Top PDF Effect of Three Different Antioxidants on Shear Bond Strength of Composites To Bleached Enamel - An In Vitro Study

Effect of Three Different Antioxidants on Shear Bond Strength of Composites To Bleached Enamel - An In Vitro Study

Effect of Three Different Antioxidants on Shear Bond Strength of Composites To Bleached Enamel - An In Vitro Study

Perhydroxyl radicals are not only associated with high permeability and diffusibility but also split the long chained, dark colored macromolecules of pigments into smaller, less colored and more diffusible molecules which are removed from the structure producing the bleaching effect. Following bleaching, these free radicals react with the organic enamel and can result in morphological alterations, surface irregularities and reduced bond strength of composite resin to enamel.

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

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

[13-17], one study showed that sodium ascorbate had the potential of forming a three-dimensional, porous physical scaffold that would entrap the pathogenic microorganisms like Streptococcus mutans and this adverse property affected its efficacy for enhancing the bond strength and highlighted the need for other antioxidants [18]. Grape seed as an herbal antioxidant contains pro- antioxidant compounds and is capable of eliminating free radicals [3]. Studies have shown that polyphenols present in green tea are rapidly metabolized and show antioxidant activity [19,20]. Catechins present in green tea such as epigallocatechin gallate (EGCG) are antioxidant compounds that can eliminate free radicals as well [21]. Sage extract also has antioxidant capacity [22]. Previous studies have shown that these herbal antioxidants can reverse the decreased bond strength of composite to bleached enamel [17,22,23]. However, some studies have reported different efficacy values for herbal products in various application times [24-28]. Also, a large number of studies have compared only one or two herbal antioxidants with sodium ascorbate [23,26,27]. In order to better assess the efficacy of herbal and chemical antioxidants, this in-vitro study was carried out to assess the effect of sodium ascorbate, grape seed, sage and green tea extracts on the bond strength of composite to bleached enamel.
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Effect of different anti oxidants on shear bond strength between nano hybrid composite and bleached enamel-an invitro study

Effect of different anti oxidants on shear bond strength between nano hybrid composite and bleached enamel-an invitro study

Since, there is a limited information available on the use of the newer natural antioxidant agents like Oligomeric Proanthocyanidin Complexes (OPCs) that they increases the bond strength of composite resin to bleached enamel. OPCs present in natural antioxidants like grape seed extract and pine bark extract have free radical scavenging activity 4 ,36 . Hence, the aim of this in-vitro study was to evaluate and compare the effect of 10% Sodium Ascorbate , 10 % pine bark extract, and Aloe vera leaf solution on the SBS of composite resin to bleached enamel.
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Comparative evaluation of reversal of shear bond strength on bleached enamel using antioxidants – sodium ascorbate, salicylic acid & N-acetyl cysteine: An in vitro study

Comparative evaluation of reversal of shear bond strength on bleached enamel using antioxidants – sodium ascorbate, salicylic acid & N-acetyl cysteine: An in vitro study

20 Prevention (CDC) has adopted guidelines for infection control of extracted teeth used for research and teaching. These guidelines require that teeth not containing amalgam be heat-sterilized by an autoclave cycle for 40 minutes before use. Teeth that contain amalgam should be stored in 10 percent formalin for two weeks before use. Although autoclaving does not seem to alter the tooth's physical properties sufficiently for research purposes, it is unknown whether autoclaving affects the chemical and micromechanical relationship between dentin and dental. In this study, we investigated the effect of storage conditions and sterilization methods on the composite-to-dentin bond strength. Within the rotations of this study, we can draw the following conclusions. When storage solutions alone are compared, 0.9 percent NaCl and 5.25 percent NaClO resulted in significantly lower SBS values an those obtained with H 2 O 2 . Therefore,
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The Effect of Titanium Tetrafluoride and Sodium Hypochlorite on the Shear Bond Strength of Methacrylate and Silorane Based Composite Resins: an In-Vitro Study

The Effect of Titanium Tetrafluoride and Sodium Hypochlorite on the Shear Bond Strength of Methacrylate and Silorane Based Composite Resins: an In-Vitro Study

2mm from central groove and parallel to the occlusal surface using a diamond disk (4138, KG soren son, Ba- rueri, SP, Brazil) under water cooling. [22] The root of the sectioned teeth were embedded in cylindrical alu- minium blocks of 2cm diameter and 2.5cm height and stabilized in acrylic resin, 1.0 mm below the CEJ. Then, the occlusal surfaces of the teeth were ground to pro- duce a flat and smooth dentin surface with 600-grit sili- con carbide abrasive paper under constant water spray. [23-24] In this study, a halogen light polymerizing unit (optilux501, sybronkerr, Danbury, CT. USA) with light intensity of 600mW/cm 2 was used for curing the adhe- sive and resin composites.
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Effect of different preventive agents on bracket shear bond strength: in vitro study

Effect of different preventive agents on bracket shear bond strength: in vitro study

In the present study, shear bond strength of orthodontic bracket was significantly impacted by the application of preventive agents as well as by the time of acid-etching, which means that both factors have almost the same impact on SBS. The SBS increased significantly when CPP-ACPF was applied after acid-etching. To our knowledge, there are no published studies of the effects of CPP-ACPF or CPP-ACP after acid-etching process on bracket SBS. Nevertheless, in all experimental groups, the bracket SBS values increased when the preventive agents were applied after acid-etching. This might be attributed to the fact that when CPP-ACP, CPP-ACPF and fluoride were applied before acid-etching, they increase the resistance of tooth enamel to acid, which can affect bracket adhesion and result in lowering the bracket SBS values [32,33]. Teeth with a higher concentration of fluoride are generally considered to be more resistant to acid-etching and need a longer etching time [34]. Moreover, enamel lesions which have been remineralised Table 3 Results from one-way ANOVA and the Tukey test comparing the SBS values between control and experimental groups
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Comparison of Shear Bond Strength of Different Orthodontic Metal Bracket-bases Bonded on Enamel Surface – an In vitro Study

Comparison of Shear Bond Strength of Different Orthodontic Metal Bracket-bases Bonded on Enamel Surface – an In vitro Study

The shear bond strength also depends on the adhesive materials. Transbond XTTM is one of the most recommended products in current orthodontics. It has been a part of various comparative adhesion studies. In this study, all data were obtained with Transbond XTTM, which strongly associated with previous studies [26-29]. Reynolds and von Fraunhofer [30] stated that all the retentive designs used in the brackets tested should have an acceptable bond force levels (6– 8 MPa). However, there are various factors related to an oral environment or moisture contamination that may affect the shear bond strength. The moisture contamination of bracket- bases with water, saliva and blood has been shown to adversely affect the shear bond strength due to deposits of an organic adhesive layer immediately after exposure that is resistant to washing and subsequently it reduces the shear bond strength of brackets [17,31-33]. Ahmad Sheibaninia et al. [34] evaluated the effect of an acidic food simulating environment on shear bond strength of self-ligating brackets and stated that the margins of bracket-bases allows an acidic food to penetrate, which gradually decreases the shear bond strength. So care should be taken in predicting the results to those conditions. Arunima Goswami [35] et al. stated that moisture contamination did not affect the shear bond strength. It has been suggested that an adverse effect of moisture contamination on orthodontic bonding can be associated with water adsorption, which produce formaldehyde
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Effect of enamel protective agents on shear bond strength of orthodontic brackets

Effect of enamel protective agents on shear bond strength of orthodontic brackets

is harder to be reflected in clinical applications [26]. The distribution of the ARI scores was found different between the three major groups. In the ICON group, for both self- etching and conventional etching subgroups, higher ARI scores tended to be more frequent, while in Clinpro and control groups, both self-etching and conventional etching subgroups, less adhesive remnant tended to be seen left on the enamel surface after debonding. This could be at- tributed to the chemical bond between the resin infiltrant and the adhesive resin. However, the adhesive remaining on the enamel surface after debonding was not different in the three major groups between the self-etching sub- group and the conventional etching subgroup indicating a similar effect of the enamel protective material with the two types of adhesive systems. These results differed from the results of Naidu et al. [36] study that found using ICON as preconditioning before bonding orthodontic brackets to sound enamel did not affect ARI scores distri- bution compared to the control groups using Transbond XT primer and Transbond PSEP. The importance of the site of bond failure was found not to be a reflection of bond strength; therefore, the site of failure did not reflect different bond strengths at different interfaces [44,45]. On the other hand, a variety of factors could affect bond strength including the type of enamel conditioner, acid concentration, length of etching time, composition of the adhesive, bracket base design, bracket material, oral envir- onment, skill of the clinician, and time of light exposure in case of light-cure approach [46].
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Evaluation of shear strength of brackets with different dental composites and enamel roughness

Evaluation of shear strength of brackets with different dental composites and enamel roughness

The objective of this study was to evaluate the enamel roughness and shear bond strength (SBS) of dental composite after removal of metal brackets bonded with dif‑ ferent materials (Transbond XT, Filtek Z100, Venus Diamond and Filtek P90). Cleaning and etching were performed in vitro on 60 premolars, which were then divided into four groups (n = 15). A metal bracket was bonded to each tooth using one of the four materials. The SBS test was performed in an Instron universal testing machine, using a chisel positioned at the junction interface with a speed of 1.0 mm/min. After test‑ ing the SBS, the teeth were analyzed using the Adhesive Remnant Index (ARI) with a stereomicroscope under 40 × magnification. The remainder of the bonding material was removed with multilaminated carbide bur (FF 9642) and the surface roughness measured. The SBS and roughness data were statistically analyzed. The average SBS for the different groups in this study ranged from 6.13 to 12.72 MPa; Transbond XT (12.57 MPa) and Filtek Z100 (12.72 MPa) showed the highest values. There were dif‑ ferences between the bonding materials in IRA scores, but no statistically significant difference for roughness. All SBS values were adequate, since none were below the minimum acceptable level (6–8 MPa), however the enamel did not return to the condi‑ tions present prior to the bonding of the brackets.
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Effect of four different conditioners on the shear bond strength of composite to glass ionomer: An In vitro study

Effect of four different conditioners on the shear bond strength of composite to glass ionomer: An In vitro study

Sheth et al 1989 16 has conducted a two-part study to evaluate the tensile bond strengths of composite resin to several glass-ionomer cements that were (a) unetched but allowed to set in air and (b) etched for 30 s with orthophosphoric acid, and to compare them with the cohesive strength of the respective cement. Using a silver nitrate staining technique, they also evaluated the microleakage of class V cavities restored with composite resin under a base of etched or unetched glass ionbomer cement. Although there were significant differences among three cements between their cohesive strength and the resin bond strength after the two surface treatments, the bond to the unetched surface was generally comparable to that of the etched surface of the cement. The remaining groups showed no statistical difference. The microleakage was similar in the two groups. SEM micrographs showed a rough topography of the unetched cement that resembled that of the etched surface. This in vitro study suggests that acid-etching a glass-ionomer base for resin-bonding may not be necessary for specific materials.
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Effect of different cavity configurations on the tensile bond strength of hybrid and nanofilled composites   in vitro study

Effect of different cavity configurations on the tensile bond strength of hybrid and nanofilled composites in vitro study

Microfilled composites are capable of being brought to a high polish due to their extremely small fillers and are thus considered as highly aesthetic, whereas, Hybrid composites show somewhat poor results but shows greater mechanical strength due to “large” fillers. The term 'nanotechnology' was coined by Prof. Kerie E. Drexler. It is engineering at the atomic or molecular scale and is used in dentistry as a nonagglomerated discrete nanoparticle that is homogeneously distributed in resins or coatings to produce Nanofilled Composites. These materials have fillers (nanomers) of 20-75 nm in size. They also contain ultra-fine radiopaque zirconium oxide fillers with a mean size of 2-5 nm. By using nanotechnology it has been possible to attain a filler proportion of approx. 72-78% by weight, which corresponds to that of a commonly used hybrid composite also the shrinkage rate of hybrid composite are unified in this new material (Zhaveri and Balaji, 2005; Christopher, 2004). With the smaller particle size there is a more chameleon-like effect with a greater scattering of light. More scattering allows excellent blending in of the restoration (the “chameleon effect”) and it also gives life-like aesthetics. The other advantage is that the strength is not compromised, with the flexural strength (128Mpa) being similar to many hybrid composites (Christopher, 2004). All these characteristics make the nanofilled composites superior to the conventional composites. Hence in the present study hybrid and nanofilled composites were used as group I and group II to study the effect of these composites on the tensile bond strength as they are used as universal composites. These experimental groups were further divided into three subgroups depending on the diameter of the cavity (i.e. 3mm, 4mm and 6mm), whereas, the depth was kept constant at 2mm. Three different diameter of the cavity was selected for both the groups to control the c-factor which was calculated using the formula, C=1+4h/d where, h – height and d – diameter of the cylindrical cavity. Thus the resultant C-factor calculated was 2.3 for 6mm diameter, 3.0 for 4mm diameter and 3.7 for 3mm diameter cavity.
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Comparison of shear bond strength of three adhesive liners to nanocomposite: an in vitro study

Comparison of shear bond strength of three adhesive liners to nanocomposite: an in vitro study

In the dental industry’s on going search for materials with improved properties, a new generation of flowable composites, known as “bulk-fill flowable composites,” has been introduced to the dental market. Ozer S, Tunc ES,Gonulol N. Bond Strengths of Silorane- and Methacrylate-Based Composites to Various Underlying Materials.BioMed Research International. 2014. SDR: Is a posterior bulk fill flowable base is a one- component, fluoride containing, visible light cured, radiopaque resin composite restorative material. Handling characterstics typical of flowable composites but can be placed in 4 mm increments with minimal polymerization stress. Designed to be overlayed with a methacrylate based universal/posterior composite. There is limited knowledge about the bonding properties of combining different materials.
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Aims: Residual peroxide on the enamel surface and in the interprismatic spaces decreases the shear bond strength (SBS) of composite to bleached enamel. Evidence shows that 10% sodium ascorbate can efficiently neutralize the singlet oxygen generated by the bleaching agents. This study aimed to assess the effect of duration of application of sodium ascorbate on SBS of composite to bleached enamel. Materials and Methods: This in vitro experimental study was conducted on 30 sound human third molars, which were randomly divided into three groups (n=10). In group 1, the teeth were bleached for 45 minutes and were then subjected to immediate bonding and restoration with composite resin. In groups 2 and 3, the teeth were bleached, immersed in 10% sodium ascorbate solution for 5 (group 2) and 10 (group 3) minutes and were then bonded and restored with composite, and the SBS was then measured. Results: The highest SBS (14.02±8.6MPa) was noted in group 3 (immersion in 10% sodium ascorbate for 10 minutes before bonding). The lowest SBS was noted in group 1 (immediate bonding after bleaching) (p<0.05). The difference in SBS of groups 1 and 2 was not significant (p=0.4). Conclusion: Application of 10% sodium ascorbate for 10 minutes increases the SBS of composite to bleached enamel.
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The effect of green tea on the shear strength of brackets after home whitening treatment

The effect of green tea on the shear strength of brackets after home whitening treatment

The diverging results between studies testing antioxidants versus the reversal of bond strength values can be attributed to the different methods used in the studies. Kimyai et al. [13] applied sodium ascorbate in the form of hydrogel or solution for 10 min or 3 h, and found that the application for 3 h obtained similar results to those of the present study, which used an application time of 1 h. In the study by Bulut et al. [6, 7], sodium ascorbate solution was stirred on enamel surface during the 10-min application time, which may have increased its effectiveness. In the present study, a small amount of green tea or sodium ascorbate was placed on the enamel surface by using individual impres- sion trays, simulating a possible clinical application.
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Effects of at-home and in-office bleaching on the shear bond  strength of metal, ceramic and composite brackets to enamel: An In vitro study

Effects of at-home and in-office bleaching on the shear bond strength of metal, ceramic and composite brackets to enamel: An In vitro study

Shinohara MS et al (2004) evaluated the effect of non vital bleaching on the shear bond strength of composite resin using three different adhesive systems. Bleaching agents used were sodium perborate and carbamide peroxide. After bleaching, the teeth in each group were cut into enamel and dentin sections. The substrates received three different adhesive namely Single Bond (solvent: alcohol/ water); Prime & Bond NT (solvent: acetone), Clearfil SE Bond (solvent: water). The results inferred that bleaching treatment influenced the shear bond strength, regardless of the adhesive system used showing reduction in shear bond strength values. On dentin, the sodium perborate bleaching agent reduced the shear bond strength values, but the carbamide peroxide bleaching did not. They inferred that non vital bleaching treatment with sodium perborate might adversely affect shear bond strength of composite resin for both enamel and dentin. Similar effects can be expected from 37% carbamide peroxide bleaching agent on enamel but not dentin, and the use of water/alcohol and acetone-based adhesive systems cannot reverse the effects of bleaching treatment on bond strengths. (53)
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Effect of Cyclic Loading on Shear Bond Strength of Orthodontic Brackets:  An In Vitro Study

Effect of Cyclic Loading on Shear Bond Strength of Orthodontic Brackets: An In Vitro Study

In the present study, 84 extracted bovine mandibular incisors were selected and disinfected by immersion in 0.5% chloramine T solution at 4°C for one week after removing the soft tissue remnants and debridement. The teeth were caries-free and had no apparent defects or enamel damage. Although bovine and human teeth are different, studies have shown that there is no significant difference in adhesive bond strength to enamel between the two [12,13]. The roots of the teeth were cut, and the crowns were stored in distilled water at 4°C until testing. The teeth were randomly divided into two groups for use of total-etch (Transbond XT; 3M Unitek Orthodontic Products, Monrovia, CA, USA) and self-etch (Transbond Plus; 3M Unitek
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Effect on enamel shear bond strength of adding microsilver and nanosilver particles to the primer of an orthodontic adhesive

Effect on enamel shear bond strength of adding microsilver and nanosilver particles to the primer of an orthodontic adhesive

We used bovine incisors for this in vitro study, owing to the difficulty of obtaining intact human teeth of sufficient quality and quantity. This usage is acceptable for bonding studies instead of human teeth according to DIN 13990 [32], and these teeth are often used in studies [51]. There are similarities between bovine and human enamel in crystallite orientation, the dimensions of the outer prisms, and the enamel matrix protein composition [52]. How- ever, there are also differences: bovine enamel contains some different chemical elements [53], and has a different prism arrangement, thicker crystallites, a wider inter- prismatic region, and increased porosity [53-57]. Although Reeh et al. [52] found a similar lubricity between human and bovine enamel, these differences resulted in greater microleakage of bovine enamel [53].
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Comparison of tensile bond strength of two different resin cements used to bond base metal alloy to human enamel: An In Vitro study

Comparison of tensile bond strength of two different resin cements used to bond base metal alloy to human enamel: An In Vitro study

Various laboratory studies have been done on layer thickness 3 , adherence energy 6 , polymerization shrinkage 60 , and the effect of storage conditions 1 of cast restoration on the bond strength of resin cements. The bond strength of the resin luting cements used to bond the base metal alloy to the tooth structure is an important feature that must be investigated. Comparisons among different studies are complicated because of the different approaches used to test adhesive ability (bonding) of resin cements. Generally, adhesive capacity has been evaluated with invitro testing, with shear and tensile tests. However, finite element analysis 10 concluded that shear test were the most efficient to disclose the cohesive resistance of the material, whereas tensile tests were better to investigate the adhesion at the interface. Since the purpose of this study was to evaluate the adhesive capacity of the resin cement rather than the stress produced during clinical function, a tensile test was used.
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Effect of Addition of Curcumin Nanoparticles on Antimicrobial Property and Shear Bond Strength of Orthodontic Composite to Bovine Enamel

Effect of Addition of Curcumin Nanoparticles on Antimicrobial Property and Shear Bond Strength of Orthodontic Composite to Bovine Enamel

The current study also assessed the antimicrobial activity of Transbond XT composite containing 1%, 5% and 10% concentrations of curcNPs against S. mutans, S. sanguinis and L. acidophilus. The three selected bacterial strains are the main constituents of dental plaque. Initiation of caries mainly depends on the activity of S. mutans while lactobacilli (mainly L. acidophilus) are responsible for progression of caries. Presence of S. sanguinis in the oral cavity decreases the population of S. mutans and these two are in equilibrium [27]. Biofilm inhibition test was carried out to assess the antimicrobial activity of composites since it has been shown that bacteria in the form of biofilm are four times more resistant to antibacterial agents compared to planktonic form [28]. The current results showed that addition of curcNPs to composite significantly decreased the bacterial count of all three strains compared to the control group in all three concentrations. The results for S. mutans were highly favorable since S. mutans colony count in presence of all concentrations of curcNPs decreased to zero. This indicates low minimum inhibitory concentration and minimum bactericidal concentration of curcNPs against S. mutans [29]. This finding is clinically significant since S. mutans is the main cariogenic microorganism in the oral cavity. On the other hand, L. acidophilus showed higher resistance, which may be due to its role in progression of caries and formation of a very strong biofilm. In
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The Effect of Aloe Vera, Pomegranate Peel, Grape Seed Extract, Green Tea, and Sodium Ascorbate as Antioxidants on the Shear Bond Strength of Composite Resin to Home-bleached Enamel

The Effect of Aloe Vera, Pomegranate Peel, Grape Seed Extract, Green Tea, and Sodium Ascorbate as Antioxidants on the Shear Bond Strength of Composite Resin to Home-bleached Enamel

peroxide for 6h/day for 7 consecutive days. They found that the SBS decreased when the samples were restored with composite resin immediately after bleaching; in addition, RMGI did not bond to the bleached enamel immediately after bleaching. Therefore, application of sodium ascorbate increased the SBS of composite resin restorations to the enamel bleached with 9.5% hydrogen peroxide. [17] In the current study, 15% carbamide per- oxide was used 6h/day for 5 consecutive days as the bleaching agent; while, in the above-mentioned study, hydrogen peroxide was used which is more potent than carbamide peroxide. It can produce more residual oxy- gen molecules that would significantly decrease the SBS. This might explain the significant effect of antiox- idant treatment in that study.
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