Shear Bond Strength Of Brackets Research Articles

Effect of Acid Surface Treatments on the Shear Bond Strength of Metal Bracket to Zirconia Ceramics

Effect of Acid Surface Treatments on the Shear Bond Strength of Metal Bracket to Zirconia Ceramics

Does surface priming increase the bond strength of orthodontic brackets? An experimental study.

To evaluate the effects of metal primer II (MP II) on the shear bond strength (SBS) of orthodontic brackets bonded to teeth and bis-acryl composite provisional material (Bis-Acryl). Twenty extracted human premolars specimens and 20 premolar shaped Bis-Acryl specimens were obtained and randomly divided into two surface groups. The first group consisted of human premolars (T) bonded to brackets in the conventional way while in the second (T-MP) MP II was applied on the bracket base before bonding. Similarly, one group of provisional material (PM) was prepared according to conventional treatment and another with the application of MP-II metal bonder (PM-MP). In all cases Ortho-brackets (Victory Series, 3 M) were bonded employing Transbond XT resin cement. Then the brackets were debonded under shear and the results were statistically analyzed by two-way analysis of variance and Holm Sidak at α = .05. The debonded surfaces of all specimens were examined by light microscopy and the Adhesive Remnant Index (ARI) was recorded. The SBS results exhibited significant differences er (p < .001). For both the T and TM the application of MP-II increased the SBS compared to respective control groups (p < .001). The T-C group was found inferior compared to PM-C (p < .001) and the same is true for the comparison between T-MP and PM-MP (p < .001). ARI indexes demonstrated that the tooth groups were characterized by a predominantly adhesive failure at the resin-dentin interface. In contrast, the control group for provisional crowns (PM-C) showed a predominantly cohesive failure mode, which moved to predominantly adhesive after the application of MP II. The application of MP II enhances the SBS on both, human enamel and provisional crown materials.

Comparision of Shear Bond Strength between Ethyl Alcohol Wet Bonding and Conventional Wet Bonding of Orthodontic Brackets – An Invitro Study

Aim : The study aimed to assess the impact of ethyl alcohol wet bonding on the shear bond strength (SBS) of orthodontic brackets compared to conventional wet bonding methods.  Materials and Methods : 12 premolar teeth were utilized and divided into two groups: conventional wet bonding and ethanol wet bonding. Each group followed its respective bonding protocol.After bonding, the teeth were immersed in water for complete polymerization.Shear bond strength was assessed using a Universal Testing Machine (UTM).Statistical analysis was performed to compare the shear bond strength between the two groups.  Results : The mean shear bond strength observed in the ethyl alcohol wet bonding group was higher compared to the conventional wet bonding group.Statistical analysis revealed a significant difference between the shear bond strengths of the two groups, with ethyl alcohol wet bonding demonstrating superior results.  Conclusion : The mean shear bond strength achieved with ethyl alcohol wet bonding (6.5 MPa) falls within the optimal range as indicated by Reynolds et al. (1976).Ethanol could serve as a cost-effective alternative to MIP (presumably a bonding agent or adhesive used in conventional wet bonding). This study suggests that ethyl alcohol wet bonding may offer advantages in terms of shear bond strength compared to conventional wet bonding methods, potentially providing a viable alternative for orthodontic bracket bonding

An In Vitro Study to Compare the Shear Bond Strength of Metal and Ceramic Brackets Using Conventional Acid Etch and Self-Etch Primer

ABSTRACT Aim: In this, in vitro study’s objective is to assess the shear bond strength (SBS) of metal and ceramic orthodontic brackets that have been adhered to enamel using a conventional acid etch/primer and self-etching primer (SEP) adhesive method. Materials and Methods: One hundred excised human premolars were bonded on brackets and were divided into group 1 –Metal brackets were bonded on teeth and group 2 –Ceramic brackets were bonded on teeth. These two groups were further subdivided: subgroup 1a – 25 metal brackets bonded using conventional acid etch/primer adhesive system, subgroup 1b – 25 metal brackets bonded using SEP, subgroup 2a – 25 ceramic brackets bonded using conventional acid etch/primer adhesive system, and subgroup 2b – 25 ceramic brackets bonded using SEP; brackets were debonded using a computerized Instron universal testing machine. Results: The mean value of SBS of metal and ceramic brackets bonded using conventional acid etch/primer adhesive systems had higher SBS than those bonded using SEP. SBS ranged from 7.95 to 12.24 MPa which was in the acceptable clinical range. Conclusion: SBS values of all four subgroups exceeded the range of 6–8 MPa observed to be acceptable for routine clinical use.

Shear bond strength of the Iingually and buccally bonded brackets via three composite systems

This study aimed to determine and compare the shear bond strength of linguallybonded brackets via: Two—paste composite (Orthodontic Mix Bonding System), No —mix composite [Orthodontic Bonding System (No—mix)] and Light—cured composite( Transbond XT .)Thirty extracted upper first premolars for orthodontic request were used for thisinvestigation. The teeth were divided into three groups; each of which consisted of l0teeth. The lingual surface of the tooth used to evaluate the lingual bond strength andthe buccal surface of the same tooth utilized to evaluate the buccal bond strength. Foreach group of teeth investigated to determine the lingual and buccal bond shearstrength, using one type of composite system for each group .The lingually bonded and buccally bonded samples were subjected to shearforce using the universal compression testing machine apparatus. The lingual andbuccal shear bond strengths were recorded and converted into Mpa and the data werestatistically analyzed .The results showed the lingual shear bond strength insignilicantly less than thatof buccal shear bond strength regarding the Orthodontic Mix Bonding System andOrthodontic Bonding System (No—mix), and the lingual shear bond strength wassignificantly less than the buccal shear bond strength regarding Light—curedcomposite (Transbond XT), The lingual and buccal shear strengths of the bondedbracket via Orthodontic Mix Bonding System were the highest than the shear bondstrength of the other composite systems

Shear bond strength of orthodontic brackets bonded with primer-incorporated orthodontic adhesives and unpolymerized 3-dimensional printing materials on 3-dimensional-printed crowns

The use of 3-dimensional (3D) printing techniques in fabricating crowns has increased the demand for bracket bonding onto these surfaces. The objective was to evaluate the shear bond strength (SBS) of orthodontic brackets bonded onto 3D-printed crowns using primer-incorporated orthodontic adhesives and 3D printing materials as orthodontic adhesives. A total of 160 crowns were printed with 2 3D printing materials, DentaTOOTH (Asiga, Sydney, Australia) (group A) and NextDent C&B Micro Filled Hybrid (3D Systems, Soesterberg, Netherlands) (group N). Each group was randomly divided into 4 adhesive subgroups (n= 20): Transbond XT (for groups A [ATX] and N [NTX]; 3M Unitek, Monrovia, Calif), Ortho Connect (for groups A [AOC] and N [NOC]; GC Corporation., Tokyo, Japan), Orthomite LC (for groups A [AOM] and N [NOM]; Sun Medical, Co Ltd, Moriyama, Shiga, Japan), and unpolymerized liquid state of 3D printing resin (for groups A [AA] and N [NN]). SBS was measured with a universal testing machine at a crosshead speed of 0.5 mm/min. The adhesive remnant index and the mode of failure were analyzed under the microscope. Statistical analysis was performed at a significance level of α= 0.05. When used as adhesives (AA and NN), 3D printing materials showed no statistically significant difference in SBS compared with Transbond XT (ATX and NTX, respectively). In group N, NN showed a significantly higher SBS than primer-incorporated orthodontic adhesives (NOC and NOM; P<0.001). Adhesive failures were only observed in primer-incorporated orthodontic adhesives (AOC, NOC, AOM, and NOM). Primer-incorporated orthodontic adhesives, as well as unpolymerized 3D printing materials employed as orthodontic adhesives on 3D-printed crowns, exhibited comparable bonding strength to Transbond XT without surface modification. Despite variations in adhesive-related factors, all measurements stayed within clinically acceptable ranges, highlighting the potential of these materials for orthodontic bonding on 3D-printed crowns, simplifying clinical procedures without compromising bond strength.

Effectiveness of Different Etching Agents on Enamel Surface and Shear Bond Strength: An In Vitro Evaluation.

Background Enamel etching is of utmost importance during the orthodontic bonding procedure. Phosphoric acid, hydrofluoric acid, and citric acid are used in specific concentrations to create surface irregularities on enamel surfaces, enhancing the bond strength of the orthodontic attachment. Therefore, it is essential to evaluate the type of etchant for reliable orthodontic bracket bonding with minimal damage to the enamel surface. Aims and objectives This study aimed to investigate the morphological changes on the enamel surface after treatment with different surface etchants, assess the depth of penetration, and evaluate the shear bond strength (SBS) of orthodontic brackets. Materials and methods One hundred and one extracted premolar teeth were used to investigate morphological changes on the enamel surface treated with 37% phosphoric acid, 11% hydrofluoric acid, and 20% citric acid. It was evaluated on a scanning electron microscope (Jeol Scientific Equipment, Jeol Limited, Akishima, Japan), and the SBS of brackets on enamel treated with different etching agents was evaluated using an Instron Universal Testing Machine (UTM; Instron Model: 5982, Universal Testing Systems, Norwood, MA). Group A had 60 test samples. Group B had 40 test samples. One control without any acid etching was used in both groups. Subgroup A1 (n = 30) was evaluated for surface characteristics of acid-etched enamel. Subgroup A2 was assessed for the penetration depth of various etchants. Group B (n = 40) was tested for SBS. The results were tabulated and analyzed using IBM SPSS Statistics, version 20.0 (IBM Corp., Armonk, NY). Post hoc Tukey HSD test and one-way analysis of variance were used to assess SBS and penetration depth of etchants (P ≤ 0.05). Pearson's correlation test was used to correlate SBS, etching pattern, and penetration depth. The chi-square test was used to test the frequency of types of etching patterns. Results Intergroup correlations between etching depth, etching pattern evaluated on SEM, and SBS evaluated on the UTM showed a high statistical correlation between etching depth & SBS, etching depth & etching pattern, and SBS & etching pattern between A1, A2, and group B (P ≤ 0.001). A highly significant negative correlation between SBS & etching pattern (P = 0.42) was observed among intra-group correlation. Non-significant correlations were found between etching depth & SBS and etching depth & etching pattern within the 20% citric acid etch group (P = 0.370 and 0.141, respectively). Conclusion Penetration depth obtained was highest with 11% hydrofluoric acid, followed by 37% phosphoric acid and20% citric acid. In addition, 11% hydrofluoric acid showed the highest bond strength. Acid etching showed better penetration depth and bond strength than control.

Evaluation of the Curing of the Primer on Shear Bond Strength of Orthodontic Brackets: An Original Research

ABSTRACT Background: The aim of this study was to evaluate the effect of separately curing the unfilled resin for increased bond strength of the orthodontic brackets as the literature shows both studies that support and contradict this aspect. Methodology: The sample consisted of 120 specimens randomly grouped into four of 30. The tooth was cleaned of tissue and debris and stored in a distilled water solution until the procedures of bonding. The surface of the enamel was conditioned with pumice, and acrylic blocks were designed for the tooth to be mounted onto them. The buccal surfaces of all the teeth were prepared by etching the enamel with 37% phosphoric acid for a time period of 30 seconds and washed for 20 seconds under running water. Stainless steel brackets (Victory Series™ MBT, 0.022 Slot) were used for all the samples in the study, and the bonding procedure was conducted on the same day for all the groups. The artificial saliva was used for the storage of samples for 24 h after bonding, and shear bond strength testing was conducted using an Instron machine in shear or peel mode at a crosshead speed. Results: The highest mean bond strength calculated was for the conventional technique (17.45 mpa), while it was the lowest for no primer adhesive (11.21 mpa). Group IV had a greater distribution of ARI scores than groups I, II, and III. Conclusion: Group IV achieved the highest bond strength when compared to other groups, with an ARI score of 3. Group III had less bond strength, likely due to incomplete curing of the primer due to insufficient exposure to light. Transbond XT can be used without primer, making bonding, debonding, and cleaning procedures easy and less time-consuming.

Does the use of universal adhesive systems improve the durability of the bond strength of orthodontic brackets to enamel?

Universal adhesive systems used for restorative clinical procedures are like orthodontics and may be a viable option. This study evaluated the effectiveness of universal adhesive systems in enhancing the durability of the shear bond strength (SBS) and adhesive remnant index (ARI) of orthodontic brackets to enamel. 100 bovine incisors were divided into five groups (n=20), according to the applied adhesive systems: Primer Transbond XT; Ambar; Ambar Universal; Single Bond Universal; Adper Single Bond 2. Bracket from each tooth were submitted to SBS test after 24 hours, and 12 months later. The amount of remaining adhesive was evaluated through ARI. After 24 hours, there was no difference in BS between the control and the other groups (p>0.05). However, there were difference between TOTALETCHING1 group and the Ambar Universal (p=0.015) and Single Bond Universal groups (p=0.011). After 12 months, Primer Transbond XT, Ambar, Ambar Universal and Adper Single Bond 2 showed no differences in the SBS (p>0.05). Nonetheless, Single Bond Universal presented superior result when compared to Primer Transbond XT (p=0.046) and Ambar (p=0.011) groups. The SBS of all groups reduced significantly after 12 months (p<0.05). There was no difference between ARI scores in each individually assessed group (p>0.05), for both periods. Following 24 hours, a difference was observed between the groups (p=0.043), fact that didn't occur after 12 months (p=0.109). Adhesive systems, such as Ambar Universal and Single Bond Universal are efficient in bonding orthodontic brackets to enamel when associated with Transbond XT adhesive paste. Key words:Bond strength; Primer Transbond XT, orthodontic brackets, adhesive systems.

To evaluate the effect of different enamel conditioning procedures on the shear bond strength of new metal bracket on previously debonded tooth surface - An in-vitro study

To evaluate the efficacy of different enamel conditioning methods while bonding a new bracket on a previously de-bonded site, and assess the difference in shear bond strength and ARI score if any. 125 human-extracted premolars were selected. 250 premolar brackets were procured. 125 brackets were bonded on the buccal surface of the premolars using different enamel conditioning methods (bonding sequence 1) and was followed by debonding using the Instron Universal testing machine (Debonding procedure I).The remaining 125 brackets were bonded (Bonding sequence II) on the same teeth after the removal of residual adhesive. Bonding sequence II was followed by debonding (Debonding procedure II), shear bond strength calculation, and ARI score calculation. There was a significant difference in SBS between the 5 groups after initial debonding. SEP group (group 4) showed the highest SBS followed by acid etching groups (groups 3, 2, and 1). The sandblasting group (group 5) had the lowest shear bond strength value. After the second debonding, SBS was found to be highest in Group 3 {37% o-phosphoric acid (Bonding I) sandblasting (Bonding II)} followed by Group 4 {SEP (Bonding I and Bonding II)}, group 2 {acid etching (Bonding I) SEP (Bonding II)}, and group 1 (acid etching in both bonding sequences). Group 5 (sandblasting in both sequences) had the least SBS. Non-significant differences were found in ARI score of the five groups. Self-etching primer group had highest SBS and sandblasting group had least SBS after first debond. The SBS of new brackets after two debonding procedures significantly decreased but was still found to be above the required bond strength. SEP and sandblasting can be used as a substitute to acid etching technique in second time bonding of brackets as these groups had higher SBS after second debond.

Shear Bond Strength of Orthodontic Brackets Bonded to Bleached Enamel using a Novel PAP-Based Bleaching Agent- An In Vitro Study.

Shear Bond Strength of Orthodontic Brackets Bonded to Bleached Enamel using a Novel PAP-Based Bleaching Agent- An In Vitro Study.

Effect of Nd:YAG and 980nm Diode laser irradiation as a hypersensitivity treatment on shear bond strength of metal orthodontic brackets to enamel

Lasers are one of the tooth hypersensitivity treatments. This study aimed to determine the effect of irradiation of Nd:YAG 1064nm and 980nm Diode lasers, used for hypersensitivity treatment, on the shear bond strength (SBS) of metal orthodontic brackets to enamel. Ethylenediaminetetraacetic acid (EDTA) was used to simulate sensitivity in 70 extracted human premolars. The teeth were radiated with 1w Nd:YAG, 1.5w Nd:YAG, 1w Diode, or 1.5w Diode. All samples were incubated at 37° for 24 hours, after bonding the metal brackets. SBS values and adhesive remnant index (ARI) for each tooth was recorded. One-way analysis of variance (ANOVA) and Kruskal-Wallis test were used to compare the mean SBS and the distribution of ARI scores between the study groups, respectively. The SBS mean from the highest to the lowest were in 1w Diode (25.71Mpa), 1w Nd:YAG (24.66Mpa), 1.5w Diode (23.08Mpa), control (21.68Mpa) and 1.5w Nd:YAG (21.53Mpa) groups. No statistically significant difference existed between different groups, in terms of SBS (p=0.211) and ARI distribution (p=0.066). The application of Nd:YAG and 980nm Diode lasers to treat tooth hypersensitivity did not change the SBS of metal orthodontic brackets to the enamel and thus, are harmless to use for orthodontic patients.

Evaluation of the Effect of Phosphoric Acid or Er: YAG Laser on the Shear Bond Strength of Orthodontic Brackets to Enamel Surfaces Followed by 980-Laser Assisted Bleaching: An In Vitro Study.

Introduction: The residual oxygen remained on tooth surface after bleaching may interfere with adhesion of brackets to enamel surface. This study aimed to evaluate the influence of phosphoric acid and Er: YAG laser as an etching technique on the shear bond strength (SBS) of orthodontic brackets to enamel surfaces after 980-laser-assisted bleaching. Methods: A total of 84 human premolars were recruited in the present study. Samples were divided into 6 groups including conventional bleaching with conventional etching, conventional bleaching with Er: YAG laser etching, laser-assisted bleaching with conventional etching, and Laser-assisted bleaching with Er: YAG laser etching, without bleaching with traditional etching, and without bleaching+Er: YAG laser etching. Following thermocycling, the debonding of brackets was conducted using a universal testing machine. Scanning electron microscope (SEM) microscope evaluation and adhesive remnant index (ARI) scores were assessed. The comparison of SBS values between groups was carried out by means of a one-way analysis of variance, followed by post-hoc tests. Results: The non-bleaching with conventional etching group showed the highest SBS mean value (23.45±5.16 MPa), whereas the conventional bleaching with conventional etching group represented the lowest SBS mean value (8.8±3.83 MPa). In all groups, the most common type of failure was classified as either score 1 or score 2. No significant difference was observed in terms of SBS mean between the groups (P=0.165); however, the average SBS of bleached teeth was significantly lower, compared to the non-bleached group (P=0.000). Honeycomb structure and porosity were observed following Er: YAG laser etching on the tooth surface. Conclusion: Increased bond strength of brackets was observed in bleached teeth following Er: YAG laser etching. Therefore, if necessary, bond the brackets on the same day of bleaching will be done, the application of Er:YAG laser as etching technique will can be recommended.

Effect of Different Desensitizer Treatments on the Shear Bond Strength of Orthodontic Metal Brackets Following In-Office Bleaching: An In Vitro Study.

One of the adverse effects of in-office bleaching is tooth hypersensitivity, which could be neutralized with a desensitizing agent. In-office bleaching and the application of desensitizing agents will affect the morphology of the enamel surface. These morphological changes have potential effects on the shear bond strength (SBS) and bonding of orthodontic brackets. This study analyzed the effects of fluoride and nonfluoride desensitizing agents after in-office bleaching on the SBS of metal brackets with resin composite cementation. Twenty-seven postextraction premolars (n = 27) were bleached with 37% hydrogen peroxide and then divided into three groups: control group (group 1), fluoride-based desensitizing agent (group 2), and nonfluoride-based desensitizing agent (group 3). After treatment, the brackets were bonded using Transbond, and then the SBS test was performed using a universal testing machine. The adhesive remnant index (ARI) was analyzed after the SBS test, whereas enamel morphological changes were observed under a scanning electron microscope. After this assessment, energy-dispersive X-ray spectroscopy was conducted to determine calcium and phosphorus elements in the enamel surface after treatments. SBS data were analyzed using the one-way analysis of variance, followed by the Tukey test, whereas ARI scores were subjected to the Kruskal-Wallis test and the Mann-Whitney test with a significance level of 5%. The SBS increased significantly in group 2 compared with groups 1 and 3 (p < 0.05). In group 2, an ARI of 2 (55.56%) was frequent, whereas in group 3, an ARI of 3 (55.56%) appeared most frequently. The application of the desensitizing agent fluoride after in-office bleaching increased the SBS and more adhesive remains on the tooth surface compared with that when nonfluoride desensitizing agents were applied on metal brackets with composite resin cementation.

Shear bond strength of orthodontic brackets bonded to high-translucent dental zirconia with different surface treatments: An in vitro study

The objective of this study was to compare the shear bond strengths of orthodontic brackets bonded to translucent dental zirconia samples which are anatomically accurate and treated with various surface treatments. This in vitro study included 156 samples from 3 brands of high-translucent zirconia split into a control group and 4 surface treatment groups: 9.6% hydrofluoric acid etching, 50-micron aluminium oxide particle air abrasion, and 30-micron tribochemical silica coating (TBS) particle air abrasion with and without silane application. After surface treatment, all groups were primed with a 10-MDP primer and bonded to metal orthodontic brackets. Shear bond strength (SBS) was tested and results were compared between all groups. Data analysis consisted of a balanced two-factor factorial ANOVA, a Shapiro-Wilks test, and a non-parametric permutation test. The significance level was set at 0.05. Among all surface treatments, aluminium oxide particle abrasion produced significantly higher SBS (P≤0.002). Lava™ Plus zirconia samples had significantly higher SBS than Cercon® samples (P<0.0001). TBS surface treatment produced significantly higher SBS on Lava™ Plus samples than it did on the other zirconia brands (P=0.032). This study indicated that mechanical abrasion using aluminium oxide in combination with a 10-MDP primer creates a higher SBS to high-translucent zirconia than the bond created by tribochemical silica coating. Also, there was no significant difference in ARI regardless of zirconia brand or surface preparation.

The Effect of Recommended Mouthwashes on the Shear Bond Strength of Orthodontic Brackets During the Covid-19 Pandemic: An In Vitro Study

Objectives: This study aimed to assess the impact of recommended mouthwashes (chlorhexidine, hydrogen peroxide, and povidone-iodine) used during the COVID-19 pandemic on the shear bond strength (SBS) of orthodontic brackets.&#x0D; Materials and Methods: A total of 52 human premolar teeth were divided into 4 groups (N=13) consisting of no intervention (control group), 0.2% chlorhexidine, 1.5% hydrogen peroxide, and 0.2% povidone-iodine. Following immersion in the mouthwashes, orthodontic brackets were bonded to enamel surfaces. Then, the brackets were debonded using a universal testing machine. The specimens were evaluated with a scanning electron microscope (SEM) and adhesive remnant index (ARI) score was assessed. One-way ANOVA and Tukey test were used for statistical analysis and P&lt;0.05 was considered significant.&#x0D; Results: The SBS of the experimental groups decreased compared to the control group. The highest SBS mean value was observed in the controls and the lowest was found in the 0.2% povidone-iodine group. Significant differences in SBS values were found between the 0.2% povidone-iodine group and the 1.5% hydrogen peroxide group when compared to the control group (P=0.023, P=0.028, respectively). SEM analysis revealed similar characteristics among the groups, with a closer resemblance between the chlorhexidine and control groups. Additionally, these groups exhibited greater etching depth compared to the other groups.&#x0D; Conclusion: Our findings highlight the importance of careful selection and application of mouthwashes in orthodontic procedures. While 1.5% hydrogen peroxide and 0.2% povidone-iodine may have some impact on bond strength, their use can still be considered acceptable within defined limits.

The Influence of Indirect Bonding Technique on Adhesion of Orthodontic Brackets and Post-Debonding Enamel Integrity-An In Vitro Study.

The increasing demand for orthodontic treatments due to the high prevalence of malocclusion has inspired clinicians and material scientists to investigate innovative, more effective, and precise bonding methods with reduced chairside time. This study aimed at comparing the shear bond strength (SBS) of metal and ceramic brackets bonded to enamel using the indirect bonding technique (IDB). Victory Series metal brackets (Metal-OPC, Metal-APC) and Clarity™ Advanced ceramic brackets (Ceramic-OPC) (3M Unitek, Monrovia, CA, USA) were bonded indirectly to extracted human premolars through the etch-and-rinse technique. A qualitative assessment of the enamel surface using microscopic methods was performed, and the amount of residual adhesive was reported as per the adhesive remnant index (ARI). Moreover, the bracket surface was evaluated with SEM-EDS. The highest SBS mean values were observed in the Ceramic-OPC group (16.33 ± 2.01 MPa), while the lowest ones were obtained with the Metal-OPC group (11.51 ± 1.40 MPa). The differences between the Metal-AOPC vs. Metal-APC groups (p = 0.0002) and the Metal-OPC vs. Ceramic-OPC groups (p = 0.0000) were statistically significant. Although the Ceramic-OPC brackets bonded indirectly to the enamel surface achieved the highest SBS, the enamel damage was significantly higher compared to that of the other groups. Thus, considering the relatively high bond SBS and favourable debonding pattern, Metal-APC brackets bonded indirectly may represent the best choice.

The Effect of Hydrogen Peroxide Colloidal-Ag Used in Dental Unit Waterline on Shear Bond Strength of Orthodontic Brackets.

The quality of the water passing through the water lines is crucial to dental procedures. Studies on bracket adhesion of hydrogen peroxide colloidal-Ag, which is widely used to prevent biofilm formation, are limited in the literature. To determine whether disinfecting the dental units' waterlines (DUW) with hydrogen peroxide colloidal-Ag has any effect on the shear bond strength (SBS) of orthodontic brackets bonded to enamel. Sixty premolar teeth were divided randomly into two groups. The study and control groups consists of 30 teeth that were etched for 30 seconds with 37% phosphoric acid. Study groups washed with hydrogen peroxide colloidal-Ag water and the control group washed with municipal water. Transbond XT adhesive system was used to bond stainless steel brackets on all the teeth. A 300-g force was applied using a tension gauge to ensure a uniform adhesive thickness and light cured with 6 seconds. The SBS was quantified by means of a universal testing machine. The residual adhesive on the enamel surface was evaluated after debonding using the adhesive remnant index (ARI). The t-test results indicated that there were no significant differences in the SBS. The comparison of the results of ARI scores was found statistically insignificant. It has been found that hydrogen peroxide colloidal-Ag, which is used to reduce the amount of biofilm in DUW, does not have a negative effect on the adhesion of the brackets.

A comparison of the shear bond strength of metal orthodontic brackets that have been treated with various light-emitting diode intensities and curing times: In-vitro research

The study aims to test the effects of LED light at three different power settings (500mW/cm2, 1000mW/cm2&amp; 1500m W/cm2) and three different exposure times (5sec, 10sec &amp; 20sec) adhesive composites for use with stainless steel orthodontic brackets, and their shear bond strengths. Current In-vitro work used 120 teeth, mostly premolars, separated into 10 equal groups of 12. After the crowns of the teeth were exposed by mounting them vertically into self-heal acrylics, the buccal-enamel exterior was prepared for bonding (PEA) 0.022”x 0.028” stainless steel premolar bracket using a thin layer of light cure adhesive primer and paste (Transbond-XT-3M Unitek Monrovia, Calif). Brackets in Group 1 comprising the Control group treated by usual halogen light source for forty sec, in remaining 9 groups (Experimental group) three commercially available LED curing light units i.e., Woodpecker, Guilin, Guangxi, China; Stealth Soft Equinox, Denmark, Holland; Radii plus, SDI, Australia, having three different light intensity 500mW/cm2, 1000mW/cm2, 1500mW/cm2 respectively were used to bond the brackets at three contact time (5/10/20 sec). The universal testing equipment was used to determine the shear bond strength of each specimen. The uppermost average SBS was found in the group cured with LED of intensity 1500 mW/cm2 for 20 sec (20.08 + 4.82 MPa) which was statistically significant compared the to control group (12.72 + 2.42 MPa). The lowest mean SBS values were obtained for groups cured with LED of intensity 500 mW/cm2 even at different curing times of 5, 10 and 20 sec i.e., 5.46 + 1.99 MPa, 8.77 + 2.38 Mpa and 11.24 + 2.59 MPa, respectively. Increasing the intensity of the LED light curing unit provides a clinically acceptable SBS even after reducing the curing times, thereby reducing the chairside time for bonding of orthodontic brackets.The study aims to test the effects of LED light at three different power settings (500mW/cm2, 1000mW/cm2&amp; 1500m W/cm2) and three different exposure times (5sec, 10sec &amp; 20sec) adhesive composites for use with stainless steel orthodontic brackets, and their shear bond strengths. Current In-vitro work used 120 teeth, mostly premolars, separated into 10 equal groups of 12. After the crowns of the teeth were exposed by mounting them vertically into self-heal acrylics, the buccal-enamel exterior was prepared for bonding (PEA) 0.022”x 0.028” stainless steel premolar bracket using a thin layer of light cure adhesive primer and paste (Transbond-XT-3M Unitek Monrovia, Calif). Brackets in Group 1 comprising the Control group treated by usual halogen light source for forty sec, in remaining 9 groups (Experimental group) three commercially available LED curing light units i.e., Woodpecker, Guilin, Guangxi, China; Stealth Soft Equinox, Denmark, Holland; Radii plus, SDI, Australia, having three different light intensity 500mW/cm2, 1000mW/cm2, 1500mW/cm2 respectively were used to bond the brackets at three contact time (5/10/20 sec). The universal testing equipment was used to determine the shear bond strength of each specimen. The uppermost average SBS was found in the group cured with LED of intensity 1500 mW/cm2 for 20 sec (20.08 + 4.82 MPa) which was statistically significant compared the to control group (12.72 + 2.42 MPa). The lowest mean SBS values were obtained for groups cured with LED of intensity 500 mW/cm2 even at different curing times of 5, 10 and 20 sec i.e., 5.46 + 1.99 MPa, 8.77 + 2.38 Mpa and 11.24 + 2.59 MPa, respectively. Increasing the intensity of the LED light curing unit provides a clinically acceptable SBS even after reducing the curing times, thereby reducing the chairside time for bonding of orthodontic brackets.

The Effect of Preheating of Orthodontic Resin on The Shear Bond Strength of Convensional Orthodontic Bracket to Enamel Surface

Adequate bond strength between enamel and orthodontic bracket is crucial, several factors affect the bond strength including the adhesive temperature prior to bonding. The objective of the study was to investigate if there is any relationship between adhesive temperature prior to bonding and the Shear Bond Strength (SBS) of orthodontic bracket to the enamel surface. Method: In this in-vitro study, A total of 64 freshly extracted premolar teeth were used which were divided into four groups each one had different adhesive temperature prior to bonding (room temperature ,30°C, 50°C, and 70°C), and each group went through SBS test under Universal Instron machine and ARI score test using Stereomicroscope. R esults: All pre-heated groups had a higher mean value t han the room temperature group, while the mean value of SBS were highest in 70°C group but at 50°C there was a dr op down in the SBS values which had a mean less than 30°C and 70°C groups. ARI scores showed not statistically sign ificant different between the groups. Conclusion: Pre-heat ing orthodontic adhesive right before bonding to 70°C ca n significantly increase bracket SBS to enamel. While, preh eating to 30°C could have a greater SBS than pre-heating to 50° C.