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

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

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

The lowest SBS was recorded with the samples treated with Clinpro before bonding the orthodontic brackets; the SBS in this group was significantly lower than the SBS in the other five groups. This could be attributed to the resistance effect that the outer enamel layer acquires from the fluoride content of the Clinpro which may be of significant effect especially when using self-etching primers in bonding due to their more superficial etching effect compared with the etching of the conventionally used phosphoric acid. Previous studies [28-30] with scanning electron microscope (SEM) indicated that although self- etch priming agents have the potential to etch the enamel surface, the etching pattern is less deep compared to the etching pattern of phosphoric acid. A chemical bonding capacity through the interaction between some functional monomers and the calcium of residual hydroxyapatite may contribute favorably to the bonding effectiveness [31-33], but fluoride affects the enamel surface rendering it more
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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

Objectives: In clinical conditions, orthodontic brackets are exposed to periodic stresses mainly induced by mastication and intraoral forces. The objective of the present study was to evaluate the effects of cyclic loading to simulate masticatory forces on shear bond strength (SBS) of metal brackets bonded to teeth using self-etch and total-etch bonding systems. Materials and Methods: Eighty-four caries- and crack-free bovine mandibular incisors were selected and randomly assigned to two groups based on the type of bonding system. After bonding, all samples were thermocycled (500 cycles) followed by cyclic loading of the half of the specimens in each group by applying 40 N load with 2 Hz frequency for 10,000 cycles. The SBS was measured using a universal testing machine. The adhesive remnant index (ARI) score was calculated subsequently. Data were analyzed using Kolmogorov-Smirnov test, two-way ANOVA and Mann-Whitney test.
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11-28-2012 12:00 AM The Effect of Surface Treatments and Bonding Agents on the Shear Bond Strengths of Orthodontic Brackets Bonded to Aged Composite Resin Restorations

11-28-2012 12:00 AM The Effect of Surface Treatments and Bonding Agents on the Shear Bond Strengths of Orthodontic Brackets Bonded to Aged Composite Resin Restorations

Reynolds 65 suggested that at the minimum, a bond strength of 6-8 MPa would be clinically acceptable. This value is often used as a benchmark in orthodontic bonding studies to enamel and non-tooth surfaces. The use of this minimum value as a reference for in vitro bond strengths has been criticized. 43,66 It has never been tested whether 6-8 MPa in vitro is clinically acceptable. It is known that bond strengths achieved in vitro are approximately 40% higher than that found in vivo. 67 Finnemore 43 recommends that extrapolation of bond strength data and comparison to a minimum reference value should be avoided. Furthermore, comparison of bond strength data between different studies is inappropriate, due to wide variation in methodology. Rather, bond strength data should only be used to assess the relative effectiveness of the adhesives within the study.
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Effect of Quaternary Ammonium Salt on Shear Bond Strength of Orthodontic Brackets to Enamel

Effect of Quaternary Ammonium Salt on Shear Bond Strength of Orthodontic Brackets to Enamel

seconds and transfer time of 10 seconds [11]. The teeth were then mounted in molds measuring 2.5x2.5 cm. The internal surface of the mold was coated with petroleum jelly and the teeth were fixed using 16x22 inch rectangular stainless steel ligature wire. Each tooth was positioned at the center of the mold and the rectangular wire was fixed to the mold using sticky wax so that the teeth remained fixed when applying acrylic resin. Auto- polymerizing acrylic resin was applied to the mold and the teeth were embedded in acrylic to the level of their cementoenamel junction. After polymerization of acrylic resin, the teeth in acrylic blocks were separated from the mold (Fig. 1). The shear bond strength test was performed in Tehran University Dental Research Center. Universal testing machine (Zwick Roell, Ulm, Germany) was used for shear bond strength testing. The teeth were placed in the machine such that the bracket base was parallel to the load application vector. Load was applied in occlusogingival direction at a crosshead speed of 0.5 mm/minute to the bracket- tooth interface (Fig. 2). Load at debonding was recorded in Newtons (N) and converted to Megapascals (MPa) by dividing the load in Newtons by the bracket base surface area in square-millimeters (mm 2 ).
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Factors Affecting the Shear Bond Strength of Orthodontic Brackets – a Review of In Vitro Studies

Factors Affecting the Shear Bond Strength of Orthodontic Brackets – a Review of In Vitro Studies

Gungor et al. (49) evaluated the effects of fluorosis and self-etching primers on the SBS of orthodontic brackets. Twenty four fluorosed teeth selected according to the mod- ified Thylstrup and Fejerskov index and 24 non-fluorosed extracted human premolar teeth were randomly assigned to 4 groups of 12 each. Standard etching protocol was followed and brackets were bonded with Light Bond in group I (non- fluorosed teeth) and II (fluorosed teeth). Similarly, Transbond Plus self-etching primer was used and brackets were bonded using Transbond XT Light Cure Adhesive in groups III (non- fluorosed teeth) and IV (fluorosed teeth). The results showed that the mean SBS in group II (Light Bond + fluorosis) was significantly lower than that of the other groups. The authors concluded that enamel fluorosis significantly decreased the SBS of orthodontic brackets when standard etching protocol was used. However, the authors reported that a satisfactory SBS was obtained when self-etching primer was used for bonding brackets to fluorosed teeth. Another study (50) com- pared the SBS of orthodontic brackets bonded to fluorosed and non-fluorosed teeth with self-etching primer and Phos- phoric acid. Forty mildly fluorosed teeth selected according to Thylstrup and Fejerskov index (1–3; mild fluorosis) and 40 non-fluorosed teeth were randomly divided into two sub- groups according to the pre-treatment: 1) 37% Phosphoric acid applied for 30 seconds; 2) self-etching primer (Trans- bond Plus). The brackets were bonded using Transbond XT, cured for 20 seconds and the SBS measured after 1000 ther- mocycles. No difference in the SBS was observed between mildly fluorosed and non-fluorosed teeth etched with 37% Phosphoric acid for 30 seconds. However, the mean SBS of orthodontic brackets bonded to mildly fluorosed teeth treat- ed with self-etching primer showed lower values compared to the non-fluorosed teeth.
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Effect of two different primers on the shear bond strength of metallic brackets to zirconia ceramic

Effect of two different primers on the shear bond strength of metallic brackets to zirconia ceramic

The aim of the present study was to test the shear bond strength between orthodontic brackets and dental zirconia ceramics using a new primer (Monobond Etch & Prime, Ivoclar Vivadent, Schaan, Principality of Liechtenstein) actually made for use in ceramic repairs. The results were compared with those of a conventional primer system from the same manufacturer (Monobond S, Ivoclar Vivadent). Both primers were applied without using hydrofluoric acid due to patient safety reasons. Be- sides the shear bond strength, possible residues of the adhesive materials either on the bracket base or on the ceramic were examined using the adhesive remnant index (ARI). A further aim of the present study was to investigate and to establish a study model that simulates intraoral forces. Artificial aging was also applied on the shear bond strength between orthodontic brackets and dental ceramics. Thus, three brackets were bonded in a simulated orthodontic leveling phase on a pretreated ceramic block. In the test group the brackets were left without any activation, while in the experimental group the brackets were activated by means of an orthodontic
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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

Wiltshire et al (2010) mentioned that debonding force is determined from the load drop on the mechanical machine and reported in units of Newtons (N), kilogram (kg), or pounds (lb). Bond strength is defined as the force of debonding divided by the area of the bonded interface measured in units of megapascals (MPa), kilograms per square centimeter (kg/cm 2 ), pounds per square inch (lb/in 2 or psi). It is difficult to estimate the optimal bond strength of an adhesive in the oral environment. This is because the orthodontic brackets are subjected to masticatory forces, which are often a mixture of shear, peel, shear-peel, and tensile force. Rather than focusing on an arbitrary numerical “clinical acceptable bond strength”, they suggested to pay more attention to potential damage to the enamel, especially when the bond strength is too high. They recommended mean bond strength of at least 3 - 4MPa in vitro for minimal reliable clinical bonding. (72)
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The Effect of Four Surface Treatment Methods on the Shear Bond Strength of Metallic Brackets to the Fluorosed Enamel

The Effect of Four Surface Treatment Methods on the Shear Bond Strength of Metallic Brackets to the Fluorosed Enamel

mild and moderate fluorosed teeth of the patients aged less than 40 years; however, this was not the case in the teeth of older patients. But, findings of our study demonstrated that increasing the etching time from 30 to 120 seconds did not result in a significant increase in the SBS of orthodontic brackets for moderate fluorosed and non-fluorosed premolar teeth. Similar results were obtained by Silva Benitez et al. [15] who etched severely fluorosed molar teeth for 150 seconds. The different results yielded by different studies are probably due to the various severities of fluorosis and different etching time used in these studies. [8, 15] Ateyah and Akpata [8] used both anterior and posterior teeth (incisor, premolar, and molar) in their study and found that the fluoride content varied among different types of the teeth. [3] In addition, they grinded to flat- ten the hypermineralized surface layer before acid etching. The differences between the findings of At- eyah and Akpata [8] and our study may be related to the different techniques employed as mentioned above. The findings of the current study showed that air abrasion followed by acid etching could increase SBS value compared with acid etching alone for both fluorosed and non-fluorosed teeth; although this dif- ference was not statistically significant. Silva-Benitez et al. [15] detected that the use of air abrasion fol-
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Evaluation of a New and Advance Curing Light on the
Shear Bond Strength of Orthodontic Brackets

Evaluation of a New and Advance Curing Light on the Shear Bond Strength of Orthodontic Brackets

Light-cured orthodontic adhesives have been used almost exclusively with light emitted from a halogen source. However, tungsten–quartz halogen curing units have several shortcomings. They have a harmful effect on teeth pulp, especially when used in orthodontic practice where most of patients are from younger age group with large pulp chambers. Only 1% of the total energy input is converted into light and the remaining is generated as heat. The short life of halogen bulbs, noisy cooling fan, and the time it takes to expose each bonded bracket to the light (10–40 seconds) are other disadvantages.
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Shear Bond Strength of Orthodontic Brackets to Composite Restorations Using Universal Adhesive

Shear Bond Strength of Orthodontic Brackets to Composite Restorations Using Universal Adhesive

Several chemical methods have also been rec- ommended such as prolonged exposure to phosphoric acid, etching with hydrofluoric acid, silanation, and application of a variety of bonding resins or adhesion promoters. Unlike the tooth enamel, the conventional phosphoric acid etching has no effect on composite restoration surfaces; therefore, creating micromechani- cal retention is difficult in such surfaces [2]. Some studies have shown that hydrofluoric acid etching is effective for producing clinically acceptable bond strength values [3, 9, 12, 14]. Bayram et al. [14] and Viwattanatipa et al. [12] both reported mean shear bond strength values of 7.2 MPa and 13.0 MPa, fol- lowing hydrofluoric acid etching, compared to 2.8 MPa and 6.5 MPa when no surface preparation was performed. However, these values were less than those values achieved following diamond bur preparation or air abrasion. In contrast, Brosh et al. [18] reported that the lowest bond strength was noted following the use of hydrofluoric acid. Hydrofluoric acid is a highly caustic substance and can cause severe damage if it in- advertently contacts the soft tissue. It also increases the chairside time since its use requires placement of a soft tissue barrier. Considering these shortcomings and the controversy regarding its positive effect on bond strength, hydrofluoric acid was not used in our study. It is also believed that silanation is an effective adhe- sion promoter for bonding to porcelain surfaces. How- ever, its efficacy for effective bonding to old compo- site resin restorations is still a matter of debate [19].
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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

This study, we evaluated the effect of green tea on the shear bond strength of metal orthodontic brackets to human enamel after home whitening treatment. Ninety premolars were selected and divided into six experimental groups: G1, no treatment (positive control); G2, whitening (negative control); G3, no whitening + 10 % sodium ascorbate (SA) gel; G4, no whitening + 10 % green tea (GT) gel; G5, whitening + SA; and G6, whitening + GT. The samples of G2, G5, and G6 were whitened with 10 % car‑ bamide peroxide for 8 h daily, during 14 days at 37 °C. G3, G4, G5, and G6 were treated with the respective antioxidants (GT or SA) for 1 h at 37 °C. After the treatments, the brackets were bonded with Transbond XT. Then, the samples were tested in a univer‑ sal testing machine and the adhesive remnant index (ARI) was examined under 40 × magnification. Data were submitted to analysis of variance, Tukey’s and Dunnett’s tests (α = 5 %). The averages (standard deviations) obtained were: G1, 17.6 (4.1); G2, 9.8 (3.6); G3, 18.1 (4.1); G4, 18.2 (4.7); G5, 14.9 (2.5); and G6, 14.8 (5.4). G2 had statistically lower values than the other groups. Concerning the ARI, all groups had a higher number of flaws type score 0 (no material adhered to the tooth). We conclude that the use of GT can be an alternative method to allow bracket bonding immediately after home whitening treatment.
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Effect of remineralizing agents on bond strength of orthodontic brackets: an in vitro study

Effect of remineralizing agents on bond strength of orthodontic brackets: an in vitro study

Very limited studies have been found to be conducted to evaluate the effect of fluoride and CPP-ACP on the bond strength. Also, studies conducted have shown con- troversial results. In a study conducted by Damon et al. [11] and Bishara et al. [12], the shear bond strength was not affected by various concentrations and methods of application of fluoride. However, the study conducted by Tabrizi and Cakirer [13] concluded that no significant difference was seen between control, CPP-ACP, and CPP-ACP with fluoride group, while fluoride application caused a significant decrease in the tensile bond strength of etch and rinse bonding technique. Kecik et al. [14] compared the effects of CPP-ACP and acidulated phos- phate fluoride on SBS values and found higher SBS values for all test groups. Xiaojun et al. [15] reported higher SBS in the CPP-ACP applied group when light-cure adhesives were used. In a study conducted on demineralized en- amel by Uysal et al. [16], fluoride and CPP-ACP en- hanced the bond strength of the orthodontic brackets compared to the control group in demineralized en- amel. In contradiction to this, Ekizer et al. [17] showed no significant difference in fluoride group and control group, while CPP-ACP enhanced the bond strength of the orthodontic brackets.
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Comparative Evaluation of Shear Bond Strength of Orthodontic Brackets on Pretreatment with CPPACP, Fluor Protector and Phosflur: An In-vitro Study

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In an earlier study conducted by Dunn it was suggested that Orthodontic brackets bonded to teeth with an ACP containing composite material failed at significantly lower forces than brackets bonded to teeth with conventional resin-based composite Ortho- dontic cements. So the question that arises is whether the dis- advantage of low bond strength due to the effect of the material outweighs its advantage as a protector against demineralization. Recent studies however show that CPP-ACP application can cause increased shear bond strength of brackets when light-cured adhesive is used. In this in vitro study the effects of pretreatment of CPP-ACP on Shear bond strength (SBS) of Orthodontic brackets was examined.
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The Influence of Resin Infiltration System on Sound Enamel Microhardness and Shear Bond Strength of Orthodontic Bands: An In Vitro Study

The Influence of Resin Infiltration System on Sound Enamel Microhardness and Shear Bond Strength of Orthodontic Bands: An In Vitro Study

The caries infiltration product ICON; a new virtually painless method, was introduced in Germany in 2009. This product utilized a special resin to seal and fill demineralized enamel without causing the loss of healthy hard tissue 29 . Icon can be used for the microinvasive treatment of initial carious lesions in the vestibular and approximal regions. The vestibular version is particularly developed for orthodontic patients after removal of braces 29 . To our knowledge, only a few studies have been conducted regarding ICON, and those have shown promising results 30 . Most studies were testing the effect on the orthodontic brackets 31-33 , other studies were investigating using the resin infiltrant for treatment of the incipient carious lesion and white spots development 34,35 .
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Does the antioxidant treatment affect the shear bond strength of orthodontic brackets: An in vitro study

Does the antioxidant treatment affect the shear bond strength of orthodontic brackets: An in vitro study

Arabia. Approval was taken from institutional review board of Qassim University. The study comprised non- carious, sound maxillary and mandibular premolars extracted for therapeutic orthodontic purposes. Teeth with hypoplastic areas, fluorosis or gross irregularities of the enamel structures were excluded. No pre-treatment with chemical agents such as alcohol, formalin, or hydrogen peroxide, or any other form of bleaching was allowed. The teeth were cleaned of blood and tissue debris and stored under refrigeration at 4°C in artificial saliva solution. The artificial saliva was refreshed daily to avoid bacterial contamination.
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Effect of multiple debonding sequences on shear bond strength of new stainless steel brackets

Effect of multiple debonding sequences on shear bond strength of new stainless steel brackets

Teeth were polished with fluoride‑free pumice paste (Dentatus, Tehran, Iran), using rubber cap for 15 s, then washed with tap water for 15 s and air‑dried. One operator performed the bonding process, after etching the specimens with 37% phosphoric acid (3M Unitek, St. Paul, MN, USA) for 30 s. Each bracket (0.022‑inch twin brackets, American Orthodontics, Sheboygan, WI, USA) was bonded with a Transbond XT adhesive (3M Unitek, St. Paul, MN, USA) and light‑cured (Bonart‑Art‑L2 Light Curing Unit, Bonart Co. Ltd., Taipei, Taiwan) according to the instruction provided by the adhesive’s manufacturer. The bracket base size was approximately 11.85 mm². No bond enhancer was used for bonding procedures. Overall, 240 SS brackets were used and bonded with 4 mm distance from the occlusal surface. The excess adhesives were removed using a dental explorer. In order to ensure all brackets were bonded in the same plane a mounting jig appliance consisting of a stand containing a 0.021 × 0.025 inch SS wire was used; this was placed in the bracket’s slot when teeth were put in molds containing self‑cure acrylic resin [Figure 1]. The specimens were not exposed to thermocycling and brackets were debonded after 24 h. During force application, each tooth with its own acrylic base was put in one jaw of the universal testing machine (Zwick/Roell Zo20, Ulm, Germany) and a specimen holder was used to ensure constant load parallel to the tooth surface [Figure 2]. The other part of the machine exerted an occlusal‑gingival load to the upper surface of the bracket between the upper wings and bracket base using a blade, producing a shear force at the bracket tooth interface. The blade, which was perpendicular to the bracket’s slot, exerted a force at a crosshead speed of 1 mm/min until rupture of the bracket‑tooth union. [22] The required forces
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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

Researchers have long been in search of methods to prevent enamel demineralization during orthodontic treatment without adversely affecting the bond strength [19,20]. Addition of nanoparticles to composite resin has been documented as an effective strategy to prevent enamel demineralization [21,22]. Advancements in nanotechnology have enabled the fabrication of nanoparticles with improved properties. However, aside from their antimicrobial efficacy, their effects on physical and mechanical properties of orthodontic composites must be evaluated [23]. Optimal antimicrobial activity of curcumin has been documented against Enterococcus faecalis [16] and S. mutans [24]. The cariostatic effect of curcumin is mediated by prevention of bacterial adhesion to enamel and destruction of bacterial cell wall via disrupting the peptidoglycan layer [24].
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Comparison of shear bond strength and adhesive remnant index between precoated and conventionally bonded orthodontic brackets

Comparison of shear bond strength and adhesive remnant index between precoated and conventionally bonded orthodontic brackets

Numerous studies have made suggestions to overcome the problems associated with the clinical applicability of results from in vitro studies. Technical specifications, as described in ISO/TS 11405:2003, provide guidance for the selection of substrates and storage and handling con- ditions, as well as the essential characteristics of different test methods for quality testing. Therefore, the purpose of this study was to compare the SBS and adhesive remnant index (ARI) at the enamel-bonding interface between precoated and conventionally bonded brackets, utilizing standardized procedures, thereby facilitating comparisons among studies.
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The Effect of CuO Nanoparticles on Antimicrobial Effects and Shear Bond Strength of Orthodontic Adhesives

The Effect of CuO Nanoparticles on Antimicrobial Effects and Shear Bond Strength of Orthodontic Adhesives

Metal brackets (Dentaurum, Discovery, Germany) were placed on buccal surface of teeth, 4 millimeter from cusp tip, and fitted completely on the tooth surface using a scaler pressure. Then excessive adhesive was removed with a scaler before curing. Nano-composites of 0.1%, 0.5%, and 1% (wt.%) were used for first, se- cond, and third groups respectively. Transbond XT (3M) adhesive was also used in control group. Then brackets were light-cured using a LED curing unit (MORITA, Japan) at 450 nm wavelength, and 500 mv/cm 2 , for 20 seconds (5 seconds from each aspect). All samples were thermo-cycled (Vafaee, Iran) for 1500 times between 5 to 55 0 C, 15 seconds in each tempera- ture with 10 seconds intervals. Then shear forces were applied to the brackets of all 4 groups, including three study groups and one control group, using a universal testing machine (Walter+bai, Switzerland) at 0.5 mm/ min crosshead speed, until the bond failure occurred. Debonding force was recorded in Newton, changed to mega-Pascal by dividing to surface area of bracket base. Disc agar diffusion test was used in this study to investigate the antibacterial effects of adhesive con- taining CuO nanoparticles against S.mutans. A suspen- sion equivalent to 0.5 McFarland turbidity (1.5×10 8 . CFU/ml) in the brain-heart-infusion (BHI) medium was produced from new cultured (24 hours) standard S.mutans. Plastic molds with a diameter of 6 mm and a thickness of 1 mm were used to make composite discs. The molds were placed on a glass slab, and were covered with another slab after putting adhesive in the mold; then the adhesives were cured for 20 seconds (10 seconds from side) with light curing device. In this way, 10 discs of 6mm diameter and 1 mm thickness were produced from each adhesive group. In order to complete curing, discs were cured for 10 seconds again. Then, using swaps, some prepared bacterial suspension was meadow cultured on the Mueller Hin- ton medium (Merck, Germany) enriched with 5% sheep blood. Then a disc from each group was placed on the plates containing medium. All culture media plates were kept in a CO 2 incubator at 37
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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

Group 1 (primer, control group): Teeth were polished with Zircate® Prophy Paste, rinsed with water and air- dried. The enamel surfaces were then etched for 30 sec- onds with a 37% phosphoric acid etching gel, then rinsed for 10 seconds with water and air-dried. A thin film of primer was applied on the etched enamel surface, and illuminated with a light source (Poly Lux II, KaVo Dental, Biberach/Riss, Germany) for 15 seconds. Then, Transbond XT adhesive was applied to the bracket base, the bracket was applied and pressed onto the enamel surface, and ex- cessive adhesive was removed prior to polymerization, which was conducted for 20 seconds each from the mesial and distal sides.
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