with extracted human molars stored in saline for 24 hr. Testing was performed using the wi...

  9. Thermal Stability and Coefficient of Friction of the Diamond Composites with the Titanium Compound Bonding Phase

    Science.gov (United States)

    Cygan, S.; Jaworska, L.; Putyra, P.; Ratuszek, W.; Cyboron, J.; Klimczyk, P.

    2017-05-01

    In this paper, processes occurring during heat treatment of the diamond-Ti compound composites without Co addition were investigated and compared with commercial PCD. Three types of materials were prepared. The first material was sintered using the mixture containing diamond and 10 mass% of TiC, the second material was prepared using diamond powder and 10 mass% of Ti-Si-C, and the third composite was sintered using the addition of 10 mass% of TiB2. During the research, it was proved that TiO2 formation contributes to material swelling and WO3 (W is present from the milling process) causes a significant increase in coefficient of friction. TiC and Ti-Si-C bonded materials are very susceptible to this process of oxidation; their hardness drops absolutely after wear test at 600 °C. The diamond composite with TiB2 is the most resistant to oxidation from investigated materials.

  10. Post-thermocycling shear bond strength of a gingiva-colored indirect composite layering material to three implant framework materials.

    Science.gov (United States)

    Komine, Futoshi; Koizuka, Mai; Fushiki, Ryosuke; Taguchi, Kohei; Kamio, Shingo; Matsumura, Hideo

    2013-09-01

    To evaluate shear bond strength of a gingiva-colored indirect composite to three implant framework materials, before and after thermocycling, and verify the effect of surface pre-treatment for each framework. Commercially pure titanium (CP-Ti), American Dental Association (ADA) type 4 casting gold alloy (Type IV) and zirconia ceramics (Zirconia) were assessed. For each substrate, 96 disks were divided into six groups and primed with one of the following primers: Alloy Primer (ALP), Clearfil Photo Bond (CPB), Clearfil Photo Bond with Clearfil Porcelain Bond Activator (CPB+Activator), Estenia Opaque Primer (EOP), Metal Link (MLP) and V-Primer (VPR). The specimens were then bonded to a gingiva-colored indirect composite (Ceramage Concentrate GUM-D). Shear bond strengths were measured at 0 and 20 000 thermocycles and data were analyzed with the Steel-Dwass test and Mann-Whitney U-test. Shear bond strengths were significantly lower after thermocycling, with the exception of Type IV specimens primed with CPB (p = 0.092) or MLP (p = 0.112). For CP-Ti and Zirconia specimens, priming with CPB or CPB+Activator produced significantly higher bond strengths at 0 and 20 000 thermocycles, as compared with the other groups. For Type IV specimens, priming with ALP or MLP produced higher bond strengths at 0 and 20 000 thermocycles. Shear bond strength of a gingiva-colored indirect composite to CP-Ti, gold alloy and zirconia ceramics was generally lower after thermocycling. Application of a hydrophobic phosphate monomer and polymerization initiator was effective in maintaining bond strength of CP-Ti and zirconia ceramics. Combined use of a thione monomer and phosphoric monomer enhanced the durable bond strength of gold alloy.

  11. Postpartum Bonding Disorder: Factor Structure, Validity, Reliability and a Model Comparison of the Postnatal Bonding Questionnaire in Japanese Mothers of Infants

    Directory of Open Access Journals (Sweden)

    Yukiko Ohashi

    2016-08-01

    Full Text Available Negative attitudes of mothers towards their infant is conceptualized as postpartum bonding disorder, which leads to serious health problems in perinatal health care. However, its measurement still remains to be standardized. Our aim was to examine and confirm the psychometric properties of the Postnatal Bonding Questionnaire (PBQ in Japanese mothers. We distributed a set of questionnaires to community mothers and studied 392 mothers who returned the questionnaires at 1 month after childbirth. Our model was compared with three other models derived from previous studies. In a randomly halved sample, an exploratory factor analysis yielded a three-factor structure: Anger and Restrictedness, Lack of Affection, and Rejection and Fear. This factor structure was cross-validated by a confirmatory factor analysis using the other halved sample. The three subscales showed satisfactory internal consistency. The three PBQ subscale scores were correlated with depression and psychological abuse scores. Their test–retest reliability between day 5 and 1 month after childbirth was measured by intraclass correlation coefficients between 0.76 and 0.83. The Akaike Information Criteria of our model was better than the original four-factor model of Brockington. The present study indicates that the PBQ is a reliable and valid measure of bonding difficulties of Japanese mothers with neonates.

  12. In-Vitro Evaluation of the Effect of Herbal Antioxidants on Shear Bond Strength of Composite Resin to Bleached Enamel

    Directory of Open Access Journals (Sweden)

    Zahra Khamverdi

    2016-11-01

    Full Text Available Objectives: A reduction in bond strength of composite to bleached enamel has been reported immediately after bleaching treatment. Application of some antioxidant agents may decrease the adverse effects of whitening agents on bond strength and enhance composite bond to enamel. This study aimed to assess the effect of green tea, sodium ascorbate, sage and grape seed extract on bond strength of composite to bleached enamel.Materials and Methods: In this in-vitro study, 90 human enamel surfaces were randomly divided into six groups as follows (n=15: G1, no bleaching; G2, bleaching with 40% hydrogen peroxide (HP; G3, HP+1000 μmol epigallocatechin gallate (EGCG for 10 minutes; G4, HP+10% sodium ascorbate for 10 minutes; G5, HP+10% sage for 10 minutes and G6, HP+5% grape seed extract for 10 minutes. The specimens were bonded to composite in all groups. The shear bond strength of specimens was measured in Megapascals (MPa. Data were analyzed using one-way ANOVA and Tukey’s HSD test (α=0.05.Results: The highest and the lowest mean shear bond strength values were observed in group 1 (22.61±3.29MPa and group 2 (5.87±1.80MPa, respectively. The reduction in bond strength in group 2 was greater than that in other groups (P<0.001. No significant difference was found among groups 1, 3, 4, 5 and 6 (P>0.05. Conclusions: All the herbal antioxidants used in this study equally compensated for the reduced bond strength of composite to bleached enamel.Keywords: Antioxidants; Tooth Bleaching; Composite Resins; Shear Strength 

  13. Effect of Various Laser Surface Treatments on Repair Shear Bond Strength of Aged Silorane-Based Composite.

    Science.gov (United States)

    Alizadeh Oskoee, Parnian; Savadi Oskoee, Siavash; Rikhtegaran, Sahand; Pournaghi-Azar, Fatemeh; Gholizadeh, Sarah; Aleyasin, Yasaman; Kasrae, Shahin

    2017-01-01

    Introduction: Successful repair of composite restorations depends on a strong bond between the old composite and the repair composite. This study sought to assess the repair shear bond strength of aged silorane-based composite following surface treatment with Nd:YAG, Er,Cr:YSGG and CO2 lasers. Methods: Seventy-six Filtek silorane composite cylinders were fabricated and aged by 2 months of water storage at 37°C. The samples were randomly divided into 4 groups (n=19) of no surface treatment (group 1) and surface treatment with Er,Cr:YSGG (group 2), Nd:YAG (group 3) and CO2 (group 4) lasers. The repair composite was applied and the shear bond strength was measured. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey posthoc test. Prior to the application of the repair composite, 2 samples were randomly selected from each group and topographic changes on their surfaces following laser irradiation were studied using a scanning electron microscope (SEM). Seventeen other samples were also fabricated for assessment of cohesive strength of composite. Results: The highest and the lowest mean bond strength values were 8.99 MPa and 6.69 MPa for Er,Cr:YSGG and control groups, respectively. The difference in the repair bond strength was statistically significant between the Er,Cr:YSGG and other groups. Bond strength of the control, Nd:YAG and CO2 groups was not significantly different. The SEM micrographs revealed variable degrees of ablation and surface roughness in laser-treated groups. Conclusion: Surface treatment with Er,Cr:YSGG laser significantly increase the repair bond strength of aged silorane-based composite resin.

  14. Impairment of resin cement application on the bond strength of indirect composite restorations

    Directory of Open Access Journals (Sweden)

    Jovito Adiel SKUPIEN

    2015-01-01

    Full Text Available The aims of this study were to evaluate the effect of immediate and delayed resin cement application on the microtensile bond strength of indirect composite resin restorations and, to evaluate adhesive strategies (for regular resin cement or humidity parameters for self-adhesive resin cement. Forty-five enamel/dentin discs (0.5 mm height and 10 mm of diameter obtained from bovine teeth were divided into nine groups (n = 5. For regular cement, the variation factors were cementation technique at three levels (immediate cementation, 5 or 30 min after adhesive system application; and type of adhesive system at two levels (three- or two-step. For self-adhesive cement, the dentin moisture was the source of variation at three levels (normal, dry, or wet cementation. The specimens were submitted to microtensile bond strength (μTBS testing using a universal testing machine. Data were analyzed by ANOVA, Tukey’s test, and linear regression. Regular cement and three-step etch-and-rinse adhesive system showed the highest values of bond strength (25.21 MPa–30 min of delay. Only for this condition, three-step adhesive showed higher bond strength than the two-step adhesive. Nevertheless, the linear regression showed that irrespective of the strategy, the use of the two-step approach when compared with three-step adhesive system decreased μTBS (p < 0.001. The failure analysis showed predominant adhesive failures for all tested groups. All groups had comparable values of bond strength to bovine dentin when the same materials were used, even in suboptimal clinical conditions.

  15. Development of structural health monitoring systems for composite bonded repairs on aircraft structures

    Science.gov (United States)

    Galea, Stephen C.; Powlesland, Ian G.; Moss, Scott D.; Konak, Michael J.; van der Velden, Stephen P.; Stade, Bryan; Baker, Alan A.

    2001-08-01

    The application of bonded composite patches to repair or reinforce defective metallic structures is becoming recognized as a very effective versatile repair procedure for many types of problems. Immediate applications of bonded patches are in the fields of repair of cracking, localized reinforcement after removal of corrosion damage and for reduction of fatigue strain. However, bonded repairs to critical components are generally limited due to certification concerns. For certification and management of repairs to critical structure, the Smart Patch approach may be an acceptable solution from the airworthiness prospective and be cost effective for the operator and may even allow some relaxation of the certification requirements. In the most basic form of the Smart Patch in-situ sensors can be used as the nerve system to monitor in service the structural condition (health or well-being) of the patch system and the status of the remaining damage in the parent structure. This application would also allow the operator to move away from current costly time-based maintenance procedures toward real-time health condition monitoring of the bonded repair and the repaired structure. TO this end a stand-alone data logger device, for the real-time health monitoring of bonded repaired systems, which is in close proximity to sensors on a repair is being developed. The instrumentation will measure, process and store sensor measurements during flight and then allow this data to be up-loaded, after the flight, onto a PC, via remote (wireless) data access. This paper describes two in-situ health monitoring systems which will be used on a composite bonded patch applied to an F/A-18. The two systems being developed consists of a piezoelectric (PVDF) film-based and a conventional electrical-resistance foil strain gauge-based sensing system. The latter system uses a primary cell (Lithium- based battery) as the power source, which should enable an operating life of 1-2 years. The patch

  16. Body composition: validity of segmental bioelectrical impedance analysis.

    Science.gov (United States)

    LaForgia, Joe; Gunn, Simon; Withers, Robert T

    2008-01-01

    Bioelectrical impedance analysis (BIA) measures the impedance associated with passage of an alternating current through the body which is proportional to total body water (TBW) and therefore can provide expedient estimates of body composition. However, little validity information is available for commercially available bathroom scale type devices which perform whole body estimates from segmental (lower limb) measurements. This study therefore compared body composition estimates between a commercially available segmental BIA device (Tanita BC-532) and four compartment criterion values. Body composition of nine males and nine females (mean +/- SD: 37.7 +/- 18.7 yr; 170.7 +/- 5.3 cm; 68.38 +/- 9.7 kg) was determined via BIA and a four compartment model incorporating measures of body density, TBW and bone mineral mass. While the mean %BF and fat free mass (FFM) values for both methods were not significantly different, considerable intra-individual differences were observed. BIA values varied from the four compartment values by -3.0 to 4.4 %BF and -3.3 to 1.9 kg FFM. The BIA estimates of TBW were significantly different from the criterion measures and intraindividual differences displayed a large range (-0.6 to 3.6 kg). Significant underestimations of TBW via BIA are concerning given that this is the parameter initially established by this method. Furthermore, the BIA data resulted in a FFM hydration value of 68.5% which was significantly (pbody composition compared with a four compartment criterion method.

  17. Two-year clinical evaluation of a posterior resin composite using a fourth- and fifth-generation bonding agent.

    Science.gov (United States)

    Gallo, John R; Burgess, John O; Ripps, Alan H; Walker, Richard S; Winkler, Mark M; Mercante, Donald E; Davidson, Jessica M

    2005-01-01

    This study evaluated the clinical performance of a posterior resin composite used with a fourth- and fifth-generation bonding agent. Sixty-two Class I and II restorations were placed with half the restorations restored with Gluma Solid Bond (a fourth-generation bonding system, or total etch two-step system) and the other half restored with Gluma Comfort Bond and Desensitizer (a fifth-generation bonding system, or total etch one-step system). Solitaire 2 was used as the restorative material for all restorations. The bonding systems and resin composite were used according to the manufacturer's instructions and all procedures were performed with rubber dam isolation. All restorations were evaluated at baseline, six months and one and two years. A modified USPHS scale was used to evaluate the restorations for marginal discoloration, recurrent caries, anatomic form, marginal adaptation and proximal contact. Statistical analysis revealed that at two years no significant differences were found between the two bonding agents. Overall, Solitaire 2 performed well clinically whether Gluma Solid Bond or Gluma Comfort Bond and Desensitizer was used. It was thus concluded that Solitaire 2 functions successfully when used as a posterior restorative material for at least two years.

  18. Influence of methyl mercaptan on the repair bond strength of composites fabricated using self-etch adhesives.

    Science.gov (United States)

    Yokokawa, Miho; Rikuta, Akitomo; Tsujimoto, Akimasa; Tsuchiya, Kenji; Shibasaki, Syo; Matsuyoshi, Saki; Miyazaki, Masashi

    2015-02-01

    The influence of methyl mercaptan on the repair bond strength of composites fabricated using self-etch adhesives was investigated. The surface free-energies were determined by measuring the contact angles of test liquids placed on composites that had been immersed in different concentrations of methyl mercaptan (0.01, 0.1, and 1.0 M). To determine the repair bond strength, self-etch adhesives were applied to the aged composite, and then newly added composites were condensed. Ten samples of each specimen were subjected to shear testing at a crosshead speed of 1.0 mm min(-1). Samples were analyzed using two-way ANOVA followed by Tukey's honestly significant difference (HSD) test. Although the dispersion force of the composites remained relatively constant, their polar force increased slightly as the concentration of methyl mercaptan increased. The hydrogen-bonding forces were significantly higher after immersion in 1.0 M methyl mercaptan, leading to higher surface-free energies. However, the repair bond strengths for the repair restorations prepared from composites immersed in 1.0 M methyl mercaptan were significantly lower than for those immersed in 0.01 and 0.10 M methyl mercaptan. Considering the results of this study, it can be concluded that the repair bond strengths of both the aged and newly added composites were affected by immersion in methyl mercaptan solutions. © 2014 Eur J Oral Sci.

  19. Effect of Different Surface Treatments on Microtensile Bond Strength of Composite Resin to Normal and Fluorotic Enamel After Microabrasion.

    Science.gov (United States)

    Bassir, Mahshid Mohammadi; Rezvani, Mohammad Bagher; Ghomsheh, Elham Tabatabai; Hosseini, Zahra Malek

    2016-11-01

    This study aimed to determine the effect of surface treatments such as tooth reduction and extending the etching time on microtensile bond strength (μTBS) of composite resin to normal and fluorotic enamel after microabrasion. Fifty non-carious anterior teeth were classified into two groups of normal and fluorotic (n=25) using Thylstrup and Fejerskov index (TFI=4-6). Teeth in each group were treated with five modalities as follows and restored with OptiBond FL and Z350 composite resin: 1-Etching (30 seconds), bonding, filling (B); 2-Tooth reduction (0.3mm), etching, bonding, filling (R-B); 3-Microabrasion (120 seconds), etching, bonding, filling (MB); 4- Microabrasion, tooth reduction, etching, bonding, filling (M-R-B); and 5- Microabrasion, etching (60 seconds), bonding, filling (M-2E-B). Ten experimental groups (n=5) were designed; 150 rectangular samples (10 in each group) with a cross-sectional area of 1×1mm2 were prepared for μTBS test. Failure mode was determined under a stereomicroscope and one specimen was selected from each group for scanning electron microscopy (SEM) analysis. Data were analyzed using two-way ANOVA and Tukey's test. The μTBS to normal enamel was higher than to fluorotic enamel in all groups except for group (R-B). The Maximum and minimum μTBS were noted in the group (normal, reduction, bonding) and (fluorosed, microabrasion, bonding), respectively. Tooth reduction increased μTBS more effectively than extended etching time after microabrasion. Fluorosis may reduce μTBS of composite resin to enamel. Microabrasion reduced the bond strength. Tooth reduction and extended etching time increased μTBS of composite resin to both normal and fluorotic enamel.

  20. Microtensile bond strength of quartz fiber posts to different composite cores

    Directory of Open Access Journals (Sweden)

    Zahra Khamverdi

    2011-08-01

    Full Text Available The aim of this in vitro study was to assess the microtensile bond strength of quartz fiber posts to different composites, and to composite combinations used as core materials. Thirty fiber posts were treated with a 24% hydrogen peroxide solution and silanized. The posts were divided into 5 groups according to the resin composite used as follows (n = 6: G1 - Ælite Flow (Bisco, Inc, G2 - Filtek Z250 (3M ESPE, G3 - Biscore (Bisco, Inc, G4 - Ælite Flow + Filtek Z250, G5 - Ælite Flow + Biscore. The resin composites were placed around the posts to produce cylindrical specimens. Two 1-mm² thick sticks containing the post in the center and composite cores on both ends were provided from each cylinder and tested for microtensile strength with a crosshead speed of 0.5 mm/min. One-way ANOVA and Tukey HSD tests were used for statistical analysis. Fractured surfaces were observed using a stereomicroscope with 20× magnification. Scanning electron microscopy (SEM was used to evaluate the interface of the fractured sticks. The results showed that G2 had the highest bond strength values, and the lowest values were seen with G3. There were significant differences between groups 1, 2, 4 and groups 3, 5 (p < 0.05. Under the stereomicroscope, most of the failures were adhesive between the post and core material. Under SEM, Ælite and Z250 had smoother surfaces than Biscore, containing less porosities and voids.

  1. Thermal shock performance of carbon-bonded carbon fiber composite and ceramic matrix composite joints for thermal protection re-entry applications

    OpenAIRE

    Triantou, K.I.; Mergia, K.; Perez, B.; Florez, S.; Stefan, A.; Ban, C.; Pelin, G.; Ionescu, G.; Zuber, C.; Fischer, W.P.P.; Barcena, J.

    2017-01-01

    Hybrid thermal protection systems for aerospace applications based on carbon-bonded carbon fiber composite (CALCARB®) and ceramic matrix composites have been investigated. Two types of ceramic composite materials were considered, Cf/SiC (SiCARBON™) and C/C-SiC. The ablative material and the ceramic matrix composite were joined using alumina, graphite and zirconia-zirconium silicate based commercial high temperature adhesives and their performance on thermal shock tests was evaluated. Microstr...

  2. COMPOSITE RESIN BOND STRENGTH TO ETCHED DENTINWITH ONE SELF PRIMING ADHESIVE

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    P SAMIMI

    2002-09-01

    Full Text Available Introduction. The purpose of this study was to compare shear bond strength of composite resins to etched dentin in both dry and wet dentin surface with active and inactive application of a single-bottle adhesive resin (Single Bond, 3M Dental products. Methods. Fourthy four intact human extracted molars and premolars teeth were selected. The facial surfaces of the teeth were grounded with diamond bur to expose dentin. Then specimens were divided into four groups of 11 numbers (9 Molars and 2 Premolars. All the samples were etched with Phosphoric Acid Gel 35% and then rinsed for 10 seconds. The following stages were carried out for each group: Group I (Active-Dry: After rinsing, air drying of dentin surface for 15 seconds, active priming of adhesive resin for 15 seconds, air drying for 5 seconds, the adhesive resin layer was light cured for 10 seconds. Group III (Inactive-Dry:After rinsing, air drying of dentin surface for 15 seconds, adhesive resin was applied and air dryied for 5 seconds, the adhesive layer was light cured for 10 seconds. Group III (Active-Wet:After rinsing, removal of excess water of dentin surface with a cotton roll, active priming of adhesive resin for 15 seconds and air drying for 5 seconds, the adhesive layer was light cured for 10 seconds. Group IV (Inactive-Wet:After rinsing, removal of excess water of dentin surface with a cotton roll, the adhesive resin was applied and air dryied for 5 seconds and then cured for 10 seconds. After adhesive resin application, composite resin (Z250, 3M Dental products was applied on prepared surface with cylindrical molds (with internal diameter of 2.8mm, & height of 5mm and light-cured for 100 seconds (5x20s. The samples were then thermocycled. They were located in 6±3c water .temperature for 10 seconds and then 15 seconds in inviromental temperature, 10s in 55±3c water temperature and then were located at room temperature for 15s. This test was repeated for 100s. All of the specimens

  3. Cold Plasma Pretreatment of Carbon Fibre Composite Substrates to Improve Adhesive Bonding Performance

    Directory of Open Access Journals (Sweden)

    Chiara Mandolfino

    2014-01-01

    Full Text Available The purpose of the paper is to investigate the effects of low pressure plasma treatment on wettability of carbon fibre reinforced polymer samples and on shear properties of adhesive bonded joints based on these substrates. In particular, two plasma process parameters, exposure time and power input, were optimized, performing contact angle evaluation on lap-shear tests. The plasma treatment was also compared with a conventional mechanical abrasion and untreated and only degreased specimens. The experimental results show that choosing the optimal parameters is possible to improve the wettability of composite substrates and reduce the contact angle.

  4. Comparison of Micro-Shear Bond Strength between Silorane-Based Composite and Conventional Methacrylate-Based Composite to the Dentin of Primary Teeth

    Directory of Open Access Journals (Sweden)

    Maryam Sharifi

    2017-12-01

    Full Text Available Introduction: Bond strength between the restorative material and tooth structure is one of the major factors in the selection of restorative materials, which plays a key role in durable restoration and reducing microleakage. Considering the recent attention of researchers to low-shrinkage composites, the present study aimed to compare the micro-shear bond strength of silorane-based composite (P90 with the conventional methacrylate-based composite (Z250 to the dentin of primary teeth. Materials and Methods: In this experimental study, 24 intact primary canines were selected. Two disks (thickness: 2 mm were prepared from each tooth, and the samples were randomly divided into four groups (n=12. Composite resin cylinders (r=0.7 were adapted on each dentin surface, as follows: g1: (silorane bond system + P90, g2: (etch + silorane bond system + P90, g3: (single bond + Z250, g4: (etch + single bond + Z250. Afterwards, the samples were subjected to a micro-shear bond strength test until failure. Data analysis was performed using Tamhane’s T2 (P

  5. The Comparison of Shear Bond Strength Between Fibre Reinforced Composite Posts with Three Different Composite Core Materials – An In vitro Study

    Science.gov (United States)

    Anche, Sampath; Kakarla, Pranitha; Kadiyala, Krishna Kishore; Sreedevi, B.; Chiramana, Sandeep; Dev J., Ravi Rakesh; Manne, Sanjay Dutt; G., Deepthi

    2014-01-01

    Aim: The aim of this study is to compare the shear bond strength between fiber reinforced composite post with three different composite core materials. Materials and Methods: The materials used for the study were: 30 maxillary central incisors, pre fabricated fiber reinforced composite post (postec plus posts), Multi-core heavy body, Ti-core, Fluoro-core, Etchant gel, Silane coupling agent, Dentin bonding agent, Standardized gutta percha points, Rely-X dual cure composite resin. A total of 30 human maxillary central incisor were selected for this study. They were divided into three groups of 10 specimens each namely A, B and C. Results: The results obtained were analyzed by using one way analysis (ANOVA) and Tukey Honestly Significant Difference and they showed highest mean shear bond strength for group C when compared with group A and group B. There is no significant difference in the shear bond strength values between group A and group B. Conclusion: The teeth restored with multicore HB showed highest shear bond strength. The teeth restored with Fluoro core showed lowest shear bond strength. No statistically significant difference exists between the shear bond strength values between Ti-core and Fluoro-core. PMID:24596784

  6. The Comparison of Shear Bond Strength Between Fibre Reinforced Composite Posts with Three Different Composite Core Materials - An In vitro Study.

    Science.gov (United States)

    Anche, Sampath; Kakarla, Pranitha; Kadiyala, Krishna Kishore; Sreedevi, B; Chiramana, Sandeep; Dev J, Ravi Rakesh; Manne, Sanjay Dutt; G, Deepthi

    2014-01-01

    The aim of this study is to compare the shear bond strength between fiber reinforced composite post with three different composite core materials. The materials used for the study were: 30 maxillary central incisors, pre fabricated fiber reinforced composite post (postec plus posts), Multi-core heavy body, Ti-core, Fluoro-core, Etchant gel, Silane coupling agent, Dentin bonding agent, Standardized gutta percha points, Rely-X dual cure composite resin. A total of 30 human maxillary central incisor were selected for this study. They were divided into three groups of 10 specimens each namely A, B and C. The results obtained were analyzed by using one way analysis (ANOVA) and Tukey Honestly Significant Difference and they showed highest mean shear bond strength for group C when compared with group A and group B. There is no significant difference in the shear bond strength values between group A and group B. The teeth restored with multicore HB showed highest shear bond strength. The teeth restored with Fluoro core showed lowest shear bond strength. No statistically significant difference exists between the shear bond strength values between Ti-core and Fluoro-core.

  7. Validating finite element models of composite aerospace structures for damage detection applications

    Science.gov (United States)

    Oliver, J. A.; Kosmatka, J. B.; Hemez, François M.; Farrar, Charles R.

    2006-03-01

    Carbon-fiber-reinforced-polymer (CFRP) composites represent the future for advanced lightweight aerospace structures. However, reliable and cost-effective techniques for structural health monitoring (SHM) are needed. Modal and vibration-based analysis, when combined with validated finite element (FE) models, can provide a key tool for SHM. Finite element models, however, can easily give spurious and misleading results if not finely tuned and validated. These problems are amplified in complex structures with numerous joints and interfaces. A small series of all-composite test pieces emulating wings from a lightweight all-composite Unmanned Aerial Vehicle (UAV) have been developed to support damage detection and SHM research. Each wing comprises two CFRP prepreg and Nomex honeycomb co-cured skins and two CFRP prepreg spars bonded together in a secondary process using a structural adhesive to form the complete wings. The first of the set is fully healthy while the rest have damage in the form of disbonds built into the main spar-skin bondline. Detailed FE models were created of the four structural components and the assembled structure. Each wing component piece was subjected to modal characterization via vibration testing using a shaker and scanning laser Doppler vibrometer before assembly. These results were then used to correlate the FE model on a component-basis, through fitting and optimization of polynomial meta-models. Assembling and testing the full wing provided subsequent data that was used to validate the numerical model of the entire structure, assembled from the correlated component models. The correlation process led to the following average percent improvement between experimental and FE frequencies of the first 20 modes for each piece: top skin 10.98%, bottom skin 45.62%, main spar 25.56%, aft spar 10.79%. The assembled wing model with no further correlation showed an improvement of 32.60%.

  8. Evaluation of Different Dentin Bonding Agents Accompanied with Composite Coronal Barrier

    Directory of Open Access Journals (Sweden)

    Zahed Mohammadi

    2015-06-01

    Full Text Available Introduction: The purpose of this study was to evaluate the sealing ability of dentin bonding agents in root canals obturated with gutta-percha and MTA. Methods: Forty-five single rooted human premolar teeth were decoronated so that remaining root portions were 12 mm in length. The samples were divided randomly into three experimental (n=13 and two control groups (n=3. All teeth were instrumented up to #40 K-file using step-back technique. The roots were obturated with gutta-percha/AH26 and MTA for 5 and 3 mm, respectively. Excite, Clearfil SE Bond, and iBond were applied for experimental groups and then 2mm was filled with composite Filtek Z250. The roots in the controls were merely instrumented and obturated. Two coats of nail varnish were applied on the surface of the teeth in the experimental and positive groups, except 2 mm around the apical foramen and coronal surfaces. In the negative control, the surfaces were completely covered by two layers of nail varnish. After thermocycling, the roots mounted in plastic caps of tubes containing BHI medium and inoculated coronally with Enterococcus faecalis. The data were statistically analyzed using Fisher's exact and Kaplan-Meier survival Analysis. Results: There were no statistically significant differences between three experimental groups regarding the leakage rate (P=0.738. Conclusion: Within the limitations of this study, it was observed that the adhesive systems in alliance with gutta-percha and MTA obturation could not entirely

  9. Effect of antioxidant agents on bond strength of composite to bleached enamel with 38% hydrogen peroxide

    Directory of Open Access Journals (Sweden)

    Juliane Marcela Guimaraes da Silva

    2011-01-01

    Full Text Available This study evaluated the effect of antioxidant agents on microtensile bond strengths (mTBS of composite to bleached enamel. Fifteen freshly extracted human third molars were selected and randomly assigned to 6 groups (n = 5: (NB enamel not bleached, (B bleached enamel, (BR7 bleached enamel and restored 7 days later, (BSA bleached enamel+sodium ascorbate, (BMC bleached enamel+malvidin chloride, (BPC bleached enamel+pelargonidin chloride. The groups were bleached with 38% hydrogen peroxide (HP - Opalescence Xtra Boost and restored with Single Bond+Filtek Z350. The specimens were thermocycled and submitted to a microtensile load at 1 mm/min crosshead speed. The data were evaluated by ANOVA and Tukey test at 5% of significance. The mean and standard-deviation for all groups were: NB: 30.95(±11.97a; BSA: 30.34(±8.73a, BPC: 22.81(6.00b, BR7: 21.41(±6.12b, B: 14.10(±4.45c, BMC: 13.25(±6.02c. Sodium ascorbate reversed the bond strengths to enamel immediately after bleaching.

  10. Significance of Shrinkage Induced Clamping Pressure in Fiber-Matrix Bonding in Cementitious Composite Materials

    DEFF Research Database (Denmark)

    Stang, Henrik

    1996-01-01

    inhomogeneity embedded in a matrix consisting of acementitious material undergoing shrinkage during hydration(autogenous shrinkage). Furthermore, the paperpresents the analysis necessary to perform an interpretation of the experimental results and which allows for thedetermination of the clamping pressure......The present paper accesses the significance of shrinkage inducedclamping pressure in fiber/matrix bonding mechanisms incementitious composite materials. The paper contains a description of an experimental setup whichallows mbox{measurement} of the clamping pressure which develops on anelastic...... acting on any elastic inhomogeneityembedded in the same cementitious matrix material. Fiber-shaped inhomogeneities are of special interest in cementitious composite material systems andresults are presented for the development of clamping pressure on three typical fiber types in two typical cementpastes...

  11. Asymptotic Sampling for Reliability Analysis of Adhesive Bonded Stepped Lap Composite Joints

    DEFF Research Database (Denmark)

    Kimiaeifar, Amin; Lund, Erik; Thomsen, Ole Thybo

    2013-01-01

    Reliability analysis coupled with finite element analysis (FEA) of composite structures is computationally very demanding and requires a large number of simulations to achieve an accurate prediction of the probability of failure with a small standard error. In this paper Asymptotic Sampling, which...... is a promising and time efficient tool to calculate the probability of failure, is utilized, and a probabilistic model for the reliability analysis of adhesive bonded stepped lap composite joints, representative for the main laminate in a wind turbine blade subjected to static flapwise bending load, is presented....... Three dimensional (3D) FEA is used for the structural analysis together with a design equation that is associated with a deterministic code-based design equation where reliability is secured by partial safety factors. The Tsai-Wu and the maximum principal stress failure criteria are used to predict...

  12. Comparative evaluation of shear bond strength and nanoleakage of conventional and self-adhering flowable composites to primary teeth dentin

    Directory of Open Access Journals (Sweden)

    Priyanka Sachdeva

    2016-01-01

    Full Text Available Background: The latest advancement in adhesive dentistry is the development of self adhering flowable composite resin which incorporates the self-etch adhesion technology to eliminate the steps of etching, rinsing, priming and bonding. Few studies have addressed resin bonding to primary teeth. Aim: The aim of this study was to compare the shear bond strength and nanoleakage of conventional and self adhering flowable composites to primary teeth dentin. Settings and Design: This study was conducted in the Department of Pedodontics and Preventive Dentistry, I.T.S Dental College, Hospital and Research Centre, Greater Noida; in association with the Department of Mechanical Engineering, I.T.S Engineering College, Greater Noida; and the Advanced Instrumentation Research Facility (AIRF, Jawaharlal Nehru University, New Delhi. Materials and Methods: Sixty of the ninety primary teeth were evaluated for shear bond strength and thirty for nanoleakage. The samples were divided into three groups; Group I - Dyad Flow (Kerr, Group II - Fusio Liquid Dentin (Pentron Clinical Technologies and Group III - G-aenial Universal Flo (GC. Shear bond strength was determined using a universal testing machine. Nanoleakage pattern was observed under scanning electron microscope. Results: The shear bond strength of conventional flowable composite was significantly greater than self adhering flowable composite (p<0.05. Nanoleakage scores of both conventional and self adhering flowable composites were comparable. Conclusions: Self adhering flowable composites combine properties of composites and self etch adhesives, eliminating the need for separate bond application that simplifies direct restorative procedure. The evolution of self adhering materials could open new horizons for pediatric dentistry.

  13. Effect of saliva contamination on bond strength witha hydrophilic composite resin

    Directory of Open Access Journals (Sweden)

    Mauren Bitencourt Deprá

    2013-02-01

    Full Text Available OBJECTIVE: To evaluate the influence of saliva contamination on the bond strength of metallic brackets bonded to enamel with hydrophilic resin composite. METHODS: Eighty premolars were randomly divided into 4 groups (n = 20 according to bonding material and contamination: G1 bonded with Transbond XT with no saliva contamination, G2 bonded with Transbond XT with saliva contamination, G3 bonded with Transbond Plus Color Change with no saliva contamination and G4 bonded with Transbond Plus Color Change with saliva contamination. The results were statistically analyzed (ANOVA/Tukey. RESULTS: The means and standard deviations (MPa were: G110.15 ± 3.75; G2 6.8 ± 2.54; G3 9.3 ± 3.36; G4 8.3 ± 2.95. The adhesive remnant index (ARI ranged between 0 and 1 in G1 and G4. In G2 there was a prevalence of score 0 and similar ARI distribution in G3. CONCLUSION: Saliva contamination reduced bond strength when Transbond XT hydrophobic resin composite was used. However, the hydrophilic resin Transbond Plus Color Change was not affected by the contamination.OBJETIVO: avaliar a influência da contaminação por saliva na resistência de união de braquetes metálicos colados ao esmalte com um compósito resinoso hidrofílico. MÉTODOS: oitenta pré-molares foram divididos aleatoriamente em quatro grupos (n=20, de acordo com o material de colagem e a presença de contaminação - G1 colagem com Transbond XT na ausência de contaminação; G2 colagem com Transbond XT na presença de contaminação; G3 colagem com Transbond Plus Color Change na ausência de contaminação; G4 colagem com Transbond Plus Color Change na presença de contaminação. Os resultados foram tratados estatisticamente (ANOVA/Tukey. RESULTADOS: as médias e desvios-padrão (MPa foram G1 = 10,15 ± 3,75; G2 = 6,8 ± 2,54; G3 = 9,3 ± 3,36; G4 = 8,3 ± 2,95. O índice de adesivo remanescente (IAR variou entre 0 e 1 no G1 e no G4; no G2, houve predomínio do escore 0 e distribuição similar no

  14. A Nonlinear Finite Element Method for Magnetoelectric Composite and the Study on the Influence of Interfacial Bonding

    Directory of Open Access Journals (Sweden)

    He-Ling Wang

    2013-01-01

    Full Text Available Magnetoelectric composite material is effective in transferring magnetic field into electric signal. In this paper, a nonlinear finite element method is present to model the magnetoelectric composite of ferroelectric and magnetostrictive material. In the method, the nonlinear and coupling behavior of magnetostrictive material such as Terfenol-D is considered. The nonuniform magnetic, electric, and mechanical field distributions are present. An interfacial transferring coefficient is defined to investigate the performance of interfacial mechanical coupling quantitatively, and the influence of the properties of interfacial bonding material and interfacial cracks on magnetoelectric coefficient is discussed. A new laminate ME composite of curved interface is proposed to overcome weak interfacial bonding.

  15. Effect of Epigallocatechin Gallate on shear bond strength of composite resin to bleached enamel: an in vitro study

    Directory of Open Access Journals (Sweden)

    Zahra Khamverdi

    2013-11-01

    Full Text Available Objectives The aim of this study was to determine the effect of epigallocatechin gallate (EGCG on the shear bond strength of composite resin to bleached enamel. Materials and Methods Ninety enamel surfaces of maxillary incisors were randomly divided into 9 groups as follows: G1: control (no bleaching; G2: bleaching; G3: bleaching and storage for seven days; G4 - 6: bleaching and application of 600, 800 and 1,000 µmol of EGCG-containing solution for 10 minutes, respectively; G7 - 9: bleaching and application of 600, 800 and 1,000 µmol of EGCG-containing solution for 20 minutes, respectively. The specimens were bleached with 30% hydrogen peroxide gel and a composite resin cylinder was bonded on each specimen using a bonding agent. Shear bond strength of the samples were measured in MPa. Data was analyzed using the two-way ANOVA and Tukey HSD tests (α = 0.05. Results The maximum and minimum mean shear bond strength values were observed in G1 and G2, respectively. Time and concentration of EGCG showed no significant effects on bond strength of the groups (p > 0.05. Multiple comparison of groups did not reveal any significant differences between the groups except for G2 and all the other groups (p < 0.05. Conclusions There is a significant decrease in bond strength of composite resin to enamel immediately after bleaching. A delay of one week before bonding and the use of EGCG increased bond strength of composite resin to bleached enamel.

  16. Efficacy of a Universal Adhesive in the Bond Strength of Composite Cements to Polymer-infiltrated Ceramic.

    Science.gov (United States)

    Rohr, Nadja; Flury, Alba; Fischer, Jens

    2017-11-17

    To investigate the effect of a universal adhesive on the bond strength of composite cements to a polymer- infiltrated ceramic network. Shear bond strength to a polymer-infiltrated ceramic network (Vita Enamic) and to its polymer and ceramic components was assessed on polished surfaces using either a conventional dual-curing resin (RelyX Ultimate) or self-adhesive composite cement (RelyX Unicem 2 Automix). Substrate surfaces were either not pretreated or a silane coupling agent (Vitasil), a universal adhesive (Scotchbond Universal Adhesive), or both were applied. Further, the shear bond strength to polymer-infiltrated ceramic network was evaluated after etching with 5% hydrofluoric acid (Vita Ceramics Etch) of 0, 15, 30, 60 or 120 s without or with application of silane, universal adhesive, or both (n = 10). Statistical analysis was performed using the Kruskal-Wallis test (p cement. Application of silane resulted in low mean bond strengths (4 to 5 MPa) to the ceramic. The universal adhesive bonded mainly to the polymer part of the polymer-infiltrated ceramic network. The best bonding performance for both cements was achieved when silane and universal adhesive were applied on the polymer-infiltrated ceramic network. Etching for 30 s or 60 s resulted in the highest mean shear bond strengths for all pretreatment groups (p adhesive dual-curing composite cement RelyX Unicem 2 Automix was found on the HF-etched polymer-infiltrated ceramic network. The conventional dual-curing composite cement RelyX Ultimate with Scotchbond Universal Adhesive may bond chemically to the polymer part of the polymer-infiltrated ceramic network. To achieve the highest bond strengths for both cements, the polymer-infiltrated ceramic network should be etched for 30 to 60 s, followed by the application of silane and universal adhesive.

  17. Effects of etching and adhesive applications on the bond strength between composite resin and glass-ionomer cements.

    Science.gov (United States)

    Pamir, Tijen; Sen, Bilge Hakan; Evcin, Ozgür

    2012-01-01

    This study determined the effects of various surface treatment modalities on the bond strength of composite resins to glass-ionomer cements. Conventional (Ketac Molar Quick Applicap) or resin-modified (Photac Fil Quick Aplicap) glass-ionomer cements were prepared. Two-step etch-rinse & bond adhesive (Adper Single Bond 2) or single-step self-etching adhesive (Adper Prompt L-Pop) was applied to the set cements. In the etch-rinse & bond group, the sample surfaces were pre-treated as follows: (1) no etching, (2) 15 s of etching with 35% phosphoric acid, (3) 30 s of etching, and (4) 60 s of etching. Following the placement of the composite resin (Filtek Z250), the bond strength was measured in a universal testing machine and the data obtained were analyzed with the two-way analysis of variance (ANOVA) followed by the Tukey's HSD post hoc analysis (p=0.05). Then, the fractured surfaces were examined by scanning electron microscopy. The bond strength of the composite resin to the conventional glass-ionomer cement was significantly lower than that to the resin-modified glass-ionomer cement (padhesives at any etching time (p>0.05). However, a greater bond strength was obtained with 30 s of phosphoric acid application. The resin-modified glass-ionomer cement improved the bond strength of the composite resin to the glass-ionomer cement. Both etch-rinse & bond and self-etching adhesives may be used effectively in the lamination of glass-ionomer cements. However, an etching time of at least 30 s appears to be optimal.

  18. Effects of etching and adhesive applications on the bond strength between composite resin and glass-ionomer cements

    Directory of Open Access Journals (Sweden)

    Tijen Pamir

    2012-12-01

    Full Text Available OBJECTIVE: This study determined the effects of various surface treatment modalities on the bond strength of composite resins to glass-ionomer cements. MATERIAL AND METHODS: Conventional (KetacTM Molar Quick ApplicapTM or resin-modified (PhotacTM Fil Quick AplicapTM glass-ionomer cements were prepared. Two-step etch-rinse & bond adhesive (AdperTM Single Bond 2 or single-step self-etching adhesive (AdperTM PromptTM L-PopTM was applied to the set cements. In the etch-rinse & bond group, the sample surfaces were pre-treated as follows: (1 no etching, (2 15 s of etching with 35% phosphoric acid, (3 30 s of etching, and (4 60 s of etching. Following the placement of the composite resin (FiltekTM Z250, the bond strength was measured in a universal testing machine and the data obtained were analyzed with the two-way analysis of variance (ANOVA followed by the Tukey's HSD post hoc analysis (p=0.05. Then, the fractured surfaces were examined by scanning electron microscopy. RESULTS: The bond strength of the composite resin to the conventional glass-ionomer cement was significantly lower than that to the resin-modified glass-ionomer cement (p0.05. However, a greater bond strength was obtained with 30 s of phosphoric acid application. CONCLUSIONS: The resin-modified glass-ionomer cement improved the bond strength of the composite resin to the glass-ionomer cement. Both etch-rinse & bond and self-etching adhesives may be used effectively in the lamination of glass-ionomer cements. However, an etching time of at least 30 s appears to be optimal.

  19. Bond strength of composite to dentin using conventional, one-step, and self-etching adhesive systems.

    Science.gov (United States)

    Bouillaguet, S; Gysi, P; Wataha, J C; Ciucchi, B; Cattani, M; Godin, C; Meyer, J M

    2001-01-01

    This in vitro study compared the dentin bonding performance of eight adhesive systems using a microtensile bond strength test. Thirty bovine teeth were ground to 600-grit to obtain flat root-dentin surfaces. Two conventional adhesive systems (Scotchbond Multipurpose Plus, OptiBond FL), four one-step adhesive systems (Scotchbond 1, Asba S.A.C., Prime and Bond NT, Excite) and two self-etching adhesive materials (Clearfil Liner Bond 2 V and Prompt L-Pop) were evaluated. Each bonding system was applied according to manufacturer's instructions and followed by composite (Z100) application. Immediately after bonding, the teeth were prepared for microtensile testing. Bond strength to dentin was measured using a Vitrodyne V-1000 universal tester. There were 14 replicates for each material. Fractured specimens were further observed by SEM. Scotchbond Multipurpose Plus exhibited significantly (p<0.05) higher bond strength values (30.3+/-9.4 MPa) than all other materials. The bond strengths of the other materials were (from highest to lowest): Opitbond FL (22.4+/-4.3 MPa); Scotchbond 1(18.9+/-3.2); Clearfil Liner Bond 2 V (18.9+/-3.0); Prime and Bond NT (18.3+/-6.9); Asba S.A.C. (14.4+/-2.9); Excite (13.8+/-3.7); and Prompt L-Pop (9.1+/-3.3). Statistical comparisons frequently overlapped, but Optibond was significantly (p<0.05) greater than Asba, Excite, and Prompt L-Pop; whereas, Scotchbond 1 was only significantly (p<0.05) greater than Prompt L-Pop. Asba, Excite and Prompt L-Pop were not significantly different. The fracture modes were mostly adhesive. The conventional adhesive systems produced higher bond strengths to root dentin than most one-step adhesives and one self-etching adhesive; with the exception of one material in each respective system.

  20. Comparison of two test designs for evaluating the shear bond strength of resin composite cements.

    Science.gov (United States)

    Hu, M; Weiger, R; Fischer, J

    2016-02-01

    To compare a shear bond strength test for resin composite cements developed in order to better consider the shrinkage stress (here termed "Swiss shear test") with the shear test design according to ISO 29022. Four restorative materials (VITA Enamic (VE), VITA Suprinity (VS), Vitablocs Mark II (VM) and VITA YZ T (YZ)) served as substrate. VE, VS and VM were polished or etched. YZ was polished, sandblasted or etched. Specimens were either bonded according to the Swiss or the ISO shear test. RelyX Unicem 2 Automix, Maxcem Elite and PermaFlo DC were used as cements. Shear bond strength (SBS) was measured. Failure modes (adhesive, cohesive or mixed) were evaluated by means of SEM. Mean SBS values obtained with the Swiss shear test were significantly lower than those obtained with the ISO shear test. VE and VM exhibited similar SBS, values of VS were significantly higher. On etched surfaces VM and VE exhibited primarily cohesive failures, VS primarily adhesive failures. On polished substrates significantly lower bond strength values and exclusively adhesive failures were observed. YZ exhibited solely adhesive failures. Compared to polished YZ, SBS significantly increased after sandblasting and even more after etching. Only for adhesively failed specimens mean SBS values of Swiss and ISO shear test were strongly correlated. Both test designs showed the same ranking of test results. When adhesive failure occurred test results were strongly correlated. When cohesive failure was involved, both test designs did not provide reliable results. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  1. Shear bond strength of composite resin bonded to preformed metal crowns for primary molars using a universal adhesive and two different surface treatments: an in vitro study.

    Science.gov (United States)

    Patil, S S; Kontham, U R; Kamath, A; Kontham, R

    2016-10-01

    This was to determine the shear bond strength of composite resin bonded to preformed metal crowns with a new adhesive. Buccal surfaces of the crowns were roughened by two different methods to increase retention. Typodont mandibular second primary molars (38) were divided into two groups (19 per group). Preformed metal crowns were cemented to the teeth with glass-ionomer cement. To enhance retention, buccal surfaces of the crowns in group I were roughened with cross-cut carbide burs (SS White #56); crowns in group II were sandblasted (aluminium oxide, 50 µm). Scotchbond Universal Adhesive (3 M-ESPE) was used to bond composite resin to the crowns. A universal testing machine tested the maximum shearing force withstood by the veneered composite surfaces. Sandblasted crowns demonstrated significantly higher resistance (p = 0.001) to shearing force (324.4 N) than did the crowns that were roughened with a bur (234.2 N). Chairside veneering of composite resin to pretreated crowns could be a feasible, aesthetically pleasing, and an economical option in paediatric dentistry.

  2. Validity of bond strength tests: A critical review-Part II

    Science.gov (United States)

    Sirisha, Kantheti; Rambabu, Tankonda; Ravishankar, Yalavarthi; Ravikumar, Pabbati

    2014-01-01

    Background: Macro-bond strength tests resulted in cohesive failures and overestimation of bond strengths. To reduce the flaws, micro-bond strength tests were introduced. They are the most commonly used bond-strength tests. Objective: Thus the objective of this review is to critically review the reliability of micro-bond strength tests used to evaluate resin-tooth interface. Data Collection: Relevant articles published between January 1994 and July 2013 were collected from Pubmed database, Google scholar and hand searched journals of Conservative Dentistry, Endodontics and Dental materials. Data Synthesis: Variables that influence the test outcome are categorized into substrate related factors, factors related to specimen properties, specimen preparation and test methodology. Impact of these variables on the test outcome is critically analyzed. Conclusion: Micro-bond tests are more reliable than macro-bond tests. However, no standard format exists for reporting the bond strength tests which could lead to misinterpretation of the data and bonding abilities of adhesives. PMID:25298640

  3. Penetration of etched enamel and dentin cavity surfaces by bonding agent/composite resin.

    Science.gov (United States)

    Brady, J M; Clarke-Martin, J A

    1990-01-01

    Mechanical and adhesive advantage of resin bonding agents depend upon the ability to penetrate microspaces created with acid-etchants and close adaptation to cavity surfaces. As a replicating material, these resins may reveal morphologic characteristics of the cavity surfaces not seen by direct scanning electron microscope (SEM) investigation. The purpose of this study was to describe, with the SEM, the resin replications of acid-etched cavity walls of Class V cavity preparations in the labial and lingual surfaces of extracted premolar teeth. Cavities were prepared in the gingival third of these surfaces in 26 freshly extracted human premolar teeth using fissure burs in water-cooled, high-speed handpieces. The cavosurface margins were bevelled. The preparations were washed in tap water, dried, etched for 20 seconds with 35% phosphoric acid, coated with light-cured bonding agent and filled with light-cured composite resin in two applications. The teeth were dissolved in acid and the cavity walls of the composite examined in the SEM. Features observed included: (a) Type II resin penetration of interrod regions, (b) resin penetration of the lamellae to the dentino-enamel junction (DEJ), (c) a 10-20 microns step in surface contour at the DEJ, with penetration of terminal tubule branches, (d) insular regions of deep dentin tubule penetration and (e) 100-300 microns deep, 10-30 microns incremental microlamellar penetrations into the enamel at the DEJ corresponding to enamel tufts.

  4. Clinical performance of resin-bonded composite strip crowns in primary incisors: a retrospective study.

    Science.gov (United States)

    Ram, D; Fuks, A B

    2006-01-01

    The purpose of this study was to assess retrospectively the longevity of resin-bonded composite strip crowns placed in primary maxillary incisors. Records for 200 out of 387 children, aged 22-48 months, treated in a private paediatric dental practice and who presented for follow-up after at least 24 months were included in the study. The parameters recorded at baseline and/or at follow-up were: habits, the number and location of the decayed surfaces, colour, texture, and chipping of the restoration. Radiographic evaluation of the restorations, the quality of the margins, and the presence of pulpal and/or periapical pathoses were recorded. More than 80% of the restorations were judged to be successful at the final follow-up examination. Only the number of carious surfaces of the tooth at baseline influenced the treatment outcome. The failure rate was higher in central incisors with four affected surfaces (P = 0.005), and in lateral incisors with four carious surfaces (P = 0.0003), than in those presenting one or two carious surfaces in both central and lateral incisors (P = 0.002). The high success rate of resin-bonded composite strip crowns with a 2-year follow-up seen in this study suggests that this treatment modality is an aesthetic and satisfactory means of restoring carious primary incisors in young children. The retention rate is lower in teeth with decay in three or more surfaces, particularly in children with a high caries risk.

  5. Toughness behavior in roll-bonded laminates based on AA6061/SiCp composites

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini Monazzah, A. [Department of Materials Science and Engineering, Sharif University of Technology, P.O. Box 11155-9466, Tehran (Iran, Islamic Republic of); Pouraliakbar, H. [Department of Advanced Materials, WorldTech Scientific Research Center (WT-SRC), Tehran (Iran, Islamic Republic of); Bagheri, R., E-mail: rezabagh@sharif.edu [Department of Materials Science and Engineering, Sharif University of Technology, P.O. Box 11155-9466, Tehran (Iran, Islamic Republic of); Seyed Reihani, S.M. [Department of Materials Science and Engineering, Sharif University of Technology, P.O. Box 11155-9466, Tehran (Iran, Islamic Republic of)

    2014-03-01

    Lamination has been shown to enhance damage tolerance of discontinuously reinforced aluminum (DRA) composites. Doing this technique, DRA layers could be laminated with ductile interlayers. In this research, two types of laminates consisting similar DRA layers and a ductile AA1050 interlayer were fabricated by means of hot roll-bonding. AA6061–5 vol% SiCp and AA6061–15 vol% SiCp composites were considered as exterior layers. Different rolling strains, was applied to control the interfacial strength which was examined by shear test. Toughness behavior of laminates was evaluated by three-point bending test in crack-divider orientation. Based on obtained results, the plastic deformation of ductile interlayer and delamination are challenging toughening mechanisms which were influenced by the degree of interfacial bonding and ceramic particle content. An increment in reinforcement content alters the toughness behavior of laminates in the way that the governing mechanism in laminates containing 5 vol% SiCp is interfacial adhesion since in laminates having 15 vol% SiCp the dominant mechanism is AA1050 deformability. Meanwhile, optical and scanning electron microscopy observations proved the importance of toughening mechanisms in each type of materials. Also, shear test results revealed that the interfacial strength of laminates increases by the number of rolling passes and deteriorated by higher reinforcement contents.

  6. Comparative evaluation of shear bond strength and nanoleakage of conventional and self-adhering flowable composites to primary teeth dentin.

    Science.gov (United States)

    Sachdeva, Priyanka; Goswami, Mousumi; Singh, Darrel

    2016-01-01

    The latest advancement in adhesive dentistry is the development of self adhering flowable composite resin which incorporates the self-etch adhesion technology to eliminate the steps of etching, rinsing, priming and bonding. Few studies have addressed resin bonding to primary teeth. The aim of this study was to compare the shear bond strength and nanoleakage of conventional and self adhering flowable composites to primary teeth dentin. This study was conducted in the Department of Pedodontics and Preventive Dentistry, I.T.S Dental College, Hospital and Research Centre, Greater Noida; in association with the Department of Mechanical Engineering, I.T.S Engineering College, Greater Noida; and the Advanced Instrumentation Research Facility (AIRF), Jawaharlal Nehru University, New Delhi. Sixty of the ninety primary teeth were evaluated for shear bond strength and thirty for nanoleakage. The samples were divided into three groups; Group I - Dyad Flow (Kerr), Group II - Fusio Liquid Dentin (Pentron Clinical Technologies) and Group III - G-aenial Universal Flo (GC). Shear bond strength was determined using a universal testing machine. Nanoleakage pattern was observed under scanning electron microscope. The shear bond strength of conventional flowable composite was significantly greater than self adhering flowable composite (pbond application that simplifies direct restorative procedure. The evolution of self adhering materials could open new horizons for pediatric dentistry.

  7. Dentin surface treatment using a non-thermal argon plasma brush for interfacial bonding improvement in composite restoration

    Science.gov (United States)

    Ritts, Andy Charles; Li, Hao; Yu, Qingsong; Xu, Changqi; Yao, Xiaomei; Hong, Liang; Wang, Yong

    2010-01-01

    The objective of this study is to investigate the treatment effects of non-thermal atmospheric gas plasmas on dentin surfaces for composite restoration. Extracted unerupted human third molars were used by removing the crowns and etching the exposed dentin surfaces with 35% phosphoric acid gel. The dentin surfaces were treated by using a non-thermal atmospheric argon plasma brush for various durations. The molecular changes of the dentin surfaces were analyzed using FTIR/ATR and an increase in carbonyl groups on dentin surfaces was detected with plasma treated dentin. Adper Single Bond Plus adhesive and Filtek Z250 dental composite were applied as directed. To evaluate the dentin/composite interfacial bonding, the teeth thus prepared were sectioned into micro-bars as the specimens for tensile test. Student Newman Keuls tests showed that the bonding strength of the composite restoration to peripheral dentin was significantly increased (by 64%) after 30 s plasma treatment. However, the bonding strength to plasma treated inner dentin did not show any improvement. It was found that plasma treatment of peripheral dentin surface up to 100 s gave an increase in interfacial bonding strength, while a prolong plasma treatment of dentin surfaces, e.g., 5 min treatments, showed a decrease in interfacial bonding strength. PMID:20831586

  8. An investigation into the effects of metal primer and surface topography on the tensile bond strength between cobalt chromium alloy and composite resin.

    Science.gov (United States)

    Newsum, David; Juszczyk, Andrzej; Clark, Robert K F; Radford, David R

    2011-03-01

    This study examined the influence of surface preparation and metal primer on the tensile bond strength between cobalt chromium alloy and composite resin. The bond strength between 168 cobalt chromium alloy dumb-bells with one of three test surfaces (beaded, machined or sandblasted) to composite resin were tested. Half of each group were treated with metal primer. The weakest bond strength was produced by the unprimed machined surface, many specimens failing before testing. The metal primer increased the bond strengths of all groups tested. The greatest bond strengths were achieved with the primed beaded and sandblasted surfaces. Within the limits of the study it has been shown that the surface preparation of the cobalt-chromium alloy did influence tensile bond strengths with composite resin and Metal Primer II increased the tensile bond strengths for all groups tested. The sandblasted surface treated with Metal Primer II is recommended for the bonding of composite resin to cobalt chromium alloy.

  9. Effect of Different Surface Treatments on Repair Micro-shear Bond Strength of Silica- and Zirconia-filled Composite Resins

    Directory of Open Access Journals (Sweden)

    Mohammad Joulaei

    2012-11-01

    Full Text Available Background and aims. Effect of surface treatments on repair bond strength of aged composite resins might be different due to their dissimilar fillers. The aim was to evaluate the effect of different surface treatments on repair micro-shear bond strength (µSBS of silica- (Spectrum TPH and zirconia-filled (Filtek Z250 composite resins. Materials and methods. Twenty-seven composite resin blocks were made from each type of composite resin: Z250 and Spectrum TPH. After aging, blocks of each type were randomly divided into three groups according to surface treatments: alloy primer, silane, and only surface roughening. Subsequently, each group was further subdivided into 3 subgroups based on the adhesive system used: Single Bond, Clearfil SE Bond, and Margin Bond. Four composite resin columns were added on each block. After thermocycling, µSBStest were done at cross head speed of 0.5 mm/min. Data was analysed using multifactor ANOVA, one-way ANOVA and a post-hoc Bonferroni tests (α = 0.05. Results. Analysis of data showed that the effect of composite resin type was not significant (p > 0.05, but the effects of the type of surface treatment (p = 0.01 and the type of adhesive system (p = 0.01 were significant on repair µSBS. In addition, the cumulative effect of the composite type-surface treatment and the composite type with the type of adhesive system were not statistically significant (p > 0.05. However, the cumulative effects of the adhesive system-surface treatment (p = 0.03 and the composite type-the adhesive system-surface treatments (p = 0.002 were significant. Conclusion. Although repair µSBS values of both silica- and zirconia-filled composite resins were similar, use of different combinations of surface treatments and adhesive systems affected their repair µSBS differently.

  10. Effects of ultraviolet irradiation on the bond strength of a composite resin adhered to stainless steel crowns.

    Science.gov (United States)

    Baeza-Robleto, Selene J; Villa-Negrete, Dulce M; García-Contreras, René; Scougall-Vílchis, Rogelio J; Guadarrama-Quiroz, Luis J; Robles-Bermeo, Norma L

    2013-01-01

    A technique whereby the practitioner could improve the esthetic appearance of anterior stainless steel crowns (SSC) could provide a cost-effective alternative to more expensive commercially available preveneered SSCs, which may not be uniformly available. The purpose of this study was to evaluate the effects of ultraviolet (UV) irradiation of the metal crown surface on the shear bond strength of composite resin adhered to stainless steel crowns. Seventy extracted anterior bovine teeth randomly divided into 2 groups (n=35/group), were restored with primary maxillary left central incisor SSCs. Surface roughening with a green stone was performed on the labial surfaces, and the crowns of the experimental group were exposed to UV irradiation for 80 minutes. All samples were treated with metal-composite adhesive, followed by composite opaquer. Standardized composite blocks were bonded on the treated surfaces, and the shear bond strength was tested at 1 mm/minute. The values were recorded in MPa and statistically analyzed. The mean value of shear bond strength was significantly higher for the experimental group (19.7 ± 4.3 MPa) than the control group (16.3 ± 4.5 MPa). Ultraviolet irradiation of primary tooth stainless steel crowns significantly increased the shear bond strength of composite resin adhered to the facial surface.

  11. Shear bond strength of self-adhering flowable composite on dentin surface as a result of scrubbing pressure and duration

    OpenAIRE

    Ferry Jaya; Siti Triaminingsih; Andi Soufyan S; Yosi Kusuma Eriwati

    2012-01-01

    Background: Self-adhering flowable composite is a combination of composite resin and adhesive material. Its application needs scrubbing process on the dentin surface, but sometimes it is difficult to determine the pressure and duration of scrubbing. Purpose: This study was aimed to analyze the effect of scrubbing pressure and duration on shear bond strength of self-adhering flowable composite to dentin surface Methods: Fifty four mandibulary third molar were cut to get the dentin surface and ...

  12. Influence of priming agents on the short-term bond strength of an indirect composite veneering material to zirconium dioxide ceramic.

    Science.gov (United States)

    Kobayashi, Kazuhisa; Komine, Futoshi; Blatz, Markus B; Saito, Ayako; Koizumi, Hiroyasu; Matsumura, Hideo

    2009-01-01

    Indirect composites are promising alternatives as veneering materials for zirconium dioxide (zirconia) ceramic frameworks. This study evaluated the effects of priming agents and a high-flow bonding agent on the short-term bond of an indirect composite material to a zirconia framework material. Indirect composite (Estenia C and B) was bonded to particle-abraded zirconia samples (Katana, n = 144) using no (control) or 1 of 8 priming agents: All Bond 2 Primer B (ABB), Alloy Primer (ALP), Clearfil Ceramic Primer (CCP), Clearfil Photo Bond (CPB), Clearfil Photo Bond with Clearfil Porcelain Bond Activator (CPB+Activator), Estenia Opaque Primer (EOP), Porcelain Liner M Liquid A (PLA), and V-Primer (VPR) with or without a high-flow bonding agent (Estenia C and B Opaque). Shear bond strength was tested after 24-hour wet storage. Data were analyzed with Levene test for equality of variance, Dunnett T3 multiple comparison, and Mann-Whitney U test (P = .05). Mean bond strengths without the high-flow bonding agent application varied from 0.1 to 13.6 MPa, whereas bond strengths with bonding agent application ranged from 0.1 to 24.2 MPa. CPB+Activator (containing phosphate MDP and silane) and CPB (containing MDP) revealed the significantly highest bond strength among the 9 groups without high-flow bonding agent application (P < .05). Application of the high-flow bonding agent significantly increased bond strengths (P < .001). Primers containing either the functional phosphate monomer MDP or an MDP-silane combination provide superior resin bonds of Estenia C and B composite to Katana zirconia. An intermediate high-flow bonding agent further improves the bond between these materials.

  13. Influence of PEEK surface modification on surface properties and bond strength to veneering resin composites.

    Science.gov (United States)

    Keul, Christine; Liebermann, Anja; Schmidlin, Patrick R; Roos, Malgorzata; Sener, Beatrice; Stawarczyk, Bogna

    2014-08-01

    To test the impact of mechanical and chemical treatments of PEEK on surface roughness (SR), surface free energy (SFE), and tensile bond strength (TBS) to veneering resin composites. PEEK specimens (N = 680) were fabricated and divided into treatment groups (n = 170/group): 1. air abrasion (AIA); 2. etching with piranha solution (PIS); 3. air abrasion + piranha acid etching (AIP); and 4. no treatment (NO). Ten specimens of each treatment group were assessed with a contact angle measuring device and profilometer to determine SFE and SR, respectively. The remaining 160 specimens of each group were divided into subgroups according to coupling method (n = 32/subgroup): 1. Monobond Plus/ Heliobond (MH); 2. Visio.link (VL); 3. Clearfil Ceramic Primer (CCP); 4. Signum PEEK Bond (SPB); and 5. control, no coupling (CG). Specimens were veneered using Signum Composite/SiCo or Signum Ceramis/SiCe (both: n = 16), incubated in water (60 days at 37°C) and thermocycled (5000 cycles of 5°C/55°C). TBS was measured and data analyzed by three- and one-way ANOVA, Kruskal-Wallis and Mann-Whitney tests (p < 0.05). A significant effect of surface treatment (p < 0.001) and coupling agent application (p < 0.001) on TBS was observed. AIA specimens with/without PIS showed the highest SFE, SR, and TBS. No differences were measured between PIS and NO, and between AIA and AIP. When no coupling agent was used, no adhesion was obtained. CCP resulted in low adhesion values, whereas MH, SPB, and VL exhibited increased TBS. No significant impact of the veneering resin composite on TBS was found (p = 0.424). AIA and AIP combined with VL, SPB, and MH can be recommended for clinical use.

  14. Comparison of shear bond strength of resin reinforced chemical cure glass ionomer, conventional chemical cure glass ionomer and chemical cure composite resin in direct bonding systems: an in vitro study.

    Science.gov (United States)

    Rao, Kolasani Srinivasa; Reddy, T Praveen Kumar; Yugandhar, Garlapati; Kumar, B Sunil; Reddy, S N Chandrasekhar; Babu, Devatha Ashok

    2013-01-01

    The acid pretreatment and use of composite resins as the bonding medium has disadvantages like scratching and loss of surface enamel, decalcification, etc. To overcome disadvantages of composite resins, glass ionomers and its modifications are being used for bonding. The study was conducted to evaluate the efficiency of resin reinforced glass ionomer as a direct bonding system with conventional glass ionomer cement and composite resin. The study showed that shear bond strength of composite resin has the higher value than both resin reinforced glass ionomer and conventional glass ionomer cement in both 1 and 24 hours duration and it increased from 1 to 24 hours in all groups. The shear bond strength of resin reinforced glass ionomer cement was higher than the conventional glass ionomer cement in both 1 and 24 hours duration. Conditioning with polyacrylic acid improved the bond strength of resin reinforced glass ionomer cement significantly but not statistically significant in the case of conventional glass ionomer cement.

  15. Comparison of the resin cement bond strength to an indirect composites treated by Er;YAG laser and sandblast

    Directory of Open Access Journals (Sweden)

    Mansure Mirzaee

    2014-04-01

    Full Text Available   Background and Aims: Indirect composites are designed to overcome the shortcomings of direct composites such as polymerization shrinkage and low degree of conversion. But, good adhesion of resin cements to indirect composites is still difficult. This research was designed to assess the effect of different powers of Er;YAG laser compared with sandblasting. On the micro tensil bond strength of resin cement to indirect composites.   Materials and Methods: Specimens were prepred using dental resin composite (Gradia GC and metallic mold (15×5×5 mm and were cured according to the manufacturer’s instructions. 24 blocks were prepared and randomly divided into 12 groups. G1:no treatment (as control, G 2-6: Er; YAG laser irradiation (2, 3, 4, 5, 6 Watt, G7: sandblast. Two composite blocks were bonded to each other with Panavia F.2. resin cement. The cylindrical sections with dimensions of 1 mm were tested in a microtensile bond strength tester device using 0.5 mm/min speed until fracture points. Data were analyzed using 2-way ANOVA and T-test.   Results: Interaction between lasers irradiation and sandblast treatments were significant (P0.05 whether samples were sandblasted or not. Samples which received 300 mJ of laser showed lower bond strength compared with no laser treatment. Other groups showed no significant difference (P>0.05.   Conclusion: It seems that application of sandblast with proper variables, is a good way to improve bond strength.Laser application had no influence in improving the bond strength between the indirect composite and resin cement.

  16. Shear bond strength of calcium enriched mixture cement and mineral trioxide aggregate to composite resin with two different adhesive systems.

    Directory of Open Access Journals (Sweden)

    Siavash Savadi Oskoee

    2014-12-01

    Full Text Available Immediate restoration after vital pulp therapy is essential in order to create and maintain effective coronal seal.The aim of this study was to evaluate the shear bond strength of recently used pulp capping materials: white mineral trioxide aggregate (MTA, and calcium enriched mixture cement (CEM to composite resin with the use of etch-and-rinse and self-etch adhesive systems and compare them with the bond strength of commonly used resin modified glass ionomer (RMGI cement.Forty specimens from each test material were fabricated, measuring 4 mm in diameter and 2 mm in depth. The specimens of each material were divided into 2 groups of 20 specimens according to the adhesive system (Single Bond vs. Clearfil SE Bond used for bonding of resin composite. The shear bond strength values were measured at a crosshead speed of 1.0 mm/min and fractured surfaces were examined. Data were analyzed using two-way ANOVA and a post hoc Tukey's test (P<0.05.Analysis of data showed a significantly higher bond strength for RMGI compared to MTA and CEM (P<0.001; however, no significant differences were observed in the bond strength values of MTA and CEM (P=0.9. Furthermore, there were no significant differences in relation to the type of the adhesive system irrespective of the type of the material used (P=0.95 All the failures were of cohesive type in RMGI, MTA and CEM.Bond strength of RMGI cement to composite resin was higher than that of MTA or CEM cement irrespective of the type of the adhesive system.

  17. Effect of filler ratio in adhesive systems on the shear bond strength of resin composite to porcelains.

    Science.gov (United States)

    Güler, Ahmet Umut; Sarikaya, Isil Biçer; Güler, Eda; Yücel, Ali cagin

    2009-01-01

    This in vitro study evaluated the effect of six different adhesive systems on the shear bond strength of resin composite to feldspathic and low-fusing porcelains. Sixty porcelain blocks were prepared for each low-fusing (Matchmaker) and feldspathic (MVK95) porcelain specimen. After surface preparation, the porcelain specimens were divided into six groups (n = 10) for different adhesive systems (Adper Prompt L-Pop, QuadrantUnil Bond, Te-Econom, PQ1, One-StepPlus and Prime&Bond NT). After adhesive application, a universal resin composite (FiltekZ250) was condensed on the specimens. The prepared specimens were then stored in distilled water at 37 degrees C for 24 hours, then all the samples were thermal cycled 1000 times between 5 degrees C and 55 degrees C. Shear testing was performed on a universal test machine using a crosshead speed of 0.5 mm/minute. The statistical analysis of the bond strength data included two-way ANOVA. Then, the means were compared by Tukey HSD test (alpha = 0.05). The lowest bond strength was observed in Adper Prompt L-Pop. No statistically significant difference was observed between One-Step Plus and Prime&Bond NT. The highest bond strength was observed in PQ1. When low-fusing or feldspathic porcelain restorations are repaired with resin composite, self-etching adhesive systems may not be indicated. If maximum bond strength is the goal in porcelain resin bonding, adhesive systems that have a high filler ratio should be used.

  18. An evaluation on shear strength of composite resin bonded to primary teeth dentin after Nd: YAG laser radiation

    Directory of Open Access Journals (Sweden)

    Kowsari A

    2002-06-01

    Full Text Available Due to the differences in the composite and morphology of dentin in primary and permanent teeth, it is necessary to make improvements in bonding techniques to promote the strength of composite resins bonded to the dentinal surface, in primary teeth. The use of lower radiation, to make structural and chemical changes in dentinal surfaces has been investigated. This research was conducted to evaluate the shear strength of the composite bonded to primary teeth dentin after Nd: YAG laser radiation and acid etching for conditioning. Peripheral dentin of the buccal and lingua! surfaces of 60 extracted posterior primary teeth were exposed and polished with 600 grit with Sic paper. The teeth were divided randomly in 3 groups of 20 teeth. In group 1 etching gel, primer and adhesive of scotch bond multipurpose system (SMP, in group 2 laser at 1.6 w and 80 mj/pulse, and in group 3 laser at 2 s and 700 mj/pulse were used. Moreover, in groups 2 and 3, after laser radiation, acid etching, primer and adhesive of SMP system were applied. After necessary laboratory tests, the mean shear bond strength in MPa were 20.99±5.3 (group 1, 23.82±6.31 (group 2 and 26.58±5.59 (group 3. ANOVA, scheffe, tukey statistical tests showed that the bond strengths of group 3 were statistically higher than group 1. The frequency of dentin cohesive failures were significantly higher in groups 2 and 3, compared to group 1 that indicates a higher bond strength in these groups. Scanning electron mirographs of laser radiated surfaces, show a porous and rough surface morphology that enhances the mechanical bond of the composite.

  19. Synthesis of chemically bonded graphene/carbon nanotube composites and their application in large volumetric capacitance supercapacitors.

    Science.gov (United States)

    Jung, Naeyoung; Kwon, Soongeun; Lee, Dongwook; Yoon, Dong-Myung; Park, Young Min; Benayad, Anass; Choi, Jae-Young; Park, Jong Se

    2013-12-17

    Chemically bonded graphene/carbon nanotube composites as flexible supercapacitor electrode materials are synthesized by amide bonding. Carbon nanotubes attached along the edges and onto the surface of graphene act as spacers to increase the electrolyte-accessible surface area. Our lamellar structure electrodes demonstrate the largest volumetric capacitance (165 F cm(-3) ) ever shown by carbon-based electrodes. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Influence of frequency on shear fatigue strength of resin composite to enamel bonds using self-etch adhesives.

    Science.gov (United States)

    Takamizawa, Toshiki; Scheidel, Donal D; Barkmeier, Wayne W; Erickson, Robert L; Tsujimoto, Akimasa; Latta, Mark A; Miyazaki, Masashi

    2016-09-01

    The purpose of this study was to determine the influence of different frequency rates on of bond durability of self-etch adhesives to enamel using shear fatigue strength (SFS) testing. A two-step self-etch adhesive (OX, OptiBond XTR), and two single step self-etch adhesives (GB, G-ӕnial Bond and SU, Scotchbond Universal) were used in this study. The shear fatigue strength (SFS) to enamel was obtained. A staircase method was used to determine the SFS values with 50,000 cycles or until failure occurred. Fatigue testing was performed at frequencies of 5Hz, 10Hz, and 20Hz. For each test condition, 30 specimens were prepared for the SFS testing. Regardless of the bond strength test method, OX showed significantly higher SFS values than the two single-step self-etch adhesives. For each of the three individual self-etch adhesives, there was no significant difference in SFS depending on the frequency rate, although 20Hz results tended to be higher. Regardless of the self-etch adhesive system, frequencies of 5Hz, 10Hz, and 20Hz produced similar results in fatigue strength of resin composite bonded to enamel using 50,000 cycles or until bond failure. Accelerated fatigue testing provides valuable information regarding the long term durability of resin composite to enamel bonding using self-etch adhesive system. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. The comparative evaluation of fracture resistance and microleakage in bonded amalgam, amalgam, and composite resins in primary molars.

    Science.gov (United States)

    Vanishree, H S; Shanthala, B M; Bobby, W

    2015-01-01

    The intense development of adhesive restorative materials and parents' preferences for esthetic restorations prompt clinicians to use alternative restorative materials for primary molars. Amalgam, however, is the choice of material when it comes to occlusal stress bearing areas, either in primary or permanent molars. To overcome the drawbacks of amalgam and restorative adhesive materials, the bonded amalgam technique is employed. To evaluate microleakage and fracture resistance of bonded amalgam in primary molars, and compare it with the microleakage and fracture resistance of high-copper amalgam and composite resin materials. An in vitro study and 60 caries-free primary molars were used. A total of 60 samples were randomly divided into two equal groups for the evaluation of microleakage and fracture resistance. Class V cavities for microleakage study prepared on 30 samples and Class II mesio-occluso-distal cavities for fracture resistance study on other 30 samples were prepared and randomly divided into three equal groups. Group I received amalgam, Group II received bonded amalgam, and Group III received composite resins. The microleakage was viewed under a stereomicroscope. The fracture resistance was evaluated using a universal testing machine. Bonded amalgam exhibited minimum microleakage, when compared to amalgam and composite resin and was found to be statistically insignificant (P = 0.203), while amalgam showed better fracture resistance compared to bonded amalgam and composite resin. It was found to be statistically insignificant (P = 0.144). Bonded amalgam appears to be comparable to amalgam when microleakage is considered and to composite resin when fracture resistance is considered; hence, bonded amalgam can also be an alternative material to amalgam in primary molars.

  2. Effects of Er:YAG Laser Pretreatment with Different Energy Levels on Bond Strength of Repairing Composite Materials.

    Science.gov (United States)

    Duran, İbrahim; Ural, Çağrı; Yilmaz, Betül; Tatar, Numan

    2015-06-01

    The purpose of this study was to investigate the effects of Erbium-doped: yttrium-aluminum-garnet (Er:YAG) laser pretreatment with different energy levels on the shear bond strength (SBS) of repairing composite materials. After long-term usage of composite resins in the mouth, they can need some repair. Repairing composite bonding so it attaches to the old restoration is important for clinical success. Sixty composite resin materials were used in this study. The aging procedure was performed with 6000 thermocycles in water from 5°C to 55°C. Different surface pretreatment methods [control (no surface treatment), sandblasting, laser treatment (energy level 75, 100, 200, and 300 mJ)] were employed, for a total of six groups. Composite resins of the same kind as their substrates were adhered onto the conditioned substrates. The SBS test was used to assess the durability of all groups. Scanning electron microscopy (SEM) analysis was performed on a representative specimen in each group. Among six surface-treated groups the lowest bond strength was observed in Group C (9.41 MPa) (pcomposite bonding to old composite may become an alternative to other surface treatment methods.

  3. Tensile bond strength of indirect composites luted with three new self-adhesive resin cements to dentin

    Directory of Open Access Journals (Sweden)

    Cafer Türkmen

    2011-08-01

    Full Text Available OBJECTIVE: The aims of this study were to evaluate the tensile bond strengths between indirect composites and dentin of 3 recently developed self-adhesive resin cements and to determine mode of failure by SEM. MATERIAL AND METHODS: Exposed dentin surfaces of 70 mandibular third molars were used. Teeth were randomly divided into 7 groups: Group 1 (control group: direct composite resin restoration (Alert with etch-and-rinse adhesive system (Bond 1 primer/adhesive, Group 2: indirect composite restoration (Estenia luted with a resin cement (Cement-It combined with the same etch-and-rinse adhesive, Group 3: direct composite resin restoration with self-etch adhesive system (Nano-Bond, Group 4: indirect composite restoration luted with the resin cement combined with the same self-etch adhesive, Groups 5-7: indirect composite restoration luted with self-adhesive resin cements (RelyX Unicem, Maxcem, and Embrace WetBond, respectively onto the non-pretreated dentin surfaces. Tensile bond strengths of groups were tested with a universal testing machine at a constant speed of 1 mm/min using a 50 kgf load cell. Results were statistically analyzed by the Student's t-test. The failure modes of all groups were also evaluated. RESULTS: The indirect composite restorations luted with the self-adhesive resin cements (groups 5-7 showed better results compared to the other groups (p0.05. The surfaces of all debonded specimens showed evidence of both adhesive and cohesive failure. CONCLUSION: The new universal self-adhesive resins may be considered an alternative for luting indirect composite restorations onto non-pretreated dentin surfaces.

  4. Static Strength of Adhesively-bonded Woven Fabric Kenaf Composite Plates

    Science.gov (United States)

    Hilton, Ahmad; Lee, Sim Yee; Supar, Khairi

    2017-06-01

    Natural fibers are potentially used as reinforcing materials and combined with epoxy resin as matrix system to form a superior specific strength (or stiffness) materials known as composite materials. The advantages of implementing natural fibers such as kenaf fibers are renewable, less hazardous during fabrication and handling process; and relatively cheap compared to synthetic fibers. The aim of current work is to conduct a parametric study on static strength of adhesively bonded woven fabric kenaf composite plates. Fabrication of composite panels were conducted using hand lay-up techniques, with variation of stacking sequence, over-lap length, joint types and lay-up types as identified in testing series. Quasi-static testing was carried out using mechanical testing following code of practice. Load-displacement profiles were analyzed to study its structural response prior to ultimate failures. It was found that cross-ply lay-up demonstrates better static strength compared to quasi-isotropic lay-up counterparts due to larger volume of 0° plies exhibited in cross-ply lay-up. Consequently, larger overlap length gives better joining strength, as expected, however this promotes to weight penalty in the joining structure. Most samples showed failures within adhesive region known as cohesive failure modes, however, few sample demonstrated interface failure. Good correlations of parametric study were found and discussed in the respective section.

  5. Hydrogen bonds, interfacial stiffness moduli, and the interlaminar shear strength of carbon fiber-epoxy matrix composites

    Directory of Open Access Journals (Sweden)

    John H. Cantrell

    2015-03-01

    Full Text Available The chemical treatment of carbon fibers used in carbon fiber-epoxy matrix composites greatly affects the fraction of hydrogen bonds (H-bonds formed at the fiber-matrix interface. The H-bonds are major contributors to the fiber-matrix interfacial shear strength and play a direct role in the interlaminar shear strength (ILSS of the composite. The H-bond contributions τ to the ILSS and magnitudes KN of the fiber-matrix interfacial stiffness moduli of seven carbon fiber-epoxy matrix composites, subjected to different fiber surface treatments, are calculated from the Morse potential for the interactions of hydroxyl and carboxyl acid groups formed on the carbon fiber surfaces with epoxy receptors. The τ calculations range from 7.7 MPa to 18.4 MPa in magnitude, depending on fiber treatment. The KN calculations fall in the range (2.01 – 4.67 ×1017 N m−3. The average ratio KN/|τ| is calculated to be (2.59 ± 0.043 × 1010 m−1 for the seven composites, suggesting a nearly linear connection between ILSS and H-bonding at the fiber-matrix interfaces. The linear connection indicates that τ may be assessable nondestructively from measurements of KN via a technique such as angle beam ultrasonic spectroscopy.

  6. Comparison of shear bond strength of calcium-enriched mixture cement and mineral trioxide aggregate to composite resin.

    Science.gov (United States)

    Oskoee, Siavash Savadi; Kimyai, Soodabeh; Bahari, Mahmoud; Motahari, Paria; Eghbal, Mohammad Jafar; Asgary, Saeed

    2011-11-01

    Adhesion of composite resin and pulp capping biomaterials remarkably influences treatment outcomes. This in vitro study aimed to compare the shear bond strength of composite resin to calcium enriched mixture (CEM) cement, mineral trioxide aggregate (MTA) and resin modified glass ionomer (RMGI) with or without acid etching. A total of 90 cylindrical acrylic blocks containing a central hole, measuring 4 mm diameter and 2 mm height were prepared. The blocks were randomly divided into three experimental groups based on being filled with CEM, MTA or RMGI. Samples in each group were then randomly divided into two subgroups, i.e. with or without phosphoric acid etching. Placing composite resin cylinders on the samples, shear bond strengths were measured using a universal testing machine. Failure modes of the samples were evaluated under a stereomicroscope. Data were analyzed using two-way ANOVA and Tukey tests. Shear bond strengths in the etched and nonetched samples were not significantly different (p = 0.60). There was a significant difference in shear bond strength values of the three experimental materials (p strength values (p material and surface etching was statistically significant (p shear bond strength of these materials to composite resin. Besides, shear bond strength values of MTA and CEM to composite resin, are favorable due to their cohesive mode of failure. When MTA and CEM biomaterials are used in vital pulp therapy, it is advisable to cover these materials with RMGI. In addition, if it is not possible to use RMGI, the surface etching of MTA and CEM biomaterials is not necessary prior to composite restoration using total-etch adhesive resin.

  7. Marginal microleakage of class V resin-based composite restorations bonded with six one-step self-etch systems.

    Science.gov (United States)

    Sánchez-Ayala, Alfonso; Farias-Neto, Arcelino; Vilanova, Larissa Soares Reis; Gomes, João Carlos; Gomes, Osnara Maria Mongruel

    2013-01-01

    This study compared the microleakage of class V restorations bonded with various one-step self-etching adhesives. Seventy class V resin-based composite restorations were prepared on the buccal and lingual surfaces of 35 premolars, by using: Clearfil S3 Bond, G-Bond, iBond, One Coat 7.0, OptiBond All-In-One, or Xeno IV. The Adper Single Bond etch-and-rinse two-step adhesive was employed as a control. Specimens were thermocycled for 500 cycles in separate water baths at 5°C and 55°C and loaded under 40 to 70 N for 50,000 cycles. Marginal microleakage was measured based on the penetration of a tracer agent. Although the control showed no microleakage at the enamel margins, there were no differences between groups (p = 0.06). None of the adhesives avoided microleakage at the dentin margins, and they displayed similar performances (p = 0.76). When both margins were compared, iBond® presented higher microleakage (p class V restorations, except for iBond®, which presented lower performance at the enamel margin.

  8. Marginal microleakage of class V resin-based composite restorations bonded with six one-step self-etch systems

    Directory of Open Access Journals (Sweden)

    Alfonso Sánchez-Ayala

    2013-06-01

    Full Text Available This study compared the microleakage of class V restorations bonded with various one-step self-etching adhesives. Seventy class V resin-based composite restorations were prepared on the buccal and lingual surfaces of 35 premolars, by using: Clearfil S 3 Bond, G-Bond, iBond, One Coat 7.0, OptiBond All-In-One, or Xeno IV. The Adper Single Bond etch-and-rinse two-step adhesive was employed as a control. Specimens were thermocycled for 500 cycles in separate water baths at 5°C and 55°C and loaded under 40 to 70 N for 50,000 cycles. Marginal microleakage was measured based on the penetration of a tracer agent. Although the control showed no microleakage at the enamel margins, there were no differences between groups (p = 0.06. None of the adhesives avoided microleakage at the dentin margins, and they displayed similar performances (p = 0.76. When both margins were compared, iBond® presented higher microleakage (p < 0.05 at the enamel margins (median, 1.00; Q3–Q1, 1.25–0.00 compared to the dentin margins (median, 0.00; Q3–Q1, 0.25–0.00. The study adhesives showed similar abilities to seal the margins of class V restorations, except for iBond®, which presented lower performance at the enamel margin.

  9. A comprehensive assessment of adhesively bonded joints between sandwich composite beams

    Science.gov (United States)

    Shahin, Khaled Omar

    Assessment of adhesively bonded joints between sandwich composite beams are presented in this thesis in three parts, each is concerned with a distinct aspect of the joint behaviour. In physical order, these include the deformations of the entire joint assembly, the state of stress in the joint overlap region, and the strain energy release at the crack-tip at the end of the overlap. Analytical models developed in this thesis, however, are not limited in their application to adhesive joint between sandwich beams. In each part of this thesis, the integrity of the proposed analytical models are tested against geometrically non-linear finite element models. In this first part of this thesis, an analytical asymptotic model is presented for the analysis of balanced and unbalanced adhesively bonded joints. The model takes advantage of the asymptotic nature of the adhesive stress functions by eliminating exponentially small terms. Analysis of balanced and unbalanced adhesive joints is greatly simplified with negligible loss in accuracy. Accurate closed-form solutions for both adhesive peel and shear stresses are presented, providing an efficient analysis and design tool and a significant contribution to the literature on unbalanced adhesively bonded joints. In the second part, the asymptotic model is extended to the analysis of strain energy release rates in adhesively bonded joints, using the crack closure concept. Closed-form expressions are presented for various joint types. The shear force and adhesive layer effects are included in the analysis, thus improving on currently available works in the literature. In joints with a long crack and a thin adhesive layer, the asymptotic model is shown to be in good agreement with classical beam theory models. In the third part, deformations in adhesively bonded joints between sandwich beams are studied. Adherends are modeled as cylindrically bent plates on elastic foundations and the overlap section is treated as a single

  10. Laser-based surface patterning of composite plates for improved secondary adhesive bonding

    KAUST Repository

    Tao, Ran

    2018-03-01

    The effects of laser irradiation surface pretreatments on the mode I fracture toughness of adhesively bonded composite joints were evaluated. First, pulsed CO2 laser irradiation was uniformly deployed on carbon fiber reinforced polymer (CFRP) substrates. Next, double cantilever beam (DCB) tests were performed to assess the effects of surface pretreatments on the mode I fracture toughness of the adhesive joints. Then, a thoughtful combination of the proposed surface pretreatments was deployed to fabricate DCB specimens with patterned interfaces. A wide range of techniques, including X-ray photoelectron spectroscopy (XPS), contact profilometry, and optical and scanning electron microscopy (SEM) were used to ascertain the effects of all investigated surface pretreatments. It is shown that patterning promoted damage mechanisms that were not observed in the uniformly treated interfaces, resulting in an effective fracture toughness well above that predicted by a classical rule of mixture.

  11. The analysis of adhesively bonded advanced composite joints using joint finite elements

    Science.gov (United States)

    Stapleton, Scott E.

    The design and sizing of adhesively bonded joints has always been a major bottleneck in the design of composite vehicles. Dense finite element (FE) meshes are required to capture the full behavior of a joint numerically, but these dense meshes are impractical in vehicle-scale models where a course mesh is more desirable to make quick assessments and comparisons of different joint geometries. Analytical models are often helpful in sizing, but difficulties arise in coupling these models with full-vehicle FE models. Therefore, a joint FE was created which can be used within structural FE models to make quick assessments of bonded composite joints. The shape functions of the joint FE were found by solving the governing equations for a structural model for a joint. By analytically determining the shape functions of the joint FE, the complex joint behavior can be captured with very few elements. This joint FE was modified and used to consider adhesives with functionally graded material properties to reduce the peel stress concentrations located near adherend discontinuities. Several practical concerns impede the actual use of such adhesives. These include increased manufacturing complications, alterations to the grading due to adhesive flow during manufacturing, and whether changing the loading conditions significantly impact the effectiveness of the grading. An analytical study is conducted to address these three concerns. Furthermore, proof-of-concept testing is conducted to show the potential advantages of functionally graded adhesives. In this study, grading is achieved by strategically placing glass beads within the adhesive layer at different densities along the joint. Furthermore, the capability to model non-linear adhesive constitutive behavior with large rotations was developed, and progressive failure of the adhesive was modeled by re-meshing the joint as the adhesive fails. Results predicted using the joint FE was compared with experimental results for various

  12. The Analysis of Adhesively Bonded Advanced Composite Joints Using Joint Finite Elements

    Science.gov (United States)

    Stapleton, Scott E.; Waas, Anthony M.

    2012-01-01

    The design and sizing of adhesively bonded joints has always been a major bottleneck in the design of composite vehicles. Dense finite element (FE) meshes are required to capture the full behavior of a joint numerically, but these dense meshes are impractical in vehicle-scale models where a course mesh is more desirable to make quick assessments and comparisons of different joint geometries. Analytical models are often helpful in sizing, but difficulties arise in coupling these models with full-vehicle FE models. Therefore, a joint FE was created which can be used within structural FE models to make quick assessments of bonded composite joints. The shape functions of the joint FE were found by solving the governing equations for a structural model for a joint. By analytically determining the shape functions of the joint FE, the complex joint behavior can be captured with very few elements. This joint FE was modified and used to consider adhesives with functionally graded material properties to reduce the peel stress concentrations located near adherend discontinuities. Several practical concerns impede the actual use of such adhesives. These include increased manufacturing complications, alterations to the grading due to adhesive flow during manufacturing, and whether changing the loading conditions significantly impact the effectiveness of the grading. An analytical study is conducted to address these three concerns. Furthermore, proof-of-concept testing is conducted to show the potential advantages of functionally graded adhesives. In this study, grading is achieved by strategically placing glass beads within the adhesive layer at different densities along the joint. Furthermore, the capability to model non-linear adhesive constitutive behavior with large rotations was developed, and progressive failure of the adhesive was modeled by re-meshing the joint as the adhesive fails. Results predicted using the joint FE was compared with experimental results for various

  13. Parental satisfaction with bonded resin composite strip crowns for primary incisors.

    Science.gov (United States)

    Kupietzky, Ari; Waggoner, William F

    2004-01-01

    The purpose of this study was to evaluate the parental satisfaction of bonded resin composite strip crowns for the treatment of maxillary anterior primary incisors and compare their satisfaction with the clinical evaluation and success of the crowns. This was a retrospective, clinical study of patients who had strip crowns (SC) placed on maxillary primary incisors, returned for at least 1 recall examination, and whose parents gave consent for them to participate in the study. Color photographs were used for evaluation by 2 independent pediatric dentists. Parental satisfaction regarding the esthetics of the crowns was evaluated by a questionnaire. One hundred and twelve restorations placed in 40 children were evaluated. The evaluations were performed after the crowns had been in place for an average of 18 months (range=6-25 months). Overall parental satisfaction with the treatment was excellent; however, satisfaction with regard to color received the lowest rating. No significant differences were found between dentist and parent evaluations of color, size, and overall appearance (Fisher exact test; P=.194,.776,.291, respectively). Parents rated their overall satisfaction as being positive regardless of their poor ratings of color, size, or overall appearance. However, a significant relationship was found between durability and overall satisfaction (P=.046). Parents who gave poor ratings to durability also rated their overall satisfaction as being poor. Parental satisfaction with bonded resin composite SCs for the treatment of primary incisors with large or multi-surface caries was excellent. Parents' dissatisfaction was most often related to color of the restorations. However, this did not affect their overall satisfaction with the crowns. The durability of restorations negatively affected the rating of overall satisfaction with the crown. Durability seems to be of more concern than excellent color match to this group of parents.

  14. Shear Bond Strength of Self-Adhering Flowable Composite and Resin-modified Glass Ionomer to Two Pulp Capping Materials.

    Science.gov (United States)

    Doozaneh, Maryam; Koohpeima, Fatemeh; Firouzmandi, Maryam; Abbassiyan, Forugh

    2017-01-01

    The aim of this study was to compare the shear bond strength of a self-adhering flowable composite (SAFC) and resin-modified glass ionomer (RMGI) to mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement. A total of 72 acrylic blocks with a central hole (4 mm in diameter and 2 mm in depth) were prepared. The holes were filled with MTA (sub group A) and CEM cement. The specimens of both restorative materials were divided into 6 groups; overall there were 12 groups. In groups 1 and 4, SAFC was used without bonding while in groups 2 and 5 SAFC was used with bonding agent. In all these groups the material was placed into the plastic mold and light cured. In groups 3 and 6, after surface conditioning with poly acrylic acid and rinsing, RMGI was placed into the mold and photo polymerized. After 24 h, the shear bond strength values were measured and fracture patterns were examined by a stereomicroscope. Data were analyzed using the two-way ANOVA and student's t-test. The use of bonding agent significantly increased the shear bond strength of FC to MTA and CEM cement (P=0.008 and 0.00, respectively). In both materials, RMGI had the lowest shear bond strength values (2.25 Mpa in MTA and 1.32 Mpa in CEM). The mean shear bond strength were significantly higher in MTA specimen than CEM cement (P=0.003). There was a significant differences between fracture patterns among groups (P=0.001). Most failures were adhesive/mix in MTA specimen but in CEM cement groups the cohesive failures were observed in most of the samples. The bond strength of self-adhering flowable composite resin to MTA and CEM cement was higher than RMGI which was improved after the additional application of adhesive.

  15. Bonding to CAD-CAM Composites: An Interfacial Fracture Toughness Approach.

    Science.gov (United States)

    Eldafrawy, M; Ebroin, M G; Gailly, P A; Nguyen, J-F; Sadoun, M J; Mainjot, A K

    2018-01-01

    The objective of this study was to evaluate the interfacial fracture toughness (IFT) of composite cement with dispersed filler (DF) versus polymer-infiltrated ceramic network (PICN) computer-aided design and computer-aided manufacturing (CAD-CAM) composite blocks after 2 different surface pretreatments using the notchless triangular prism (NTP) test. Two DFs (Cerasmart [CRT] and Lava Ultimate [LVA]), 2 PICNs (Enamic [ENA] and experimental PICN [EXP]), and e.max CAD lithium disilicate glass-ceramic (EMX, control) prism samples were bonded to their counterparts with Variolink Esthetic DC composite cement after either hydrofluoric acid etching (HF) or gritblasting (GR). Both procedures were followed by silanization. All samples ( n = 30 per group) were thermocycled (10,000 cycles) and tested for their IFT in a water bath at 36°C. Moreover, representative samples from each group were subjected to a developed interfacial area ratio (Sdr) measurement by profilometry and scanning electron microscopy (SEM) characterization. EXP-HF gave the highest IFT (1.85 ± 0.39 MPa·m1/2), followed by EMX-HF and ENA-HF, while CRT-HF gave the lowest (0.15 ± 0.22 MPa·m1/2). PICNs gave significantly better results with HF, and DF showed better results with GR. A 2-way analysis of variance indicated that there were significantly higher IFT and Sdr for PICNs than for DF. A positive correlation ( r² = 0.872) was found between IFT and Sdr. SEM characterization showed the specific microstructure of the surface of etched PICNs, indicating the presence of a retentive polymer-based honeycomb structure. Etching of the typical double-network microstructure of PICNs causes an important increase in the Sdr and IFT, while DF should be gritblasted. DF exhibited significantly lower Sdr and IFT values than PICNs. The present results show the important influence of the material class and surface texture, and consequently the micromechanical bond, on the adhesive interface performance of CAD

  16. GPM GROUND VALIDATION COMPOSITE SATELLITE OVERPASSES MC3E V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation Composite Satellite Overpasses MC3E dataset provides satellite overpasses from the AQUA satellite during the Midlatitude Continental...

  17. In vitro analysis of shear bond strength and adhesive remnant index comparing light curing and self-curing composites.

    Science.gov (United States)

    Neves, Murilo Gaby; Brandão, Gustavo Antônio Martins; de Almeida, Haroldo Amorim; Brandão, Ana Maria Martins; de Azevedo, Dário Ribeiro

    2013-01-01

    To evaluate, in vitro, the shear bond strength of self-curing (ConciseTM - 3M and Alpha Plast - DFL) and light-curing composites (TransbondTM XT - 3M and Natural Ortho - DFL) used in orthodontics bonding, associated to Morelli metal brackets, with further analysis of adhesive remnant index (ARI) and enamel condition in scanning electron microscopy (SEM). Forty human premolars, just extracted and stored in physiologic solution 0.9 % were used. Randomly, these samples were divided in four groups: G1 group, the brackets were bonded with ConciseTM - 3M composite; in G2 group, Alpha Plast - DFL composite was used; in G3 group, TransbondTM XT - 3M was used; in G4 group, Natural Ortho - DFL composite was used. These groups were submitted to shear strength tests in universal testing machine, at 0.5 mm per minute speed. Statistical difference between G3 and G4 groups was recorded, as G4 showing higher strength resistance than G3. In the other hand, there were no statistical differences between G1, G2 and G3 and G1, G2 and G4 groups. ARI analysis showed that there was no statistical difference between the groups, and low scores were recorded among then. The scanning electron microscopy (SEM) analysis revealed the debonding spots and the enamel surface integrity. Shear bond strength was satisfactory and similar between the composites, however Natural Ortho - DFL revealed best comparing to TransbondTM XT - 3M.

  18. Effect of organic solvents compared to sandblasting on the repair bond strength of nanohybrid and nanofilled composite resins

    Directory of Open Access Journals (Sweden)

    Rafael Torres Brum

    2017-01-01

    Full Text Available Background: This study evaluated the effect of different surface treatments on the repair bond strength of nanohybrid (Empress Direct and nanofilled (Filtek Z350 XT composite resins. Materials and Methods: A total of 120 specimens of each material (7.5 x 4.5 x 3 mm were prepared and polished with SiC paper. Half of the specimens were kept in water for seven days and the other half for six months; they were then divided into six groups according to the type of surface treatment: negative control (no treatment, Al2O3sandblasted, liquid acetone, acetone gel, liquid alcohol and alcohol gel. Following application of the silane coupling agent and the adhesive system, composite resin cylinders were fabricated on the specimens and light cured (20 seconds. The same composite resins were used for the repair. Additionally, ten intact specimens of each composite resin (without repair were prepared (positive control. The specimens were then loaded to failure in the microshear mode. Three additional specimens were fabricated in each group, and the surface treatments were analyzed by atomic force microscopy, energy-dispersive X-ray spectroscopy (EDS and scanning electron microscopy (SEM. Results: The nanofilled composite resin showed higher cohesive strength and repair bond strength than the nanohybrid composite resin. The aging process affected the repair bond strength of the nanofilled composite resin. Al2O3sandblasting was more efficient for the nanofilled composite resin and promoted greater surface roughness in both materials. The solvents demonstrated higher efficacy for the nanohybrid composite resin. Conclusion: The strengths resulting from the solvents were material dependent, and Al2O3sandblasting resulted in superior repair bond strength in both materials.

  19. Microtensile bond strength of indirect resin composite to resin-coated dentin: interaction between diamond bur roughness and coating material.

    Science.gov (United States)

    Kameyama, Atsushi; Oishi, Takumi; Sugawara, Toyotarou; Hirai, Yoshito

    2009-02-01

    This aim of this study was to determine the effect of type of bur and resin-coating material on microtensile bond strength (microTBS) of indirect composite to dentin. Dentin surfaces were first ground with two types of diamond bur and resin-coated using UniFil Bond (UB) or Adper Single Bond (SB), and then bonded to a resin composite disc for indirect restoration with adhesive resin cement. After storage for 24 hr in distilled water at 37 degrees C, microTBS was measured (crosshead speed 1 mm/min). When UB was applied to dentin prepared using the regular-grit diamond bur, microTBS was significantly lower than that in dentin prepared using the superfine-grit bur. In contrast, no significant difference was found between regular-grit and superfine-grit bur with SB. However, more than half of the superfine-grit specimens failed before microTBS testing. These results indicate that selection of bur type is important in improving the bond strength of adhesive resin cement between indirect resin composite and resin-coated dentin.

  20. Effect of amalgam corrosion products in non-discolored dentin on the bond strength of replaced composite resin

    Science.gov (United States)

    Ghavamnasiri, Marjaneh; Eslami, Samaneh; Ameri, Hamide; Chasteen, Joseph E.; Majidinia, Sara; Moghadam, Fatemeh Velayaty

    2015-01-01

    Objectives: To evaluate the effect of amalgam corrosion products in non-discolored dentin on the bond strength of replaced composite resin. Materials and Methods: One hundred and sixty-one Class I cavities were prepared on extracted premolars and divided into seven groups. Group 1: Light-cured composite; Groups 2, 3, and 4: Amalgam stored in 37°C normal saline for respectively 1, 3, and 6 months and then replaced with composite leaving the cavity walls intact. Groups 5, 6, and 7: Identical to Groups 2, 3, and 4, except the cavity walls were extended 0.5 mm after amalgam removal. Eighteen specimens from each group were selected for shear bond strength testing, while on remaining five samples, elemental microanalysis was conducted. Data were analyzed using Mann-Whitney and Freidman (α = 0.05). Results: There was a significant difference between Groups 1 and 4 and also between Group 1 and Groups 5, 6, and 7. However, Groups 1, 2, and 3 showed no significant difference regarding bond strength. Bond strengths of Group 4 was significantly less than Groups 2 and 3. However, Groups 5, 6, and 7 showed similar bond strength. There was no difference among all groups in terms of metal elements at any storage times. PMID:25657522

  1. In Vitro Evaluation of Various Surface Treatments of Fiber Posts on the Bond Strength to Composite Core

    Directory of Open Access Journals (Sweden)

    Sareh Nadalizadeh

    Full Text Available Introduction: The reliable bond at the root-post-core interface is critical for the clinical success of post-retained restorations. To decrease the risk of fracture, it is important to optimize the adhesion. Therefore, various post surface treatments have been proposed. The purpose of this study was to investigate the influence of various surface treatments of fiber posts on the bond strength to composite core. Materials & Methods: In this study, 40 fiber reinforced posts were used. After preparing and sectioning them, resulting specimens were divided into four groups (N=28. The posts received different surface treatments such as no surface treatment (control group, preparing with hydrogen peroxide 10%, preparing with silane, preparing with HF and silane. Then, posts were tested in micro tensile testing machine. The results were analyzed by One-Way ANOVA and Dunnett T3 test. Results: The greatest bond strength observed was in treatment with hydrogen peroxide 10% (19.84±8.95 MPa, and the lowest strength was related to the control group (12.44±3.40 MPa. The comparison of the groups with Dunnett T3 test showed that the differences between the groups was statistically significant (α=0.05.Conclusion: Based on the results of this study, preparing with H2O2 -10 % and silane increases the bond strength of FRC posts to the composite core more than the other methods. Generally, the bond strength of posts to the composite core increases by surface treatment.

  2. Effect of composite surface treatment and aging on the bond strength between a core build-up composite and a luting agent.

    Science.gov (United States)

    Cotes, Caroline; Cardoso, Mayra; Melo, Renata Marques de; Valandro, Luiz Felipe; Bottino, Marco Antonio

    2015-01-01

    The purpose of this study was to assess the influence of conditioning methods and thermocycling on the bond strength between composite core and resin cement. Eighty blocks (8×8×4 mm) were prepared with core build-up composite. The cementation surface was roughened with 120-grit carbide paper and the blocks were thermocycled (5,000 cycles, between 5°C and 55°C, with a 30 s dwell time in each bath). A layer of temporary luting agent was applied. After 24 h, the layer was removed, and the blocks were divided into five groups, according to surface treatment: (NT) No treatment (control); (SP) Grinding with 120-grit carbide paper; (AC) Etching with 37% phosphoric acid; (SC) Sandblasting with 30 mm SiO2 particles, silane application; (AO) Sandblasting with 50 mm Al2O3 particles, silane application. Two composite blocks were cemented to each other (n=8) and sectioned into sticks. Half of the specimens from each block were immediately tested for microtensile bond strength (µTBS), while the other half was subjected to storage for 6 months, thermocycling (12,000 cycles, between 5°C and 55°C, with a dwell time of 30 s in each bath) and µTBS test in a mechanical testing machine. Bond strength data were analyzed by repeated measures two-way ANOVA and Tukey test (α=0.05). The µTBS was significantly affected by surface treatment (p=0.007) and thermocycling (p=0.000). Before aging, the SP group presented higher bond strength when compared to NT and AC groups, whereas all the other groups were statistically similar. After aging, all the groups were statistically similar. SP submitted to thermocycling showed lower bond strength than SP without thermocycling. Core composites should be roughened with a diamond bur before the luting process. Thermocycling tends to reduce the bond strength between composite and resin cement.

  3. Microtensile bond strength and failure modes of flowable composites on primary dentin with application of different adhesive strategies

    Directory of Open Access Journals (Sweden)

    Simge Durmuslar

    2017-01-01

    Full Text Available Background: Resin composite is an option for the restoration of primary teeth, and new materials with simplified procedures are increasingly being suggested. Aims: This study aims to evaluate the microtensile bond strengths and fracture modes of flowable composites on primary dentin with application of different adhesive strategies. Materials and Methods: Sixty extracted noncaries primary molars were abraded from buccal surfaces to expose dentin surface. The teeth were randomly divided into three groups as follows: Group 1, Vertise™ Flow (Kerr (self-adhering flowable composite; Group 2, G-aenial Universal Flo® (GC Europe (used with one-step self-etch system; Group 3, Tetric® N-Flow (Ivoclar/Vivadent (used with two-step total etch system. Then, the flowable composites were applied to buccal dentin surfaces with the help of guide mold. Samples were embedded in acrylic blocks and sectioned to form dentin-composite sticks with a surface area of approximately 1 mm2. Finally, a total of 180 sticks were obtained to give each group of 60 sticks. Microtensile bond strengths were measured using a universal testing machine (1 mm/min. Fracture modes were evaluated with scanning electron microscopy. Statistical Analysis: Microtensile bond strengths data were analyzed by Kruskal–Wallis nonparametric test. Results: The microtensile bond strengths of G-aenial (15.5 megapascals [Mpa] and Tetric (13.0 MPa were statistically significant higher than Vertise (2.3 MPa. It was recorded that most of fractures in G-aenial was 40% cohesive, Tetric was 53.3% mixed, and Vertise was 83.3% adhesive. Conclusions: The self-adhering flowable composite Vertise™ Flow had the lowest and G-aenial Universal Flo® had the highest microtensile bond values.

  4. Effect of dentin dehydration and composite resin polymerization mode on bond strength of two self-etch adhesives

    Directory of Open Access Journals (Sweden)

    Pooran Samimi

    2016-01-01

    Full Text Available Background: Dual-cured composite resins are similar to self-cured composite resins in some of their clinical applications due to inadequate irradiation, lack of irradiation, or delayed irradiation. Therefore, incompatibility with self-etch adhesives (SEAs should be taken into account with their use. On the other, the extent of dentin dehydration has a great role in the quality of adhesion of these resin materials to dentin. The aim of this study was to investigate the effect of dentin dehydration and composite resin polymerization mode on bond strength of two SEAs. Materials and Methods: A total of 120 dentinal specimens were prepared from extracted intact third molars. Half of the samples were dehydrated in ethanol with increasing concentrations. Then Clearfil SE Bond (CSEB and Prompt L-Pop (PLP adhesives were applied in the two groups. Cylindrical composite resin specimens were cured using three polymerization modes: (1 Immediate light-curing, (2 delayed light-curing after 20 min, and (3 self-curing. Bond strength was measured using universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with two-way ANOVA and Duncan post hoc tests. Statistical significance was defined at P 0.05. PLP showed significant differences between subgroups with the lowest bond strength in hydrated dentin with delayed light-curing and self-cured mode of polymerization. Conclusion: Within the limitations of this study, a delay in composite resin light-curing or using chemically cured composite resin had a deleterious effect on dentin bond strength of single-step SEAs used in the study.

  5. Effect of 2-hydroxyethyl methacrylate pre-treatment on micro-tensile bond strength of resin composite to demineralized dentin.

    Science.gov (United States)

    Doi, J; Itota, T; Torii, Y; Nakabo, S; Yoshiyama, M

    2004-11-01

    The purpose of this study was to evaluate the effect of 2-hydroxyethyl methacrylate (HEMA) application on the micro-tensile bond strength of resin composite to demineralized dentin. Artificially demineralized lesions were formed on bovine dentin surfaces and treated with 10, 30, 50, 70 and 100 wt% HEMA aqueous solution. The surfaces were then applied and covered with SE Bond and AP-X according to the manufacturer's instruction. After immersion in 37 degrees C water for 24 h, bond strength were measured using a universal testing machine. Bond strengths to both demineralized dentin and normal dentin, without HEMA application, were also measured. Scanning electron microscopic (SEM) observation and confocal laser scanning microscopy (CLSM) analysis at the resin-dentin interface were also performed. The bond strength data were statistically compared with anova and Scheffe's test (P < 0.05). Bond strength to demineralized dentin treated with over 30 wt% HEMA aqueous solution were significantly higher than that to demineralized dentin without HEMA application, but significantly lower than that to normal dentin. SEM observation revealed that the hybrid layer and resin-tags thickened and lengthened with HEMA application. In CLSM, the diffusion of adhesive primer into demineralized dentin increased with HEMA application. These results indicated that HEMA application might increase the bond strength to demineralized dentin by the enhancement of resin monomer penetration of HEMA.

  6. Active Metal Brazing and Adhesive Bonding of Titanium to C/C Composites for Heat Rejection System

    Science.gov (United States)

    Singh, M.; Shpargel, Tarah; Cerny, Jennifer

    2006-01-01

    Robust assembly and integration technologies are critically needed for the manufacturing of heat rejection system (HRS) components for current and future space exploration missions. Active metal brazing and adhesive bonding technologies are being assessed for the bonding of titanium to high conductivity Carbon-Carbon composite sub components in various shapes and sizes. Currently a number of different silver and copper based active metal brazes and adhesive compositions are being evaluated. The joint microstructures were examined using optical microscopy, and scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS). Several mechanical tests have been employed to ascertain the effectiveness of different brazing and adhesive approaches in tension and in shear that are both simple and representative of the actual system and relatively straightforward in analysis. The results of these mechanical tests along with the fractographic analysis will be discussed. In addition, advantages, technical issues and concerns in using different bonding approaches will also be presented.

  7. Bond strength comparison of amalgam repair protocols using resin composite in situations with and without dentin exposure.

    Science.gov (United States)

    Ozcan, Mutlu; Schoonbeek, Geert; Gökçe, Bülent; Cömlekoglu, Erhan; Dündar, Mine

    2010-01-01

    The replacement of defective amalgam restorations leads to loss of tooth material and weakens the tooth, creating an increased risk of cusp fracture. The repair of such defects is a minimal intervention technique. The current study compared the repair bond strengths of a resin composite to amalgam and an amalgam-dentin complex after various surface conditioning methods. The specimens (N = 50) consisted of sound human canines with cylindrical preparations (diameter: 2.3 mm, depth: 3 mm) with amalgam-dentin complex (N = 30, n = 10/per group) and two groups with amalgam only (N = 20, n = 10/per group). The teeth were embedded in auto-polymerized polymethylmethacrylate (PMMA). The preparations were filled with non-Gamma 2 amalgam. The enamel was removed to expose dentin. The specimens with the amalgam-dentin complex were randomly assigned to one of the following conditioning methods: Group 1: Silicacoating amalgam, etching dentin, silane application on amalgam, primer/bonding on dentin, opaquer on amalgam, resin composite on both; Group 2: Etching dentin, silicacoating amalgam, silane application on amalgam, primer/bonding on dentin, opaquer on amalgam, resin composite on both and Group 3: Etching dentin, primer/bonding on dentin, opaquer, resin composite. The specimens with only amalgam were assigned to one of the following conditioning methods: Group 4: Silicacoating, silane application, opaquer, resin composite and Group 5: Opaquer, resin composite. For the two control groups, where no dentin was involved (Groups 4 and 5), bonding was achieved only on amalgam and Group 5 had no conditioning. The specimens were kept in water at 37 degrees C for five weeks before bond strength (MPa +/- SD) testing (Universal Testing Machine). After debonding, the failure types were analyzed. The results were significantly affected by the surface conditioning method (ANOVA). Only dentin conditioning (Group 3) showed the highest bond strength (39.9 +/- 14). The unconditioned control

  8. Bond strength and ultimate tensile strength of resin composite filled into dentine cavity; effect of bulk and incremental filling technique.

    Science.gov (United States)

    Nayif, Ma'an M; Nakajima, Masatoshi; Foxton, Richard M; Tagami, Junji

    2008-03-01

    The aim of this study was to evaluate the relationship between micro-tensile bond strength (muTBS) and ultimate tensile strength (UTS) of resin composite restorations in cavities filled by a bulk or incremental technique using the micro-tensile test. Class I cavities (4mm long, 3mm wide, 3mm deep) were prepared into dentine of sixteen human molars. All cavities were bonded with Clearfil SE Bond and restored with AP-X composite with either a bulk or incremental technique. After storage in water for 24h, the teeth were vertically sectioned to yield two slabs. Each slab was sectioned into three sticks. Sticks of one slab were trimmed into an hourglass of 0.7 mm2 area at resin-dentine interface for bond strength measurement while the other sticks were trimmed at the centre of the restoration for UTS measurement. Specimens were tested in tension at 1mm/min until failure. The results obtained were statistically analysed using two-way ANOVA and post hoc test (alpha=0.05). Pearson's correlation test was used to identify any correlation between muTBS and UTS for each filling method. Both muTBS and UTS of resin composite decreased towards the bottom of the cavity (pvariables. There was a relationship between muTBS and UTS of resin composite filled into dentin cavity in bulk technique.

  9. Clinical longevity of ceramic laminate veneers bonded to teeth with and without existing composite restorations up to 40 months

    NARCIS (Netherlands)

    Gresnigt, Marco M. M.; Kalk, Warner; Ozcan, Mutlu

    This study evaluated the survival rate of ceramic laminate veneers bonded to teeth with and without existing composite restorations (ECR). Twenty patients (mean age: 49.7 years) received 92 feldspathic ceramic laminate veneers (Shofu Vintage AL) on the maxillary teeth (intact teeth: n = 26; teeth

  10. Shear bond strength between porcelain and nano filler composite resin with or without 9% hydrofluoric acid etching

    Directory of Open Access Journals (Sweden)

    Kun Ismiyatin

    2009-06-01

    Full Text Available Background: Reparation technique on restorations with broken or damaged porcelain which are still attached with the teeth are difficult, because it is very hard to remove the porcelain restoration without damaging it, and it needs a long time. Various ways have been developed to repair the broken porcelain, one of them is the use of composite resin as the material for the restoration of fractured porcelain. Repairing porcelain inside the mouth without removing the restoration of the damaged porcelain using light cured composite resins material seems to be an advantageous option because it is relatively simple, has low risks, good esthetically and cheap. Purpose: The objective of this study was to find out the difference of shear bond strength in porcelain reparation using nano filler composite resin with or without 9% hydrofluoric acid etching by using Autograph measuring device. Methods: Twenty pieces of the porcelain samples devided into 2 groups. Group I: etching process using 9% hydrofluoric acid, and group II : without etching process. Result: The data was analyzed using t test in a p value of 0.0001 (p≤0.05, which means there is a significant different of shear bond strength between treated group I and II. The biggest shear bond strength was in treatment group I. Conclusion: The use of 9% hydrofluoric acid on the surface of porcelain can increase the shear bond strength between porcelain and nano filler composite resin.

  11. Comparative in vitro evaluation of internal adaptation of resin-modified glass ionomer, flowable composite and bonding agent applied as a liner under composite restoration: A scanning electron microscope study.

    Science.gov (United States)

    Soubhagya, M; Goud, K Mallikarjun; Deepak, B S; Thakur, Sophia; Nandini, T N; Arun, J

    2015-04-01

    The use of resin-modified glass Ionomer cement in sandwich technique is widely practiced with the advent of various newer generation of composites the bond between resin-modified glass Ionomer and these resins should be validated. This study is done to evaluate the interfacial microgaps between different types of liners and dentin, liners and composite (Filtek p60 [FLp60]) using scanning electron microscope (SEM). Standardized Class V preparations were performed in buccal/lingual surfaces of 30 caries, crack and defect-free extracted human third molars. The prepared teeth were divided into three groups. Group I: Single bond (SB), Group II: SB + synergy flow, Group III: SB + vitrebond. They were restored with composite resin FLp60, according to the manufacturer instructions. The SB + vitrebond, cross-sectioned through the canter of the restoration. The specimens were fixed, dehydrated, polished, and processed for SEM. The internal adaptation of the materials to the axial wall was analyzed under SEM with ×1000 magnification. The data obtained were analyzed with nonparametric tests (Kruskal-Wallis, P < 0.05). flowable composite or resin-modified glass ionomer applied in conjunction with adhesive resulted in statistically wider microgaps than occurred when the dentin was only hybridized prior to the restoration. Hybridization of dentin only provides superior sealing of the dentin-restoration interface than does flowable resin or resin-modified glass ionomer.

  12. Assessment of the Shear Bond Strength between Nanofilled Composite Bonded to Glass-ionomer Cement Using Self-etch Adhesive with Different pHs and Total-Etch Adhesive.

    Science.gov (United States)

    Sharafeddin, Farahnaz; Choobineh, Mohammad Mehdi

    2016-03-01

    In the sandwich technique, the undesirable bond between the composite resin and glass-ionomer cement (GIc) is one of the most important factors which lead to the failure of restoration. Total-etch and self-etch adhesives may improve the bond strength based on their pH. The purpose of this study was to evaluate the shear bond strength between the nanofilled composite resin and GIc using different adhesives. In this experimental study, 40 specimens (6×6mm) in 4 groups (n=10) were prepared in acrylic mold. Each specimen contained conventional GI ChemFil Superior with a height of 3mm, bonded to Z350 composite resin with a height measured 3mm. In order to bond the composite to the GI, the following adhesives were used, respectively: A: mild Clearfil SE Bond self-etch (pH=2), B: intermediate OptiBond self-etch (pH=1.4), C: strong Adper Prompt L-Pop (pH=1), and D: Adper Single Bond 2 total-etch (pH=7.2). The shear bond strength was measured by using universal testing machine with a crosshead speed of 1mm/min. One-way ANOVA and Tukey's test were used to analyze the data (pself-etch) was significantly different from group D (total-etch) (pself-etch) with D (p= 0.024). The results of this study showed that applying the mild self-etch adhesive between the composite and the GIc results in stronger shear bond strength compared to intermediate and strong self-etch adhesives. Moreover, the self-etch adhesive increased the shear bond strength between composite resin and GIc more significantly than total-etch adhesive.

  13. Numerical modelling of the bonding process for wind turbine blades: model validation

    DEFF Research Database (Denmark)

    Uzal, Anil; Spangenberg, Jon; W. Nielsen, Michael

    behaviour of theadhesive is approximated with the Bingham material model. The numerical model is in good agreementwith the experimental results. In the future, the model will be used to optimize the bonding process ofwind turbine blades, save weight and reduce the levelized cost of energy....

  14. High conductivity composite flip-chip joints and silver-indium bonding to bismuth telluride for high temperature applications

    Science.gov (United States)

    Lin, Wen P.

    Two projects are reported. First, the barrier layer and silver (Ag)-indium (In) transient liquid phase (TLP) bonding for thermoelectric (TE) modules at high temperature were studied, and followed with a survey of Ag microstructure and grain growth kinetics. Second, the high electrical conductivity joint materials bonded by both Ag-AgIn TLP and solid-state bonding processes for small size flip-chip applications were designed. In the first project, barrier and Ag-In TLP bonding layer for TE module at high temperature application were studied. Bismuth telluride (Bi2 Te3) and its alloys are used as materials for a TE module. A barrier/bonding composite was developed to satisfy the TE module for high temperature operation. Titanium (Ti)/ gold (Au) was chosen as the barrier layers and an Ag-rich Ag-In joint was chosen as the bonding layer. An electron-beam evaporated Ti layer was selected as the barrier layer. An Ag-In fluxless TLP bonding process was developed to bond the Bi 2Te3 chips to the alumina substrates for high temperature applications. To prepare for bonding, the Bi2Te3 chips were coated with a Ti/Au barrier layer followed by a Ag layer. The alumina substrates with titanium-tungsten (TiW)/Au were then electroplated with the Ag/In/Ag structure. These Bi2Te3 chips were bonded to alumina substrates at a bonding temperature of 180ºC with a static pressure as low as 100psi. The resulting void-free joint consists of five regions: Ag, (Ag), Ag2In, (Ag), and Ag, where (Ag) is Ag-rich solid solution with In atoms in it and Ag is pure Ag. This joint has a melting temperature higher than 660ºC, and it manages the coefficient of thermal expansion (CTE) mismatch between the Bi2Te3 and alumina substrate. The whole Ti/Au barrier layer and Ag-In bonding composite between Bi 2Te3 and alumina survived after an aging test at 250°C for 200 hours. The Ag-In joint transformed from Ag/(Ag)/Ag2In/(Ag)/Ag to a more reliable (Ag) rich layer after the aging test. Ag thin films were

  15. Shear bond strength of self-adhering flowable composite on dentin surface as a result of scrubbing pressure and duration

    Directory of Open Access Journals (Sweden)

    Ferry Jaya

    2012-09-01

    Full Text Available Background: Self-adhering flowable composite is a combination of composite resin and adhesive material. Its application needs scrubbing process on the dentin surface, but sometimes it is difficult to determine the pressure and duration of scrubbing. Purpose: This study was aimed to analyze the effect of scrubbing pressure and duration on shear bond strength of self-adhering flowable composite to dentin surface Methods: Fifty four mandibulary third molar were cut to get the dentin surface and divided into nine groups (n = 6. Dentin surface was scrubbed with 1, 2, and 3 grams of scrubbing pressure, each for 15, 20, and 25 seconds respectively. surface was scrubbed with 1, 2, and 3 grams of scrubbing pressure, each for 15, 20, and 25 seconds respectively. Composite resin was applied incrementally and polymerized for 20 seconds. All specimens were immersed in saline solution at 37º C for 24 hours. Shear bond strength was tested for all specimens by using Universal Testing Machine (Shimadzu AG-5000E, Japan at a crosshead speed of 1 mm/minute and analyzed by ANOVA and Post Hoc Test Bonferonni. The interface between self-adhering flowable interface between self-adhering flowable composite and dentin was observed with a Scanning Electron Microscope (JEOL JSM 6510LA. Results: The highest shear bond strength was obtained by 3 grams scrubbing pressure for 25 seconds or equal to applying the brush applicator in 0º relative to dentin surface. Conclusion: Increasing the scrubbing pressure and duration will increase the shear bond strength of self adhering flowable composite resin to dentinal surface. The highest shear bond strength was obtained when the applicator in 0º relative to dentin surface. Latar belakang: Self-adhering flowable composite merupakan gabungan resin komposit dengan material adhesif yang dalam penggunaannya memerlukan teknik scrubbing pada permukaan dentin, namun sulit untuk menentukan besar tekanan yang tepat saat scrubbing. Tujuan

  16. Structuring of composite hydrogel bioadhesives and its effect on properties and bonding mechanism.

    Science.gov (United States)

    Pinkas, Oded; Goder, Daniella; Noyvirt, Roni; Peleg, Sivan; Kahlon, Maayan; Zilberman, Meital

    2017-03-15

    Bioadhesives are polymeric hydrogels that can adhere to a tissue after crosslinking and are an essential element in nearly all surgeries worldwide. Several bioadhesives are commercially available. However, none of them are ideal. The main limitation of current tissue adhesives is the tradeoff between biocompatibility and mechanical strength, especially in wet hemorrhagic environments. Our novel bioadhesives are based on the natural polymers gelatin (coldwater fish) and alginate, crosslinked by carbodiimide (EDC). Two types of hemostatic agents with a layered silicate structure, montmorillonite (MMT) and kaolin, were loaded in order to improve the sealing ability in a hemorrhagic environment. The effect of the adhesive's components on its mechanical strength was studied by three different methods - burst strength, lap shear and compression. The viscosity, gelation time and structural features of the adhesive were also studied. A qualitative model that describes the effect of the bioadhesive's parameters on the cohesive and adhesive strength was developed. A formulation based on 400mg/mL gelatin, 10mg/mL alginate and 20mg/mL EDC was found as optimal, enabling a burst strength of 387mmHg. Incorporation of kaolin increased the burst strength by 25% due to microcomposite structuring, whereas MMT increased the burst strength by 50% although loaded in a smaller concentration, due to nano-structuring effects. This research clearly shows that the incorporation of kaolin and MMT in gelatin-alginate surgical sealants is a very promising novel approach for improving the bonding strength and physical properties of surgical sealants for use in hemorrhagic environments. The current manuscript focuses on novel bioadhesives, based on natural polymers and loaded with hemostatic agents with a layered silicate structure, in order to improve the sealing ability in hemorrhagic environment. Such composite bioadhesives have not been developed and studied before. The effect of the adhesive

  17. A strategy to synthesize graphene-incorporated lignin polymer composite materials with uniform graphene dispersion and covalently bonded interface engineering

    Science.gov (United States)

    Wang, Mei; Duong, Le Dai; Ma, Yifei; Sun, Yan; Hong, Sung Yong; Kim, Ye Chan; Suhr, Jonghwan; Nam, Jae-Do

    2017-08-01

    Graphene-incorporated polymer composites have been demonstrated to have excellent mechanical and electrical properties. In the field of graphene-incorporated composite material synthesis, there are two main obstacles: Non-uniform dispersion of graphene filler in the matrix and weak interface bonding between the graphene filler and polymer matrix. To overcome these problems, we develop an in-situ polymerization strategy to synthesize uniformly dispersed and covalently bonded graphene/lignin composites. Graphene oxide (GO) was chemically modified by 4,4'-methylene diphenyl diisocyanate (MDI) to introduce isocyanate groups and form the urethane bonds with lignin macromonomers. Subsequential polycondensation reactions of lignin groups with caprolactone and sebacoyl chloride bring about a covalent network of modified GO and lignin-based polymers. The flexible and robust lignin polycaprolactone polycondensate/modified GO (Lig-GOm) composite membranes are achieved after vacuum filtration, which have tunable hydrophilicity and electrical resistance according to the contents of GOm. This research transforms lignin from an abundant biomass into film-state composite materials, paving a new way for the utilization of biomass wastes.

  18. Effects of carbon fiber surface characteristics on interfacial bonding of epoxy resin composite subjected to hygrothermal treatments

    Science.gov (United States)

    Li, Min; Liu, Hongxin; Gu, Yizhuo; Li, Yanxia; Zhang, Zuoguang

    2014-01-01

    The changes of interfacial bonding of three types of carbon fibers/epoxy resin composite as well as their corresponding desized carbon fiber composites subjecting to hygrothermal conditions were investigated by means of single fiber fragmentation test. The interfacial fracture energy was obtained to evaluate the interfacial bonding before and after boiling water aging. The surface characteristics of the studied carbon fiber were characterized using X-ray photoelectron spectroscopy. The effects of activated carbon atoms and silicon element at carbon fiber surface on the interfacial hygrothermal resistance were further discussed. The results show that the three carbon fiber composites with the same resin matrix possess different hygrothermal resistances of interface and the interfacial fracture energy after water aging can not recovery to the level of raw dry sample (irreversible changes) for the carbon fiber composites containing silicon. Furthermore, the activated carbon atoms have little impact on the interfacial hygrothermal resistance. The irreversible variations of interfacial bonding and the differences among different carbon fiber composites are attributed to the silicon element on the carbon fiber bodies, which might result in hydrolyzation in boiling water treatment and degrade interfacial hygrothermal resistance.

  19. Bonding over Dentin Replacement Materials.

    Science.gov (United States)

    Meraji, Naghmeh; Camilleri, Josette

    2017-08-01

    Dentin replacement materials are necessary in large cavities to protect the pulp and reduce the bulk of filling material. These materials are layered with a composite resin restorative material. Microleakage caused by poor bonding of composite resin to underlying dentin replacement material will result in pulp damage. The aim of this study was to characterize the interface between dentin replacement materials and composite resin and to measure the shear bond strength after dynamic aging. Biodentine (Septodont, Saint Maur-des-Fosses, France), Theracal LC (Bisco, Schaumburg, IL), and Fuji IX (GC, Tokyo, Japan) were used as dentin replacement materials. They were then overlaid with a total-etch and bonding agent or a self-etch primer and composite resin or a glass ionomer cement. All combinations were thermocycled for 3000 cycles. The interface was characterized using scanning electron microscopy and elemental mapping. Furthermore, the shear bond strength was assessed. The Biodentine surface was modified by etching. The Theracal LC and Fuji IX microstructure was unchanged upon the application of acid etch. The Biodentine and glass ionomer interface showed an evident wide open space, and glass particles from the glass ionomer adhered to the Biodentine surface. Elemental migration was shown with aluminum, barium, fluorine, and ytterbium present in Biodentine from the overlying composite resin. Calcium was more stable. The bond strength between Theracal LC and composite using a total-etch technique followed by self-etch primer achieved the best bond strength values. Biodentine exhibited the weakest bond with complete failure of bonding shown after demolding and thermocycling. Dynamic aging is necessary to have clinically valid data. Bonding composite resin to water-based dentin replacement materials is still challenging, and further alternatives for restoration of teeth using such materials need to be developed. Copyright © 2017 American Association of Endodontists

  20. Reparability of aged silorane with methacrylate-based resin composite: micro-shear bond strength and scanning electron microscopy evaluation.

    Science.gov (United States)

    Giachetti, L; Scaminaci Russo, D; Baldini, M; Goracci, C; Ferrari, M

    2012-01-01

    To evaluate the compatibility between aged siloranes and methacrylate-based composites by simulating a common repair-technique. Twenty substrates were constructed using silorane (Filtek Silorane, 3M ESPE) and methacrylate composites (Filtek Supreme XT, 3M ESPE). Substrates were aged in 0.9% NaCl solution at 37°C for 72 hours. Silorane build-ups were constructed on silorane substrates without any intermediate layer (IL). Methacrylate build-ups were constructed on silorane substrates without any IL, with a methacrylate IL (Heliobond, Ivoclar Vivadent), or with a phosphate-methacrylate IL (Silorane System Adhesive Bond, 3M ESPE). Methacrylate build-ups were also constructed on methacrylate substrates without any IL. The micro-shear bond strength test was carried out after thermocycling. Bond strength data were statistically analyzed using analysis of variance and Tukey post hoc tests. Failure modes were assessed by means of scanning electron microscopy observations. The silorane-methacrylate group without any IL showed the lowest bond strength values (0.4 ± 0.1 MPa). The use of a methacrylate-based IL (1.6 ± 1.7 MPa) led to a slight increase in bond strength, whereas the use of phosphate-methacrylate IL (9.1 ± 5.4 MPa) significantly increased bond strength. There was no statistically significant difference in bond strength between silorane-silorane (7.9 ± 3.6 MPa) and methacrylate-methacrylate (9.5 ± 4.1 MPa) groups without any IL.

  1. Durability of fiber post-to-composite bonds achieved by physical vapor deposition and tribochemical silica coating.

    Science.gov (United States)

    Rathke, Andreas; Frehse, Henry; Muche, Rainer; Haller, Bernd

    2014-12-01

    To evaluate post-to-composite bonds in terms of their durability, achieved either by physical vapor deposition (PVD) or tribochemical silica coating (TSC) compared to coupling strategies for fiber posts at chairside. Thirty uncoated fiber posts (DT Light) each were either left untreated (control) or silanized with a one-bottle (Monobond Plus) or a two-bottle (Clearfil SE Bond/Porcelain Bond Activator) silane at the chairside. Thirty coated fiber posts each had already been silica coated and silanized by the manufacturer using PVD (DT Light SL) or TSC (DentinPost Coated) deposition techniques. Surface analysis was carried out by profilometry and x-ray microanalysis. All the posts were surrounded by 2-mm-thick disks of a dual-curing composite resin (MultiCore Flow). After water storage for 24 h at 37°C, the specimens in each group were randomly divided into three subgroups (n=10) and subjected to 0, 1500, and 20,000 thermocycles (5°C to 55°C) prior to push-out testing. Failure modes were evaluated by optical and scanning electron microscopy. The statistical significance was determined with two-way ANOVA, the Student-Newman-Keuls test, and Fisher's exact test. The conditioned posts had significantly higher interfacial bond strengths than the control posts after thermocycling (p0.05). Coatings deposited by TSC reached the highest bond values (pdelamination (pcomposite. PVD and TSC techniques enhanced the bond durability of fiber posts. TSC led to a superior post-tocomposite bond, probably based on more effective micromechanical adhesion due to the higher surface roughness.

  2. Bonding of lithium-disilicate ceramic to enamel and dentin using orthotropic fiber-reinforced composite at the interface.

    Science.gov (United States)

    Ergun, Gulfem; Cekic, Isil; Lassila, Lippo V J; Vallittu, Pekka K

    2006-10-01

    To evaluate the effect of orthotropic fiber-reinforced composite (FRC) at the interface on bonding of lithium-disilicate ceramic to dentin and enamel using different adhesive systems. Dentin and enamel surfaces were ground occlusally on human molar teeth. Ceramic blocks of IPS Empress 2 (Ivoclar-Vivadent) were fabricated. Following acid etching and silane treatment of the ceramics, the teeth were divided into two groups (dentin and enamel). Ceramic blocks were bonded to the tooth substance with or without a layer of FRC and dual-polymerizing composite cement (Duolink). Total-etching (etchant (Etch 37) with adhesive (One Step Plus)) and self-etching (self-priming etchant (Tyrian SPE) with adhesive (One Step Plus)) systems were used, with five test specimens in each group. The cement was polymerized with a LED curing unit (Elipar Freelight LED 2) with standard mode of 40 s. The specimens were thermocycled for 6000 cycles and tested with the microtensile tester at a rate of 5 mm/min. Fracture mode analyses were done by light microscope and with SEM. The data were analyzed using three-way analysis of variance (ANOVA). ANOVA showed that enamel had statistically significant (p<0.001) higher bond strength values than dentin. Bond strength values were significantly higher (p=0.012) with the total-etching system than with the self-etching system. The existence of FRC also had a minor effect on bond strength values (p=0.013). The enamel and total-etching system provided more reliable bonding than dentin and the self-etching system. Use of an FRC layer at the interface did not improve bond strength values, but instead changed fracture pattern behavior.

  3. Design and demonstration of automated data analysis algorithms for ultrasonic inspection of complex composite panels with bonds

    Science.gov (United States)

    Aldrin, John C.; Forsyth, David S.; Welter, John T.

    2016-02-01

    To address the data review burden and improve the reliability of the ultrasonic inspection of large composite structures, automated data analysis (ADA) algorithms have been developed to make calls on indications that satisfy the detection criteria and minimize false calls. The original design followed standard procedures for analyzing signals for time-of-flight indications and backwall amplitude dropout. However, certain complex panels with varying shape, ply drops and the presence of bonds can complicate this interpretation process. In this paper, enhancements to the automated data analysis algorithms are introduced to address these challenges. To estimate the thickness of the part and presence of bonds without prior information, an algorithm tracks potential backwall or bond-line signals, and evaluates a combination of spatial, amplitude, and time-of-flight metrics to identify bonded sections. Once part boundaries, thickness transitions and bonded regions are identified, feature extraction algorithms are applied to multiple sets of through-thickness and backwall C-scan images, for evaluation of both first layer through thickness and layers under bonds. ADA processing results are presented for a variety of complex test specimens with inserted materials and other test discontinuities. Lastly, enhancements to the ADA software interface are presented, which improve the software usability for final data review by the inspectors and support the certification process.

  4. Effect of Silane Solvent on Microtensile Bond Strength of Hy-drogen Peroxide-Treated Fiber Post and Composite Core

    Directory of Open Access Journals (Sweden)

    Sh. Kasraei

    2008-09-01

    Full Text Available Objective: The aim of this in vitrostudy was to evaluate the effect of the type of solvent in silane solution on microtensile bond strength of fiber posts to composite resin cores af-ter application of 24% hydrogen peroxide.Materials and Methods: Eighteen white fiber posts, immersed in 24% hydrogen peroxide were divided into three groups (n=6. In the group A post surfaces were silanized with an ethanol based solution, in group B with an acetone based solution, in the group C with and un-diluted methacryloxytrimethoxysilane (as the control group. The cores were built up using flowable composite. Microtensile bond strength test and evaluations using stereomi-croscope were performed on the samples and the data were analyzed using one-way ANOVA and Tukey HSD tests.Results: A significant difference was observed between the amounts of microtensile bond strength of fiber poststo composite cores in the groups A and B, and the ones in group C (P0.05.Conclusion: The type of solvent in silane solution has no effect on microtensile bond strength between fiber post andcomposite resin core after application of 24% Hydrogen Peroxide.

  5. Effect of Different Surface Treatments on Microtensile Bond Strength of Composite Resin to Normal and Fluorotic Enamel After Microabrasion

    OpenAIRE

    Bassir, Mahshid Mohammadi; Rezvani, Mohammad Bagher; Ghomsheh, Elham Tabatabai; Hosseini, Zahra Malek

    2016-01-01

    Objectives: This study aimed to determine the effect of surface treatments such as tooth reduction and extending the etching time on microtensile bond strength (µTBS) of composite resin to normal and fluorotic enamel after microabrasion. Materials and Methods: Fifty non-carious anterior teeth were classified into two groups of normal and fluorotic (n=25) using Thylstrup and Fejerskov index (TFI=4-6). Teeth in each group were treated with five modalities as follows and restored with OptiBond F...

  6. Comparison of push-out bond strength of fiber-reinforced composite resin posts according to cement thickness.

    Science.gov (United States)

    Park, Jun-Seong; Lee, Jeong-Sub; Park, Jeong-Won; Chung, Won-Gyun; Choi, Eun-Hee; Lee, Yoon

    2017-09-01

    Post space size and cement thickness can differ because of variations in root canal morphology, such as an oval shape, and because the entire canal space cannot be included in the post space preparation. As a result, increased cement thickness around the post may affect the bond strength between the post and the dentin. The purpose of this in vitro study was to evaluate the push-out bond strength of fiber-reinforced composite resin posts to root dentin with cement layers of varying thickness. Thirty human premolars were endodontically treated and restored with fiber-reinforced composite resin posts. Post space was prepared using a drill with a 1.5-mm diameter and diameters of 1.25 mm (small [S] group), 1.375 mm (medium [M] group), and 1.5 mm (large [L] group) were cemented. The specimens were sectioned horizontally into 1-mm-thick slices, and the push-out bond strengths of the apical and coronal fragments were evaluated. Bond strength was compared using analysis of variance and 2-sample t tests (α=.05). No significant differences were found in the debonding force and push-out bond strength among fiber-reinforced composite posts of different sizes (P>.05). The mean debonding force and standard deviation of the posts were 25.05 ±9.52 N for the S group, 28.17 ±11.38 N for the M group, and 33.78 ±12.47 N for the L group. The corresponding push-out bond strength values were 3.11 ±1.54 MPa, 3.39 ±1.4 MPa, and 4.15 ±1.75 MPa. The differences in debonding force between the apical (26.43 ±10.72 N) and coronal (31.57 ±12.03 N) areas were not significant (P>.05). However, the differences in push-out bond strength between the apical (4.27 ±1.73 MPa) and coronal areas (2.83 ±1.08 MPa) were significant (Ppost spaces and, consequently, the increased cement thickness do not significantly affect the bond strength of fiber-reinforced composite resin posts to root dentin. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc

  7. Effects of ethanol concentrations of acrylate-based dental adhesives on microtensile composite-dentin bond strength and hybrid layer structure of a 10 wt% polyhedral oligomeric silsesquioxane (POSS-incorporated bonding agent

    Directory of Open Access Journals (Sweden)

    Seyed Mostafa Mousavinasab

    2018-01-01

    Conclusion: Incorporation of 31% ethanol as solvent into a 10 wt% POSS-incorporated experimental dental adhesive might increase the bond strength of composite to dentin and improve the quality and morphology of the hybrid layer. However, higher concentrations of the solvent might not improve the bond strength or quality of the hybrid layer.

  8. Flexural Strength of Preheated Resin Composites and Bonding Properties to Glass-Ceramic and Dentin

    Directory of Open Access Journals (Sweden)

    Matthias Richard Kramer

    2016-01-01

    Full Text Available To test the impact of preheating (25, 37, 54, or 68 °C of TetricEvoCeram (TEC, FiltekSupremeXT (FSXT, and Venus (V on flexural strength (FS, shear bond strength (SBS and interfacial tension (IFT. FS was tested with TEC and FSXT. For SBS, glass-ceramic and human dentin substrate were fabricated and luted with the preheated resin composite (RC. SBSs of 1500 thermal cycled specimens were measured. For IFT, glass slides covered with the non-polymerized RC were prepared and contact angles were measured. Data were analyzed using 2/1-way ANOVA with Scheffé-test, and t-test (p < 0.05. Preheated TEC (37–68 °C showed higher FS compared to the control-group (25 °C (p < 0.001. FSXT presented higher FS than TEC (p < 0.001. For SBS to dentin higher values for FSXT than TEC were found. The preheating temperature showed no impact on SBS to dentin. SBS to glass-ceramic revealed a positive influence of temperature for TEC 25–68 °C (p = 0.015. TEC showed higher values than V and FSXT (p < 0.001. IFT values increased with the preheating temperature. A significant difference could be observed in every RC group between 25 and 68 °C (p < 0.001.

  9. Flexural Behavior of RC Members Using Externally Bonded Aluminum-Glass Fiber Composite Beams

    Directory of Open Access Journals (Sweden)

    Ki-Nam Hong

    2014-03-01

    Full Text Available This study concerns improvement of flexural stiffness/strength of concrete members reinforced with externally bonded, aluminum-glass fiber composite (AGC beams. An experimental program, consisting of seven reinforced concrete slabs and seven reinforced concrete beams strengthened in flexure with AGC beams, was initiated under four-point bending in order to evaluate three parameters: the cross-sectional shape of the AGC beam, the glass fiber fabric array, and the installation of fasteners. The load-deflection response, strain distribution along the longitudinal axis of the beam, and associated failure modes of the tested specimens were recorded. It was observed that the AGC beam led to an increase of the initial cracking load, yielding load of the tension steels and peak load. On the other hand, the ductility of some specimens strengthened was reduced by more than 50%. The A-type AGC beam was more efficient in slab specimens than in beam specimens and the B-type was more suitable for beam specimens than for slabs.

  10. Bonding to Different PEEK Compositions: The Impact of Dental Light Curing Units.

    Science.gov (United States)

    Lümkemann, Nina; Eichberger, Marlis; Stawarczyk, Bogna

    2017-01-14

    This study investigated the impact of different light curing units (LCUs) for the polymerization of adhesive system visio.link (VL) on the tensile bond strength (TBS) of different PEEK compositions. For TBS measurements, 216 PEEK specimens with varying amounts of TiO₂ (PEEK/0%, PEEK/20%, PEEK/>30%) were embedded, polished, air abraded (Al₂O₃, 50 µm, 0.4 MPa), conditioned using VL, and polymerized using either a halogen LCU (HAL-LCU) or a LED LCU (LED-LCU) for chairside or labside application, respectively. After thermocycling (5000×, 5/55 °C), TBS was measured, and fracture types were determined. Data was analyzed using a 2-way ANOVA followed by Tukey-HSD, Kruskal-Wallis H and Mann-Whitney U tests as well as a Chi²-test and a Ciba-Geigy table (p 30%, PEEK/20% resulted in a higher TBS after using HAL-LCU for labside application. No significant differences were found between PEEK/0% and PEEK/>30%. HAL-LCU with PEEK/20% for labside application showed a higher TBS than HAL-LCU with PEEK/20% for chairside application, whereas LED-LCU with PEEK/>30% for chairside application showed a higher TBS than LED-LCU with PEEK/>30% for labside application.

  11. Can cement film thickness influence bond strength and fracture resistance of fiber reinforced composite posts?

    Science.gov (United States)

    Penelas, Alice Gonçalves; Piedade, Valery Martins; Borges, Ana Carolina Oliveira da Silva; Poskus, Laiza Tatiana; da Silva, Eduardo Moreira; Guimarães, José Guilherme Antunes

    2016-05-01

    This study compared the influence of cement film thickness (CFT) on bond strength (BS) and fracture resistance (FR) of fiber-reinforced composite (FRC) posts to root canal. One hundred bovine incisors were used for BS and FR analysis (n = 10) and distributed into five experimental groups according to FRC post diameters (WhitePost DC no. 0.5, no. 1, no. 2, no. 3, no. 4), leading to five different CFTs. The canals were prepared using drill no. 4 provided by the post manufacturer and irrigated with 2.5% NaOCl. After conditioning (24% H2O2/5 min) and silanization, posts were cemented with resin cement. BS was evaluated using push-out test and FR using the compression test at 45°. A stereomicroscope was used to measure CFT and to analyze failure pattern. BS data were subjected to two-way ANOVA and Scheffé test for contrast (α = 0.05); FR data were subjected to one-way ANOVA. BS was significantly affected by CFT, as the most well-adapted post achieved the highest values (p post well adapted to the root canal results in higher BS values. Different CFTs did not influence the FR of teeth restored with FRC posts. The results indicate that post retention is improved when a well-adapted post is used, although this has not been critical to fracture resistance.

  12. Grinding performance evaluation of porous composite-bonded CBN wheels for Inconel 718

    Directory of Open Access Journals (Sweden)

    Chen Zhenzhen

    2014-08-01

    Full Text Available For high-efficiency grinding of difficult-to-cut materials such as titanium and nickel alloys, a high porosity is expected and also a sufficient mechanical strength to satisfy the function. However, the porosity increase is a disadvantage to the mechanical strength. As a promising pore forming agent, alumina bubbles are firstly induced into the abrasive layer to fabricate porous cubic boron nitride (CBN wheels. When the wheel porosity reaches 45%, the bending strength is still high up to 50 MPa with modified orderly pore distribution. A porous CBN wheel was fabricated with a total porosity around 30%. The grinding performance of the porous composite-bonded CBN wheel was evaluated in terms of specific force, specific grinding energy, and grinding temperature, which were better than those of the vitrified one under the same grinding conditions. Compared to the vitrified CBN wheel, clear straight cutting grooves and less chip adhesion are observed on the ground surface and there is also no extensive loading on the wheel surface after grinding.

  13. Effect of adherend thickness and mixed mode loading on debond growth in adhesively bonded composite joints

    Science.gov (United States)

    Mangalgiri, P. D.; Johnson, W. S.; Everett, R. A., Jr.

    1986-01-01

    Symmetric and unsymmetric double cantilever beam (DCB) specimens were tested and analyzed to assess the effect of: (1) adherend thickness, and (2) a predominantly mode I mixed mode loading on cyclic debond growth and static fracture toughness. The specimens were made of unidirectional composite (T300/5208) adherends bonded together with EC3445 structural adhesive. The thickness was 8, 16, or 24 plies. The experimental results indicated that the static fracture toughness increases and the cyclic debond growth rate decreases with increasing adherend thickness. This behavior was related to the length of the plastic zone ahead of the debond tip. For the symmetric DCB specimens, it was further found that displacement control tests resulted in higher debond growth rates than did load control tests. While the symmetric DCB tests always resulted in cohesive failures in the bondline, the unsymmetric DCB tests resulted in the debond growing into the thinner adherend and the damage progressing as delamination in that adherend. This behavior resulted in much lower fracture toughness and damage growth rates than found in the symmetric DCB tests.

  14. Academy of Dental Materials guidance on in vitro testing of dental composite bonding effectiveness to dentin/enamel using micro-tensile bond strength (μTBS) approach.

    Science.gov (United States)

    Armstrong, Steve; Breschi, Lorenzo; Özcan, Mutlu; Pfefferkorn, Frank; Ferrari, Marco; Van Meerbeek, Bart

    2017-02-01

    An ideal dental adhesive should provide retentive strength, marginal seal, be relatively simple to achieve and demonstrate clinical durability. Future improvements in adhesive bonding to tooth structure require in vitro test methods that provide reliable data for materials development and/or evaluation of experimental variables. The objective of this project was to identify a test method that is relatively easy to perform, repeatable and ultimately useful for predicting clinical outcomes. The Academy of Dental Materials initiated a project to develop and distribute guidance documents on laboratory test methods that are useful for the evaluation of dental adhesives and cements, composite resins and ceramics. The dental adhesive sub-group has identified the micro-tensile bond strength test, especially after subjecting the specimens to a durability challenge, as currently the best practical surrogate measure of dental composite restoration retention. The following μTBS guidance is meant to aid the researcher in conducting the μTBS test. The authors, while recognizing the limitations of a static, strength-based test method, welcome comments and suggestions for improvements of this guidance document in future revisions. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  15. Validation and factor analysis of mother-infant bonding questionnaire in pregnant and postpartum women in Japan.

    Science.gov (United States)

    Ohara, Masako; Okada, Takashi; Kubota, Chika; Nakamura, Yukako; Shiino, Tomoko; Aleksic, Branko; Morikawa, Mako; Yamauchi, Aya; Uno, Yota; Murase, Satomi; Goto, Setsuko; Kanai, Atsuko; Masuda, Tomoko; Ozaki, Norio

    2016-07-07

    The Mother-Infant Bonding Questionnaire (MIBQ) has been widely used to assess maternal emotional involvement with infants. Although the reliability and validity of the MIBQ in the postpartum period has been confirmed, it remains unclear whether the MIBQ is appropriate to assess maternal bonding in both pregnancy and the postpartum period over time. Our study were aimed to 1) examine the reliability and validity of the MIBQ for clinical use among pregnant and postpartum women; and 2) examine the factor structure of the items, create subscales, and confirm the stability of the MIBQ in the pregnancy and postpartum periods. Participants (n = 751, mean age 32.1 ± 4.4 years) completed the MIBQ and the Edinburgh Postnatal Depression Scale (EPDS) in early pregnancy (before week 25), in late pregnancy (around week 36), 5 days after delivery, and 1 month after delivery. We randomly divided participants into two sample sets. We conducted an exploratory factor analysis of the nine MIBQ items using data from one group of mothers (Group 1; n = 376) in all four periods. The factor structure derived from the exploratory factor analysis was confirmed by a confirmatory factor analysis in the second group (Group 2; n = 375) of mothers in all four periods. Exploratory factor analysis yielded two factors: Lack of Affection (LA) and Anger and Rejection (AR). Confirmatory factor analysis demonstrated that LA and AR factors existed for the MIBQ in all periods. Cronbach's alpha coefficients were 0.879 and 0.584, respectively. The scores for LA and AR were significantly correlated over the four time periods. Mothers with higher AR scores on the MIBQ at any of the four periods had higher scores on the EPDS. The MIBQ has two subscales regardless of the timing of the assessment. The MIBQ is appropriate for pregnant as well as postpartum women to assess maternal bonding toward the fetus and infant.

  16. Novel manufacturing process of nanoparticle/Al composite filler metals of tungsten inert gas welding by accumulative roll bonding

    Energy Technology Data Exchange (ETDEWEB)

    Fattahi, M., E-mail: fattahi.put@gmail.com [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Noei Aghaei, V. [Aerospace Engineering Department, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Dabiri, A.R. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Amirkhanlou, S. [Young Researchers and Elite Club, Najafabad Branch, Islamic Azad University, Najafabad (Iran, Islamic Republic of); Akhavan, S.; Fattahi, Y. [Materials Engineering Department, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    2015-11-11

    In the present work, accumulative roll bonding (ARB) was used as an effective method for manufacturing nanoparticle/Al composite filler metals of tungsten inert gas (TIG) welding. After welding, the distribution of ceramic nanoparticles and mechanical properties of welds were investigated. By applying ARB, ceramic nanoparticles were uniformly dispersed in the composite filler metals. Consequently, the welds produced by these filler metals had a uniform dispersion of ceramic nanoparticles in their compositions. The test results showed that the yield strength of welds was greatly increased when using the nanoparticle/Al composite filler metals. The improvement in the yield strength was attributed to the coefficient of thermal expansion mismatch and Orowan strengthening mechanisms. Therefore, according to the results presented in this paper, it can be concluded that the nanoparticle/Al composite filler metals can serve as a novel filler metal for TIG welding of aluminum and its alloys.

  17. Evaluation of Microleakage of Silorane and Methacrylate Based Composite Materials in Class I Restorations by Using Two Different Bonding Techniques.

    Science.gov (United States)

    Alshetili, Mohsen S; Aldeyab, Sultan S

    2015-01-01

    To evaluate the microleakage of silorane-based composite material (Filtek P90) with that of two homologous methacrylate-based composites materials (Filtek Z250 and Filtek Z250 XT), by using two different bonding techniques. Sixty extracted human maxillary first premolars prepared for standardized Class I cavities (4 mm × 2 mm × 2 mm) were randomly divided into three groups. Group A (n = 20) was filled with Filtek Z250 (Methacrylate) using single bond universal total etching technique, Group B (n = 20) was filled with Filtek Z250 XT (Methacrylate) using single bond universal self-etching technique and Group C (n = 20) restored with Filtek P90 (Silorane) with dedicated two-step self-etching prime and bond adhesive system (P90 system adhesive). Teeth were subjected to thermocycling regime (500×, 5-55°C), and dye penetration by immersing in 2% methylene blue for 24 h. Tooth sectioning was performed, and extent of the dye penetration was scored based on dye penetration scale to evaluate the microleakage. Statistical analysis included descriptive statistics and inferential statistics of Kruskal-Wallis test to compare the mean ranks between groups. There was no significant difference observed for microleakage among the three composite materials tested in the present study. However, the cavities restored with silorane (Filtek P90) based composite displayed higher microleakage than the Filtek Z250, Z250 XT. All the restorative systems tested in this study exhibited microleakage, but the silorane technology showed more microleakage when compared to the methacrylate-based composite systems.

  18. Viscoelasticity of Axisymmetric Composite Structures: Analysis and Experimental Validation

    Science.gov (United States)

    2013-02-01

    analysis can be applied to composite pressure vessels, gun barrels, and flywheels . 15. SUBJECT TERMS viscoelasticity, creep, composite, gun barrel... flywheel 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 28 19a. NAME OF RESPONSIBLE PERSON Jerome T...method to study the viscoelastic behavior of thick-walled composite cylinders. The analysis can be applied to the design of flywheel machinery and

  19. Validation of the Malay Version of the Parental Bonding Instrument among Malaysian Youths Using Exploratory Factor Analysis

    Science.gov (United States)

    MUHAMMAD, Noor Azimah; SHAMSUDDIN, Khadijah; OMAR, Khairani; SHAH, Shamsul Azhar; MOHD AMIN, Rahmah

    2014-01-01

    Background: Parenting behaviour is culturally sensitive. The aims of this study were (1) to translate the Parental Bonding Instrument into Malay (PBI-M) and (2) to determine its factorial structure and validity among the Malaysian population. Methods: The PBI-M was generated from a standard translation process and comprehension testing. The validation study of the PBI-M was administered to 248 college students aged 18 to 22 years. Results: Participants in the comprehension testing had difficulty understanding negative items. Five translated double negative items were replaced with five positive items with similar meanings. Exploratory factor analysis showed a three-factor model for the PBI-M with acceptable reliability. Four negative items (items 3, 4, 8, and 16) and item 19 were omitted from the final PBI-M list because of incorrect placement or low factor loading (< 0.32). Out of the final 20 items of the PBI-M, there were 10 items for the care factor, five items for the autonomy factor and five items for the overprotection factor. All the items loaded positively on their respective factors. Conclusion: The Malaysian population favoured positive items in answering questions. The PBI-M confirmed the three-factor model that consisted of care, autonomy and overprotection. The PBI-M is a valid and reliable instrument to assess the Malaysian parenting style. Confirmatory factor analysis may further support this finding. Keywords: Malaysia, parenting, questionnaire, validity PMID:25977634

  20. In vitro evaluation of the fracture resistance and microleakage of porcelain laminate veneers bonded to teeth with composite fillings after cyclic loading

    OpenAIRE

    Sadighpour, Leyla; Geramipanah, Farideh; Allahyari, Somayeh; Fallahi Sichani, Babak; Kharazi Fard, Mohamd Javad

    2014-01-01

    PURPOSE There is insufficient data regarding the durability of porcelain laminate veneers bonded to existing composite fillings. The aim of the present study was to evaluate the fracture resistance and microleakage of porcelain laminate veneers bonded to teeth with existing composite fillings. MATERIALS AND METHODS Thirty maxillary central incisors were divided into three groups (for each group, n=10): intact teeth (NP), teeth with class III composite fillings (C3) and teeth with class IV cav...

  1. Bonding of composite resins to PEEK: the influence of adhesive systems and air-abrasion parameters.

    Science.gov (United States)

    Stawarczyk, Bogna; Taufall, Simon; Roos, Malgorzata; Schmidlin, Patrick R; Lümkemann, Nina

    2017-06-24

    The objective of the study was to investigate the tensile bond strength (TBS) to polyaryletheretherketone (PEEK) after different pretreatment and conditioning methods. Four hundred PEEK specimens were fabricated and allocated to the following air-abrasion methods (n 1 = 80/pretreatment): (i) 50 μm Al2O3 (0.05 MPa); (ii) 50 μm Al2O3 (0.35 MPa); (iii) 110 μm Al2O3 (0.05 MPa); (iv) 110 μm Al2O3 (0.35 MPa); and (v) Rocatec 110 μm (0.28 MPa). These pretreatments were combined with the following conditioning methods (n 2 = 20/pretreatment/conditioning): (a) visio.link (VL); (b) Monobond Plus/Heliobond (MH); (c) Scotchbond Universal (SU); and (d) dialog bonding fluid (DB). After veneering of all specimens with dialog occlusal and aging (28 days H2O, 37 °C + 20,000 thermal cycles, 5/55 °C), TBS was measured. Data was analysed using Kaplan-Meier survival analysis with Breslow-Gehan test and Cox-regressions. The major impact on TBS showed the conditioning, followed by the air-abrasion-pressure, while the grain size of the air-abrasion powder did not show any effect. Specimens air-abraded at 0.35 MPa showed the highest survival rates. However, within VL groups, this observation was not statistically significant. Within MH groups, pretreatment using 110 μm Al2O3 and 0.05 MPa resulted in higher survival rates compared to groups treated with 50 and 110 μm Al2O3 using a pressure of 0.35 MPa. The use of VL showed the highest survival rates between the adhesive systems and the TBS values higher than 25 MPa independent of the pretreatment method. As an exception, only VL showed significantly higher survival rates when compared to MH. The adequate choice of the adhesive system and higher pressures improved the TBS between PEEK and veneering resin composite. The particle size had no major impact. According to this study, best veneering of PEEK with dialog occlusal can be achieved by conditioning with visio.link in combination with the pretreatment of

  2. Evaluation of class V composite restorations microleakage in premolars with/without electric current while applying variant dentin bondings

    Directory of Open Access Journals (Sweden)

    Narges Dorri

    2014-06-01

    Full Text Available   Background and Aims: The ability of composite restorations to prevent microleakage needs desirable bonding material for proper sealing . The purpose of this study was to evaluate class V composite restorations microleakage in premolars with/without electric current while applying variant dentin bonding in vitro.   Materials and Methods: 120 non-carious human premolars were used for this study and standardized class v cavities were prepared. The tooth roots were cut by discs at a distance of 5 mm from CEJ and pulp tissue was removed. The teeth were divided into six groups of 20. In the first group, electric current was applied, Single bond (3M ESPE, St Paul, MN, USA with a broom motion attached to the cathode and a sponge containing bonding was used as anode. The used current was 15µA and the Single bond in the second group was used without electricity. Then two bondings PQ1 (Ultradent, Germany and Optibond solo plus (Kerr, USA were used with and without electricity. After adhesive application and curing the bonding agents, cavities were restored by a composite (Valux Plus. The root ends were sealed by wax and all teeth surfaces, except 1 mm around the restorations were covered with a nail varnish. The specimens were thermocycled for 1000 cycles and placed in fushin for 24 hours and were then sectioned vertically and examined under a stereomicroscope. Data were scored on a 0-4 scale based on microleakage at the gingival margins and analyzed using Kruskal-Wallis and Mann-whitney test.   Results: Based on the results, the extent of microleakage in the groups of electric current was significantly less than the groups without using the electric current (P=0.05. The lowest degree of microleakage was found in PQ1 group, and the greatest difference between the groups with and without electricity was also found in PQ1 group. Single bond and Optibond Solo Plus with electric current showed a lower degree of microleakge.   Conclusion: The result

  3. Effect of endodontic irrigation and dressing procedures on the shear bond strength of composite to coronal dentin

    Directory of Open Access Journals (Sweden)

    Sahar E. Abo-Hamar

    2013-01-01

    Full Text Available This study aimed to evaluate the effects of three sodium hypochlorite (NaOCl-endodontic irrigation procedures used alone or in combinations with two intermediate dressing materials on bond strengths of two adhesive composite systems to coronal dentin. Surfaces were treated with NaOCl or NaOCl–Glyde-File-Prep (H2O2 and EDTA with or without chlorhexidine (CHX as a final rinse. Intermediate dressing materials of calcium hydroxide (Ca(OH2 and sodium perborate (SP were combined with surface treatments. Surface treatment groups (n = 10/group included (1 distilled water (control, (2 5.25% NaOCl (30 min, (3 NaOCl/Glyde (30 min, (4 NaOCl/Glyde (30 min + CHX (2 min, (5 NaOCl/Glyde (30 min + Ca(OH2 (5 days + CHX (2 min, and (6 NaOCl/Glyde (30 min + SP (9 days + CHX (2 min. For each surface treatment group, dentin shear bond strengths of two different composite systems (Excite/Tetric Flow Chroma, [EX/TFC], and Clearfil Protect Bond/Protect Liner F [PB/PLF] were evaluated. Median shear bond strengths (EX/TFC, PB/PLF for each surface treatment group in MPa were (1 21, 18; (2 26, 18; (3 21, 17; (4 22, 16; (5 17, 11; and (6 14, 11, respectively. NaOCl significantly increased the bond strength of EX/TFC (p  0.05, whereas it significantly decreased PB/PLF (p < 0.05. Ca(OH2 and SP significantly decreased the bond strengths of both adhesive systems (p < 0.05. Adhesion to coronal dentin is dependent upon the irrigation regimen and the type of adhesive.

  4. Effect of endodontic irrigation and dressing procedures on the shear bond strength of composite to coronal dentin

    Science.gov (United States)

    Abo-Hamar, Sahar E.

    2012-01-01

    This study aimed to evaluate the effects of three sodium hypochlorite (NaOCl)-endodontic irrigation procedures used alone or in combinations with two intermediate dressing materials on bond strengths of two adhesive composite systems to coronal dentin. Surfaces were treated with NaOCl or NaOCl–Glyde-File-Prep (H2O2 and EDTA) with or without chlorhexidine (CHX) as a final rinse. Intermediate dressing materials of calcium hydroxide (Ca(OH)2) and sodium perborate (SP) were combined with surface treatments. Surface treatment groups (n = 10/group) included (1) distilled water (control), (2) 5.25% NaOCl (30 min), (3) NaOCl/Glyde (30 min), (4) NaOCl/Glyde (30 min) + CHX (2 min), (5) NaOCl/Glyde (30 min) + Ca(OH)2 (5 days) + CHX (2 min), and (6) NaOCl/Glyde (30 min) + SP (9 days) + CHX (2 min). For each surface treatment group, dentin shear bond strengths of two different composite systems (Excite/Tetric Flow Chroma, [EX/TFC], and Clearfil Protect Bond/Protect Liner F [PB/PLF]) were evaluated. Median shear bond strengths (EX/TFC, PB/PLF) for each surface treatment group in MPa were (1) 21, 18; (2) 26, 18; (3) 21, 17; (4) 22, 16; (5) 17, 11; and (6) 14, 11, respectively. NaOCl significantly increased the bond strength of EX/TFC (p  0.05), whereas it significantly decreased PB/PLF (p < 0.05). Ca(OH)2 and SP significantly decreased the bond strengths of both adhesive systems (p < 0.05). Adhesion to coronal dentin is dependent upon the irrigation regimen and the type of adhesive. PMID:25685402

  5. Study on the bonding strength between calcium phosphate/chitosan composite coatings and a Mg alloy substrate

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Jie [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Pharmacy College, Jiamusi University, Jiamusi 154007 (China); Dai Changsong, E-mail: changsd@hit.edu.cn [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Wei Jie [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); School of Chemistry and Bioengineering, Suzhou Science Technology University, Suzhou 215009 (China); Wen Zhaohui, E-mail: wenzhaohui1968@163.com [Department of Neuro intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Calcium phosphate/chitosan composite coatings on the MAO-AZ91D alloy were prepared. Black-Right-Pointing-Pointer The bonding force between the coating and the magnesium alloy was optimized. Black-Right-Pointing-Pointer The composite coating slowed down the corrosion rate of magnesium alloy in m-SBF. - Abstract: In order to improve the bonding strength between calcium phosphate/chitosan composite coatings and a micro-arc oxidized (MAO)-AZ91D Mg alloy, different influencing parameters were investigated in the process of electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). Surface morphology and phase constituents of the as-prepared materials were investigated by using X-ray diffractometer (XRD), Fourier-transformed infrared spectrophotometer (FTIR), Raman spectrometer, scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS), and a thermo gravimetric and differential thermal analyzer (TG-DTA). Scratch tests were carried out to study the bonding properties between the coatings and the substrates. In vitro immersion tests were conducted to determine the corrosion behaviors of samples with and without deposit layers through electrochemical experiments. In the EPD process, the acetic acid content in the electrophoresis suspension and the electrophoretic voltage played important roles in improving the bonding properties, while the contents of chitosan (CS) and nano-hydroxyapatite (nHA, Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}) in the suspension had less significant influences on the mechanical bonding strength. It was observed that the coatings showed the excellent bonding property when an electrophoretic voltage was in a range of 40-110 V with other reagent amounts as follows: acetic acid: 4.5 vol.%, CS {<=} 0.25 g, nHA {<=} 2.0 g in 200 ml of a CS-acetic acid aqueous solution and nHA {<=} 2.5 g in 300 ml of absolute ethanol. The morphology of the composite coating

  6. Bond Strength of Resin Composite to Dentin with Different Adhesive Systems: Influence of Relative Humidity and Application Time.

    Science.gov (United States)

    Amsler, Fabienne; Peutzfeldt, Anne; Lussi, Adrian; Flury, Simon

    2015-06-01

    To investigate the influence of relative humidity and application time on bond strength to dentin of different classes of adhesive systems. A total of 360 extracted human molars were ground to mid-coronal dentin. The dentin specimens were treated with one of six adhesive systems (Syntac Classic, OptiBond FL, Clearfil SE Bond, AdheSE, Xeno Select, or Scotchbond Universal), and resin composite (Filtek Z250) was applied to the treated dentin surface under four experimental conditions (45% relative humidity/application time according to manufacturers' instructions; 45% relative humidity/reduced application time; 85% relative humidity/application time according to manufacturers' instructions; 85% relative humidity/reduced application time). After storage (37°C, 100% humidity, 24 h), shear bond strength (SBS) was measured and data analyzed with nonparametric ANOVA followed by Kruskal-Wallis tests and Mann-Whitney U-tests with Bonferroni-Holm correction for multiple testing (level of significance: α = 0.05). Increased relative humidity and reduced application time had no effect on SBS for Clearfil SE Bond and Scotchbond Universal (p = 1.00). For Syntac Classic, OptiBond FL, AdheSE, and Xeno Select there was no effect on SBS of reduced application time of the adhesive system (p ≥ 0.403). However, increased relative humidity significantly reduced SBS for Syntac Classic, OptiBond FL, and Xeno Select irrespective of application time (p ≤ 0.003), whereas for AdheSE, increased relative humidity significantly reduced SBS at recommended application time only (p = 0.002). Generally, increased relative humidity had a detrimental effect on SBS to dentin, but reduced application time had no effect.

  7. Effects of different acids and etching times on the bond strength of glass fiber-reinforced composite root canal posts to composite core material.

    Science.gov (United States)

    Güler, Ahmet Umut; Kurt, Murat; Duran, Ibrahim; Uludamar, Altay; Inan, Ozgur

    2012-01-01

    To investigate the effects of different acids and etching times on the bond strength of glass fiber-reinforced composite (FRC) posts to composite core material. Twenty-six FRC posts (FRC Postec Plus) were randomly divided into 13 groups (each n = 2). One group received no surface treatment (control). The posts in the other groups were acid etched with 35% phosphoric acid and 5% and 9.6% hydrofluoric acid gel for four different etching times (30, 60, 120, and 180 seconds). A cylindric polytetrafluoroethylene mold was placed around the treated posts and filled with dual-cure composite core material (MultiCore Flow). All samples were light cured for 60 seconds. After 24 hours of water storage, the specimens were sectioned perpendicularly to the bonded interface under water cooling to obtain 2-mm post-and-core specimens. Eight specimens were made from each group. Push-out tests were performed at a crosshead speed of 0.5 mm/min using a universal testing machine. Data were analyzed by one-way ANOVA followed by the Tukey honestly significant difference test (alpha = .05). The lowest bond strength was observed in the control group (12.51 megapascal [MPa]). No statistical significant difference was observed among group H5-120 (20.31 MPa), group H9-120 (20.55 MPa), or group P-180 (20.57 MPa) (P > .05). These groups demonstrated the highest bond strength values (P posts, all acid-etching procedures tested showed significantly increased bond strength when compared with the control group. Acid-etching with 5% hydrofluoric acid and 9.6% hydrofluoric acid for 2 minutes and with 35% phosphoric acid for 3 minutes (groups H5-120, H9-120, and P-180, respectively) demonstrated the highest bond strength values between the FRC post and composite core material. Although the bond strength was increased by prolonged acid etching, the microstructure of the FRC posts might have been damaged.

  8. Shear bond strength of Biodentine, ProRoot MTA, glass ionomer cement and composite resin on human dentine ex vivo.

    Science.gov (United States)

    Kaup, Markus; Dammann, Christoph Heinrich; Schäfer, Edgar; Dammaschke, Till

    2015-04-19

    The aim of this study was to compare the shear bond strength of Biodentine, ProRoot MTA (MTA), glass ionomer cement (GIC) and composite resin (CR) on dentine. 120 extracted human third molars were embedded in cold-cured-resin and grinned down to the dentine. For each material 30 specimens were produced in standardised height and width and the materials were applied according to manufacturers´ instructions on the dentine samples. Only in the CR group a self-etching dentine-adhesive was used. In all other groups the dentine was not pre-treated. All specimens were stored at 37.5 °C and 100% humidity for 2d, 7d and 14d. With a testing device the shear bond strength was determined (separation of the specimens from the dentine surface). The statistical evaluation was performed using ANOVA and Tukey-test (p Biodentine increased significantly compared to the 2d investigation period (p Biodentine showed a significantly higher shear bond strength than MTA (p Biodentine and GIC was not significant (p > 0.05). After 7d Biodentine showed comparable shear bond values than GIC, whereas the shear bond values for MTA were significantly lower even after 14d. The adhesion of Biodentine to dentine surface seams to be superior compared to that of MTA.

  9. COMPARISON OF SHEAR BOND STRENGTH OF COMPOSITE TO DECIDUOUS TEETH ENAMEL FOLLOWING PHOSPBORIC ACID AND ND:YAG LASER ETCHING

    Directory of Open Access Journals (Sweden)

    M MOUSAVINASAB

    2002-09-01

    Full Text Available Introduction. Enamel acid etching prior to repair dental caries and fractures with composites has been quite satisfactory and economic, however, etching on deciduous dentition has shown less effective due to its resistance to acids. The purpose of this study was to evaluate composite bond strength on decidious teeth treated with laser instead of being acid etched. Methods. Forty four deciduous molars without any restoration or buccal decay were chased and randomly divided in the four groups of 10. Four other teeth were prepared for SEM observation. Group 1: samples were treated with Nd: YA Glaser (20 pps, 1.6 w. Group 2: samples, treated with Nd: YA Glaser (10 pps, 0.8 w. Group 3: samples acid etched with 37% phosphoric acid. Group 4: samples in this group were taken as control with no treatment on enamel. Shear bond strength of the composite and teeth in all 4 groups were then measured with universal tast machine (Dartec.Data were analysed statistically using ANOVA test. Results. The least mean amount of bond strength was related to group 4 (control, which was significantly different from other groups (P < 0.05. The most mean amount was related to group 3 (acid etched with statistically significant difference from other groups (P < 0.05. Among the samples treated with laser, group 1 has greater amount of mean strength comparing to group 2, however this difference was not significant (P > 0.05. Discussion. In order to obtain optimum bond strength for composite restorations, enamel surface should be prepared. Use of Nd: YAG laser for enamel etching under the condition of our study is not recommended on deciduous dentition.

  10. Atomic-Scale Chemical Imaging of Composition and Bonding at Perovskite Oxide Interfaces

    Science.gov (United States)

    Fitting Kourkoutis, L.

    2010-03-01

    Scanning transmission electron microscopy (STEM) in combination with electron energy loss spectroscopy (EELS) has proven to be a powerful technique to study buried perovskite oxide heterointerfaces. With the recent addition of 3^rd order and now 5^th order aberration correction, which provides a factor of 100x increase in signal over an uncorrected system, we are now able to record 2D maps of composition and bonding of oxide interfaces at atomic resolution [1]. Here, we present studies of the microscopic structure of oxide/oxide multilayers and heterostructures by STEM in combination with EELS and its effect on the properties of the film. Using atomic-resolution spectroscopic imaging we show that the degradation of the magnetic and transport properties of La0.7Sr0.3MnO3/SrTiO3 multilayers correlates with atomic intermixing at the interfaces and the presence of extended defects in the La0.7Sr0.3MnO3 layers. When these defects are eliminated, metallic ferromagnetism at room temperature can be stabilized in 5 unit cell thick manganite layers, almost 40% thinner than the previously reported critical thickness of 3-5 nm for sustaining metallic ferromagnetism below Tc in La0.7Sr0.3MnO3 thin films grown on SrTiO3.[4pt] [1] D.A. Muller, L. Fitting Kourkoutis, M. Murfitt, J.H. Song, H.Y. Hwang, J. Silcox, N. Dellby, O.L. Krivanek, Science 319, 1073-1076 (2008).

  11. Adhesive-Bonded Composite Joint Analysis with Delaminated Surface Ply Using Strain-Energy Release Rate

    Science.gov (United States)

    Chadegani, Alireza; Yang, Chihdar; Smeltzer, Stanley S. III

    2012-01-01

    This paper presents an analytical model to determine the strain energy release rate due to an interlaminar crack of the surface ply in adhesively bonded composite joints subjected to axial tension. Single-lap shear-joint standard test specimen geometry with thick bondline is followed for model development. The field equations are formulated by using the first-order shear-deformation theory in laminated plates together with kinematics relations and force equilibrium conditions. The stress distributions for the adherends and adhesive are determined after the appropriate boundary and loading conditions are applied and the equations for the field displacements are solved. The system of second-order differential equations is solved to using the symbolic computation tool Maple 9.52 to provide displacements fields. The equivalent forces at the tip of the prescribed interlaminar crack are obtained based on interlaminar stress distributions. The strain energy release rate of the crack is then determined by using the crack closure method. Finite element analyses using the J integral as well as the crack closure method are performed to verify the developed analytical model. It has been shown that the results using the analytical method correlate well with the results from the finite element analyses. An attempt is made to predict the failure loads of the joints based on limited test data from the literature. The effectiveness of the inclusion of bondline thickness is justified when compared with the results obtained from the previous model in which a thin bondline and uniform adhesive stresses through the bondline thickness are assumed.

  12. Effect of composite surface treatment and aging on the bond strength between a core build-up composite and a luting agent

    Science.gov (United States)

    COTES, Caroline; CARDOSO, Mayra; de MELO, Renata Marques; VALANDRO, Luiz Felipe; BOTTINO, Marco Antonio

    2015-01-01

    Objective The purpose of this study was to assess the influence of conditioning methods and thermocycling on the bond strength between composite core and resin cement. Material and Methods Eighty blocks (8×8×4 mm) were prepared with core build-up composite. The cementation surface was roughened with 120-grit carbide paper and the blocks were thermocycled (5,000 cycles, between 5°C and 55°C, with a 30 s dwell time in each bath). A layer of temporary luting agent was applied. After 24 h, the layer was removed, and the blocks were divided into five groups, according to surface treatment: (NT) No treatment (control); (SP) Grinding with 120-grit carbide paper; (AC) Etching with 37% phosphoric acid; (SC) Sandblasting with 30 mm SiO2 particles, silane application; (AO) Sandblasting with 50 mm Al2O3 particles, silane application. Two composite blocks were cemented to each other (n=8) and sectioned into sticks. Half of the specimens from each block were immediately tested for microtensile bond strength (µTBS), while the other half was subjected to storage for 6 months, thermocycling (12,000 cycles, between 5°C and 55°C, with a dwell time of 30 s in each bath) and µTBS test in a mechanical testing machine. Bond strength data were analyzed by repeated measures two-way ANOVA and Tukey test (α=0.05). Results The µTBS was significantly affected by surface treatment (p=0.007) and thermocycling (p=0.000). Before aging, the SP group presented higher bond strength when compared to NT and AC groups, whereas all the other groups were statistically similar. After aging, all the groups were statistically similar. SP submitted to thermocycling showed lower bond strength than SP without thermocycling. Conclusion Core composites should be roughened with a diamond bur before the luting process. Thermocycling tends to reduce the bond strength between composite and resin cement. PMID:25760269

  13. Effect of composite surface treatment and aging on the bond strength between a core build-up composite and a luting agent

    Directory of Open Access Journals (Sweden)

    Caroline COTES

    2015-02-01

    Full Text Available Objective The purpose of this study was to assess the influence of conditioning methods and thermocycling on the bond strength between composite core and resin cement. Material and Methods Eighty blocks (8×8×4 mm were prepared with core build-up composite. The cementation surface was roughened with 120-grit carbide paper and the blocks were thermocycled (5,000 cycles, between 5°C and 55°C, with a 30 s dwell time in each bath. A layer of temporary luting agent was applied. After 24 h, the layer was removed, and the blocks were divided into five groups, according to surface treatment: (NT No treatment (control; (SP Grinding with 120-grit carbide paper; (AC Etching with 37% phosphoric acid; (SC Sandblasting with 30 mm SiO2 particles, silane application; (AO Sandblasting with 50 mm Al2O3 particles, silane application. Two composite blocks were cemented to each other (n=8 and sectioned into sticks. Half of the specimens from each block were immediately tested for microtensile bond strength (µTBS, while the other half was subjected to storage for 6 months, thermocycling (12,000 cycles, between 5°C and 55°C, with a dwell time of 30 s in each bath and µTBS test in a mechanical testing machine. Bond strength data were analyzed by repeated measures two-way ANOVA and Tukey test (α=0.05. Results The µTBS was significantly affected by surface treatment (p=0.007 and thermocycling (p=0.000. Before aging, the SP group presented higher bond strength when compared to NT and AC groups, whereas all the other groups were statistically similar. After aging, all the groups were statistically similar. SP submitted to thermocycling showed lower bond strength than SP without thermocycling. Conclusion Core composites should be roughened with a diamond bur before the luting process. Thermocycling tends to reduce the bond strength between composite and resin cement.

  14. Model-driven description and validation of composite learning content

    OpenAIRE

    Melia, Mark; Pahl, Claus

    2010-01-01

    Authoring of learning content for courseware systems is a complex activity requiring the combination of a range of design and validation techniques. We introduce the CAVIAr courseware models allowing for learning content description and validation. Model-based representation and analysis of different concerns such as the subject domain, learning context, resources and instructional design used are key contributors to this integrated solution. Personalised learning is particularly difficult to...

  15. Effective application duration of sodium ascorbate antioxidant in reducing microleakage of bonded composite restoration in intracoronally-bleached teeth

    Directory of Open Access Journals (Sweden)

    Jae-Young Park

    2013-02-01

    Full Text Available Objectives The aim of this study was to determine an appropriate application duration of sodium ascorbate (SA antioxidant gel in reducing microleakage of bonded composite restoration in intracoronally-bleached teeth. Materials and Methods Eighty endodontically-treated human incisors were randomly divided into eight groups: control, no bleaching; IB and DB, immediate and delayed bonding after bleaching, respectively; S10m, S60m, S24h, S3d and S7d, bleaching + SA gel for 10 min, 60 min, 24 hr, 3 day and 7 day, respectively. For bleaching, a mixture of 30% hydrogen peroxide and sodium perborate was applied for 7 day. All access cavities were restored using One-Step adhesive (Bisco Inc. and then Aelite LS Packable composite (Bisco Inc.. The bonded specimens were subjected to 500 thermal cycles, immersed in 1% methylene blue for 8 hr, and longitudinally sectioned. Microleakage was assessed with a 0 - 4 scoring system and analyzed using nonparametric statistical methods (α = 0.05. Results Group IB showed a significantly higher microleakge than the control group (p = 0.006 and group DB a statistically similar score to the control group (p > 0.999. Although groups S10m, S60m, and S24h exhibited significantly higher scores than group DB (p 0.999. Conclusions Application of SA gel for 3 day after nonvital bleaching was effective in reducing microleakage of composite restoration in intracoronally-bleached teeth.

  16. Effective application duration of sodium ascorbate antioxidant in reducing microleakage of bonded composite restoration in intracoronally-bleached teeth

    Science.gov (United States)

    Park, Jae-Young; Kwon, Tae-Yub

    2013-01-01

    Objectives The aim of this study was to determine an appropriate application duration of sodium ascorbate (SA) antioxidant gel in reducing microleakage of bonded composite restoration in intracoronally-bleached teeth. Materials and Methods Eighty endodontically-treated human incisors were randomly divided into eight groups: control, no bleaching; IB and DB, immediate and delayed bonding after bleaching, respectively; S10m, S60m, S24h, S3d and S7d, bleaching + SA gel for 10 min, 60 min, 24 hr, 3 day and 7 day, respectively. For bleaching, a mixture of 30% hydrogen peroxide and sodium perborate was applied for 7 day. All access cavities were restored using One-Step adhesive (Bisco Inc.) and then Aelite LS Packable composite (Bisco Inc.). The bonded specimens were subjected to 500 thermal cycles, immersed in 1% methylene blue for 8 hr, and longitudinally sectioned. Microleakage was assessed with a 0 - 4 scoring system and analyzed using nonparametric statistical methods (α = 0.05). Results Group IB showed a significantly higher microleakge than the control group (p = 0.006) and group DB a statistically similar score to the control group (p > 0.999). Although groups S10m, S60m, and S24h exhibited significantly higher scores than group DB (p 0.999). Conclusions Application of SA gel for 3 day after nonvital bleaching was effective in reducing microleakage of composite restoration in intracoronally-bleached teeth. PMID:23493742

  17. Effective application duration of sodium ascorbate antioxidant in reducing microleakage of bonded composite restoration in intracoronally-bleached teeth.

    Science.gov (United States)

    Park, Jae-Young; Kwon, Tae-Yub; Kim, Young-Kyung

    2013-02-01

    The aim of this study was to determine an appropriate application duration of sodium ascorbate (SA) antioxidant gel in reducing microleakage of bonded composite restoration in intracoronally-bleached teeth. Eighty endodontically-treated human incisors were randomly divided into eight groups: control, no bleaching; IB and DB, immediate and delayed bonding after bleaching, respectively; S10m, S60m, S24h, S3d and S7d, bleaching + SA gel for 10 min, 60 min, 24 hr, 3 day and 7 day, respectively. For bleaching, a mixture of 30% hydrogen peroxide and sodium perborate was applied for 7 day. All access cavities were restored using One-Step adhesive (Bisco Inc.) and then Aelite LS Packable composite (Bisco Inc.). The bonded specimens were subjected to 500 thermal cycles, immersed in 1% methylene blue for 8 hr, and longitudinally sectioned. Microleakage was assessed with a 0 - 4 scoring system and analyzed using nonparametric statistical methods (α = 0.05). Group IB showed a significantly higher microleakge than the control group (p = 0.006) and group DB a statistically similar score to the control group (p > 0.999). Although groups S10m, S60m, and S24h exhibited significantly higher scores than group DB (p 0.999). Application of SA gel for 3 day after nonvital bleaching was effective in reducing microleakage of composite restoration in intracoronally-bleached teeth.

  18. In vitro evaluation of repair bond strength of composite: Effect of surface treatments with bur and laser and application of universal adhesive.

    Science.gov (United States)

    Kiomarsi, Nazanin; Espahbodi, Melika; Chiniforush, Nasim; Karazifard, Mohammad Javd; Kamangar, Sedighe Sadat Hashemi

    2017-09-30

    This study aimed to assess the effect of surface treatment by bur and laser and application of universal adhesive on repair bond strength of composite resin. A total of 120 composite blocks measuring 6×4×4 mm were fabricated of Filtek Z250 composite. All samples were subjected to 5,000 thermal cycles and divided into two groups for surface preparation by bur and by Er,Cr:YSGG laser (n = 60). The surfaces were then etched with orthophosphoric acid, rinsed with water and divided into three groups (silane, silane plus Single Bond and silane plus Single Bond Universal). Repair composite was then bonded to aged composite. Half of the samples in each group were stored in distilled water at 37°C for 24 hours and the other half underwent 5000 thermal cycles. All samples were then subjected to shear bond strength testing using a universal testing machine at a crosshead speed of 1 mm/minute. The data were analyzed using one-way ANOVA and Tukey's HSD test. Mode of failure was determined using a stereomicroscope. Bur preparation plus universal adhesive yielded the highest bond strength (30.16 µ 2.26 MPa). Laser plus silane yielded the lowest bond strength (5.63 µ 2.43 MPa). Bur preparation yielded significantly higher bond strength than laser (P composite by bur and application of universal adhesive can improve the repair bond strength of composite. Application of silane (without adhesive) in the process of repair cannot provide adequately high repair bond strength.

  19. Explicit treatment of hydrogen bonds in the universal force field: Validation and application for metal-organic frameworks, hydrates, and host-guest complexes

    Science.gov (United States)

    Coupry, Damien E.; Addicoat, Matthew A.; Heine, Thomas

    2017-10-01

    A straightforward means to include explicit hydrogen bonds within the Universal Force Field (UFF) is presented. Instead of treating hydrogen bonds as non-bonded interaction subjected to electrostatic and Lennard-Jones potentials, we introduce an explicit bond with a negligible bond order, thus maintaining the structural integrity of the H-bonded complexes and avoiding the necessity to assign arbitrary charges to the system. The explicit hydrogen bond changes the coordination number of the acceptor site and the approach is thus most suitable for systems with under-coordinated atoms, such as many metal-organic frameworks; however, it also shows an excellent performance for other systems involving a hydrogen-bonded framework. In particular, it is an excellent means for creating starting structures for molecular dynamics and for investigations employing more sophisticated methods. The approach is validated for the hydrogen bonded complexes in the S22 dataset and then employed for a set of metal-organic frameworks from the Computation-Ready Experimental database and several hydrogen bonded crystals including water ice and clathrates. We show that the direct inclusion of hydrogen bonds reduces the maximum error in predicted cell parameters from 66% to only 14%, and the mean unsigned error is similarly reduced from 14% to only 4%. We posit that with the inclusion of hydrogen bonding, the solvent-mediated breathing of frameworks such as MIL-53 is now accessible to rapid UFF calculations, which will further the aim of rapid computational scanning of metal-organic frameworks while providing better starting points for electronic structure calculations.

  20. Explicit treatment of hydrogen bonds in the universal force field: Validation and application for metal-organic frameworks, hydrates, and host-guest complexes.

    Science.gov (United States)

    Coupry, Damien E; Addicoat, Matthew A; Heine, Thomas

    2017-10-28

    A straightforward means to include explicit hydrogen bonds within the Universal Force Field (UFF) is presented. Instead of treating hydrogen bonds as non-bonded interaction subjected to electrostatic and Lennard-Jones potentials, we introduce an explicit bond with a negligible bond order, thus maintaining the structural integrity of the H-bonded complexes and avoiding the necessity to assign arbitrary charges to the system. The explicit hydrogen bond changes the coordination number of the acceptor site and the approach is thus most suitable for systems with under-coordinated atoms, such as many metal-organic frameworks; however, it also shows an excellent performance for other systems involving a hydrogen-bonded framework. In particular, it is an excellent means for creating starting structures for molecular dynamics and for investigations employing more sophisticated methods. The approach is validated for the hydrogen bonded complexes in the S22 dataset and then employed for a set of metal-organic frameworks from the Computation-Ready Experimental database and several hydrogen bonded crystals including water ice and clathrates. We show that the direct inclusion of hydrogen bonds reduces the maximum error in predicted cell parameters from 66% to only 14%, and the mean unsigned error is similarly reduced from 14% to only 4%. We posit that with the inclusion of hydrogen bonding, the solvent-mediated breathing of frameworks such as MIL-53 is now accessible to rapid UFF calculations, which will further the aim of rapid computational scanning of metal-organic frameworks while providing better starting points for electronic structure calculations.

  1. On-orbit validation system for space structure composite actuators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project delivers an On-orbit Validation System (OVS) that provides performance and durability data for Macro Fiber Composite (MFC) active piezocomposite...

  2. Effect of mucoprotein on the bond strength of resin composite to human dentin.

    Science.gov (United States)

    Pinzon, Lilliam Marie; Powers, John M; O'Keefe, Kathy L; Dusevish, Vladimir; Spencer, Paulette; Marshall, Grayson W

    2011-07-01

    The purpose of this study was to test the bond strength and analyze the morphology of the dentin-adhesive interface of two etch and rinse and two self-etch adhesive systems with two kinds of artificial saliva (with and without 450 mg/L mucin) contamination under different conditions of decontaminating the interface. Bonded specimens were sectioned perpendicularly to the bonded surface in 1-mm thick slabs. These 1-mm thick slabs were remounted in acrylic blocks and sectioned in sticks perpendicular to the bonding interfaces with a 1-mm(2) area. Nine specimens from each condition were tested after 24 h on a testing machine (Instron) at a speed of 0.5 mm/min for a total of 360 specimens. Mean and standard deviations of bond strength (MPa) were calculated. ANOVA showed significant differences as well as Fisher's PLSD intervals (p < 0.05). The following values are the results for different groups: Control group 34-60 MPa, saliva without mucin 0-52 MPa, and saliva with mucin 0-57 MPa. Failure sites were mixed and adhesive failure was common for the low bond strength results. P&BNT with ideal conditions and following the manufacturer's instructions (control) had the highest bond strengths and the dentin-adhesive interface exhibited an ideal morphology of etch-and-rinse system. SEM gave complementary visual evidence of the effect in the dentin/adhesive interface structure with some contaminated conditions compared with their respective control groups. This in vitro artificial saliva model with and without mucin showed that an organic component of saliva could increase or decrease the bond strength depending on the specific bonding agent and decontamination procedure.

  3. Influence of method and period of storage on the microtensile bond strength of indirect composite resin restorations to dentine

    Directory of Open Access Journals (Sweden)

    Fernanda Ribeiro Santana

    2008-12-01

    Full Text Available This study evaluated the influence of the method and period of storage on the adhesive bond strength of indirect composite resin to bovine dentin. Ninety bovine incisors were stored in three different solutions: 0.2% thymol, 10% formalin, and 0.2% sodium azide, during 3 periods of storage: 7 days, 30 days and 6 months, resulting in 9 groups (n = 10. The roots were cut off and the buccal surface was ground with #600-grit silicon carbide paper. The surface was conditioned with 37% phosphoric acid for 15 s and a composite resin restoration (TPH Spectrum was fixed using a one-bottle adhesive system (Adper Single Bond and a dual-cured resinous cement (Rely X ARC under a load of 500 g for 5 minutes. The samples were serially cut perpendicular to the bonded interface to obtain slices of 1.2 mm in thickness. Each slab was trimmed with a cylindrical diamond bur resulting in an hourglass shape with a cross-sectional area of approximately 1 mm². The microtensile bond strength (μTBS testing was performed in a testing machine (EMIC 2000 DL at a 0.5 mm/minute crosshead-speed until failure. After fracture, the specimens were examined under SEM to analyze the mode of fracture. μTBS Means were expressed in MPa and the data were analyzed by two-way ANOVA (3X3 and the Tukey test (α = 0.05. The storage times of 7 and 30 days produced no significant difference irrespective of the solution type. The formalin and thymol solutions, however, did have a negative influence on bond strength when the teeth were stored for 6 months.

  4. Effect of Storage Media and Sterilization Method on Shear Bond Strength of Composite to Enamel of Extracted Teeth

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    Alireza Boruziniat

    2017-09-01

    Full Text Available Aim: To evaluate the effect of storage media and autoclaving on shear bond strength of composite to enamel. Materials and Methods: 100 human premolars were randomly divided into ten groups of ten as follows: C: freshly extracted teeth. A: Autoclaved freshly extracted teeth. CH-6: 6 month storage in 0.5 % chloramine T. CA-6: 6 month storage in 0.5 % chloramine T + autoclaving. T-6: 6 month storage in 0.04 % thymol. TA-6: 6 month storage in 0.4% thymol + autoclaving. Ch-12:12 month storage in 0.5 % chloramine T. CA-12: 12 month storage in 0.5 % chloramine T + autoclaving. T-12: 12 month storage in 0.4% thymol. TA-12:12 month storage in 0.4% thymol + autoclaving. One composite cylinder was bonded on each specimen for evaluation of shear bond strength (SBS and failure modes. Data were analyzed using three-way ANOVA, Tukey’s post hoc and Chi square tests and the level of significance was set  at P= 0.05. Results: Autoclaving and storage media had no significant effect on SBS (P-value = 0.818 for storage media and P-value = 0.221 for autoclaving. However, storage duration significantly changed SBS (P-value = 0.00. There were no correlations among the variables (P-value > 0.05. Storage media and duration had no significant effect on failure modes (P-value > 0.05, but autoclaving significantly increased cohesive failure of enamel (P-value =0.039. Conclusion: Storage of teeth in chloramine T and thymol had no significant effect on bond strength to enamel. Although autoclaving of specimens may not alter bond strength, it can significantly increase the cohesive failure of enamel.

  5. Effect of viscosity of dual-cure luting resin composite core materials on bond strength to fiber posts with various surface treatments

    Directory of Open Access Journals (Sweden)

    Juthatip Aksornmuang

    2014-12-01

    Conclusion: Bond strengths between luting resin composites and fiber posts were affected by post surface treatments, depending on the resin composite used. Application of a low-viscosity adhesive resin to the post surface seemed to be beneficial for a high-viscosity luting resin composite.

  6. Assessing attachment: convergent validity of the adult attachment interview and the parental bonding instrument.

    Science.gov (United States)

    Manassis, K; Owens, M; Adam, K S; West, M; Sheldon-Keller, A E

    1999-08-01

    The aim of this study was to determine whether or not the Parental Bonding Instrument (PBI) can provide information about parent-child attachment that is comparable to information obtained from the Adult Attachment Interview (AAI), a more complex measure of attachment. One hundred and thirty emotionally and/or behaviourally disturbed adolescents (73 male, 57 female; ages 13-19 years, x = 15.3 +/- 1.47 years) participating in a study of attachment and suicidality completed the PBI and the AAI. Data from these measures were compared within participants. Maternal care and overprotection on the PBI differed significantly by AAI attachment classification (F3,122 = 2.79, p = 0.012), with autonomous participants showing the most optimal and unresolved participants the least optimal PBI results. Maternal love and maternal involvement/role reversal on the AAI were significant predictors of maternal care and maternal overprotection, respectively, on the PBI (R2 = 0.15; R2 = 0.16). These predictions improved when AAI scales measuring idealisation and involving anger towards the mother were included in the regression analyses (R2 = 0.35; R2 = 0.20). Autonomous participants on AAI showed the highest scale correlations across instruments. Attachment information obtained from the PBI and the AAI is comparable in participants with optimal attachment histories, but not in participants showing idealisation or anger towards their mothers. Caution is, therefore, advisable when using the PBI to obtain attachment information in clinical samples where suboptimal attachment histories are likely.

  7. Repair of amalgam restorations with composite resin and bonded amalgam: A microleakage study

    Directory of Open Access Journals (Sweden)

    Daniela Araújo Veloso Popoff

    2011-01-01

    Conclusions: The use of adhesive systems significantly affected the ability to seal the repair/ tooth interface. However, at the level of the repair/restoration interface, the bonded amalgam technique may increase microleakage.

  8. VALIDITY OF SINGLE VARIABLES AND COMPOSITE INDEXES FOR MEASURING DISEASE-ACTIVITY IN RHEUMATOID-ARTHRITIS

    NARCIS (Netherlands)

    VANDERHEIJDE, DMFM; VANTHOF, MA; VANRIEL, PLCM; VANLEEUWEN, MA; VANRIJSWIJK, MH; VANDEPUTTE, LBA

    There is no agreement as to which variable best mirrors disease activity in rheumatoid arthritis (RA) and no studies have been performed on the validity of disease activity variables. In this study the validity of 10 commonly used single variables and three composite indices was tested. All patients

  9. Effect of Desensitization Using Bioactive Glass, Hydroxyapatite, and Diode Laser on the Shear Bond Strength of Resin Composites Measured at Different Time Intervals: An In vitro Study.

    Science.gov (United States)

    Gupta, Timsi; Nagaraja, Shruthi; Mathew, Sylvia; Narayana, Indiresha H; Madhu, K S; Dinesh, K

    2017-01-01

    Dentin desensitizers may change the properties of smear layer and have adverse effects on the bonding performance of adhesive systems. The aim of this study was to compare the effect of bioactive glass (BG), hydroxyapatite, and diode laser desensitization on shear bond strength of resin composites to dentin at different time intervals. Seventy-two caries-free maxillary premolars were selected. Buccal surfaces were flattened to expose dentin. Teeth were divided into four groups (Groups 1, 2, 3, and 4) according to treatment modality (control with no pretreatment, Sensodyne Repair and Protect, Teethmate Desensitizer, diode laser). Bonding was performed using self-etch adhesive followed by composite buildup. Universal testing machine was used to determine shear bond strengths immediately after bonding, after 3 months, and 5 months storage in artificial saliva. Pretreatment with BG and hydroxyapatite desensitizers increased, whereas diode laser decreased mean shear bond strength of composite to dentin as compared to control group. No statistical significant difference in shear bond strength values was seen in groups after storage. Desensitizing toothpastes incorporating remineralizing agents not only occluded open dentinal tubules but also increased shear bond strength of composite to dentin.

  10. Effect of desensitization using bioactive glass, hydroxyapatite, and diode laser on the shear bond strength of resin composites measured at different time intervals: An In vitro Study

    Directory of Open Access Journals (Sweden)

    Timsi Gupta

    2017-01-01

    Full Text Available Background: Dentin desensitizers may change the properties of smear layer and have adverse effects on the bonding performance of adhesive systems. Aim: The aim of this study was to compare the effect of bioactive glass (BG, hydroxyapatite, and diode laser desensitization on shear bond strength of resin composites to dentin at different time intervals. Materials and Methods: Seventy-two caries-free maxillary premolars were selected. Buccal surfaces were flattened to expose dentin. Teeth were divided into four groups (Groups 1, 2, 3, and 4 according to treatment modality (control with no pretreatment, Sensodyne Repair and Protect, Teethmate Desensitizer, diode laser. Bonding was performed using self-etch adhesive followed by composite buildup. Universal testing machine was used to determine shear bond strengths immediately after bonding, after 3 months, and 5 months storage in artificial saliva. Results: Pretreatment with BG and hydroxyapatite desensitizers increased, whereas diode laser decreased mean shear bond strength of composite to dentin as compared to control group. No statistical significant difference in shear bond strength values was seen in groups after storage. Conclusion: Desensitizing toothpastes incorporating remineralizing agents not only occluded open dentinal tubules but also increased shear bond strength of composite to dentin.

  11. Reliability and validity for measurement of body composition: A field ...

    African Journals Online (AJOL)

    Because all three instruments can estimate the percentage of body fat, but it is important to identify the most appropriate instruments and have high reliability. Hence, this study was conducted to determine the reliability and convergent validity of the instruments. A total of 40 students, males and females aged between 13 ...

  12. Comparative evaluation of effects of different surface treatment methods on bond strength between fiber post and composite core.

    Science.gov (United States)

    Mosharraf, Ramin; Baghaei Yazdi, Najmeh

    2012-05-01

    Debonding of a composite resin core of the fiber post often occurs at the interface between these two materials. The aim of this study was to evaluate the effects of different surface treatment methods on bond strength between fiber posts and composite core. Sixty-four fiber posts were picked in two groups (Hetco and Exacto). Each group was further divided into four subgroups using different surface treatments: 1) silanization; 2) sandblasting; 3) Treatment with 24% H(2)O(2), and 4) no treatment (control group). A cylindrical plexiglass matrix was placed around the post and filled with the core resin composite. Specimens were stored in 5000 thermal cycles between 5℃ and 55℃. Tensile bond strength (TBS) test and evaluation using stereomicroscope were performed on the specimen and the data were analyzed using two-way ANOVA, Post Hoc Scheffe tests and Fisher's Exact Test (α=.05). There was a significant difference between the effect of different surface treatments on TBS (Pstrength of fiber posts to composite resin core, but there were not any significant differences between these groups and control group. There was not any significant difference between two brands of fiber posts that had been used in this study. Although silanization and sandblasting can improve the TBS, there was not any significant differences between surface treatments used.

  13. Effect of different adhesives combined with two resin composite cements on shear bond strength to polymeric CAD/CAM materials.

    Science.gov (United States)

    Bähr, Nora; Keul, Christine; Edelhoff, Daniel; Eichberger, Marlis; Roos, Malgorzata; Gernet, Wolfgang; Stawarczyk, Bogna

    2013-01-01

    This study tested the impact of different adhesives and resin composite cements on shear bond strength (SBS) to polymethyl methacrylate (PMMA)- and composite-based CAD/CAM materials. SBS specimens were fabricated and divided into five main groups (n=30/group) subject to conditioning: 1. Monobond Plus/Heliobond (MH), 2. Visio.link (VL), 3. Ambarino P60 (AM), 4. exp. VP connect (VP), and 5. no conditioning-control group (CG). All cemented specimens using a. Clearfil SA Cement and b. Variolink II were stored in distilled water for 24 h at 37 °C. Additionally, one half of the specimens were thermocycled for 5,000 cycles (5 °C/55 °C, dwell time 20 s). SBS was measured; data were analyzed using descriptive statistics, four- and one-way ANOVA, unpaired two-sample t-test and Chi(2)-test. CAD/CAM materials without additional adhesives showed no bond to resin composite cements. Highest SBS showed VL with Variolink II on composite-based material, before and after thermocycling.

  14. Microstructure, Tensile Adhesion Strength and Thermal Shock Resistance of TBCs with Different Flame-Sprayed Bond Coat Materials Onto BMI Polyimide Matrix Composite

    Science.gov (United States)

    Abedi, H. R.; Salehi, M.; Shafyei, A.

    2017-10-01

    In this study, thermal barrier coatings (TBCs) composed of different bond coats (Zn, Al, Cu-8Al and Cu-6Sn) with mullite top coats were flame-sprayed and air-plasma-sprayed, respectively, onto bismaleimide matrix composites. These polyimide matrix composites are of interest to replace PMR-15, due to concerns about the toxicity of the MDA monomer from which PMR-15 is made. The results showed that pores and cracks appeared at the bond coat/substrate interface for the Al-bonded TBC because of its high thermal conductivity and diffusivity resulting in transferring of high heat flux and temperature to the polymeric substrate during top coat deposition. The other TBC systems due to the lower conductivity and diffusivity of bonding layers could decrease the adverse thermal effect on the polymer substrate during top coat deposition and exhibited adhesive bond coat/substrate interfaces. The tensile adhesion test showed that the adhesion strength of the coatings to the substrate is inversely proportional to the level of residual stress in the coatings. However, the adhesion strength of Al bond-coated sample decreased strongly after mullite top coat deposition due to thermal damage at the bond coat/substrate interface. TBC system with the Cu-6Sn bond coat exhibited the best thermal shock resistance, while Al-bonded TBC showed the lowest. It was inferred that thermal mismatch stresses and oxidation of the bond coats were the main factors causing failure in the thermal shock test.

  15. Modeling of fracture and durability of paste-bonded composite joints subjected to hygro-thermal-mechanical loading

    Science.gov (United States)

    Harris, David Lee

    The objective of the research is to characterize the behavior of composite/composite joints with paste adhesive using both experimental testing and analytical modeling. In comparison with the conventional tape adhesive, joining composites using paste adhesive provides several advantages. The carbon fiber laminate material systems employed in this study included IM7 carbon fibers and 977-3 epoxy matrix assembled in prepreg tape, and AS4 carbon fibers and 977-3 epoxy matrix as a five-harness satin weave. The adhesive employed was EA 9394 epoxy. All laminates and test specimens were fabricated and inspected by Boeing using their standard propriety procedures. Three types of test specimens were used in the program. They were bonded double-lap shear (DLS), bonded double cantilever beam (DCB) and bonded interlaminar tension (ILT) specimens. A group of specimens were conditioned at elevated temperature and humidity in an environmental chamber at Boeing's facility and their moisture absorption recorded with time. Specimens were tested at room temperature dry and elevated temperatures. DCB and DLS specimens were tested in fatigue as well as static conditions. Two-dimensional finite element models of the three configurations were developed for determining stresses and strains using the ABAQUS finite element package code. Due to symmetry, only the one-half of the specimen needed to be considered thus reducing computational time. The effect of the test fixture is not taken into account instead equivalent distributed stresses are applied directly on the composite laminates. For each of the specimen, the distribution of Mises stress and the first strain invariant J1 are obtained to identify potential failure locations within a specimen.

  16. Microleakage and shear punch bond strength in class II primary molars cavities restored with low shrink silorane based versus methacrylate based composite using three different techniques.

    Science.gov (United States)

    Fahmy, Amal Ezzeldin; Farrag, Nadia Moustafa

    2010-01-01

    This in vitro study aimed to evaluate the gingival microleakage in class II cavities in primary molars restored with a low shrink silorane resin composite (Filtek P90) or a nanohybride composite resin (Filtek supreme XT) using three different techniques, (total bonding, closed or open sandwich techniques) lined by nano-filled resin modified glass ionomer cement RMGIC (Ketac N100). Additionally, the shear punch bond strength between the two types of composite and KNIO0 was also examined. For microleakage test, two standardized class II slot cavities were prepared in proximal surfaces of 60 sound extracted primary molars which were divided into 2 groups of 30 each according to the type of composite. Each group was subdivided into 3 groups (n = 10) according to the restorative technique used. The restored teeth were examined for microleakage after immersion in 2% methylene blue dye using stereomicroscope at 20 X. Microleakage scores among the groups were compared using Kruskal Wallis test followed by pair wise Mann Whitney U test at P < or = 0.05. Thirty disc specimens were prepared for determining the shear punch bond strength between the two composite materials and the KN100. Specimens were divided into 5 groups (n = 6) according to the adhesive protocol. The differences in mean bond strength values in MPa between groups were statistically analyzed using ANOVA followed by pair wise Tukey Post hoc test at P < or = 0. 05. Mode of failure was also evaluated for all groups. Both the silorane resin and nano-composite resin showed superior marginal seal with the total bonding technique compared to closed and open sandwich techniques. The recorded mean shear punch bond strength values showed no statistical significant difference between the two resin composites without or with their adhesive bonding systems when bonded to the nano-ionomer. All specimens showed cohesive mode of failures except for silorane resin with Adper Easy Bond Self Etch Adhesive (AEBSEA) which showed

  17. Validation of Predicted Precipitate Compositions in Al-Si-Ge

    Energy Technology Data Exchange (ETDEWEB)

    Dracup, B; Turchi, P A; Radmilovic, V; Dahmen, U; Morris, Jr., J W

    2004-04-21

    Aged alloys of Al-0.5Si-0.5Ge (at.%) contain diamond cubic (A4) precipitates in a dispersion that is much finer than is found in alloys with Si or Ge alone. To help understand this aging behavior, the present work was undertaken to determine alloy composition as a function of aging temperature. The composition was estimated theoretically using a CALPHAD approach, and measured experimentally with energy dispersive spectroscopy (EDS) in a high-resolution electron microscope. Theory and experiment are in reasonable agreement. As the aging temperature rises, the precipitates become enriched in Si, changing from 50 at. % in the low-temperature limit to about 80 at.% Si as temperature approaches 433 C, the high-temperature limit of the precipitate field.

  18. Uncovering and Validating Toughening Mechanisms in High Performance Composites

    Science.gov (United States)

    2015-09-17

    start [Patek, S.N., Korff, W.L. & Caldwell, R.L. Biomechanics : Deadly strike mechanism of a mantis shrimp - This shrimp packs a punch powerful enough to...also be applied to man-made composites. Possible applications are found in helmets for sports and military protection. Since the duration of the...Biomaterials, Biomechanics and Regenerative Medicine, RutaN, Medellin, Colombia, May 16, 2014. "Numerical Investigation of Naturally-Occurring High

  19. Effect of aging conditions on the repair bond strength of a microhybrid and a nanohybrid resin composite.

    Science.gov (United States)

    Ozcan, Mutlu; Cura, Cenk; Brendeke, Johannes

    2010-12-01

    this study evaluated the effect of different aging methods on the repair bond strength and failure types of a microhybrid and a nanohybrid composite. disk-shaped microhybrid (Quadrant Anterior Shine-QA) and nanohybrid (Tetric EvoCeram-TE) resin composite specimens (N = 192, n = 12/per group) were photopolymerized and randomly assigned to one of the three aging conditions: (1) immersion in deionized water (37°C, 2 months), (2) thermocycling (5000 times, 5 to 55 °C), (3) immersion in citric acid (pH: 3.0; 1 week). The control group was stored dry for 24 h at 37°C. After aging procedures, the specimens were silica coated (30 microm SiO2) (CoJet-Sand) using an intraoral air abrasion device, silanized (ESPESil) and an intermediate adhesive resin was applied (Visio-Bond, 3M ESPE). Resin composites, once of the same kind as the substrate (QA-QA, TE-TE) and once other than the substrate material (QA-TE, TE-QA) were adhered onto the conditioned substrates. Shear force was applied to the adhesive interface in a universal testing machine (cross-head speed: 1 mm/min). a significant influence of the aging method was observed (p 0.05) (chi-square). Citric acid aging yielded significantly less incidence of score A (8-75%) compared to the control group in all composite combinations (p < 0.05). both microhybrid and nanohybrid composites could be used either as a substrate or as relayering composites in early repairs. Aging factors may diminish the repair quality.

  20. Effectively Exerting the Reinforcement of Dopamine Reduced Graphene Oxide on Epoxy-Based Composites via Strengthened Interfacial Bonding.

    Science.gov (United States)

    Li, Wenbin; Shang, Tinghua; Yang, Wengang; Yang, Huichuan; Lin, Song; Jia, Xiaolong; Cai, Qing; Yang, Xiaoping

    2016-05-25

    The effects of dopamine reduced graphene oxide (pDop-rGO) on the curing activity and mechanical properties of epoxy-based composites were evaluated. Taking advantage of self-polymerization of mussel-inspired dopamine, pDop-rGO was prepared through simultaneous functionalization and reduction of graphene oxide (GO) via polydopamine coating. Benefiting from the universal binding ability of polydopamine, good dispersion of pDop-rGO in epoxy matrix was able to be achieved as the content of pDop-rGO being below 0.2 wt %. Curing kinetics of epoxy composites with pDop-rGO were systematically studied by nonisothermal differential scanning calorimetry (DSC). Compared to the systems of neat epoxy or epoxy composites containing GO, epoxy composites loaded with pDop-rGO showed lower activation energy (Eα) over the range of cure (α). It revealed that the amino-bearing pDop-rGO was able to react with epoxy matrix and enhance the curing reactions as an amine-type curing agent. The nature of the interactions at GO-epoxy interface was further evaluated by Raman spectroscopy, confirming the occurrence of chemical bonding. The strengthened interfacial adhesion between pDop-rGO and epoxy matrix thus enhanced the effective stress transfer in the composites. Accordingly, the tensile and flexural properties of EP/pDop-rGO composites were enhanced due to both the well dispersion and strong interfacial bonding of pDop-rGO in epoxy matrix.

  1. Effectiveness of silica-lasing method on the bond strength of composite resin repair to Ni-Cr alloy.

    Science.gov (United States)

    Madani, Azam S; Astaneh, Pedram Ansari; Nakhaei, Mohammadreza; Bagheri, Hossein G; Moosavi, Horieh; Alavi, Samin; Najjaran, Niloufar Tayarani

    2015-04-01

    The aim of this study was to evaluate the effectiveness of silica-lasing method for improving the composite resin repair of metal ceramic restorations. Sixty Ni-Cr cylindrical specimens were fabricated. The bonding surface of all specimens was airborne-particle abraded using 50 μm aluminum oxide particles. Specimens were divided into six groups that received the following surface treatments: group 1-airborne-particle abrasion alone (AA); group 2-Nd:YAG laser irradiation (LA); group 3-silica coating (Si-CO); group 4-silica-lasing (metal surface was coated with slurry of opaque porcelain and irradiated by Nd:YAG laser) (Si-LA); group 5-silica-lasing plus etching with HF acid (Si-LA-HF); group 6-CoJet sand lased (CJ-LA). Composite resin was applied on metal surfaces. Specimens were thermocycled and tested in shear mode in a universal testing machine. The shear bond strength values were analyzed using ANOVA and Tukey's tests (α = 0.05). The mode of failure was determined, and two specimens in each group were examined by scanning electron microscopy and wavelength dispersive X-ray spectroscopy. Si-CO showed significantly higher shear bond strength in comparison to other groups (p 0.05). The failure mode was 100% adhesive for AA, Si-LA, Si-LA-HF, and CJ-LA. LA and Si-CO groups showed 37.5% and 87.5% cohesive failure, respectively. Silica coating of Ni-Cr alloy resulted in higher shear bond strength than those of other surface treatments. © 2014 by the American College of Prosthodontists.

  2. Development and validation of nondestructive inspection techniques for composite doubler repairs on commercial aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Roach, D.; Walkington, P.

    1998-05-01

    Composite doublers, or repair patches, provide an innovative repair technique which can enhance the way aircraft are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is possible to bond a single boron-epoxy composite doubler to the damaged structure. In order for the use of composite doublers to achieve widespread use in the civil aviation industry, it is imperative that methods be developed which can quickly and reliably assess the integrity of the doubler. In this study, a specific composite application was chosen on an L-1011 aircraft in order to focus the tasks on application and operation issues. Primary among inspection requirements for these doublers is the identification of disbonds, between the composite laminate and aluminum parent material, and delaminations in the composite laminate. Surveillance of cracks or corrosion in the parent aluminum material beneath the doubler is also a concern. No single nondestructive inspection (NDI) method can inspect for every flaw type, therefore it is important to be aware of available NDI techniques and to properly address their capabilities and limitations. A series of NDI tests were conducted on laboratory test structures and on full-scale aircraft fuselage sections. Specific challenges, unique to bonded composite doubler applications, were highlighted. An array of conventional and advanced NDI techniques were evaluated. Flaw detection sensitivity studies were conducted on applicable eddy current, ultrasonic, X-ray and thermography based devices. The application of these NDI techniques to composite doublers and the results from test specimens, which were loaded to provide a changing flaw profile, are presented in this report. It was found that a team of these techniques can identify flaws in composite doubler installations well before they reach critical size.

  3. Effect of different surface treatments on microtensile bond strength of two resin cements to aged simulated composite core materials.

    Science.gov (United States)

    Esmaeili, Behnaz; Alaghehmand, Homayoon; Shakerian, Mohadese

    2015-01-01

    Roughening of the aged composite resin core (CRC) surface seems essential for durable adhesion. The aim of this study was to investigate the influence of various surface treatments and different resin cements on microtensile bond strength (µ TBS) between two aged core build-up composites (CBCs) and feldspathic ceramic. A total of 16 composite blocks made of two CBCs, Core.it and Build-it were randomly assigned to four surface treatment groups after water storage and thermocycling (2 weeks and 500 cycles). Experimental groups included surface roughening with air abrasion (AA), hydrofluoric acid, pumice, and laser and then were bonded to computer-aided design/computer-aided manufacturing feldspathic ceramic blocks using two resin cements, Panavia F2 (PF), and Duo-link (DL). The µ TBS was tested, and the fracture mode was assessed. The data were analyzed with multiple analysis of variance to estimate the contribution of different surface treatments, resin cements, and two aged CRCs on µ TBS. Statistical significance level was set at α strength (P strength was in AA group cemented with PF (31.83 MPa). The most common failure mode was cohesive fracture in the cement. Different surface treatments had different effects on µ TBS of aged CRCs to feldspathic ceramics. PF was significantly better than DL.

  4. Microstructure, mechanical properties and texture of an AA6061/AA5754 composite fabricated by cross accumulative roll bonding

    Energy Technology Data Exchange (ETDEWEB)

    Verstraete, K., E-mail: kevin.verstraete@u-psud.fr [Université Paris-Sud, SP2M, ICMMO, UMR CNRS 8182, 91405 Orsay Cedex (France); Helbert, A.L. [Université Paris-Sud, SP2M, ICMMO, UMR CNRS 8182, 91405 Orsay Cedex (France); Brisset, F. [Université Paris-Sud, ICMMO, UMR CNRS 8182, 91405 Orsay Cedex (France); Benoit, A.; Paillard, P. [Institut des Matériaux Jean Rouxel (IMN), UMR 6502, Polytech’Nantes, Nantes Cedex (France); Baudin, T. [Université Paris-Sud, SP2M, ICMMO, UMR CNRS 8182, 91405 Orsay Cedex (France)

    2015-07-29

    AA6061 alloy is a widely used material in the automotive and aerospace industries, but is prone to hot cracking, which limits its weldability. To prevent this phenomenon, the AA6061/AA5754 composite was formed using a severe plastic deformation technique, Cross Accumulative Roll Bonding (CARB), at an elevated temperature (350 °C) to ensure good bonding between layers. This technique was efficient to maintain a small grain size, even under the process temperature conditions, and consequently, preserve good mechanical properties. The composite had better mechanical properties than the initial aluminium alloys. Microstructure and texture remained stable after two cycles and yield stress tended towards an equal value in the rolling and the transverse directions. After two cycles, the main component was the {001}〈110〉 rotated Cube, which was maintained for up to 10 cycles. Diffusion was more effective as the strain increased. Finally, a tungsten inert gas (TIG) welding process was performed on the composite and confirmed resistance to hot cracking.

  5. Validation of air displacement plethysmography for assessing body composition.

    Science.gov (United States)

    Wagner, D R; Heyward, V H; Gibson, A L

    2000-07-01

    The purpose of this study was to verify the validity of an air displacement plethysmography device (Bod Pod) for estimating body density (Db). The Db from the Bod Pod (DbBP) was compared with the Db from hydrostatic weighing (DbHW) at residual lung volume in a heterogeneous sample of 30 black men who varied in age (32.0 +/- 7.7 yr), height (180.3 +/- 7.5 cm), body mass (84.2 +/- 15.0 kg), body fatness (16.1 +/- 7.5%), and self-reported physical activity level and socioeconomic status. The Db for each method was converted to relative body fat (%BF) using race-specific conversion formulas and subsequently compared with %BF obtained from dual-energy x-ray absorptiometry (%BFDXA). Linear regression, using DbHW as the dependent variable and DbBP as the predictor, produced an R2 = 0.84 and SEE = 0.00721 g x cc(-1). However, the mean difference between the two methods (0.00450 +/- 0.00718 g x cc(-1) was significant (P Bod Pod underestimated the Db of 73% of the sample. The %BF estimates from the Bod Pod, HW, and DXA differed significantly (P Bod Pod significantly and systematically underestimated Db, resulting in an overestimation of %BF. More cross-validation research is needed before recommending the Bod Pod as a reference method.

  6. Effect of Addition of Curcumin Nanoparticles on Antimicrobial Property and Shear Bond Strength of Orthodontic Composite to Bovine Enamel

    Directory of Open Access Journals (Sweden)

    Pedram Baghaeian

    2016-12-01

    Full Text Available Objectives: This study sought to assess the effect of curcumin nanoparticles (curcNPs on antimicrobial property and shear bond strength (SBS of orthodontic composite to bovine enamel.Materials and Methods: In this in vitro, experimental study, 1%, 5% and 10% curcNPs were added to Transbond XT composite. Stainless steel brackets were bonded to 48 sound bovine incisors in four groups (n=12 using composite containing 0% (control, 1%, 5% and 10% curcNPs. The bracket-tooth SBS was measured by a universal testing machine. The adhesive remnant index (ARI score was calculated after debonding using a stereomicroscope. Also, 180 discs were fabricated of the four composites; 108 were subjected to eluted component test, 36 were used for disc diffusion test and 36 were used for biofilm test to assess their antimicrobial activity against Streptococcus mutans, Streptococcus sanguinis and Lactobacillus acidophilus.Results: The highest and lowest SBS belonged to control and 10% curcNP groups, respectively. The difference in SBS was significant among the four groups (P=0.008. The SBS of control group was significantly higher than that of 10% curcNPs (P=0.006. The four groups were not significantly different in terms of ARI score (P>0.05. Growth inhibition zones were not seen in any group. In biofilm test, the colony counts of all bacteria significantly decreased by an increase in percentage of curcNPs. Colony count significantly decreased only at 30 days.Conclusions: At 1% concentration, curcNPs have significant antimicrobial activity against cariogenic bacteria with no adverse effect on SBS. However, insolubility of curcNPs remains a major drawback.Keywords: Curcumin; Nanoparticles; Shear Strength; Composite Resins; Orthodontic Brackets; Anti-Bacterial Agents

  7. Shear bond strength of acidic primer, light-cure glass ionomer, light-cure and self cure composite adhesive systems - an in vitro study.

    Science.gov (United States)

    D, Krishnakanth Reddy; V, Kishore M S; Safeena, Safeena

    2013-06-01

    The purpose of this study was to determine shear bond strength and the effect on the bracket/ adhesive failure mode when an acidic primer and other etchants were used to condition the enamel surface before bonding. Group I: Brackets bonded with Ultimate cure-on-light Light-cure composite adhesive system. Group II: Brackets bonded with Ortho-one no-mix. Self-cure composite adhesive system. Group III: Brackets bonded with Light-cure glass ionomer adhesive system. Group IV: Brackets bonded with Transbond plus self etching primer. The results of this study indicated that the shear bond strength when using Transbond plus self etching primer showed the highest bond strength Group- IV(8.69 2.54 MPa) followed by Ultimate cure-on-light Group-I (8.62 1.84 MPa), Ortho-one no-mix (Bisco Inc. USA)Group-II (8.07 1.72 MPa), and least bond strength was seen in G.C. Fuji Ortho L.C. Group-III (6.01 1.6) MPa Conclusion: Use of self etching primer saves chairside time and satisfactory high bond strength was obtained. Care should be taken during debonding of ceramic brackets How to cite this article: Reddy K D, Kishore M S V, Safeena S. Shear Bond Strength of Acidic Primer, Light-Cure Glass Ionomer, Light-Cure and Self Cure Composite Adhesive Systems - An In Vitro Study. J Int Oral Health 2013; 5(3):73-78.

  8. Anomalously Strong Effect of the Ion Sign on the Thermochemistry of Hydrogen Bonded Aqueous Clusters of Identical Chemical Composition

    Directory of Open Access Journals (Sweden)

    Alexey B. Nadykto

    2009-02-01

    Full Text Available The sign preference of hydrogen bonded aqueous ionic clusters Χ±(H2Oi (n =1-5, Χ = F; Cl; Br has been investigated using the Density Functional Theory and ab initio MP2 method. The present study indicates the anomalously large difference in formation free energies between cations and anions of identical chemical composition. The effect of vibrational anharmonicity on stepwise Gibbs free energy changes has been investigated, and possible uncertainties associated with the harmonic treatment of vibrational spectra have been discussed.

  9. Repair bond strength of a resin composite to alumina-reinforced feldspathic ceramic

    NARCIS (Netherlands)

    Goia, Tamiye Simone; Pereira Leite, Fabiola Pessoa; Valandro, Luiz Felipe; Oezcan, Mutlu; Bottino, Marco Antonio

    2006-01-01

    This study compared the microtensile bond strength of a repair resin to an alumina-reinforced feldspathic ceramic (Vitadur-alpha, Vita) after 3 surface conditioning methods: Group 1, etching with 9.6% hydrofluoric acid for 1 minute plus rinsing and drying, followed by application of silane for 5

  10. Effects of two erbium-doped yttrium aluminum garnet lasers and conventional treatments as composite surface abrasives on the shear bond strength of metal brackets bonded to composite resins

    Science.gov (United States)

    Sobouti, Farhad; Dadgar, Sepideh; Sanikhaatam, Zahra; Nateghian, Nazanin; Saravi, Mahdi Gholamrezaei

    2016-01-01

    Background: Bonding brackets to dental surfaces restored with composites are increasing. No studies to date have assessed the efficacy of laser irradiation in roughening of composite and the resulted shear bond strength (SBS) of the bonded bracket. We assessed, for the 1st time, the efficacy of two laser beams compared with conventional methods. Materials and Methods: Sixty-five discs of light-cured composite resin were stored in deionized distilled water for 7 days. They were divided into five groups of 12 plus a group of five for scanning electron microscopy (SEM): Bur-abrasion followed by phosphoric acid etching (bur-PA), hydrofluoric acid conditioning (HF), sandblasting, 3 W and 2 W erbium-doped yttrium aluminum garnet laser irradiation for 12 s. After bracket bonding, specimens were water-stored (24 h) and thermocycled (500 cycles), respectively. SBS was tested at 0.5 mm/min crosshead speed. The adhesive remnant index (ARI) was scored under ×10 magnification. SEM was carried out as well. Data were analyzed using analysis of variance (ANOVA), Kruskal–Wallis, Tukey, Dunn, one-sample t-test/Wilcoxon tests, and Weibull analysis (α =0.05). Results: The SBS values (megapascal) were bur-PA (11.07 ± 1.95), HF (19.70 ± 1.91), sandblasting (7.75 ± 1.10), laser 2 W (15.38 ± 1.38), and laser 3 W (20.74 ± 1.73) (compared to SBS = 6, all P = 0.000). These differed significantly (ANOVA P = 0.000) except HF versus 3 W laser (Tukey P > 0.05). ARI scores differed significantly (Kruskal–Wallis P = 0.000), with sandblasting and 2 W lasers having scores inclined to the higher end (safest debonding). Weibull analysis implied successful clinical outcome for all groups, except for sandblasting with borderline results. Conclusion: Considering its high efficacy and the lack of adverse effects bound with other methods, the 3 W laser irradiation is recommended for clinical usage. PMID:26998473

  11. Shear bond strength of veneering porcelain to zirconia: Effect of surface treatment by CNC-milling and composite layer deposition on zirconia.

    Science.gov (United States)

    Santos, R L P; Silva, F S; Nascimento, R M; Souza, J C M; Motta, F V; Carvalho, O; Henriques, B

    2016-07-01

    The purpose of this study was to evaluate the shear bond strength of veneering feldspathic porcelain to zirconia substrates modified by CNC-milling process or by coating zirconia with a composite interlayer. Four types of zirconia-porcelain interface configurations were tested: RZ - porcelain bonded to rough zirconia substrate (n=16); PZ - porcelain bonded to zirconia substrate with surface holes (n=16); RZI - application of a composite interlayer between the veneering porcelain and the rough zirconia substrate (n=16); PZI - application of a composite interlayer between the porcelain and the zirconia substrate treated by CNC-milling (n=16). The composite interlayer was composed of zirconia particles reinforced porcelain (30%, vol%). The mechanical properties of the ceramic composite have been determined. The shear bond strength test was performed at 0.5mm/min using a universal testing machine. The interfaces of fractured and untested specimens were examined by FEG-SEM/EDS. Data was analyzed with Shapiro-Wilk test to test the assumption of normality. The one-way ANOVA followed by Tukey HSD multiple comparison test was used to compare shear bond strength results (α=0.05). The shear bond strength of PZ (100±15MPa) and RZI (96±11MPa) specimens were higher than that recorded for RZ (control group) specimens (89±15MPa), although not significantly (p>0.05). The highest shear bond strength values were recorded for PZI specimens (138±19MPa), yielding a significant improvement of 55% relative to RZ specimens (p<0.05). This study shows that it is possible to highly enhance the zirconia-porcelain bond strength - even by ~55% - by combining surface holes in zirconia frameworks and the application of a proper ceramic composite interlayer. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Comparison of Microleakage of Class V Cavities restored with the Embrace WetBond Class V Composite Resin and Conventional Opallis Composite Resin.

    Science.gov (United States)

    Tavangar, Maryam; Zohri, Zahra; Sheikhnezhad, Hosein; Shahbeig, Shahrzad

    2017-10-01

    This study was undertaken to compare the micro-leakage of class V cavities restored with the newly introduced Embrace WetBond class V (EWC) composite resin and conventional Opallis composite resin. In this in vitro study, class V cavities were prepared on 30 extracted bovine incisors, with the gingival floor and the coronal margin of the cavities 1 mm apical and coronal to the cementoenamel junction (CEJ) respectively. The cavities measured 3 mm in length, 2 mm in width, and 1.5 mm in depth. The teeth were randomly divided into two groups. In group I, the cavities were restored with Opallis composite resin in association with ExciTE adhesive system (total-etch); in group II, the EWC composite resin was used for restorations. After 500 thermocycling procedures, the teeth were immersed in 0.5% fuchsin solution for 24 hours. Then, the samples were placed within a polyester model and sectioned in the buccolingual direction. The samples were evaluated under a stereomicroscope at ×30 for the penetration of dye. The enamel and dentin margins were evaluated separately. To test ordinal results, we used nonparametric statistical methods. To find out whether each independent composite groups I and II came from the same populations, we used Mann-Whitney U test and to compare two related samples' coronal margin and gingival margin, Wilcoxon signed-rank test was used. There was significantly more microleakage in group II at both the enamel and dentin margins (coronal margin: p = 0.04; gingival margin: p = 0.21). In both groups, microleakage at gingival margins was significantly higher than that at coronal margins (group I: p = 0.008; group II: p = 0.26). Despite the high speed and the short process of restoration with Embrace WetBond, it is not a reliable restorative material for class V cavities due to its inadequate marginal seal.

  13. Effect of TiO2 nanoparticles incorporation on antibacterial properties and shear bond strength of dental composite used in Orthodontics.

    Science.gov (United States)

    Sodagar, Ahmad; Akhoundi, Mohamad Sadegh Ahmad; Bahador, Abbas; Jalali, Yasamin Farajzadeh; Behzadi, Zahra; Elhaminejad, Farideh; Mirhashemi, Amir Hossein

    2017-01-01

    Plaque accumulation and bond failure are drawbacks of orthodontic treatment, which requires composite for bonding of brackets. As the antimicrobial properties of TiO2 nanoparticles (NPs) have been proven, the aim of this study was to evaluate the antimicrobial and mechanical properties of composite resins modified by the addition of TiO2 NPs. Orthodontics composite containing 0%, 1%, 5% and 10% NPs were prepared. 180 composite disks were prepared for elution test, disk agar diffusion test and biofilm inhibition test to collect the counts of microorganisms on three days, measure the inhibition diameter and quantify the viable counts of colonies consequently. For shear bond strength (SBS) test, 48 intact bovine incisors were divided into four groups. Composites containing 0%, 1%, 5% and 10% NPs were used for bonding of bracket. The bracket/tooth SBS was measured by using an universal testing machine. All concentration of TiO2 NPs had a significant effect on creation and extension of inhibition zone. For S. mutans and S. sanguinis, all concentration of TiO2 NPs caused reduction of the colony counts. Composite containing 10% TiO2 NPs had significant effect on reduction of colony counts for S. mutans and S. sanguinis in all three days. The highest mean shear bond strength belonged to the control group, while the lowest value was seen in 10% NPs composite. Incorporating TiO2 nanoparticles into composite resins confer antibacterial properties to adhesives, while the mean shear bond of composite containing 1% and 5% NPs still in an acceptable range.

  14. Effect of TiO2 nanoparticles incorporation on antibacterial properties and shear bond strength of dental composite used in Orthodontics

    Directory of Open Access Journals (Sweden)

    Ahmad Sodagar

    Full Text Available ABSTRACT Introduction: Plaque accumulation and bond failure are drawbacks of orthodontic treatment, which requires composite for bonding of brackets. As the antimicrobial properties of TiO2 nanoparticles (NPs have been proven, the aim of this study was to evaluate the antimicrobial and mechanical properties of composite resins modified by the addition of TiO2 NPs. Methods: Orthodontics composite containing 0%, 1%, 5% and 10% NPs were prepared. 180 composite disks were prepared for elution test, disk agar diffusion test and biofilm inhibition test to collect the counts of microorganisms on three days, measure the inhibition diameter and quantify the viable counts of colonies consequently. For shear bond strength (SBS test, 48 intact bovine incisors were divided into four groups. Composites containing 0%, 1%, 5% and 10% NPs were used for bonding of bracket. The bracket/tooth SBS was measured by using an universal testing machine. Results: All concentration of TiO2 NPs had a significant effect on creation and extension of inhibition zone. For S. mutans and S. sanguinis, all concentration of TiO2 NPs caused reduction of the colony counts. Composite containing 10% TiO2 NPs had significant effect on reduction of colony counts for S. mutans and S. sanguinis in all three days. The highest mean shear bond strength belonged to the control group, while the lowest value was seen in 10% NPs composite. Conclusions: Incorporating TiO2 nanoparticles into composite resins confer antibacterial properties to adhesives, while the mean shear bond of composite containing 1% and 5% NPs still in an acceptable range.

  15. Enhanced capacity of chemically bonded phosphorus/carbon composite as an anode material for potassium-ion batteries

    Science.gov (United States)

    Wu, Xuan; Zhao, Wei; Wang, Hong; Qi, Xiujun; Xing, Zheng; Zhuang, Quanchao; Ju, Zhicheng

    2018-02-01

    Potassium-ion batteries are attracting great attention as a promising alternative to lithium-ion batteries due to the abundance and low price of potassium. Herein, the phosphorus/carbon composite, obtained by a simple ball-milling of 20 wt% commercial red phosphorus and 80 wt% graphite, is studied as a novel anode for potassium-ion batteries. Considering the high theoretical specific capacity of phosphorus and formation of stable phosphorus-carbon bond, which can alleviate the volume expansion efficiently, the phosphorus/carbon composite exhibits a high charge capacity of 323.5 mA h g-1 after 50 cycles at a current density of 50 mA g-1 with moderate rate capability and cycling stability. By the X-ray diffraction analysis, the alloying-dealloying mechanism of phosphorus is proposed to form a KP phase. Meanwhile, prepotassiation treatment is conducted to improve the low initial coulomb efficiency.

  16. The Effect of Titanium Tetrafluoride and Sodium Hypochlorite on the Shear Bond Strength of Methacrylate and Silorane Based Composite Resins: an In-Vitro Study.

    Science.gov (United States)

    Sharafeddin, Farahnaz; Koohpeima, Fatemeh; Razazan, Nader

    2017-06-01

    The bond strength of composites with different adhesive systems with dentin is an important factor in long term durability of composite restorations. The effect of titanium tetrafluoride (TiF4) as anti caries agent and sodium hypochlorite (NaOCl) as disinfectant on the shear bond of nanofilled and silorane based composite resins have not been investigated in previous studies. This study was conducted to determine bond strength between dentin and two composite systems, by means of shear bond test using TiF4 and NaOCl. Middle dentin of 60 intact extracted maxillary premolar teeth were exposed by sectioning the crowns at a depth of 2mm from central groove and parallel to the occlusal surface. Standardized smear layer was created using a 600-grit silicon carbide paper and then samples were embedded in acrylic resin blocks. Then the samples were randomly divided into 6 \\groups summarized as Group I: Z350, Group II: Z350+ NaOCl, Group III: Z350+ TiF4, Group IV: P90, Group V: P90+ NaOCl, Group VI: P90+ TiF4 according to manufacturer's instruction. Then samples were subjected to shear bond strength (SBS) test using universal testing machine and data were analyzed using ANOVA and Tukey tests (pcomposite resin (p= 0.004), and also silorane based composite resin (p= 0.006). Application of 4% TiF4 caused a significant increase in SBS of silorane based composite resin (p= 0.001). The effect of TiF4 on nanofilled composite was not statistically significant. Using TiF4 has a positive effect on increasing the shear bond while NaOCl has negative effect on bond strength.

  17. Effect of surface conditioning modalities on the repair bond strength of resin composite to the zirconia core / veneering ceramic complex.

    Science.gov (United States)

    Ozcan, Mutlu; Valandro, Luiz Felipe; Pereira, Sarina Maciel; Amaral, Regina; Bottino, Marco Antonio; Pekkan, Gurel

    2013-06-01

    This study evaluated the effect of different surface conditioning protocols on the repair strength of resin composite to the zirconia core / veneering ceramic complex, simulating the clinical chipping phenomenon. Forty disk-shaped zirconia core (Lava Zirconia, 3M ESPE) (diameter: 3 mm) specimens were veneered circumferentially with a feldspathic veneering ceramic (VM7, Vita Zahnfabrik) (thickness: 2 mm) using a split metal mold. They were then embedded in autopolymerizing acrylic with the bonding surfaces exposed. Specimens were randomly assigned to one of the following surface conditioning protocols (n = 10 per group): group 1, veneer: 4% hydrofluoric acid (HF) (Porcelain Etch) + core: aluminum trioxide (50-µm Al2O3) + core + veneer: silane (ESPE-Sil); group 2: core: Al2O3 (50 µm) + veneer: HF + core + veneer: silane; group 3: veneer: HF + core: 30 µm aluminum trioxide particles coated with silica (30 µm SiO2) + core + veneer: silane; group 4: core: 30 µm SiO2 + veneer: HF + core + veneer: silane. Core and veneer ceramic were conditioned individually but no attempt was made to avoid cross contamination of conditioning, simulating the clinical intraoral repair situation. Adhesive resin (VisioBond) was applied to both the core and the veneer ceramic, and resin composite (Quadrant Posterior) was bonded onto both substrates using polyethylene molds and photopolymerized. After thermocycling (6000 cycles, 5°C-55°C), the specimens were subjected to shear bond testing using a universal testing machine (1 mm/min). Failure modes were identified using an optical microscope, and scanning electron microscope images were obtained. Bond strength data (MPa) were analyzed statistically using the non-parametric Kruskal-Wallis test followed by the Wilcoxon rank-sum test and the Bonferroni Holm correction (α = 0.05). Group 3 demonstrated significantly higher values (MPa) (8.6 ± 2.7) than those of the other groups (3.2 ± 3.1, 3.2 ± 3, and 3.1 ± 3.5 for groups 1, 2, and 4

  18. Push-out bond strength between composite core buildup and fiber-reinforced posts after different surface treatments.

    Science.gov (United States)

    Arslan, Hakan; Barutcigil, Cagatay; Yılmaz, Cenk Burak; Ceyhanlı, Kadir Tolga; Topcuoglu, Hüseyin Sinan

    2013-07-01

    The aim of this study was to evaluate the effects of different surface treatments on the pushout bond strength of fiber-reinforced posts to composite resin cores. Twenty-five translucent glass fiber posts were divided into five groups according to surface treatment methods as follows: an untreated control group, a group coated with silicated alumina particles (Co-Jet system, 3M ESPE, St. Paul, MN), and three groups undergoing surface preparation with erbium:yttrium-aluminum-garnet (Er:YAG) laser under three different power settings (150, 300, and 450 mJ at 10 Hz for 60 sec at 100 μs duration). After surface treatment, fiber posts were built up to a dual cure composite resin core. All of the specimens were set and sectioned perpendicularly along the long axis of the post using a saw. Two discs (thickness of 2 mm) were obtained from each post-core sample; finally, each group consisted of 10 samples. For artificial aging, the specimens were stored in water (37°C) for 24 h and subjected to thermal cycling (5000 cycles, 5-55°C, and 30 sec dwell time). Pushout tests were performed using a universal testing machine at a crosshead speed of 0.5 mm/min. The pushout pressure values were measured in MPa and analyzed using one way analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) post-hoc test (pFiber post surface images were obtained using a scanning electron microscope (SEM). The bond strength values ranged between 14,949 and 23,879 MPa. The lowest values were observed in the groups treated with the Er:YAG laser at 150 mJ. Irradiation by the Er:YAG laser at 450 mJ affected the bond strength significantly (pfiber-reinforced posts to composite resin cores depending upon the power applied; Co-Jet sandblasting also increased the bond strength.

  19. Advances in the analysis and design of adhesive-bonded joints in composite aerospace structures

    Science.gov (United States)

    Hart-Smith, L. J.

    1974-01-01

    Several aspects of adhesive-bonded joint analysis and design are presented from the reference of size of structure or load intensity. This integrates the individual characterizations of double-lap, single-lap, stepped-lap, tapered-lap and scarf joints. The paper includes an overview of bonded joint selection from the standpoints of design, fabrication, and processing, each bearing in mind the influence of such considerations on the strength of the joint. A case study is presented of the optimization of a specific relatively thick titanium-to-graphite epoxy stepped-lap joint, using the digital computer analysis program A4EG. The factors accounted for are adhesive plasticity, adherend stiffness imbalance, adherend thermal mismatch, and change of material properties within the range of temperature environment and with load direction. The strength increases obtainable by refining the initial design are demonstrated.

  20. Reactive Silicate Coatings for Protecting and Bonding Reinforcing Steel in Cement-Based Composites

    Science.gov (United States)

    2008-12-01

    Research done on the use of porcelain enamel as at interface using smooth mild steel rods has demonstrated that the a glass enamel coating...enamel coating. Vitreous enamel typically has a volume resistivity of 1×1014 ohm·cm, so a perfect enamel surface is an insulator . Defects were...C., and Malone, P., 2006: The Use of Porcelain Enamel Coatings on Reinforcing Steel to Enhance the Bond to Concrete. Proceeding of the

  1. Effect of three surface conditioning methods to improve bond strength of particulate filler resin composites

    NARCIS (Netherlands)

    Özcan, M.; Alander, P.; Vallittu, P.K.; Huysmans, M.C.; Kalk, W.

    2004-01-01

    The use of resin-based composite materials in operative dentistry is increasing, including applications in stress-bearing areas. However, composite restorations, in common with all restorations, suffer from deterioration and degradation in clinical service. Durable repair alternatives by layering a

  2. Effect of three surface conditioning methods to improve bond strength of particulate filler resin composites

    NARCIS (Netherlands)

    Özcan, M.; Alander, P.; Vallittu, P.K.; Huysmans, M.C.; Kalk, W.

    2005-01-01

    The use of resin-based composite materials in operative dentistry is increasing, including applications in stress-bearing areas. However, composite restorations, in common with all restorations, suffer from deterioration and degradation in clinical service. Durable repair alternatives by layering a

  3. Effect of three surface conditioning methods to improve bond strength of particulate filler resin composites

    NARCIS (Netherlands)

    Ozcan, M; Alander, P; Vallittu, PK; Huysmans, MC; Kalk, W

    The use of resin-based composite materials in operative dentistry is increasing, including applications in stress-bearing areas. However, composite restorations, in common with all restorations, suffer from deterioration and degradation in clinical service. Durable repair alternatives by layering a

  4. Evaluation of shear bond strength of two resin-based composites and glass ionomer cement to pure tricalcium silicate-based cement (Biodentine®

    Directory of Open Access Journals (Sweden)

    Kenan CANTEK?N

    2014-07-01

    Full Text Available Objectives: Tricalcium silicate is the major constituent phase in mineral trioxide aggregate (MTA. It is thus postulated that pure tricalcium silicate can replace the Portland cement component of MTA. The aim of this study was to evaluate bond strength of methacrylate-based (MB composites, silorane-based (SB composites, and glass ionomer cement (GIC to Biodentine® and mineral trioxide aggregate (MTA. Material and Methods: Acrylic blocks (n=90, 2 mm high, 5 mm diameter central hole were prepared. In 45 of the samples, the holes were fully filled with Biodentine® and in the other 45 samples, the holes were fully filled with MTA. The Biodentine® and the MTA samples were randomly divided into 3 subgroups of 15 specimens each: Group-1: MB composite; Group-2: SB composite; and Group-3: GIC. For the shear bond strength (SBS test, each block was secured in a universal testing machine. Results: The highest (17.7±6.2 MPa and the lowest (5.8±3.2 MPa bond strength values were recorded for the MB composite-Biodentine® and the GIC-MTA, respectively. Although the MB composite showed significantly higher bond strength to Biodentine (17.7±6.2 than it did to MTA (8.9±5.7 (p<0.001, the SB composite (SB and MTA=7.4±3.3; SB and Biodentine®=8.0±3,6 and GIC (GIC and MTA=5.8±3.2; GIC and Biodentine=6.7±2.6 showed similar bond strength performance with MTA compared with Biodentine (p=0.73 and p=0.38, respectively. Conclusions: The new pure tricalcium-based pulp capping, repair, and endodontic material showed higher shear bond scores compared to MTA when used with the MB composite.

  5. Effect of two abrasive systems on resin bonding to laboratory-processed indirect resin composite restorations.

    Science.gov (United States)

    Bouschlicher, M R; Cobb, D S; Vargas, M A

    1999-01-01

    This study compared two methods of surface roughening or preparation, with or without the use of proprietary surface wetting agents, to evaluate their effect on resin cement adhesion to the following laboratory-processed, indirect restorations: Artglass (AG), belleGlass HP (BG), Concept (C), and Targis (T). Methods of surface roughening or preparation included microetching with aluminum oxide (AO): 50 microns at 34 psi and silanized silica coating, CoJet-Sand (CJ): 30 microns at 34 psi. Artglass and Concept were tested with and without the use of their respective surface wetting agents: Artglass Liquid (AGL) and Special Bond II (SB). One hundred twenty specimens, each consisting of a pair of cylinders (7.0 x 3 mm and 4.3 x 3 mm) were fabricated. The larger cylinder or base was embedded in self-curing resin in a phenolic ring, and bonding surfaces were finished with 320-grit silicon carbide paper. Specimen pairs for each restorative material were randomly assigned to treatment groups (n = 10) and received the following surface treatments prior to cementation: group 1 (AG/AO/+AGL), group 2 (AG/AO/-AGL), group 3 (AG/CJ/+AGL), group 4 (AG/CJ/-AGL), group 5 (BG/AO), group 6 (BG/CJ), group 7 (C/AO/+SB), group 8 (C/AO/-SB), group 9 (C/CJ/+SB), group 10 (C/CJ/-SB), group 11 (T/AO), and group 12 (T/CJ). Specimen pairs were cemented with a dual-cure resin cement (Dual) and a standardized force of 1 MPa. Specimens were light-cured 40 seconds per side (80 s total), then thermocycled 300 times at between 5 degrees and 55 degrees C. Shear bond strengths (MPa) were determined using a Zwick Materials Testing Machine at a crosshead speed of 5 mm per minute. One-way analysis of variance (ANOVA) and Duncan's multiple range test (alpha = 0.05) by restoration type indicated no significant differences in shear bond strength between BG group 5 (29.8 +/- 5.8), BG group 6 (28.3 +/- 4.3), T group 11 (29.3 +/- 4.9), and T group 12 (29.0 +/- 4.4). Shear bond strength in AG group 3 (35.9 +/- 3

  6. Effects of air abrasion with alumina or glass beads on surface characteristics of CAD/CAM composite materials and the bond strength of resin cements.

    Science.gov (United States)

    Nobuaki, Arao; Keiichi, Yoshida; Takashi, Sawase

    2015-01-01

    The study aimed to evaluate effects of air abrasion with alumina or glass beads on bond strengths of resin cements to CAD/CAM composite materials. CAD/CAM composite block materials [Cerasmart (CS) and Block HC (BHC)] were pretreated as follows: (a) no treatment (None), (b) application of a ceramic primer (CP), (c) alumina-blasting at 0.2 MPa (AB), (d) AB followed by CP (AB+CP), and (e) glass-beads blasting at 0.4 MPa (GBB) followed by CP (GBB+CP). The composite specimens were bonded to resin composite disks using resin cements [G-CEM Cerasmart (GCCS) and ResiCem (RC)]. The bond strengths after 24 h (TC 0) and after thermal cycling (TC 10,000 at 4-60°C) were measured by shear tests. Three-way ANOVA and the Tukey compromise post hoc tests were used to analyze statistically significant differences between groups (α=0.05). For both CAD/CAM composite materials, the None group exhibited a significant decrease in bond strength after TC 10,000 (p0.05). The AB+CP group showed a significantly higher bond strength after TC 10,000 than did the AB group for RC (pcomposite materials than was using an alumina powder and a CP.

  7. Design, testing, and damage tolerance study of bonded stiffened composite wing cover panels

    Science.gov (United States)

    Madan, Ram C.; Sutton, Jason O.

    1988-01-01

    Results are presented from the application of damage tolerance criteria for composite panels to multistringer composite wing cover panels developed under NASA's Composite Transport Wing Technology Development contract. This conceptual wing design integrated aeroelastic stiffness constraints with an enhanced damage tolerance material system, in order to yield optimized producibility and structural performance. Damage tolerance was demonstrated in a test program using full-sized cover panel subcomponents; panel skins were impacted at midbay between stiffeners, directly over a stiffener, and over the stiffener flange edge. None of the impacts produced visible damage. NASTRAN analyses were performed to simulate NDI-detected invisible damage.

  8. Reliability and Validity of Composite Scores from the NIH Toolbox Cognition Battery in Adults

    Science.gov (United States)

    Heaton, Robert K.; Akshoomoff, Natacha; Tulsky, David; Mungas, Dan; Weintraub, Sandra; Dikmen, Sureyya; Beaumont, Jennifer; Casaletto, Kaitlin B.; Conway, Kevin; Slotkin, Jerry; Gershon, Richard

    2014-01-01

    This study describes psychometric properties of the NIH Toolbox Cognition Battery (NIHTB-CB) Composite Scores in an adult sample. The NIHTB-CB was designed for use in epidemiologic studies and clinical trials for ages 3 to 85. A total of 268 self-described healthy adults were recruited at four university-based sites, using stratified sampling guidelines to target demographic variability for age (20–85 years), gender, education, and ethnicity. The NIHTB-CB contains seven computer-based instruments assessing five cognitive sub-domains: Language, Executive Function, Episodic Memory, Processing Speed, and Working Memory. Participants completed the NIHTB-CB, corresponding gold standard validation measures selected to tap the same cognitive abilities, and sociodemographic questionnaires. Three Composite Scores were derived for both the NIHTB-CB and gold standard batteries: “Crystallized Cognition Composite,” “Fluid Cognition Composite,” and “Total Cognition Composite” scores. NIHTB Composite Scores showed acceptable internal consistency (Cronbach’s alphas = 0.84 Crystallized, 0.83 Fluid, 0.77 Total), excellent test–retest reliability (r: 0.86–0.92), strong convergent (r: 0.78–0.90) and discriminant (r: 0.19–0.39) validities versus gold standard composites, and expected age effects (r = 0.18 crystallized, r = − 0.68 fluid, r = − 0.26 total). Significant relationships with self-reported prior school difficulties and current health status, employment, and presence of a disability provided evidence of external validity. The NIH Toolbox Cognition Battery Composite Scores have excellent reliability and validity, suggesting they can be used effectively in epidemiologic and clinical studies. PMID:24960398

  9. Effect of Metal Primers on Bond Strength of a Composite Resin to Nickel-Chrome Metal Alloy.

    Science.gov (United States)

    Nima, Gabriel; Ferreira, Paulo Vitor Campos; Paula, Andreia Bolzan de; Consani, Simonides; Giannini, Marcelo

    2017-01-01

    This study evaluated the effects of three metal primers and one multi-mode adhesive system on the shear bond strength (SBS) of a flowable composite resin to nickel-chrome metal alloy (Ni-Cr). Ninety plates were cast from Ni-Cr and divided in nine groups (n=10). The surfaces were sandblasted with Al2O3 and primed with three adhesive primers: Alloy Primer (AP), Universal Primer (TP) and RelyX Ceramic Primer (CP), and a multi-mode adhesive (Scotchbond Universal, SU). The Adper Single Bond Plus (SB) and SU adhesives were also combined with adhesive primers. Control group did not have any surface treatment. The groups were: AP, AP+SB, AP+SU, TP+SB, TP+SU, CP+SB, CP+SU and SU. Composite cylinders were built on alloy surface. After 24 h, half the specimens were subjected to SBS and the other half to thermal cycling before testing. Data were analyzed by two-way ANOVA and Tukey's test (a=0.05). Failure modes were assessed by SEM observation. Higher SBS were obtained with AP and TP combined with adhesives at 24 h and the lowest one for control group. Thermocycling reduced SBS for AP, CP+SU and SU. Combination between TP and SU resulted in the highest SBS after the thermocycling. TP groups showed all types of failures and high incidence of mixed failures. The use of AP and UP metal primers before application of SU and SB adhesive systems increased the SBS of composite to Ni-Cr. These combinations between metal primers and adhesives had the highest SBS after thermocycling.

  10. Evaluation of shear bond strength of two resin-based composites and glass ionomer cement to pure tricalcium silicate-based cement (Biodentine®).

    Science.gov (United States)

    Cantekin, Kenan; Avci, Serap

    2014-01-01

    Tricalcium silicate is the major constituent phase in mineral trioxide aggregate (MTA). It is thus postulated that pure tricalcium silicate can replace the Portland cement component of MTA. The aim of this study was to evaluate bond strength of methacrylate-based (MB) composites, silorane-based (SB) composites, and glass ionomer cement (GIC) to Biodentine® and mineral trioxide aggregate (MTA). Acrylic blocks (n=90, 2 mm high, 5 mm diameter central hole) were prepared. In 45 of the samples, the holes were fully filled with Biodentine® and in the other 45 samples, the holes were fully filled with MTA. The Biodentine® and the MTA samples were randomly divided into 3 subgroups of 15 specimens each: Group-1: MB composite; Group-2: SB composite; and Group-3: GIC. For the shear bond strength (SBS) test, each block was secured in a universal testing machine. The highest (17.7 ± 6.2 MPa) and the lowest (5.8 ± 3.2 MPa) bond strength values were recorded for the MB composite-Biodentine® and the GIC-MTA, respectively. Although the MB composite showed significantly higher bond strength to Biodentine (17.7 ± 6.2) than it did to MTA (8.9 ± 5.7) (p Biodentine® = 8.0 ± 3,6) and GIC (GIC and MTA = 5.8 ± 3.2; GIC and Biodentine = 6.7 ± 2.6) showed similar bond strength performance with MTA compared with Biodentine (p = 0.73 and p = 0.38, respectively). The new pure tricalcium-based pulp capping, repair, and endodontic material showed higher shear bond scores compared to MTA when used with the MB composite.

  11. INFLUENCE OF SILANE HEAT TREATMENT ON THE TENSILE BOND STRENGTH BETWEEN EX-3 SYNTHETIC VENEERING PORCELAIN AND COMPOSITE RESIN USING FIVE DIFFERENT ACTIVATION TEMPERATURES

    Directory of Open Access Journals (Sweden)

    Spartak Yanakiev

    2017-02-01

    Full Text Available Purpose: The purpose of the present study is to assess the effect of five different silane activation temperatures and eight activation methods on the tensile bond strength between one veneering porcelain and one composite resin material. Material and methods: A total of 81 ceramic rods were made of EX-3 veneering ceramic (Kuraray Noritake Dental, Japan. Sintered ceramic bars were grinded with diamond disks to size 10x2x2mm ± 0,05mm. The front part of each bar was polished. After ultrasonic cleaning in distilled water, the specimens were divided into nine groups. Silane was activated with air at room temperature, 38º С, 50º С, 100º С, 120º С using a custom made blow drier. In a silicone mold, a composite resin Z250 (3М ESPE, St. Paul, USA was condensed toward the bond ceramic surface. A total of 81 specimens approximately 2,0 cm long were prepared for tensile bond testing. One way ANOVA, followed by Bonferroni and Games-Howell tests were used for statistical analysis. Results: The lowest tensile bond strength was observed in the control group (3,51MPa. Group 2 yielded the highest bond strength among all groups (19,54MPa. Silane heat treatment enhanced the bond strength for all treatment methods. Within the polished specimens, the highest bond strength was yielded with warm air at 120ºС (11,31MPa. Conclusion: The most effective method for bonding Z250 composite resin to EX-3 veneering ceramic includes HF etching, silane, and adhesive resin. The most effective heat treatment method for bonding is hot air at 120ºС.

  12. Verification and Validation of a Three-Dimensional Generalized Composite Material Model

    Science.gov (United States)

    Hoffarth, Canio; Harrington, Joseph; Rajan, Subramaniam D.; Goldberg, Robert K.; Carney, Kelly S.; DuBois, Paul; Blankenhorn, Gunther

    2015-01-01

    A general purpose orthotropic elasto-plastic computational constitutive material model has been developed to improve predictions of the response of composites subjected to high velocity impact. The three-dimensional orthotropic elasto-plastic composite material model is being implemented initially for solid elements in LS-DYNA as MAT213. In order to accurately represent the response of a composite, experimental stress-strain curves are utilized as input, allowing for a more general material model that can be used on a variety of composite applications. The theoretical details are discussed in a companion paper. This paper documents the implementation, verification and qualitative validation of the material model using the T800-F3900 fiber/resin composite material

  13. Bonding fixed prosthodontic composite resin and precious metal alloys with the use of a vinyl-thiol primer and an adhesive opaque resin.

    Science.gov (United States)

    Atsuta, M; Matsumura, H; Tanaka, T

    1992-03-01

    Adhesive bonding of a light-cured fixed prosthodontic composite resin joined to silver- and gold-based alloys was investigated with the use of a metal primer and an adhesive opaque resin. The primer contained an adhesive bonding promoter for precious alloys, 6- (4-vinylbenzyl-n-propyl) amino-1, 3, 5-triazine-2, 4-dithiol (VBATDT). The cast metal specimens were alumina-blasted and primed with VBATDT acetone solution. A self-curable 4-META/MMA-TBB opaque resin was used to bond the primed metals and a light-cured composite resin. Prepared specimens were thermocycled in water and bond strengths were determined. The shear bond strengths after 100,000 thermocycles (4 degrees C to 60 degrees C for 1 minute) were 28.4 MPa for Ag-Pd-Cu-Au alloy and 20.8 MPa for type III gold alloy. This simple method may be used to bond silver or gold alloy and light-activated fixed prosthodontic composite resin.

  14. Reliability and validity of individual and composite recall pain measures in patients with cancer.

    Science.gov (United States)

    Jensen, Mark P; Wang, Wei; Potts, Susan L; Gould, Errol M

    2012-10-01

    To evaluate and compare the validity and reliability of individual and composite recall pain intensity measures. Secondary analyses using data from a published 14-day open-label crossover clinical trial comparing two active treatments. Multiple settings. Fifty-two adults with a history of chronic cancer pain. Recall ratings of least, worst, and average pain during the past 2 days; composite score representing recalled characteristic pain in the past 2 days; and daily diary ratings of pain intensity from which "actual" least, worst, and average pain scores were derived. Recall ratings of least and average pain, and a composite score representing recalled characteristic pain were accurate (differed no more than three points from "actual" scores on a 0-100 scale). Although the recall rating of worst pain significantly (P recall measures demonstrated validity via their strong associations with the measures of actual pain intensity. The recall measures also demonstrated excellent test-retest stability, although the diary-derived measures tended to be more stable than the recall measures did. The composite measure of recalled characteristic pain demonstrated a high level of internal consistency (Cronbach's α = 0.90). Individual recall ratings and a composite score representing recalled characteristic pain intensity are reliable and valid measures of actual pain in patients with cancer. The findings support their use as outcome measures in clinical trials. Wiley Periodicals, Inc.

  15. Liquid-phase diffusion bonding: Temperature effects and solute redistribution in high temperature lead-free composite solders

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iver [Ames Lab. and Iowa State Univ., Ames, IA (United States); Iowa State Univ., Ames, IA (United States); Choquette, Stephanie [Ames Lab. and Iowa State Univ., Ames, IA (United States); Iowa State Univ., Ames, IA (United States)

    2015-05-17

    Liquid-phase diffusion bonding (LPDB) is being studied as the primary phenomena occurring in the development of a high temperature lead-free composite solder paste composed of gas-atomized Cu-10Ni, wt.% (Cu-11Ni, at.%) powder blended with Sn-0.7Cu-0.05Ni-0.01Ge (Sn-1.3Cu-0.1Ni-0.02Ge, at.%) Nihon-Superior SN100C solder powder. Powder compacts were used as a model system. LPDB promotes enhanced interdiffusion of the low-melting alloy matrix with the solid Cu-10Ni reinforcement powder above the matrix liquidus temperature. The initial study involved the effective intermetallic compound (IMC) compositions and microstructures that occur at varying reflow temperatures and times between 250-300°C and 30-60s, respectively. Certain reflow temperatures encourage adequate interdiffusion to form a continuous highly-conductive network throughout the composite solder joints. The diffusion of nickel, in particular, has a disperse pattern that foreshadows the possibility of a highly-conductive low-melting solder that can be successfully utilized at high temperatures.

  16. Effect of irradiance and light source on contraction stress, degree of conversion and push-out bond strength of composite restoratives.

    Science.gov (United States)

    Cunha, Leonardo Gonçalves; Alonso, Roberta Caroline Bruschi; Pfeifer, Carmem Silvia Costa; de Góes, Mario Fernando; Ferracane, Jack Liborio; Sinhoreti, Mário Alexandre Coelho

    2009-06-01

    To evaluate the influence of five curing methods on contraction stress, stress rate, and degree of conversion (DC) of a composite and on bond strength of composite restoratives. For the stress test, composite was applied between two 5-mm diameter glass rods, mounted in a servohydraulic machine. Stress rates were calculated as the change in stress vs. time. DC was measured by FTIR. Bond strength testing was performed using a push-out test in bovine incisors. The C-factor was 3.0 for all tests. Five methods were evaluated: High Intensity LED (LED HI), Continuous Halogen Light (QTH CL), Medium Intensity LED (LED MI), Low Intensity LED (LED LI), and Pulse Delay Halogen Light (QTH PD). Results were analyzed by ANOVA and Tukey's test (alpha = 0.05). Stress values ranged from 9.25 MPa (QTH PD) to 10.46 MPa (LED MI). No statistical difference was observed among the methods. Bond strength values ranged from 24.6 MPa (LED HI) to 35.4 MPa (QTH PD), with the QTH PD presenting a statistically higher value compared to the other methods. Stress rate and bond strength presented an inverse linear correlation (r2 = 0.79). LED HI presented the highest maximum stress rate, followed by LED MI, QTH CL, LED LI, and QTH PD. The reduction in stress rate observed for the low intensity groups was associated with a general increase in bond strength, with no adverse effect on the degree of conversion of the restorative composite.

  17. Atomic-scale chemical imaging of composition and bonding by aberration-corrected microscopy.

    Science.gov (United States)

    Muller, D A; Kourkoutis, L Fitting; Murfitt, M; Song, J H; Hwang, H Y; Silcox, J; Dellby, N; Krivanek, O L

    2008-02-22

    Using a fifth-order aberration-corrected scanning transmission electron microscope, which provides a factor of 100 increase in signal over an uncorrected instrument, we demonstrated two-dimensional elemental and valence-sensitive imaging at atomic resolution by means of electron energy-loss spectroscopy, with acquisition times of well under a minute (for a 4096-pixel image). Applying this method to the study of a La(0.7)Sr(0.3)MnO3/SrTiO3 multilayer, we found an asymmetry between the chemical intermixing on the manganese-titanium and lanthanum-strontium sublattices. The measured changes in the titanium bonding as the local environment changed allowed us to distinguish chemical interdiffusion from imaging artifacts.

  18. Optimal tubular adhesive-bonded lap joint of the carbon fiber epoxy composite shaft

    Science.gov (United States)

    Kim, Ki S.; Kim, Won T.; Lee, Dai G.; Jun, Eui J.

    The effects of the adhesive thickness and the adherend surface roughness on the fatigue strength of a tubular adhesive-bonded single lap joint were investigated using fatigue test specimens whose adherends were made of S45C carbon steel. Results of fatigue tests showed that the optimal arithmetic surface roughness of the adherends is about 2 microns and the optimal adhesive thickness is about 0.15 mm. Using these values, the prototype torsional adhesive joints were manufactured for power transmission shafts of an automotive vehicle or a small helicopter, and static tests under torque were performed on a single-lap joint, a single-lap joint with scarf, a double-lap joint, and a double-lap joint with scarf. It was found that the double-lap joint was superior among the joints, in terms of torque capacity and manufacturing cost.

  19. Effects of different surface treatments and accelerated artificial aging on the bond strength of composite resin repairs

    Directory of Open Access Journals (Sweden)

    Marco Aurélio Veiga de Melo

    2011-12-01

    Full Text Available The purpose of the present study was to assess the bond strength of composite resin repairs subjected to different surface treatments and accelerated artificial aging. 192 cylindrical samples (CSs were prepared and divided into 24 groups (n = 8. Half of the CSs were stored in water for 24 h, and the other half were subjected to C-UV accelerated aging for non-metallic specimens. The treatments were phosphoric acid + silane + adhesive (PSA; phosphoric acid + adhesive (PA; diamond bur + phosphoric acid + silane + adhesive (DPSA; diamond bur + phosphoric acid + adhesive (DPA; air abrasion + phosphoric acid + silane + adhesive (APSA; and air abrasion + phosphoric acid + adhesive (APA. The repair was performed and the specimens were again aged as described above. A control group (n = 8 was established and did not receive any type of aging or surface treatment. The specimens were loaded to failure in shear mode with a crosshead speed of 0.5 mm/min until fracture. Data were analyzed by one-way ANOVA/Tukey's test (p < 0.05. No statistically significant differences were found among DPSA, DPA, APSA, APA, and the control group. The aged PSA and PA achieved low bonding values and were statistically different from the control group, whereas the non-aged PSA and PA presented no statistically significant difference from the control group. Repairs with the proposed surface treatments were viable on both recent and aged restorations; however, phosphoric acid + adhesive alone were effective only on recent restorations.

  20. Effect of in-situ bonding system and surface modification of montmorillonite on the properties of butyl rubber/MMT composites

    Science.gov (United States)

    Halim, S. F.; Lawandy, S. N.; Nour, M. A.

    2012-07-01

    Isobutylene-isoprene rubber (IIR)/nanoclay composites were prepared by solution intercalation method. Cloisite Na+ nanoclays and organo-modified montmorillonite (OMT) Cloisite 10 A,.15 A and 20 A were used in this study. The effect of In-situ bonding system HRH (hexametylene tetramine: resorcinol: hydrated silica) on the dispersion of used nanoclays in the rubber matrix were examined by X-ray diffraction and atomic force microscopy (AFM). Characterization of the prepared composites was performed by studying the rheometeric and mechanical properties. The burning out behavior of the nanocomposites with and without the bonding system was also measured.

  1. Influence of Dissimilar Adherends on the Stress Distribution in Adhesively Bonded Composite Joints Subjected to Impact Loadings

    Science.gov (United States)

    Hazimeh, R.; Challita, G.; Khalil, K.; Othman, R.

    2015-01-01

    The influence of nonsymmetric rotation of laminates on the shear and peel stresses in the adhesive layer of adhesively bonded double-lap composite joints (DLJ) subjected to in-plane impact compressive loadings is investigated by using a three-dimensional finite-element analysis. The compressive in-plane impact on DLJ is simulated using the direct Hopkinson bar system, and the specimen is impacted by an incident bar. It is found that the rotation of any adherend from the 0° orientation leads to a decrease in the average shear stress in the adhesive layer, but the maximum peel stress is affected only by the longitudinal stiffness of the outer adherend and decreases when this stiffness diminishes.

  2. Efficacy of Esthetic Retainers: Clinical Comparison between Multistranded Wires and Direct-Bond Glass Fiber-Reinforced Composite Splints

    Directory of Open Access Journals (Sweden)

    Andrea Scribante

    2011-01-01

    Full Text Available The purpose of this longitudinal prospective randomized study was to evaluate the reliability of two different types of orthodontic retainers in clinical use: a multistrand stainless steel wire and a polyethylene ribbon-reinforced resin composite. Moreover the level of satisfaction of the patient about the esthetic result was also analyzed by means of a Visual Analogue Scale (VAS. 34 patients (9 boys and 25 girls, mean age 14.3, in the finishing phase of orthodontic treatment, were selected for the study. Since splints were applied the number, cause, and date of splint failures were recorded for each single tooth over 12 months. Statistical analysis was performed using a paired -test, Kaplan Meier survival estimates, and the log-rank test. Kruskal Wallis test was performed to analyze VAS recordings. Differences between the bond failure rates were not statistically significant. Esthetic result of VAS was significantly higher for polyethylene ribbon-reinforced resin retainers than for stainless steel wires.

  3. Design of Au/SPIO composite nanoparticle for facile and biocompatible surface functionalization via Au-S bond

    Energy Technology Data Exchange (ETDEWEB)

    Seino, Satoshi, E-mail: seino@mit.eng.osaka-u.ac.jp; Shibata, Yujin; Yamanaka, Masayuki; Nakagawa, Takashi [Osaka University, Graduate School of Engineering (Japan); Mukai, Yohei; Nakagawa, Shinsaku [Osaka University, Graduate School of Pharmaceutical Sciences and Center for Advanced Medical Engineering and Informatics (Japan); Yamamoto, Takao A. [Osaka University, Graduate School of Engineering (Japan)

    2013-01-15

    Immobilization of Au nanoparticles on super-paramagnetic iron-oxide (SPIO) enables facile and biocompatible surface functionalization via Au-S bond. Au/SPIO composite nanoparticle is easily modified by thiol-modified polyethylene glycol (PEG-SH), and they are successfully applied on MR tumor imaging. However, its large hydrodynamic size ({approx}150 nm) still causes the accumulation to liver in vivo. In this study, we controlled the hydrodynamic size of Au/SPIO by testing different raw SPIOs and stabilizing polymers. As the best candidate, Au/Molday-ION which was synthesized from Molday-ION and polyvinyl alcohol comprised the hydrodynamic size of 56 nm. Moreover, PEGylated Au/Molday-ION showed excellent dispersibility in blood serum, with the hydrodynamic size of 65 nm. This surface functionalization strategy is effective for the constructions of magnetic nanocarriers for in vivo applications.

  4. Effects of different surface treatments on bond strength of an indirect composite to bovine dentin

    Directory of Open Access Journals (Sweden)

    Laiza Tatiana Poskus

    2015-01-01

    Conclusions: Sandblasting was a safe surface treatment for the indirect composite, increasing the BS values. Hydrofluoric acid applied after sandblasting damaged the BS values and should not be recommended while ethanol and H2O2, when applied after sandblasting, were effective in increasing BS values.

  5. Validation of Material Models For Automotive Carbon Fiber Composite Structures Via Physical And Crash Testing (VMM Composites Project)

    Energy Technology Data Exchange (ETDEWEB)

    Coppola, Anthony [General Motors Company, Flint, MI (United States); Faruque, Omar [Ford Motor Company, Dearborn, MI (United States); Truskin, James F [FCA US LLC, Auburn Hills, MI (United States); Board, Derek [Ford Motor Company, Dearborn, MI (United States); Jones, Martin [Ford Motor Company, Dearborn, MI (United States); Tao, Jian [FCA US LLC, Auburn Hills, MI (United States); Chen, Yijung [Ford Motor Company, Dearborn, MI (United States); Mehta, Manish [M-Tech International LLC, Dubai (United Arab Emirates)

    2017-09-27

    As automotive fuel economy requirements increase, the push for reducing overall vehicle weight will likely include the consideration of materials that have not previously been part of mainstream vehicle design and manufacturing, including carbon fiber composites. Vehicle manufacturers currently rely on computer-aided engineering (CAE) methods as part of the design and development process, so going forward, the ability to accurately and predictably model carbon fiber composites will be necessary. If composites are to be used for structural components, this need applies to both, crash and quasi-static modeling. This final report covers the results of a five-year, $6.89M, 50% cost-shared research project between Department of Energy (DOE) and the US Advanced Materials Partnership (USAMP) under Cooperative Agreement DE-EE-0005661 known as “Validation of Material Models for Automotive Carbon Fiber Composite Structures Via Physical and Crash Testing (VMM).” The objective of the VMM Composites Project was to validate and assess the ability of physics-based material models to predict crash performance of automotive primary load-carrying carbon fiber composite structures. Simulation material models that were evaluated included micro-mechanics based meso-scale models developed by the University of Michigan (UM) and micro-plane models by Northwestern University (NWU) under previous collaborations with the DOE and Automotive Composites Consortium/USAMP, as well as five commercial crash codes: LS-DYNA, RADIOSS, VPS/PAM-CRASH, Abaqus, and GENOA-MCQ. CAE predictions obtained from seven organizations were compared with experimental results from quasi-static testing and dynamic crash testing of a thermoset carbon fiber composite front-bumper and crush-can (FBCC) system gathered under multiple loading conditions. This FBCC design was developed to demonstrate progressive crush, virtual simulation, tooling, fabrication, assembly, non-destructive evaluation and crash testing

  6. Challenges of NDE simulation tool validation, optimization, and utilization for composites

    Science.gov (United States)

    Leckey, Cara A. C.; Seebo, Jeffrey P.; Juarez, Peter

    2016-02-01

    Rapid, realistic nondestructive evaluation (NDE) simulation tools can aid in inspection optimization and prediction of inspectability for advanced aerospace materials and designs. NDE simulation tools may someday aid in the design and certification of aerospace components; potentially shortening the time from material development to implementation by industry and government. Furthermore, ultrasound modeling and simulation are expected to play a significant future role in validating the capabilities and limitations of guided wave based structural health monitoring (SHM) systems. The current state-of-the-art in ultrasonic NDE/SHM simulation is still far from the goal of rapidly simulating damage detection techniques for large scale, complex geometry composite components/vehicles containing realistic damage types. Ongoing work at NASA Langley Research Center is focused on advanced ultrasonic simulation tool development. This paper discusses challenges of simulation tool validation, optimization, and utilization for composites. Ongoing simulation tool development work is described along with examples of simulation validation and optimization challenges that are more broadly applicable to all NDE simulation tools. The paper will also discuss examples of simulation tool utilization at NASA to develop new damage characterization methods for composites, and associated challenges in experimentally validating those methods.

  7. To evaluate and compare the effect of different Post Surface treatments on the Tensile Bond Strength between Fiber Posts and Composite Resin.

    Science.gov (United States)

    Shori, Deepa; Pandey, Swapnil; Kubde, Rajesh; Rathod, Yogesh; Atara, Rahul; Rathi, Shravan

    2013-10-01

    Fiber posts are widely