Shear Bond Strength Of Brackets Research Articles

Effect of different surface conditioning methods and low pH solutions on the shear bond strength of orthodontic brackets to newly introduced CAD/CAM materials

AimTo evaluate the shear bond strength (SBS) of ceramic and metallic orthodontic brackets bonded to lithium disilicate ceramics or hybrid ceramics and subjected to different surface conditioning treatments. Materials and methodsIn total, 300 specimens were fabricated from GC LiSi (lithium disilicate) and GC Cerasmart (hybrid) ceramic blocks. The specimens were divided into four groups according to the following surface treatments: hydrofluoric acid (HF); sandblasting with 50 μm aluminum oxide; Monobond Etch and Prime; and erbium-doped yttrium aluminum garnet (Er-YAG) laser. Metal (Victory Series) and ceramic (Clarity) brackets were bonded using an orthodontic adhesive resin (Transbond XT; 3M Unitek, CA, USA). The specimens were then stored in three different mediums (artificial saliva, mouth rinse, and gastric juice) and thermocycled. An SBS test was performed after 1 week. The surface morphology was examined after the conditioning treatments using a scanning electron microscope. Data were analyzed using analysis of variance, t-test, and Duncan test. ResultsThe SBS data revealed that the type of computer-aided design/computer-aided manufacturing (CAD/CAM) block and surface conditioning method significantly affected the SBS. The highest SBS was recorded (10.112 MPa) for the HF-treated hybrid ceramic blocks stored in the saliva medium, while the lowest SBS (1.862 MPa) was reported for the Er-YAG laser-treated lithium disilicate ceramic blocks stored in the gastric juice medium. GC Cerasmart exhibited better bond strength than that of GC LiSi; however, no significant difference was observed between the ceramic and metal brackets. ConclusionThe CAD/CAM material, surface conditioning method, and medium affect the SBS.

Shear Bond Strength of Ceramic Brackets on Enamel Conditioned With CO2 Laser

Shear Bond Strength of Ceramic Brackets on Enamel Conditioned With CO2 Laser

Evaluation of the Conventional Acid-Etching System and the Self-Etching Primer in Bonding Metallic Orthodontic Brackets: An In-Vitro and In-Vivo Study.

This study aimed to compare the shear bond strength (SBS) of enamel-bonded orthodontic brackets with the conventional acid etching (CAE) system and the self-etching primer (SEP)in vitro and to compare the clinical performance of both systems when used in the treatment of malocclusion patients. In the first part of the study, 40 extracted human premolars were randomly divided into two groups containing 20 teeth. The first group (the conventional enamel etching group) employed37% phosphoric acid before bonding the metallic brackets (0.022-inch slot, MBT prescription, American Orthodontics, Sheboygan, WI, USA). The etching system wasTetric 5th (Ivoclar Vivadent, Schaan, Liechtenstein). The second group used a SEP (Sep Tetric 7th, Ivoclar Vivadent, Schaan, Liechtenstein) to bond the same brackets. In the first part of the study, SBS was evaluated, followed by the adhesive remnant index (ARI) assessment. The second part of the study (i.e., the clinical part) assessed a cohort of 30 patients during a 6-month observation period. The upper 10 teeth (from the second premolar on the right side to the second on the right side) were bonded using the chosen method for each patient in the clinical assessment. That is, 150 teeth in each group were evaluated regarding the failure rate. The ARI was assessed for those teeth that lost their brackets. The mean SBS was greater in the SEP group compared to the CAE group (17.93 MPa and 16.60 MPa, respectively; P = 0.014). The difference was not statistically significant. Conversely, the failure rate was lower in the CAE group compared to the SEP group, with a failure rate of 6% and 14.7%, respectively. The difference was statistically significant (P = 0.014). However, the ARI showed no statistically significant difference in in-vivo and in-vitro analyses, as most bracket failures were at the adhesive level. Laboratory results showed no statistical difference in the SBS mean values between the two groups. Clinically, the SEP group showed a greater failure rate than the CAE group, but both failure rates in the two groups were within the clinically acceptable range. The ARI did not show any difference between the two groups in terms of the failure site when the evaluation was conducted in vivo and in vitro, as most of the areas of failure were concentrated in the material itself.

Comparative Analysis of Shear Bond Strength in Orthodontic Brackets Between Milled and 3D-Printed Definitive CAD/CAM Restorations

Objective: The objective of this study was to evaluate the effect of different surface treatment methods on the shear bond strength (SBS) of metal brackets bonded to two types of CAD/CAM composite restorations: milled and 3D-printed. Materials and Methods: A total of 160 flat-shaped specimens (10 × 10 × 2 mm3) were prepared from four different CAD/CAM composites; two milled (Lava Ultimate™ [LU] and Grandio™ [GR]) and two 3D-printed (Crowntec™ [CT] and C&B Permanent™ [CB]). These specimens underwent thermocycling (5000 cycles at 5–55 °C), then were categorized based on the surface treatment into four groups (n = 10): Group C (control, no surface treatment), Group HF (treated with 9.6% hydrofluoric acid), Group DB (mechanical roughening by a diamond bur), and Group SB (sandblasting using aluminum oxide). Metal brackets were bonded using Transbond XT Primer and universal adhesive, stored in artificial saliva for 24 h, then thermocycled again. Shear bond strength (SBS) was tested using a universal testing machine until bracket debonding occurred. The adhesive remnant index (ARI) was assessed using a stereomicroscope to quantify the residual adhesive following debonding. Result: Regarding material, GR and LU restorations had significantly higher SBS values compared to CT and CB, ranging from 13.90 MPa to 20.35 MPa. Regarding surface treatment, SB and HF groups showed significantly higher SBS values. The ARI scores showed different adhesive modes of failure, with higher instances of scores 0 and 1, which indicate no or minimal adhesive remaining. Conclusions: Both milled and 3D-printed materials had adequate SBS for clinical use, with milled materials showing superior results. Surface treatments like sandblasting and HF significantly improved bond strength, with adhesive failure being common.

The effect of addition of Bioglass 45S5 to orthodontic adhesive on shear bond strength of metal orthodontic brackets, An in vitro study

Aim: This study aimed to evaluate the effect of incorporating Bioglass (BG) 45S5 into an orthodontic adhesive on the shear bond strength (SBS) of metal orthodontic brackets bonded to enamel and the adhesive remnant index (ARI) score. Methods: In this in vitro study, 55 extracted sound premolars were randomly divided into five groups (n=11 each). Metal brackets were bonded using Ambar FGM orthodontic adhesive without BG (control group) and with BG 45S5 added at concentrations of 5%, 10%, 15%, and 20% by weight in groups 2 to 5, respectively. The SBS was measured using a universal testing machine, and the ARI score was determined under a stereomicroscope at ×10 magnification. Data were analyzed using one-way ANOVA at a significance level of α=0.05. Results: The highest mean SBS was observed in the 20% BG Group (48.28±24.5 MPa), followed by the control group (35.81±11.11 MPa), 15% BG Group (19.64±5.42 MPa), 10% BG Group (16.3±9.33 MPa), and 5% BG Group (14.21±4.23 MPa). The SBS in the 20% BG Group was significantly higher than in the control (P=0.013), 5% BG (P=0.000), and 10% BG (P=0.002) groups. No significant differences were found in ARI scores among the groups (P=0.810). Conclusion: Adding BG 45S5 to the orthodontic adhesive at concentrations of 5%, 10%, and 15% did not significantly affect the SBS, but a 20% concentration increased the SBS. Incorporating BG at these levels does not adversely impact the SBS or ARI scores.

Evaluation of Etching Time Effect on Shear Bond Strength of Orthodontic Brackets Bonded with Self-Adhesive Composite: An in-Vitro Study

Introduction: Precise acid etching of the tooth surface is a significant factor in the strength of the bracket bond. The current study aimed to determine the effect of different application times of acid etching on the shear bond strength of metallic orthodontic brackets under controlled laboratory conditions. Methods: Sixty intact premolar teeth were selected for this in-vitro study. The samples were divided into four groups based on the different acid etching times: 20, 25, 30, and 35 seconds. The teeth surfaces were etched with 37% phosphoric acid according to the specified times, and brackets were bonded to the enamel surface using GC Ortho connect composite. Shear bond strength values of the brackets was measured using a Universal Testing Machine. The amount of Adhesive Remnant Index was also observed using a stereomicroscope. Additionally, the surface roughness of the tooth enamel after bracket bonding was examined using SEM. The results related to shear bond strength were analyzed with one-way ANOVA statistical test and using SPSS version 16 software. The non-parametric Kruskal Wallis (Wallis-Kruskal) test was also used to check the frequency of ARI index. Results: The highest shear bond strength was observed at 25 seconds, and the lowest at 30 seconds. However, there was no significant difference in the shear bond strength of brackets was observed among the four groups (p=0.186). The highest ARI score was observed at 35 seconds, and the lowest at 20 seconds. No statistically significant difference was observed in the ARI scores in different groups. SEM images revealed that the enamel surface porosity was highest at 20 seconds. Conclusion: The results indicate that the shear bond strength and ARI at different acid etching times do not significantly differ. Therefore, orthodontic bracket bonding can be performed with less acid etching time.

Shear Bond Strength of Orthodontic Brackets to Resin-Infiltrated Enamel

Abstract Objectives This study aims to evaluate shear bond strength (SBS) of orthodontic brackets to enamel after resin infiltration pretreatment using different adhesive systems. Materials and Methods Sixty extracted maxillary first premolars were divided into five groups (n = 12). Group I: sound enamel + Transbond XT; group II: resin-infiltrated enamel (ICON) + Transbond XT; group III: ICON + Scotchbond Universal Plus; group IV: ICON + Assure PLUS; group V: ICON + Transbond Plus Self Etching. The SBS was measured using universal testing machine and analyzed using analysis of variance (ANOVA). The adhesive remnant index (ARI) score after debonding was determined under stereomicroscope with a 10× magnification. Statistical Analysis A one-way ANOVA and post hoc Tukey's test were used to compare the data. Further, the ARI scores were evaluated using a chi-squared test. The level of significance was set at p = 0.05. Results SBS of group I, II, III, IV, and V were 11.70 ± 3.17, 11.23 ± 3.06, 9.52 ± 1.73, 8.97 ± 1.12, and 9.14 ± 0.70 MPa, respectively. SBS of group IV and V was significantly lower than group I and II (p < 0.05). There was no significant difference in the ARI scores among the five groups (p > 0.05). Conclusion The SBS of enamel resin infiltration pretreatment depends on the adhesive system. The SBS of all groups was within adequate SBS range in clinical use. The most common ARI score was 2, which indicated lower risk of enamel fractures when debonding.

Evalution of shear bond strength of brackets bonded using different hydrophobic and hydrophilic adhesives: An invitro study

A review of the long history of orthodontic bonding adhesives shows that many evolutional developments have occurred from the first chemically-cured composite resins to the most recently introduced light-cured color-change adhesives. An ideal orthodontic adhesive should have adequate bond strength while maintaining unblemished enamel after debonding. Therefore, researchers have been working hard to achieve the best quality and gentlest materials for bonding orthodontic brackets.To evaluate the shear bond strength of brackets bonded using four different adhesives in both dry and in moist environment.A total of 80 orthodontically extracted premolars will be selected. They are divided into 4 equal groups of different adhesives which are further sub-divided into 2 group each (dry and in presence of moisture). All the selected teeth will be cleaned and store in saline until it use. All teeth will be mounted on acrylic block. The shear bond strength will be measured by Lloyd’s Universal testing machine. The obtained data will be statistically evaluated using SPSS22 for Windows using ANOVA test at statistical significance.: The shear bond strength of the four groups were tested with Instron universal testing machine; breaking load at which bond failure occurred was recorded and bond strength was calculated. Data obtained was compiled on MS Office Excel Sheet (2007, Microsoft Redmond Campus, Redmond. Washington, United States.)Data was subjected to statistical package for social sciences (SPSS v 21).Statistically significant difference seen between the hydrophobic and hydrophilic adhesives. In the present study we did Tukey’s post hoc test for pairwise comparison of different hydrophobic and hydrophilic adhesives. It show highly significant values. : The greatest bond strength values were achieved with TransbondXT in both dry and saliva contamination condition. These values were significantly greater than those achieved with Greengloo, RMGIC and Aqualine LC. The overall study conclude that TransbondXT was considered the feasible adhesive material for orthodontic bonding followed by Aqualine LC.

The shear bond strength of orthodontic brackets after surface conditioning of Zirconia, Ceramic and E. max models

The current study aims to evaluate the shear bond strength (SBS) of metal orthodontic brackets after surface conditioning by hydrofluoric acid (HF) and aluminum oxide air abrasion (Al2O3) and using two prime types and to determines the adhesive remnant index (ARI). We compared the bond strength of different types of models (full glazed zirconia, ceramic faced zirconia and E. max faced zirconia) with different surface conditioning methods for attaching metal orthodontic brackets. The study used 60 models for each material, divided into subgroups based on the type of prime material and surface preparation method. The bond strength was measured using a universal testing machine and the results were analyzed using statistical software. Shear bond strength of the Aluminum oxide was statistically (p<0.05) higher than the hydrofluoric acid and control groups in all groups (full glazed zirconia, ceramic faced zirconia and E. max faced zirconia). The Assure® Plus primer with Aluminum oxide surface treatment give rise to the highest shear bond strength than 3M™ Transbond™ XT, while there was no significant difference between Assure® Plus and 3M™ Transbond™ XT primer for both control and hydrofluoric acid groups. The highest shear bond strength was obtained with Aluminum oxide conditioning method for all types of ceramic materials used in this study.

Comparison of Shear Bond Strength of Orthodontic Brackets Bonded to Enamel Prepared by Er: Yag Laser and Conventional Acid Etching Technique-An in-Vitro Study

Background: Brackets are one of the important components in orthodontic treatment which helps in transferring forces to the teeth to appreciate teeth movement. So, it is very important to have a better bond strength between brackets and teeth which can be achieved by different materials and techniques. Initially, etching (surface preparation) was done on the surface of the teeth by acid (37% phosphoric acid) to bond brackets directly to the teeth. Later with the introduction of lasers, surface preparation was done using Er: YAG laser which was considered as an alternative and better technique when compared with the conventional acid technique. Objective: To compare the differences in shear bond strength of orthodontic brackets bonded to enamel prepared by Er: Yag laser and conventional acid etching technique. Results: The shear bond strength of the acid group showed the least bond strength. ARI Index shows that group 3 laser etched group had major bond failure at favorable site with most number of score value between score1 to 3. ARI Index of group A & B showed most number of score value between score4 to 5 with major bond failure at unfavorable site. Conclusion: ANOVA and Chi-square test revealed statistically significant difference between 3 different groups on assessing the SBS and ARI Index. Group C (laser etched group at W. 1mJ & 10Hz) showed better bond strength at a clinically acceptable level and also had major bond failure at favorable site which produces least damage to the enamel surface. Group B laser etched group even though had higher bond strength of 15.95 MPa, their value highly deviates from the clinically required level of 8Mpa.

Enamel Deproteinization or Sandblasting for Enamel Reconditioning Before Acid Etching to Enhance the Shear Bond Strength of Metallic Brackets in a Third Bonding: An In Vitro Study.

Enamel conditioning with 37% phosphoric acid is the most common technique during orthodontic bracket bonding procedures. However, due to the repeated de-bonding of the orthodontic brackets during treatment, other methods were needed to condition the enamel surface and increase the bond strength. This study aimed to compare the effect of conditioning the enamel surface by sandblasting with aluminum oxide particles or 5.25% sodium hypochlorite gel in combination with acid etching compared to acid etching alone on shear bond strength (SBS). One hundred eight extracted upper premolars were randomly divided into three groups according to the conditioning enamel surface method. After the first and second bonding of metal brackets, new metal brackets were bonded with a total-etching adhesive after enamel conditioning using different methods: acid etching only (37% phosphoric acid for 30 seconds) (AE group), sodium hypochlorite associated with acid etching (5.25% NaOCl gel for 60 seconds and then acid etching for 30 seconds) (NaOCl-AE group), and sandblasting associated with acid etching (sandblasting for five seconds and then acid etching for 30 seconds) (SB-AE group). The shear bond strengths of the brackets were tested with a universal testing machine. One-way analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) tests were used to detect significant differences in shear bond strength among groups at the third bonding. Repeated-measure ANOVA and Bonferroni's tests were used to detect significant differences in shear bond strength among the bonding attempts within each group. 5.25% sodium hypochlorite associated with the acid etching method produced significantly greater shear bond strength than sandblasting associated with acid etching and acid etching only methods at the third bonding (16.40 ± 5.80 MPa, 13.60.47 ± 6.40 MPa, and 9.90 ± 4.40 MPa, respectively; P < 0.001). However, there was no significant difference between the AE and SB-AE groups (P = 0.247). In addition, we found a significant decrease in the shear bond strength within each group after each bonding attempt. Conditioning the enamel surface with 5.25% sodium hypochlorite associated with acid etching produced greater bond strength than conditioning by sandblasting associated with acid etching and acid etching only at the third bonding. The bond strength of the metal bracket decreased with increasing bonding attempts, even with the application of enamel surface conditioning methods.

The Effect of Casein Phosphopeptide-amorphous Calcium Phosphate after Bleaching on the Shear Bond Strength of Ceramic Brackets

The Effect of Casein Phosphopeptide-amorphous Calcium Phosphate after Bleaching on the Shear Bond Strength of Ceramic Brackets

Shear bond strength in two types of indirect orthodontic cementation.

To compare the shear bond strength of brackets cemented to dental enamel according to the cementation techniques. Experimental study. We used 90 premolars and placed them in printed polylactic acid (PLA) filament models to simulate the dental arch shape and to then cement brackets using the direct, indirect technique with Transbond™XT and indirect technique with Orthocem®. Then, we carried out a shear bond strength test using a universal testing machine, and we evaluated the enamel surface using the adhesive resin remaining index. Dunn's test was used for the inferential statistical analysis of shear bond strength, and Fisher's exact test was used for the adhesive resin remaining index. The shear bond strength of the brackets recorded mean values of 16.74±4.48Mpa, 15.93±6.49Mpa and 12.09±5.07Mpa in the direct, indirect technique with Transbond™XT and indirect technique with Orthocem® respectively. At an inferential level, a lower statistically significant difference was found in the indirect group with OrthoCem® in contrast to the other two groups. In the evaluation of resin remaining after detachment, the direct technique group registered 46.7% of teeth with more than half of resin remaining and the indirect technique groups with Transbond™XT and Orthocem® registered less than half of resin remaining with an incidence of 53.3% and 43.3% respectively. At an inferential level, a statistically significant difference between groups was evidenced. The indirect cementation technique using Transbond™ XT is more recommended since it presents a higher shear bond strength than using Orthocem®. Key words:Orthodontics, Adhesion, orthodontic adhesives, shear bond strength.

The effect of antimicrobial peptide-added adhesive resins on shear bond strength and the adhesive remnant index of orthodontic brackets

ObjectivesThe aim of this study was to evaluate the effect of in-vivo produced Nisin which is an antimicrobial peptide (AMP) added to adhesive resin on shear bond strength (SBS) and the adhesive remnant index (ARI) of orthodontic brackets.MethodsBacterial AMP was produced by fermentation and the ideal AMP/Bond concentration and antimicrobial efficacy of the mixture were tested. To evaluate the SBS and ARI scores of AMP-added adhesive resins, 80 maxillary premolar teeth extracted for orthodontic purposes were used and randomly assigned into 2 groups (n = 40). Group 1: Control Group (teeth bonded with standard adhesive resin); Group 2: Experimental Group (teeth bonded with AMP-added adhesive resin). Statistical analysis was performed using the SPSS package program and applying the Mann-Whitney U and Fisher’s exact tests. P < 0.05 was considered as statistically significant.ResultsNisin synthesized in-vivo from Lactococcus lactis (L. lactis) (ATCC 7962) bacteria was provided to form a homogenous solution at an ideal concentration To find the minimum AMP/Bond mixture ratio that showed maximum antimicrobial activity, AMP and Bond mixtures were tested at various concentration levels between 1/160 and 1/2 (AMP/Bond). As a result, the optimum ratio was determined as 1/40. The antimicrobial efficacy of Nisin-added adhesive resin was tested against Streptococcus mutans (S. mutans) (ATCC 35,688) and Lactobacillus strains (cariogenic microorganisms). AMP formed a 2.7 cm diameter zone alone, while 1/40 AMP-bond mixture formed a 1.2 cm diameter zone. SBS values of the teeth bonded with Nisin added adhesive (17.49 ± 5.31) were significantly higher than the control group (14.54 ± 4.96) (P = 0.004). According to the four point scale, Nisin added adhesive provided a higher ARI score in favour of the adhesive and tooth compared to the control group (ARI = 3, n = 20).ConclusionsNisin produced from L. lactis (ATCC 7962) had greater antimicrobial effects after mixing with adhesive bond against cariogenic microorganisms S. mutans (ATCC 35,688) and Lactobacillus strains. Nisin added adhesive increased shear bond strength (SBS) of orthodontic brackets and ARI scores in favor of adhesive & teeth.Clinical relevanceClinicians should take into account that using Nisin-added adhesive resin in orthodontic treatments can provide prophylaxis against tooth decay, especially in patients with poor oral hygiene.

Shear bond strength of orthodontic brackets to single-shade composite surfaces: An in-vitro comparative study of different surface preparations

Purpose > The primary objective of this study was to determine which single-shade composite surface yielded clinically acceptable shear bond strength (SBS) to metal orthodontics brackets. The secondary objectives were to identify the best composite surface treatment to enhance SBS and determine which surface treatment produced the least surface damage at debond.Methods > Forty dental composite samples were selected from four different manufacturers (n=160) and grouped by manufacturer, one standard multi-shade dental system (FilTek™ Supreme Ultra) and three single-shade dental composites systems (OmniChroma®, SimpliShade™and Venus® Diamond One). Each group of forty samples was randomly divided into four sub-groups (n=10). Each sub-group was identified by the surface treatment used, hydrofluoric acid (HFA), micro-etching (MIC), or phosphoric acid (PA). Shear bond strength testing and adhesive remnant index (ARI) were performed. Statistical analyses included Kruskal-Wallis, Wilcoxon rank-sum, and two-factorial ANOVA.Results > OmniChroma® had statistically significant lower shear bond strength than the other composite materials tested. The control groups had statistically significant lower shear bond strength than Group 1/HFA (p<.001) and Group 2/MIC (p<.001). Group 1/HFA had the lowest distribution ARI score overall, while MIC had the highest ARI score distributions.Conclusions > The results of this in vitro study found that all tested composite materials achieved clinically acceptable shear bond strengths. The utilization of micro etching produced higher SBS. Significant Adhesive Remnant Index scores (< 0.001) were only found for OmniChroma® without any surface preparation.

Shear bond strength and adhesive remnant index evaluation of three different orthodontic adhesive systems using three different light curing times

BackgroundSuccess of long orthodontic treatment using orthodontic brackets depends mainly on the efficiency of the adhesive system used and it's degree of resistance in the face of stresses and foresees applied during treatment. The aim of this study was to evaluate the shear bond strength of orthodontic brackets bonded with three adhesive systems using different light curing times. Materials and methodsThe 126 human extracted premolars were randomly divided into three equal groups (n = 42) depending on the type of adhesive system used; total-etch (Transbond XT), self-etch (Transbond Plus), and self-adhesive (GC-Ortho Connect) system. Then each group was randomly subdivided into three subgroups (n = 14) based on the curing time; 1-s, 3-s, and 20-s. The shear bond strength (SBS) and adhesive remnant index (ARI) were evaluated in each subgroup using universal testing machine and stereomicroscope respectively. The data were analyzed statistically by a two-way ANOVA for SBS, and Scheirer Ray Hare Test for ARI. The significance level was set at P ≤ 0.05. ResultsThe results showed a statistically significant difference in shear bond strength at the three-time points for each adhesive system (p < 0.001) with the highest SBS value in 20-sec groups followed by 3-sec groups while 1-sec groups was the lowest. However, there was no statistically significant difference in Shear bond strength between the three adhesive systems except 20-sec groups (p < 0.001). ARI showed a statistically significant difference between all adhesive systems with the highest scores in TE groups, while the lowest in SE groups. ConclusionAll adhesive systems provided acceptable values of SBS at all curing times except the 1-sec group in SE and SA adhesive systems where the SBS values were the lowest and below the acceptable range.

Comparative evaluation of shear bond strength of orthodontic brackets bonded with two self-etching adhesive systems: an in vitro study

Abstract Objective To evaluate and compare the shear bond strength (SBS of the new Optibond eXTRa Universal and Adper Prompt L-Pop self-etch adhesive systems using an in vitro experimental design. Patients and methods The sample included 40 freshly extracted human maxillary first premolars collected from orthodontic patients, adhering to ethical guidelines. The teeth were randomly assigned to two groups, one treated with Optibond eXTRa Universal self-etch adhesive and the other with Adper Prompt L-Pop. Stainless-steel brackets were then bonded to the teeth using BracePaste orthodontic adhesive composite resin. After storage and thermocycling, SBS was measured using a universal testing machine, and adhesive remnant index (ARI) scores were assessed under a digital microscope. Statistical analyses were performed, including the Shapiro–Wilk method, Student’s t-test for SBS, and χ 2 test for ARI scores. Results The mean SBS showed no significant difference between both groups (P = 0.076). However, the distribution of ARI scores exhibited a highly significant difference between the two groups (P &lt; 0.001). Conclusion While both adhesives exhibited similar bond strengths, variations in adhesive residue patterns highlight the importance of considering adhesive performance in orthodontic applications such as ease of cleanup and potential impact on enamel health.

Assessment of Effect of Flowable Composite on the Shear Bond Strength of Sapphire Bracket Bonded to Composite Restoration: An in Vitro Study

Introduction: We aimed to assess the effect of flowable composite on shear bond strength (SBS) of sapphire bracket bonded to composite restoration. Methods: Forty composite discs (3M Filtek Z250) were allocated into four groups: control group (C) conventional primer (Transbond XT) with conventional composite (Transbond XT adhesive paste) was used, group (F1): conventional bonding agent, group (F2): universal bonding agent (Scotchbond) and group (F3): all surface bonding agent (Assure plus) were used with bulk fill flowable composite (3M Filtek), then sapphire brackets were bonded to the composite discs. After bonding, the specimens were thermocycled for 5000 cycles, SBS was measured, and the adhesive remnant index (ARI) was determined. Results: One-way analysis of variance and the post-hoc Tukey’s test demonstrated significant differences between conventional and flowable composite. Kruskal–Wallis test found that there was no significant difference in ARI between the study groups. Conclusion: Flowable composite groups had significantly lower SBS than the control group.

Effect of Different Conditioning Methods on Shear Bond Strength of Orthodontic Ceramic Brackets Bonded to Porcelain Ceramic Surface

The study aimed to investigate the shear bond strength (SBS) of orthodontic ceramic brackets bonded to porcelain ceramic surfaces that had undergone various conditioning methods. Materials and Methods: Forty ceramic discs were fabricated (vita vmk master®, zahnfabric, Germany) with a diameter of (4*10mm). Ceramic discs were divided into four groups (n = 10) according to ceramic surface conditioning methods, 37% phosphoric acid (PH), 9%hydrofluoric acid (HF), and surface conditioning with a fine diamond bur. Transbond XT light-cure composite was used to bond ceramic brackets. Before bonding, extra samples from each group were chosen to be examined using a scanning electron microscope (SEM) to determine the topography of the ceramic surface. The Shear Bond Strength data were evaluated using one-way analysis of variance (ANOVA) and Tukey HSD tests. Under an optical stereomicroscope, debond surfaces were examined. Results: Surface conditioning with a fine diamond bur + HF acid etching group produced the highest SBS (30.64 ± 7.28 MPa), and the lowest SBS was investigated in the PH acid etching group (14.75 ±3.32 MPa). Conclusions: Different conditioning methods affected the porcelain ceramic surface's shear bond strength (P &lt; 0.05). The highest SBS was found in the fine diamond bur_+ HF acid etching group; however, this had a deleterious effect on the ceramic surface after debonding.

Rebonding of orthodontic metallic brackets: Comparative analysis of shear bond strength using different sandblasting particles

IntroductionThis study aimed to evaluate the effect of two different sandblasting particles on the shear bond strength of rebonded metallic brackets to dental enamel. MethodsForty-eight metallic orthodontic brackets were divided into 4 experimental groups (n = 12) according to the surface treatment they received at their bases: positive control group (Metal), negative control group (MetalU), sandblasted with Rocatec Soft (MetalRoc) and sandblasted with Glass beads (MetalGlas). An elementary and topographic analysis of the base of the brackets was performed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) after the surface treatment. The brackets rebonded to dental enamel were tested for their shear bond strength. The obtained data were subjected to statistical analysis one-way ANOVA and Tukey's test (α = 0.05). The fracture surfaces of the specimens after the mechanical test were analyzed using optical microscopy to classify the failure mode. ResultsSEM photomicrographs for the MetalRoc and MetalGlas groups showed efficient removal of the remaining resin composite. In both sandblasting treatments, the presence of silicon (Si) and oxygen (O) at the base of the brackets were verified by means of the EDS, suggesting the occurrence of silica coating. MetalGlas group showed greater bond strength (9.38 ± 2.78 MPa) compared to the MetalU group (5.31 ± 1.2Mpa). Metal (8.82 ± 4.14 MPa) and MetalRoc (8.29 ± 3.95 MPa) groups showed similar bond strengths. The failure mode predominantly found in the sandblasted groups was the totally adhesive failure between resin composite and tooth. SignificanceThe sandblasting treatment using the glass beads was efficient in removing the remaining resin composite of recycled brackets and generated fewer surface defects and topographic changes in the bracket bases.