Bond Orthodontic Brackets Research Articles

Effects of Thermocycling with Two Different Curing Techniques on Enamel Micro-Cracks Formation, Debonding, and Failure Modes of Ceramic Brackets: An In Vitro Study.

Despite the rise in popularity of ceramic braces for adults, the risk of enamel microcracks (EMCs) upon removal remains a significant drawback for both dental professionals and patients. Our study aimed to assess the effects of thermocycling, pre-curing, and co-curing techniques with different bonding agents on the enamel surface of teeth after the removal of ceramic brackets. We also examined the incidence, quantity, length, and direction of EMCs on tooth surfaces. Additionally, the adhesive remnant index (ARI) scores and orthodontic bracket bond failure modes were evaluated and compared. The study divided 40 extracted upper canine teeth into ten groups for further analysis. Two groups had intact enamel as the negative control, while the remaining groups had orthodontic ceramic brackets bonded using different bonding agents and curing techniques. Thermocycling was performed in five groups, and ARI was assessed after debonding. The study findings were statistically significant (p < 0.05) in demonstrating the impact of curing techniques on EMCs and debonding outcomes. Seventh-generation bonding agents resulted in complete adhesive removal (ARI = 0). The microcracks' incidence, number, and length showed insignificant results. Differences in ARI between thermocycler and non-thermocycler samples were insignificant. Both co-curing and pre-curing techniques yielded comparable ARI results. This study highlights the importance of using advanced bonding agents to minimize enamel damage during ceramic bracket debonding.

Shear Bond Strength of Orthodontic Brackets Bonded with Thermo-Cured Glass-Based Materials-An In Vitro Study.

The results of orthodontic therapy largely depend, among other factors, on the preparation of the tooth enamel itself and the choice of material used to bond orthodontic brackets. The aim of this in vitro study was to determine the shear bond strength (SBS) and adhesive remnant index (ARI) score of thermo-cured glass-ionomers on different pretreated enamel, in comparison with the commonly used composite cement. Three commercially available nano-ionomer or highly viscous glass-ionomer cements (EQUIA Forte® Fil, EQUIA Fil, Ketac Universal) and two types of compo-sites (Heliosit Orthodontic, ConTec Go!) were investigated in this study. The research involved two hundred human premolars. The teeth were cleaned and polished, then randomly divided into five groups according to the enamel preparation method and the type of material. The enamel was treated in three different ways: polyacrylic acid, phosphoric acid, 5% NaOCl + etching with phosphoric acid, and a control group without treatment. Glass-ionomer cement was thermo-cured with heat from a polymerization unit during setting. Statistical analysis was performed using a Chi-square test and one-way ANOVA for independent samples. Spearman's Rho correlation coefficient was used to examine the relationship. Regardless of the material type, the results indicated that the weakest bond between the bracket and tooth enamel was found in samples without enamel pretreatment. The majority of the materials stayed on the brackets in samples without enamel preparation, according to ARI scores. The study's findings demonstrated that the strength of the adhesion between the bracket and enamel is greatly influenced by enamel etching and glass-ionomer thermo-curing. Clinical investigations would be required to validate the outcomes.

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

In vivo comparative assessment of bracket bond failure rates of single-component adhesives.

Single-component adhesives do not require the application of a primer on the enamel surface that has been etched and has been reported to have acceptable shear bond strengths on in vitro evaluation. This split-mouth study aimed to examine and assess the rates of bracket bond failure of hydroxyethyl methacrylate (HEMA)-based (Aqualine LC) and bisphenol A-glycidyl methacrylate (BisGMA)-based (Orthofix SPA) single-component adhesives used to bond orthodontic brackets over 6 months. This in vivo study involved the participation of 50 adult subjects, with 1080 metallic brackets directly bonded to the labial/facial surface in a split-mouth design. After 6 months of treatment, 49 patients with 490 brackets bonded using a HEMA-based adhesive and 490 brackets bonded using a BisGMA-based adhesive were evaluated for bracket bond failures. Descriptive statistics and chi-square tests were done to compare the results. The overall bracket bond failure rate (BFR) with single-component adhesives was 6.02%. Bracket BFRs of HEMA-based and BisGMA-based adhesives were 4.16% and 7.8%, respectively, and the difference was statistically significant (P < 0.05). Significant differences in BFRs between maxillary teeth (4.28%) and mandibular teeth (7.75%) were noted (P < 0.05). No significant differences in bond failures between either side or region were noted. Bond failures were more in brackets bonded with BisGMA-based adhesive (Orthofix SPA) compared with HEMA-based adhesive (Aqualine LC). Bond failures were less in the maxillary arch.

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.

Flowable Composite for Orthodontic Bracket Bonding (in vitro study)

Flowable resin composites have been recommended for many clinical uses and have been formulated in a variety of compositions and viscosities to meet various uses. The aim of this study was to determine if flowable composite with or without resins could be used as orthodontic bracket bonding. Sixty noncarious human premolars were divided into three equal groups. Metal brackets were bonded to etched enamel using a composite resin control (Resilience® orthodontic adhesive) and flowable composite with and without sealant resin (Resilience® flowable composite). After 72 hours of incubation in deionized water at 37 C°, debonding was performed with a shearing force. The shear bond strength (SBS) and the mode of bond failure were examined. High significant difference was observed in the SBS between control and flowable groups. Clinically acceptable SBS was found for the two flowable adhesives with bond failures occurred mostly in the bracket–adhesive interface. No significant differences between flowable groups. In conclusion, the use of flowable composite with and without sealant resin is advocated for orthodontic bracket bonding

Accuracy of Computer-Aided Full Tray vs Computer-Aided Sectional Tray in Indirect Bonding of Orthodontic Brackets; A Randomized Clinical Trial

Accuracy of Computer-Aided Full Tray vs Computer-Aided Sectional Tray in Indirect Bonding of Orthodontic Brackets; A Randomized Clinical Trial

The Effecacy of Different Surface Conditioning on Shear Bond Strength of Orthodontic Bracket Bonded to Lithium Disilcate Crowns; An in Vitro Study

Background and objective: Lithium disilicate widely used, and it is important to correctly bond orthodontic brackets to such materials. This study aimed to assess the impact of various types of surface conditioning methods on the shear bond strength (SBS) of orthodontic metal brackets to lithium disilicate crown. Materials and methods: In this in vitro study, 30 lithium disilicate specimens were prepared based on the type of surface conditioning into three surface conditioning groups (n=10 for each group). First group the semi-crowns surface was conditioned with 10% hydrofluoric acid etching, the second group was micro-etched with sandblast particles (50 um aluminum oxide particles) and the last group was conditioned with ultrasonic scaler. Valo light cure was utilized with 3200mw/cm2 light intensity. SBS was measured using a universal testing machine. The findings were statistically examined. Result: The results showed significant difference among the three groups where the sandblasting group had the higher mean of SBS, while the hydrofluoric acid etching group had the lower value and in between, the mean of ultra-sonic intermediate. &nbsp;&nbsp;&nbsp; &nbsp;Conclusions: &nbsp;Although the means of the three types of surface conditioning were significantly different, shear bond strength was positively affected by all of them and subsequently all types may be considered recommended techniques for reliable shear bond strength

Evaluation of Shear Bond Strength of Various Orthodontic Bracket Bonding Agents

Due to the development of properties of adhesive materials currently used in dentistry, the bonding ability between the brackets and the tooth enamel has been greatly improved. In general, in situations where cooperation can be obtained, adhesion of the orthodontic bracket through the conventional three-step process can show excellent bonding strength. However, if it is difficult to expect patient cooperation, as in the pediatric dentistry area, or if moisture isolation is not properly performed, the binding strength that does not reach the expected effect. As a result, various products that simplify the process for adhesion are being developed. The aim of this study was to evaluate and compare the shear bonding strength between the conventional 3-step adhesion system, self-etching primer system and one-step adhesion system that reduces the priming process. A total of 60 human maxillary, mandibular premolars were prepared. Group I (control group) were followed conventional 3-step bonding process. Group II were conditioned with self-etching primer. Group III were etched with 37% phosphoric acid and brackets were bonded with self-priming adhesive. The resultant shear bond strength of each group was measured and an adhesive remnant index (ARI) was recorded. The mean shear bond strength of group I, II, III were 14.69 MPa, 11.21 MPa and 12.21 MPa respectively. Significant differences could only be found between group I, II and group I, III (p &lt; 0.05). The ARI indicated no significant difference among all groups.

Accuracy of Orthodontic Indirect Bracket Bonding by CAD/CAM Transfer Tray

Introduction: Indirect bonding is a technique in which orthodontic attachments are transferred from dental casts (working models) and bonded onto dentition using a transfer tray. Indirect bonding is a preferred technique for many orthodontists as it is less time consuming compared to direct bonding. Evolution in technology allowed forming transfer trays digitally by the integration of computer-aided design and computer-aided manufacturing (CAD/CAM). This study was conducted to measure transfer accuracy of CAD/CAM indirect three dimensional printed bonding trays. Materials and methods: 140 teeth (all upper and lower incisors, canines and premolars) in 7 patients were bonded by vacuum-formed transfer tray formed on 3 dimensional (3D) printed models with resin brackets. Intra oral scanner was used initially to obtain stereolithographic file for virtual brackets positioning and another scan was taken after brackets bonding. Superimposition of virtual STL files and post bonding STL files was done by Geomagic Qualify software to measure linear and angular deviation of brackets positions. Results: One sample t-test was performed to determine whether the mean transfer error was statistically within the selected acceptable limits of 0.5 mm for linear measurements. P-values of less than 0.05 indicated differences within the limits of 0.5 mm for linear measurements. All brackets were transferred within the accepted deviation limits Conclusions: CAD/CAM designed and printed transfer trays had high transfer accuracy in linear measurements in all teeth.

Damage characterization of dental nanocomposite adhesive in orthodontic treatment applications

In orthodontic treatments, mechanical characterization of orthodontic bracket bonded to the tooth is essential to determine the bond strength and mechanical behavior of the bracket-adhesive-tooth system. In this study, the linear-nonlinear mechanical behavior and damage characterization of Filtek Z350 XT (3M ESPE) nanocomposite as a dental adhesive material to bond orthodontic brackets to tooth enamel, are investigated using numerical and experimental methods. Full sets of tensile, shear, and mixed modes I/II and I/II/III debonding experiments are conducted to extract the mechanical properties of the nanocomposite adhesive as the bracket/tooth interface. The results of the experiments are used to obtain the cohesive law and the damage model parameters. Three-dimensional finite element models of the bracket debonding tests are developed, while the cohesive zone model (CZM) is used to define the constitutive behavior of the nanocomposite interface under the tensile, shear, and mixed-mode loading conditions. The FE results showed a good correlation with the measured data, indicated the validity of the constitutive model, damage properties, and simulation process. The bond strengths of the nanocomposite adhesive are obtained 8.35 and 4.12MPa in modes I and II loadings, respectively.

Effect of Enamel Pretreatment with Pastes Presenting Different Relative Dentin Abrasivity (RDA) Values on Orthodontic Bracket Bonding Efficacy of Microfilled Composite Resin: In Vitro Investigation and Randomized Clinical Trial.

Bonding failure is a clinical issue frequently encountered in orthodontic practice. The aim of this study was to evaluate enamel pretreatment both in vitro and clinically using agents with different RDA values before brackets’ bonding, to assess if RDA can affect the Shear Bond Strength (SBS), Adhesive Remnant Index (ARI) and clinical failure rate of orthodontic brackets. For the in vitro study, 220 bovine teeth were pretreated with agents with different RDA values. Subsequently, brackets were bonded. For the clinical study, 20 patients underwent bonding of 20 brackets each with a split-mouth design. Low and high RDA toothpastes were used for enamel pretreatment. SBS, ARI and failures were recorded. Higher SBS values were found for teeth pretreated with lower RDA agents; conversely, lower SBS values were found for teeth pretreated with higher RDA agents (p < 0.05). For high ARI values, RDA increased too (p > 0.05). In the clinical study, a significantly lower failure rate was reported for teeth pretreated with low RDA toothpaste (2.5% in low RDA group, 7.0% in high RDA group; p < 0.05). No significant differences were assessed comparing the two dental arches and anterior and posterior sites. Enamel pretreatment with low RDA toothpastes could increase brackets’ survival rate. Further in vitro and clinical studies would be welcomed to confirm these findings.

Siloranes–Suitability of a Novel Adhesive for Orthodontic Bracket Bonding

Recently, an epoxy-based resin-Filtek Silorane-has been proposed for restorative fillings. It was the aim of the investigation to evaluate the suitability of this novel resin for orthodontic bracket bonding on unground enamel. Shear bond strength was measured for two adhesives-Filtek Silorane, Transbond XT-in combination with steel, ceramic and polymer brackets. For Filtek Silorane etching was performed with the Silorane self-etching primer, as well as phosphoric acid. The Transbond XT samples were etched with phosphoric acid only and served as the control group. All samples were thermo-cycled (1000×, 5–55 °C). Shear testing was carried out with an Instron 3344. In addition, ARI scores were evaluated. The Shear bond strength showed a weak adhesion of Filtek Silorane to unprepared enamel, either with the self-etching primer or the conventional etching (0.87–4.28 MPa). The Shear bond strength of the control group was significantly higher (7.6–16.5 MPa). The ARI scores showed a clear failure at the enamel-adhesive interface for all Filtek Silorane samples. For the combination of Transbond XT and different brackets the failure was found at the adhesive–bracket interface. The novel epoxy-based resin Filtek Silorane is not appropriate for bracket bonding to unprepared enamel.

Comparative Evaluation of Shear Bond Strength of Brackets Bonded with self Etch Primer/Adhesive and Conventional Etch/Primer and Adhesive System.

Introduction:The shear bond strength obtained with an acid primer might not be clinically reliable. The present study evaluated the use of a new self-etch primer as compared with the conventional bonding procedure. The findings indicated that the use of a self-etch primer to bond orthodontic brackets to the namel surface provided lower, but clinically accept-able, shear bond forces (mean, 7.1 ± 4.4 MPa). Hence, this study has been designed to evaluate the shear bond strength of orthodontic brackets bonded with a self-etching primer system, and compare it with the conventional acid etching priming system.Materials and Methods:This study was designed to compare the shear bond strength of orthodontic brackets bonded with conventional acid etching- priming and a self-etching primer. For this purpose, one hundred and twenty noncarious, not subjected to any pretreatment chemical agents (e.g. hydrogen peroxide), no cracks caused by the presence of the extraction forceps, no caries and unrestored human maxillary 1st and 2nd premolars, freshly extracted for orthodontic treatment were collected and stored in distilled water before bonding. Separate molds of cold-cure acrylic were prepared and the extracted premolar teeth were embedded in the cold cure acrylic up to the cement enamel junction.Results:For the control group, the mean shear bond strength was 9.38 ± 6.02 MPa and for the experimental group, it is 6.91 ± 3.58 MPa. Group comparison using Chi-square test for the self-etching primer group adhesive remnant index (ARI) scores shows that more than half of the adhesive left over the tooth surface (score 3 and 4). For the conventional group, ARI scores show that there was no or slight amount of adhesive left over the tooth surface (score 5). The proportion of ARI score is significantly (P < 0.001) more in conventional (68.33%) as compared to self-etch primer (SEP) (28.33%). The proportion of ARI scores 4 and less is significantly more in SEP (71.67%) as compared to Conventional (6.67%) with P = 0.004 as per the Chi-square test.Conclusion:The bond strength of SEP is comparatively lesser than the conventional acid etching technique, but is definitely more or less to the required bond strength to resist masticatory forces. Majority of the studies conducted on self-etching primer are in vitro studies. Results of these cannot be extrapolated to the intraoral environment. Hence, further long-term clinical studies need to be carried out before actually recommending the use of self-etching primer in routine orthodontic bonding.

Enamel Deproteinization: Will It Save The Shear Bond Strength For The Sake Of Preventing White Spot Lesions?

Objective: This study attempted to investigate the effect of enamel deproteinization using citric acid, PEG 400 and NaOCL on the shear bond strength of orthodontic brackets to enamel using nano-silver modified resin for the prevention of white spot lesions. Material and Methods: 68 premolars were used in the study; nano-silver modified adhesive resin was used to bond orthodontic brackets to the enamel. Specimens were divided into 4 groups according to the applied surface treatment before bonding. Group I (control): acid etching with 37% phosphoric acid. Group II: deproteinization using 5.25% sodium hypochlorite (NaOCl) before acid etching. Group III:deproteinization using 10% citric acid before acid etching. Group IV:deproteinization using 5% polyethylene glycol (PEG 400) before acid etching. The specimens were then thermo- cycled for 6000 cycles. They were examined for surface roughness, shear bond strength and using electron microscope. electron microscope Results: In both surface roughness and shear bond strength tests, Group III (citric acid) showed the highest values, followed by Group II (sodium hypochlorite); (p &lt; 0.001). The least values were shown for Groups I (control) and IV (PEG 400), with no statistically significant difference between them (p = 0.948). SEM revealed etching pattern type 1 and 2 in the citric acid group while PEG 400 showed shallower micro- porosities. Conclusions: Deproteinization of enamel using either NaOCl or citric acid increased the bond strength of nano-sliver modified resin to enamel, with citric acid showing greater increase in bond strength. Deproteinization using PEG 400 did not increase the bond strength. Keywords Deproteinization; Sodium hypochlorite; Citric acid; PEG 400; Nano- silver modified adhesives.

Shear bond strength of orthodontic brackets bonded with resin coating material

The purpose of this study was to determine whether a system using a resin coating material (PRG Barrier Coat) with anticariogenic ability can effectively bond orthodontic brackets to human teeth. Resin-modified glass-ionomer cement system (Fuji Ortho LC, group 1) and resin composite cement systems (BeautyOrtho Bond) combined with a self-etching primer (group 2), with the resin coating material (group 3), and with the resin coating material after an organic acid etching agent (group 4) were used for bracket bonding. The mean shear bond strength (SBS) was significantly higher in group 1 than in groups 2, 3 and 4. Groups 2 and 4 exhibited a significantly higher mean SBS than group 3. The resin composite cement system combined with the resin coating material after the organic acid etching agent can serve as an alternative for orthodontic bracket bonding.

Are Flowable Restorative Composites Suitable for Orthodontic Bracket Bonding?

Are Flowable Restorative Composites Suitable for Orthodontic Bracket Bonding?

The Performance of Universal Adhesives on Orthodontic Bracket Bonding

Abstract Objective This article aimed to assess the effects of double application of universal adhesives on the shear bond strength of orthodontic brackets. Materials and Method Seventy-five extracted human premolars were used. The teeth were randomly assigned into five groups based on the adhesive procedure (n = 15). The universal adhesives Scotchbond Universal (3M Oral Care) and Prime&amp;Bond Universal (Dentsply) were used (following manufacturer’s instructions and double application). Transbond XT Primer (3M Unitek) was employed as control. Following adhesive application, the brackets were bonded on the tooth surfaces. After storage in distilled water for 24 hours at 37°C, the specimens were subjugated to the shear bond strength test under a universal testing machine (Autograph AGS-X; Shimadzu). Data were analyzed with one-way analysis of variance and least significant difference tests (p = 0.05). The adhesive remnant index (ARI) was determined using a stereomicroscope (S4E; Leica Microsystems). Data of ARI scores were submitted to Pearson’s chi-square test. Results The highest shear bond strengths were acquired with Scotchbond Universal (p &lt; 0.05). The double application of Scotchbond Universal did not impact the shear bond strength. The lowest shear bond strength was found in Prime&amp;Bond Universal (p &lt; 0.05). The double application of Prime&amp;Bond Universal increased the shear bond strength (p &lt; 0.05). There were no significant differences in ARI scores among the groups (p &gt; 0.05). Conclusion The universal adhesives may be an alternative for the bonding of orthodontic brackets. The double application of universal adhesives might improve the shear bond strength of orthodontic brackets depending on the material.

Remineralization Potential and Shear Bond Strength of Surface Treated Hypomineralized Enamel in Bonding of Orthodontic Brackets: An In Vitro Study

Aim: To investigate the effect of different conditioning methods on remineralization potential of hypomineralized enamel and its shear bond strength (SBS) to orthodontic brackets. Materials and Methods: An in vitro study was conducted at Mansoura University, Egypt. Eighty premolars were collected and randomly classified into four groups ( n = 20 each) as follows: Group 1. Control (sound teeth), Group 2. Demineralized, Group 3. Demineralized and treated with nanohydroxyapatite (nano-HA) varnish, Group 4. Demineralized and treated with casein phosphopeptide–amorphous calcium phosphate (CPP–ACP) paste. To detect the rate of remineralization on the surface of treated specimens, energy dispersive X-ray (EDX) analysis was used in conjunction with the scanning electron microscope (SEM). The SBS was measured with a universal testing machine. One-way ANOVA test was carried out to analyze differences between the tested groups. Result: SE micrographs of Group 3 and Group 4 specimens showed smoother and less porous enamel surface than that of the Group 2 specimens. EDX analysis showed highest calcium (Ca) (25.47%) and phosphorous (P) (12.76%) values for Group 4 while Group 2 showed the lowest Ca and P values (16.96%) and (10.20%), respectively ( P &lt; .001). Demineralized enamel showed lowest (3.70 MPa) SBS mean value compared to sound (10.69 MPa) and remineralized enamel (Group 3—9.90 MPa, Group 4—10.32 MPa) ( P &lt; .001). Conclusion: Nano-HA and CPP–ACP have equal remineralizing effect on hypomineralized enamel lesions and positive influence on SBS.

Optimized Er: YAG Laser Irradiation Distance to Achieve the Strongest Bond Strength Between Orthodontic Brackets and Zirconia-Ceramics

Introduction: In recent decades zirconium oxide has been introduced in the field of dentistry as a high-strength ceramic. Unlike its mechanical advantages, however, due to its inert chemical properties, it bonds poorly to other substrates, so improving bonding strength to an adhesive material is necessary. Methods: In this experimental study, 70 ceramic zirconia blocks were prepared and distributed randomly among 7 groups. Then the shear bond strengths were determined and the samples were examined by a scanning electron microscope (SEM). Statistical analysis was performed by one-way ANOVA and multiple Tukey comparisons. Results: One-way analysis of variance (ANOVA) showed that laser irradiation distance has a significant effect on orthodontics brackets bond strength to zirconia-ceramics. Based on the Tukey post hoc test, each group was compared with other groups and the contact mode and 2 mm distance groups showed significantly higher bond strength than other groups (P value <0.05). Conclusion: Orthodontic bracket bond strength to zirconia-ceramics will be reduced by increasing Er: YAG laser irradiation distance from samples. The highest bond strength will be achieved when laser irradiation distance is 2 mm or when the laser beam is in contact with samples.