Bond Strength Of Orthodontic Brackets Research Articles

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.

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.

The Use of Lasers in Enhancing the Bond Strength of Orthodontic Brackets

ABSTRACT Background: The use of lasers in orthodontics has garnered interest for its potential to enhance the bond strength between orthodontic brackets and tooth surfaces, a crucial factor for successful orthodontic treatment. This study aims to investigate the effect of laser irradiation on the bond strength of orthodontic brackets in a sample of 30 patients. Materials and Methods: Thirty patients undergoing orthodontic treatment were divided into two groups. In Group A, brackets were bonded using conventional methods, while in Group B, brackets were bonded after laser irradiation. A diode laser operating at 810 nm was used, with an energy setting of 2.5 W for 20 s. After bonding, a universal testing machine measured the bond strength in megapascals (MPa). The adhesive remnant index (ARI) was also recorded to determine the mode of bond failure. Statistical analyses were conducted to compare the results between the groups. Results: The mean bond strength in Group B (laser irradiation) was significantly higher (P &lt; 0.05) than in Group A (conventional bonding). Group B exhibited a mean bond strength of 9.72 MPa, whereas Group A showed a mean bond strength of 7.41 MPa. The ARI scores indicated that Group B had more adhesive remaining on the tooth surface, suggesting a stronger bond. Conclusion: Laser irradiation prior to orthodontic bracket bonding resulted in significantly enhanced bond strength compared to conventional bonding methods. The increased bond strength and greater adhesive remnant on the tooth surface indicate that laser irradiation improves the adhesion between brackets and tooth enamel. Integrating lasers into orthodontic procedures has the potential to elevate treatment outcomes by ensuring durable bracket adhesion.

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.

Desensitizing agents’ post-bleaching effect on orthodontic bracket bond strength

Background: Nowadays, many patients wanting to bleach and do orthodontic treatment simultaneously, in-office bleaching is more favorable because of the instant results. However, in-office bleaching procedures result in severe enamel surface demineralization and decreasing the attachment of the orthodontic bracket. Applying a desensitizing agent after in-office bleaching can remineralize the enamel surface. There are two types of desensitizing agents: Fluoride-based and non-fluoride-based. Purpose: This study aims to analyze the effect of applying fluoride-based and non-fluoride-based desensitizing agents after in-office bleaching on orthodontic brackets. Methods: Twenty-seven post-extraction upper premolars were divided into three groups (n=9): Control group, fluoride-based group, and non-fluoride-based group. The samples were subjected to an in-office bleaching procedure before a fluoride desensitizing agent was applied to the fluoride group and a non-fluoride desensitizing agent was applied to the non-fluoride group. Then, a brackets bonding procedure was performed on all samples. The samples were tested for shear bond strength (SBS), and the adhesive remnant index (ARI) was measured. The data was analyzed by a one-way analysis of variance on the SBS test, while the ARI scores were analyzed by the Kruskal–Wallis test. Results: The fluoride and non-fluoride groups showed a significantly increased SBS of the brackets after in-office bleaching (P &lt; 0.05), with the fluoride-based desensitizing agent having the highest SBS score, while the ARI scores had an insignificant difference between all groups (P &gt; 0.05). Conclusion: The application of desensitizing agents after in-office bleaching increased the metal brackets' SBS but could not change the ARI scores.

Effect of Different Chemical Solvents on Bond Strength of Orthodontic Brackets: An In Vitro Study.

The purpose of the present study was to evaluate the impact of various chemical solvents on bond strength of orthodontic brackets. One hundred healthy human premolars with undamaged buccal surfaces that were extracted for orthodontic purposes were gathered. Using 37% orthophosphoric acid, primer, and Transbond XT adhesive, ceramic 0.018" × 0.022" slot orthodontic brackets were adhered to the tooth surface. Following thermocycling, all samples were divided into four groups, with 25 samples in each group: group I: control; group II: application of ethanol; group III: application of acetone; and group IV: application of dimethyl sulfoxide (DMSO). Following the debonding tests, a double-ocular stereomicroscope was used to inspect the tooth surfaces. Additionally, adhesive remnant index (ARI) values were evaluated at 40× magnification. Data were recorded and statistically analyzed. The bond strength was lesser in acetone applied group (16.18 ± 3.64) followed by DMSO applied group (22.08 ± 2.86), ethanol applied group (24.36 ± 4.02), and control group (27.14 ± 3.68). There was a highly significant difference found between the chemical solvents group. The ARI score 3 was present in control (12%), ethanol (8%), and DMSO (4%), and it was absent in acetone applied group. The ARI score 0 was more in acetone applied group (24%). The present study concluded that the reduced debonding force was found with the application of acetone solvent followed by DMSO, ethanol, and control groups. Applying acetone can be a substitute technique to help with ceramic bracket debonding. Orthodontic bracket debonding cannot occur without shear bond strength (SBS). The need for an ideal debonding technique for ceramic brackets without negative consequences arises from the risk of enamel damage that frequently follows the process. Acetone treatment prior to ceramic bracket debonding could be an alternate clinical technique to preventing enamel damage and facilitating debonding. How to cite this article: Bhushan R, Singh S, Sam G, et al. Effect of Different Chemical Solvents on Bond Strength of Orthodontic Brackets: An In Vitro Study. J Contemp Dent Pract 2023;24(12):940-943.

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.

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.

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 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.

Comparison of the Shear Bond Strength of Orthodontic Composites Containing Silver and Amorphous Tricalcium Phosphate Nanoparticles: an ex vivo Study.

It is important to use orthodontic composites with favorable properties, which are easily removed after the end of the treatment but not easily debonded during treatment. Nanoparticles have drawn attention for their antibacterial properties when added to composite resins. However, the effect of addition of nanoparticle on shear bond strength is not broadly discussed. The present study was designed to compare the shear bond strength of orthodontic brackets bonded by orthodontic composite containing silver nanoparticles with orthodontic composite containing amorphous tricalcium phosphate nanoparticles. In this ex vivo study, 36 sound extracted human premolars were used and randomly divided into three groups. The brackets were bonded in the first group by composite without nanoparticles, in the second group by composite containing 3% amorphous tricalcium phosphate nanoparticles and in the third group by composite containing 0.3% silver nanoparticles at the buccal surface of the teeth. The shear bond strengths of the samples were measured 24 hours after preparation by a universal testing machine. Data were analyzed using SPSS 21 software through one-way ANOVA and Tamhane's T2 multiple comparison tests. pValues under 0.05 were considered significant. There was no significant difference between the mean shear bond strength of composite containing amorphous tricalcium phosphate nanoparticles with composite without nanoparticles (p= 0.142). However, the mean shear bond strength in the composite containing silver nanoparticles was significantly lower than the other two groups (p< 0.001). According to the results of this study, the addition of amorphous tricalcium phosphate nanoparticles to orthodontic composite does not significantly decrease the shear bond strength while silver nanoparticles reduce the shear bond strength of orthodontic composite.

An In-Vitro Analysis of the Surface Treatment of Orthodontic Bracket Bases With Er,Cr:YSGG Laser and Its Effect on Shear Bond Strength.

Introduction Shear bond strength is indispensable to prevent the debonding of orthodontic brackets. Lasers have been proven to alter the bond strength of orthodontic brackets, but their efficiency has not been validated in many trials. The study aimed to evaluate the impact of the Er,Cr:YSGG laser on the bases of orthodontic brackets and determine their bond strength with the enamel surface. Materials and methods The Waterlase iPlus (made in the USA in 2012), comprising an Er,Cr:YSGG laser, was used. Based on the surface treatment of brackets, two groups were assigned (n=10), comprising laser-treated and untreated bracket bases. The brackets were treated with the minimum laser intensity (50 Hz, 4.5 W). Then, the brackets of both groups were attached to the labial surfaces of previously extracted premolars, respectively. The shear bond strength of brackets (SBS) was assessed using the universal testing device, and the Adhesive Remnant Index (ARI) was also measured. An independent sample t-test was used to compare the bond strength between the laser-treated and untreated brackets. Results The mean bond strength of laser-treated and control group brackets was 5 MPa and 8.63 MPa, respectively. The laser-treated brackets showed lower bond strength than the control brackets, but the results were statistically insignificant (p=0.23). The ARI analysis stated that bond failures occurred mostly in the region of the bracket and adhesive interface. Conclusion Laser-etched bracket bases showed lesser shear bond strength than the untreated ones, though the difference was statistically insignificant.

Effect of re-mineralizing surface treatment on the shear bond strength of orthodontic bracket: A systematic review and meta-analysis of in-vitro studies

Re-mineralizing surface pretreatment is essential for both controlling and preventing white spot lesion (WSL) throughout the time of fixed orthodontic treatment. It is also important that the re-mineralizing have no negative impact on the bonding between the bracket, adhesive, and enamel. Therefore, this review is aimed to investigate the orthodontic brackets' shear bond strength after re-mineralizing surface treatment of enamel. The review was conducted following the PRISMA 2020 guidelines. In-vitro experimental studies measuring shear bond strength (SBS) of orthodontic brackets on both demineralized and intact enamel following re-mineralizing surface treatment were included. Database search was done in PubMed, Scopus, and Science Direct during July 2023. Methodological quality of the studies was assessed according to the guidelines for the reporting of pre-clinical in-vitro studies. Both qualitative and quantitative analyses of the included studies were done. Matching the inclusion criteria, 46 and 37 studies were selected for qualitative and quantitative analysis respectively. On intact enamel re-mineralizing agents had no negative impact on the brackets' SBS. On the contrary, they seemed to enhance the bond strength remarkably on the demineralized enamel. Re-mineralizing surface pretreatment is crucial prior to fixed orthodontic treatment as it did not reduce the bond strength. Although, it cannot be judged depending solely on the in-vitro results with high heterogeneity. Clinical evidence is required to support the statement.

Shear bond strength of orthodontic brackets to specimens fabricated from temporary restorative materials by 3D-printing, CAD/CAM technology, and the conventional technique after surface treatment by sandblasting and laser

This study assessed the shear bond strength (SBS) of stainless steel (SS) orthodontic brackets to specimens fabricated from polymethyl methacrylate (PMMA) temporary restorative material by 3D-printing, computer-aided design/computer-aided manufacturing (CAD/CAM) technology, and the conventional technique, after surface treatment by sandblasting and laser. In this in vitro study, 60 disc-shaped specimens with 8mm diameter and 1mm height were fabricated from PMMA temporary restorative material by 3D-printing, CAD/CAM, and the conventional technique. In each group (n=20), half of the specimens were sandblasted while the other half underwent Er,Cr:YSGG laser irradiation. Brackets were bonded to the specimens and underwent thermocycling followed by SBS testing. Data were analysed by one-way ANOVA, independent t-test, and LSD test (alpha=0.05). A significant difference existed among the three fabrication methods in SBS in both laser (P<0.001) and sandblasting (P<0.001) surface treatment groups. In laser group, the mean SBS of CAD/CAM (P=0.000) and conventional (P=0.000) groups was significantly lower than that of 3D-printing group. In sandblasting group, the SBS of CAD/CAM group was significantly lower than 3D-printing (P=0.000) and conventional (P=0.000) groups. The mean SBS of laser-treated specimens was significantly higher than sandblasted specimens in 3D-printing group (P=0.000), and significantly lower than sandblasted specimens in the conventional group (P=0.000). A significantly higher SBS was obtained by laser treatment compared with sandblasting irrespective of the fabrication method (P=0.000). The highest SBS of SS orthodontic brackets to temporary restorative material was recorded for 3D-printed specimens treated by Er,Cr:YSGG laser irradiation.

Bond Strength of Orthodontic Brackets to Temporary Crowns: In vitro Effects of Surface Treatment.

To evaluate bond strength of orthodontic brackets to temporary crowns. A bis-acrylic composite was used to create a total of 25 discs, which were then divided into five groups based on how their surfaces were treated with black, blue, green, and sandblasted diamond burs, in addition to a control group. Software called SPSS was used to analyze the outcome. The average pressures measured for the green bur, black bur, and sandblasting, respectively, were 12.05 MPa, 12.87 MPa, and 19.25 MPa. Comparing the control and blue groups, a substantial variation in shear bond strength was only noticed with reference to sandblasting. The binding strength of orthodontic brackets is increased by sandblasting temporary crowns.

Effect of Ethyl Alcohol Wet Bonding on Shear Bond Strength in Orthodontic Brackets - An In vitro Study.

To evaluate the effect of ethyl alcohol wet bonding on the shear bond strength of orthodontic brackets. 90 premolar teeth were collected and divided into 6 groups - conventional dry, conventional wet, MIP dry, MIP wet, ethanol dry, and ethanol wet. The teeth were bonded as per the requirements for each group. The teeth were then immersed in water to ensure complete polymerization. Shear bond strength was evaluated using a UTM machine and the ARI scores were also noted. Statistical analysis was done for the SBS and ARI scores obtained. The highest SBS was obtained with conventional dry and the least SBS was obtained with conventional wet groups. The SBS of ethanol wet bonding was significantly less than that of the MIP wet group but was significantly more than the conventional wet group. ARI scores also suggested that there is more cohesive failure than adhesive failure in the wet MIP and ethanol groups. The mean SBS (6.5 MPa) was within the optimal bond strength as per the study by Reynolds et al. (1976). Ethanol can be used as a cheaper alternative to MIP.

In vitro Evaluation of Shear Bond Strength of Orthodontic Brackets Bonded with Different Adhesives.

To endure the orthodontic forces used throughout treatment, the bond strength of bonded orthodontic brackets must be enough with assessment of shear bond strength when bonding orthodontic brackets with various adhesives. Overall, forty extracted premolars due to orthodontic treatment were included. They were split into four equal cohorts with various primers. With both adhesives, shear bond strength had been assessed with and without salivary contamination. SPSS software was used to assess the outcomes. Consideration was given to statistical significance of P value of less than 0.05. Several groups' average bond strengths in MPa were assessed in both dry and contaminated saliva conditions. When it was dry, Transbond Plus demonstrated greater shear bond strength. Hydrophilic Transbond Plus resin outperformed hydrophobic Transbond XT resin in terms of shear bond strength under both situations.

Impact of a High-Power Light-Emitting Diode Unit With Reduced Curing Times on the Shear Bond Strength of Orthodontic Brackets and Their Adhesive Remnant Index Scores.

This study aims to evaluate the curing time minimally required for bonding stainless-steel (SS) brackets using a high-power light-emitting diode (LED) light curing unit (LCU) and examine the debonded enamel surface for adhesive remnant. Based on the LED LCU and curing time employed, 80 human maxillary first premolar teeth were equally segregated into four groups. Three groups were cured using a high-power LED unit (Guilin Woodpecker Medical Instrument Co., Ltd., Guilin, Guangxi, China) for one, two, and three seconds. The fourth group served as a control and was bonded with another intensive LED unit (Elipar™ S10 LED Curing Light; 3M, Saint Paul, Minnesota, United States) for 20 seconds. Transbond™ XT Light Cure Adhesive (3M, United States) adhesive was used for bonding the SS brackets. All the samples were exposed to shear bond strength (SBS) testing after a 24-hour immersion period in distilled water at 37°C. A stereomicroscope was used to examine and score the adhesive remnant on the debonded surface using a modified adhesive remnant index (ARI). Kruskal-Wallis-ANOVA and post-hoc Mann-Whitney U tests for multiple pairwise comparisons were performed to analyze the data. Time and intensity significantly affected the SBS (P<0.001). A higher SBS value (16.04 megapascals (MPa)) was obtained in the six-second group when compared to the three-second (11.58 MPa), one-second (10.69 MPa), and 20-second control (13 MPa) groups. The ARI was significantly affected by the curing method. Higher SBSs were recorded for the six-second group using the high-power LED. A greater ARI score is associated with a reduced curing duration and vice versa.

Antioxidant effect on shear bond strength of orthodontic brackets after tooth bleaching: A scoping review of in vitro studies

Tooth bleaching was reported to decrease bond strength of orthodontic brackets. The antioxidant application was investigated to reverse the bleaching effect for immediate bracket bonding. This scoping review of in vitro studies is to assess systematically the effect of antioxidant application on shear bond strength (SBS) before orthodontic bracket bonding after tooth bleaching. This review was provided according to the Preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews (PRISMA-ScR) guidelines. An electronic literature search was performed for full-text articles in English via Scopus, Web of Science, MEDLINE/PubMed, and Google Scholar databases from 2012 to May 9, 2023. A total of 549 records were retrieved from the electronic search, and 361 after discarding duplicates. According to eligibility criteria, 23 records were included in this study. Included studies revealed that antioxidants could increase the SBS of brackets after bleaching. However, there was controversiality whether SBS was just improved or restored to the unbleached level according to various factors, including the antioxidant type, concentration, application time, and form. Most studies reported that 10% sodium ascorbate (SA), ascorbic acid, green tea (GT), and tocopherol solutions restored SBS of metal brackets but not ceramic brackets. The result of 10% SA and GT gel was controversial. Lower concentrations than 10% was effective with pink bark, grape seed, quercetin flavonoid, and chamomile to restore SBS. The included studies revealed that retinol acetate, gooseberry, and dimethyl sulfoxide did not restore SBS.