Bond Strength Of Ceramic Brackets Research Articles

Comparative Assessment of the Shear Bond Strength of Ceramic Brackets Bonded to the Enamel Surface with a Self-adhesive System

Objectives: This study aimed to evaluate the shear bond strength of ceramic brackets bonded to the enamel surface using Vertise Flow, with or without the application of phosphoric acid. Materials and Methods: Forty-five extracted human premolar teeth were randomly assigned to three groups (N=15) based on the adhesive used for bonding: 1) Transbond XT, etch, and bond; 2) Vertise Flow; 3) Etch and Vertise Flow. After a 500-round thermocycling procedure, the shear bond strength was measured using a universal testing machine. The samples were then evaluated under a stereomicroscope to determine failure modes, and the Adhesive Remnant Index (ARI) was measured for each group. The data were analyzed with one-way ANOVA and post-hoc Tamhane at a significance level of P<0.05. Results: The highest shear bond strength values were observed in the Transbond XT (13.5±5.38MPa), acid etch and Vertise Flow (11.2±2.89MPa), and Vertise Flow (6.2±3.16MPa) groups, respectively, in descending order. The Vertise Flow group exhibited a significantly lower shear bond strength value compared to the other two groups, with no significant difference between the latter two. Conclusion: While all three study groups demonstrated clinically acceptable shear bond strength values, Vertise Flow showed lower values compared to the other two adhesives. The Vertise Flow composite resin system, whether used alone or with acid etching, remains a suitable choice for bonding ceramic brackets, offering the advantage of a simplified bonding procedure.

Effect of a Desensitizing Agent on Shear Bond Strength of Ceramic Bracket on Previously Bleached Teeth

This study aims to analyze the effect of desensitizing agents on the shear bond strength (SBS) of ceramic brackets after in-office bleaching procedures. Twenty-seven extracted premolars were equally divided into three groups (n = 9). Group 1 served as the control; bleaching was performed with 37% hydrogen peroxide. In group 2, bleaching and the application of a fluoride-containing desensitizing agent (CPP-ACFP) were performed. In group 3, bleaching and the application of a non-fluoride-containing desensitizing agent (CPP-ACP) were performed. Ceramic brackets were bonded with composite resin. SBS was tested using a universal testing machine. The site of bonding failure was measured using the adhesive remnant index (ARI) score. There was a statistically significant difference in mean SBS values (p < 0.05). Group 1 showed the lowest SBS value (6.32 ± 4.83 MPa), which differed significantly with groups 2 and 3 (p < 0.05). There was no significant difference between group 2 (15.36 ± 4.67 MPa) and group 3 (12.19 ± 6.81 MPa) (p > 0.05). The ARI score did not show a significant difference. The conclusion is that the application of fluoride-containing and non-fluoride desensitizing agents increases the shear bond strength of ceramic brackets on bleached teeth with composite resin cementation. The application of both desensitizing agents had no impact on the results of the ARI score, with the highest ARI score in each group being 4, indicating that less than 10% of the adhesive substance remains on the enamel.

Effects of Ultrasonic Instrumentation on the Shear Bond Strength of Ceramic Brackets: An In Vitro Study

Aim: Accumulation of plaque during orthodontic treatment makes oral prophylaxis a regular necessity. The use of esthetic brackets has gained popularity, it becomes necessary to assess the consequences of ultrasonic instrumentation during oral prophylaxis on ceramic bracket’s shear bond strength (SBS). Materials and Methods: Fifty-four premolar teeth which were extracted due to therapeutic reasons were divided into six groups with each group containing nine teeth each. Ceramic brackets were bonded onto the labial surfaces using two different adhesive systems (Ormco Enlight and Transbond) and were subjected to ultrasonic scaling at different scaler tip angulations. The samples were then rendered a debonding force in a Universal testing machine and the bond strengths were assessed. Results: In terms of angulation of ultrasonic instrumentation, among the groups bonded with the Ormco Enlight, the 45° angulation group had statistically significant higher bond strength values compared to the 0° angulation group. Among the transbond groups, there was no statistically significant difference in the bond strengths even though the 45° angulation group had slightly higher bond strength value than the 0° angulation group. Conclusion: Supragingival scaling around the bracket base at 0° around the ceramic brackets for 1 min resulted in the reduction of SBS. Therefore, the clinicians should be cautious during plaque removal, avoid performing extended ultrasonic instrumentation at the bracket base, especially at 0° angulation.

Bonding of orthodontic ceramic brackets: Optimal conditioning method of lithium disilicate restorations

Introduction. According to the data obtained from the American Orthodontic Society survey conducted in 2015, the number of adult patients that requested orthodontic treatment increased from 14% to 27% between 2010 and 2014. Because of the increased age of the patients, fixed orthodontic treatment is expected to be performed on restored teeth, including all ceramic restorations. The objectives of the present study were to evaluate the influence of different surface treatments on the bond strength of ceramic brackets to lithium disilicate ceramic and to determine the mode of fracture. Material and method. 45 ceramic rectangular specimens were obtained from lithium disilicate CAD/CAM blocks which were divided in five groups according to the performed surface conditioning method: 1. grinding with a fine diamond bur (control group); 2. sandblasting with 29 ?m alumina (Al2O3); 3. etching with 4% hydrofluoric acid (HF); 4. sandblasting followed by conditioning with a universal primer - silanization (Al2O3 + S); 5. HF acid etching followed by silanization (HF + S). Shear bond strength test was performed after storing the samples in water bath for 7 days. All of the fractured samples were analyzed with optical microscope to determine the type of fracture. Results. HF acid etching followed by silanization performed the highest bond strength of 8.03 MPa, while sandblasting followed by silanization - 6.69 MPa. Mechanical surface conditioning with either HF acid etching or sandblasting resulted in significantly lower bond strength (2.65 MPa and 1.51 MPa respectively). Mainly adhesive mode of fractures was noticed after sandblasting and silanization, indicating minor chance of damaging the ceramic restoration after debonding, at the end of the orthodontic treatment, unlike the ceramic specimens in the Group 5 (HF + S) with 42.8% mixed and 14.4% cohesive fractures; 100% adhesive fractures were observed after mechanical treatments. Conclusion. According to the SBS test results and fracture type, sandblasting followed by the application of a universal primer can be considered as an adequate method for conditioning the lithium disilicate ceramic restorations before the bonding of ceramic orthodontic brackets.

COMPARSION OF THE SHEAR BOND STRENGTH OF CERAMIC BRACKETS BONDED TO PORCELAIN FUSED METAL CROWNS AND METAL FREE CERAMIC CROWNS WITH AND WITHOUT SILANE COUPLING AGENT- AN IN VITRO STUDY.

Aim-The aim of this study is to evaluate and compare the shear bond strength of ceramic brackets bonded to porcelain fused metal crowns and metal free ceramic crowns with and without silane coupling agent.Material and Method: 40 metal free zirconia crowns and 40 PFM crowns were fabricated with glazed surfaces according to the manufacturer's instructions for the study purpose.The samples were divided in two groups A and B and each group was subdivided into two subgroups (A1, A2) and (B1, B2) Sub-Group A1 and A2: Twenty metal free ceramic crowns were etched with 9% buffered HF acid gel for 2 minutes,thoroughly washed and air dried.Relyx ceramic primer (silane coupling agent) was applied to the treated surface.Subgroup B1 and B2: 20 porcelain fused metal crowns were etched with 9% buffered HF acid gel for 2 minutes,thoroughly washed and air dried.Relyx ceramic primer (silane coupling agent) was applied to the treated surface. The shear bond strength of ceramic brackets bonded to porcelain fused metal crowns and metal free ceramic crowns with and without silane coupling agent. Statistical Analysis: ANOVA and Post hoc Tukey's test (HSD) tests were used for statistical analysis. Result: The result showed that group B1 demonstrate the maximum shear bond strength among all groups which is 9%HF +Relyx ceramic primer application on porcelain fused metal crowns (10.27+1.31Mpa) and has highly significant value.Whereas lowest shear bond strength belongs to group B2which is 9%HF and primer is not applied(5.4+0.73 Mpa).Conclusion: Hence it can be concluded that Relyx ceramic primer is more apropriate choice for bonding orthodontic metal brackets on PFM and zirconia surfaces with conventional bonding system.

Effectiveness of surface treatment on bond strength of ceramic brackets to two types of CAD/CAM-prepared nanohybrid composites.

The aim of this study was to assess the influence of surface treatment on the shear bond strength of two different adhesive-coated orthodontic ceramic brackets to computer-aided design/computer-aided manufacturing (CAD/CAM) nanohybrid composite. A total of 120specimens (10 mm × 10 mm × 3 mm) were prepared from each type of CAD/CAM block (Grandio [GR], VOCO Cuxhaven, Germany; Lava Ultimate [LU], 3M ESPE, St. Paul, MN, USA). For each type of CAD/CAM block, the plates were divided into four groups based on the applied surface treatment: hydrofluoric acid (HF), grinding bur (GB), silica coating with CoJet system (CS), and titanium tetrafluoride (TiF4) 2 wt/v%. Maxillary central incisors of adhesive-coated ceramic orthodontic brackets (APC Flash-free Clarity Advanced Ceramic, 3M Unitek, Monrovia, CA, USA) were bonded using Transbond XT Primer (3M Unitek, Monrovia, CA, USA). Shear bond strength was conducted, and the modes of failure were assessed utilizing the adhesive remnant index. Surface roughness and topography of treated CAD/CAM were evaluated. Data were statistically analyzed using two-way analysis of variance (ANOVA) and Tukey's test. The Weibull analysis was conducted on shear bond strength data. Surface treatment with 2% TiF4 wt/v revealed significantly higher bond strength (GR, 14.51 ± 2.57 MPa; LU, 11.19 ± 2.17 MPa) than other groups for both types of CAD/CAM restorative materials (p < 0.05). Adhesive failures were the predominant mode of failure. Surface treatment with CS revealed higher surface roughness than other groups (p < 0.05). Surface treatment with 2% TiF4 wt/v enhanced the adhesion between orthodontic ceramic brackets to GR and LU CAD/CAM composite restorative materials. GR CAD/CAM nanohybrid composite had higher bond strength than LU to ceramic orthodontic brackets.

Shear bond strength of ceramic brackets bonded to glazed lithium disilicate using different bonding protocols

Shear bond strength of ceramic brackets bonded to glazed lithium disilicate using different bonding protocols

Comparative evaluation of the shear bond strength of ceramic brackets of three different base designs bonded to amalgam and composite restorations with different surface treatment.

Nowadays, due to the increasing number of adult orthodontic applicants, who also have multiple dental restorations, it is important to have the ability to bond an orthodontic appliance to restoration surfaces. The aim of this paper was to determine the shear bond strength of ceramic brackets of 3 different base designs bonded to amalgam and composite restorations after using different surface treatment methods in vitro. In an in vitro study, the surfaces of 180 amalgam and composite specimens were prepared by using sandblasting and the erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser irradiation. Ceramic brackets of 3 base designs, including Star, Cross and Slot, for upper central teeth were bonded to amalgam and composite surfaces by using Transbond™ XT Light Cure Adhesive. All specimens were incubated at a temperature of 37°C for 1 week, and then subjected to shear bond strength tests after 1,000 cycles of thermal cycling. The bond strength of the groups was analyzed by means of the one-way and two-way analysis of variance (ANOVA), and the comparison of the 2 groups was made with Tukey's test. Residual adhesives were also determined by a 4-part criterion (0-3) in different groups and the results were analyzed with the χ2 test. There was a significant difference in the shear bond strength of brackets of 3 base designs bonded to amalgam and composite surfaces with different surface treatment. According to the results of this study, all surface treatment methods and different bracket base designs were able to provide sufficient shear bond strength on composite and amalgam surfaces. As far as the bracket base design is concerned, the use of each of the 3 base designs in the amalgam group brought desirable results in terms of the adhesive remnant index (ARI) and shear bond strength values; the use of the Star base design in the composite group proved to be suitable.

Influence of dental erosion on shear bond strength of ceramic brackets bonded with two different adhesive systems: an in vitro study

This study aimed to analyze the shear bond strength (SBS) of ceramic orthodontic brackets bonded with two different adhesive systems to intact and eroded teeth. Ceramic brackets were bonded to 72 bovine central incisors divided into four groups, defined by two study factors: enamel condition (control group, kept in artificial saliva; and experimental group, eroded by using immersion cycles in Coke™ for 90 seconds, every six hours for five days), and adhesive system type (Transbond™ XT or Transbond™ Plus Color Change). Polycrystalline ceramic brackets were adhesively fixed on all specimens using the same light curing protocol. SBS was tested using 0.5 mm/min and the failure mode was classified. SBS data was analyzed using two-way ANOVA followed by Tukey test. The adhesive remnant index (ARI) scores were analyzed using Kruskal-Wallis test with Dunn's post-hoc pairwise comparison (α=0.05). Percentages of ARI scores between the groups were compared by Fisher’s exact test. Spearman's correlation coefficient was applied to investigate the correlation between ARI scores and SBS values. Only the adhesive system factor had significant effect on SBS (p=0.014), Transbond™ Plus Color Change showing higher values. No significance was found for enamel condition (p=0.665) or the interaction between adhesive system and enamel condition (p=0.055). ARI scores frequencies differed between groups (p&lt;0.001). The median ARI scores were statistically different for most comparisons among the groups. However, no significant correlation was found between ARI scores and SBS. In conclusion, the type of adhesive system affected the SBS of ceramic brackets to dental enamel, but the enamel condition, intact or eroded, had no significant effect. There was no correlation between ARI scores and SBS values, although eroded enamel tended to retain more adhesive after bracket removal.

Comparsion of the shear bond strength of ceramic brackets bonded to porcelain fused metal crowns and metal free ceramic crowns with and without silane coupling agent- an in vitro study

The aim of this study is to evaluate and compare the shear bond strength of ceramic brackets bonded to porcelain fused metal crowns and metal free ceramic crowns with and without silane coupling agent. 40 metal free zirconia crowns and 40 PFM crowns were fabricated with glazed surfaces according to the manufacturer’s instructions for the study purpose. The samples were divided in two groups A and B and each group was subdivided into two subgroups (A1, A2) and (B1, B2) Twenty metal free ceramic crowns were etched with 9% buffered HF acid gel for 2 minutes, thoroughly washed and air dried. Relyx ceramic primer (silane coupling agent) was applied to the treated surface.20 porcelain fused metal crowns were etched with 9% buffered HF acid gel for 2 minutes, thoroughly washed and air dried. Relyx ceramic primer (silane coupling agent) was applied to the treated surfaceThe shear bond strength of ceramic brackets bonded to porcelain fused metal crowns and metal free ceramic crowns with and without silane coupling agent. ANOVA and Post hoc Tukey’s test (HSD) tests were used for statistical analysis. The result showed that group B1 demonstrate the maximum shear bond strength among all groups which is 9%HF +Relyx ceramic primer application on porcelain fused metal crowns (10.27+1.31Mpa) and has highly significant value. Whereas lowest shear bond strength belongs to group B2which is 9%HF and primer is not applied (5.4+0.73 MPa). Hence it can be concluded that Relyx ceramic primer is more aooropriate choice for bonding orthodontic metal brackets on PFM and zirconia surfaces with conventional bonding system.

Evaluation of shear bond strength of ceramic brackets bonded to three different types of porcelain crowns: In vitro study

Evaluation of shear bond strength of ceramic brackets bonded to three different types of porcelain crowns: In vitro study

Effect of different surface treatments on shear bond strength of ceramic brackets to old composite

BackgroundAt present, the demand for orthodontic treatment is on the rise. On the other hand, evidence shows that the bond strength of composite resins to old composite restorations is often unreliable. Therefore, the aim of this in vitro study was to assess the effect of different surface treatments on shear bond strength (SBS) of ceramic brackets to old composite restorations.MethodsIn this in vitro experimental study, 60 nano-hybrid composite discs were fabricated. For aging, the discs were incubated in deionized water at 37 °C for 1 month. Next, they underwent 4 different surface treatments namely acid etching with 37% phosphoric acid, sandblasting, grinding, and Er,Cr:YSGG laser irradiation. Ceramic brackets were then bonded to the discs and underwent SBS testing.ResultsThe maximum mean SBS value was obtained in the grinding group (9.16 ± 2.49 MPa), followed by the sandblasting (8.13 ± 2.58 MPa) and laser (6.57 ± 1.45 MPa) groups. The minimum mean SBS value was noted in the control group (5.07 ± 2.14 MPa).ConclusionAll groups except for the control group showed clinically acceptable SBS. Therefore, grinding, sandblasting, and Er,Cr:YSGG laser are suggested as effective surface treatments for bonding of ceramic orthodontic brackets to aged composite.

Priming and bonding metal, ceramic and polycarbonate brackets

Objective: To investigate if primers can be used to modify bonding characteristics of orthodontic brackets.Materials and methods: Stainless steel, zirconia-alumina ceramic and polycarbonate brackets were bonded to enamel with and without universal and bracket material specific primers on the bracket base. Orthodontic adhesive cement (Transbond™XT) was used for bonding. The primers in each group (n = 10) were silane based (RelyX™ Ceramic Primer) and universal primer (Monobond Plus) for ceramic and metal brackets, and adhesive resin (Adper™ Scotchbond™ Multi-Purpose Adhesive) and composite primer (GC Composite Primer) for polycarbonate brackets. Controls with no primer were used for all bracket types. Teeth with bonded brackets were stored in distilled water in 37 °C for 7 days and debonded with static shear loading. Debonding forces were recorded and analyzed with ANOVA. Adhesive remnant index (ARI) was determined and enamel damage examined.Results: The bond strength without primers was 8.14 MPa (±1.49) for metal, 21.9 MPa (±3.55) for ceramic and 10.47 MPa (±2.11) for polycarbonate brackets (p < .05). Using silane as primer increased the bond strength of ceramic brackets significantly to 26.45 MPa (±5.00) (p < .05). ARI-scores were mostly 2–3 (>50% of the adhesive left on the enamel after debonding), except with silane and ceramic brackets, ARI-score was mostly 0–1 (>50% of the adhesive left on the bracket). Debonding caused fractured enamel in four specimens with ceramic brackets.Conclusions: Bond strength was highest for ceramic brackets. Silane primer increased bond strength when used with ceramic brackets leading to enamel fractures, but otherwise primers had only minor effect on the bond strength values.

Effect of Er:YAG and Er,Cr:YSGG Lasers on Ceramic Bracket Debonding from Composite Blocks.

Objectives:This study aimed to assess the effect of erbium-doped yttrium aluminum garnet (Er:YAG) and erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) lasers on the shear bond strength (SBS) of ceramic brackets debonding from the surface of composite blocks.Materials and Methods:Thirty-six composite blocks were fabricated using Filtek Z250 light-cure composite. Block surfaces were etched with 37% phosphoric acid for 30 seconds and then rinsed with water for 20 seconds and dried. Maxillary right central incisor ceramic orthodontic brackets were bonded to the surfaces of composite blocks using Transbond XT adhesive and were cured for 40 seconds. Twelve samples were irradiated with Er:YAG laser, while 12 samples were irradiated with Er,Cr:YSGG laser, and the brackets were then debonded using a universal testing machine. Twelve samples served as controls (debonding using the universal testing machine without using a laser). The adhesive remnant index (ARI) score and bracket or composite cracks were evaluated under a stereomicroscope. One-way analysis of variance (ANOVA) was used for the comparison of the three groups. Kruskal-Wallis test was used to compare the ARI scores.Results:The mean SBS was 17.01±5.22 MPa with Er:YAG laser, 18.03±6.46 MPa with Er,Cr:YSGG laser, and 16.61±6.73 MPa in the control group; the difference of the three groups was not significant (P=0.835). The difference in the ARI scores and enamel and composite cracks was not significant either (P>0.05).Conclusion:This study did not show any reduction in the bond strength of ceramic bracket to composite blocks after Er:YAG and Er,Cr:YSGG laser irradiation.

Bond strength of pre-coated flash-free adhesive ceramic brackets. An in vitro comparative study on the second mandibular premolars

Clinical studies show a mean bond failure rate of orthodontic brackets, which ranges between 6% and 8%, with a predominance for the second mandibular premolars. The pre-coated flash-free adhesive ceramic brackets allow to obtain, according to their manufacturer, a low bond failure rate, while ensuring a simplified implementation. The aim of this study was to measure the shear bond strength of ceramic brackets bonded with the direct method using a pre-coated flash-free adhesive system, and to compare it with the shear bond strength of the old generation precoated brackets and that of operator coated brackets to the buccal surface of the second mandibular premolars. 45-second mandibular premolars extracted for orthodontic purposes were randomly distributed into 3 groups of 15 teeth each. In the first group, the brackets were precoated with the APC™ Flash-Free® system (3M Unitek; in the second group, with the APC Plus® system (3M Unitek), and in the third group, the brackets were bonded manually with the Transbond XT® composite (3M Unitek). The enamel surface was prepared in the same way for the 3 groups: etching using 36% orthophosphoric acid, followed by the application of the Transbond XT® primer adhesive (3M Unitek). Each sample was submitted to shear bond strength forces using a Universal Testing Machine LRX® (Lloyd Instruments LTD., Fareham, UK) in shear mode with a crosshead speed of 1.0mm/min. The bond strength values of the brackets were recorded in megapascals (MPa) for each tooth. The mean values were then compared using the one-way ANOVA test. Although the mean shear bond strength value for the APC Flash-Free® group was lower than those of the two other groups, this difference was not statistically significant (P=0.276). Given the experimental conditions of this in vitro study, the shear bond strength of the brackets precoated with the APC Flash-Free® system is comparable to the two other conventional systems.

Assessment the Bond Strength of Ceramic Brackets to CAD/CAM Nanoceramic Composite and Interpenetrating Network Composite after Different Surface Treatments.

Adult orthodontics may confront problems related to the bonding performance of orthodontic brackets to new generation restorative materials used for crown or laminate restorations. The aim of the present study was to investigate the shear bond strength of ceramic brackets to two new generation CAD/CAM interpenetrating network composite and nanoceramic composite after different surface treatments. Er,Cr:YSGG Laser, hydrofluoric acid (9%), sandblasting (50 μm Al2O3), and silane were applied to the surfaces of 120 CAD/CAM specimens with 2 mm thickness and then ceramic brackets were bonded to the treated surfaces of the specimens. Bond strength was evaluated using the shear bond strength test. According to the results, CAD/CAM block types and surface treatment methods have significant effects on shear bond strength. The lowest bond strength values were found in the specimens treated with silane (3.35 ± 2.09 MPa) and highest values were found in the specimens treated with sandblast (8.92 ± 2.77 MPa). Sandblasting and hydrofluoric acid surface treatment led to the most durable bonds for the two types of CAD/CAM blocks in the present study. In conclusion, different surface treatments affect the shear bond strength of ceramic brackets to CAD/CAM interpenetrating network composite and nanoceramic composite. Among the evaluated treatments, sandblasting and hydrofluoric acid application resulted in sufficient bonding strength to ceramic brackets for both of the CAD/CAM materials.

Shear bond strength of ceramic brackets bonded to surface-treated feldspathic porcelain after thermocycling.

The aim of this study was to evaluate the effect of six different surface conditioning methods on the shear bond strength of ceramic brackets bonded to feldspathic porcelain. A total of 60 feldspathic porcelain disks were fabricated and divided into six subgroups including 10 specimens in each. Specimens were first treated one of the following surface conditioning methods, namely, 37% phosphoric acid (G-H3PO4), 9.4% hydrofluoric acid (G-HF), grinding with diamond burs (G-Grinding), Nd:YAG laser (G-Nd:YAG), Airborne-particle abrasion (G-Abrasion). Specimens were also coated with silane without surface treatment for comparison (G-Untreated). A total of 60 ceramic brackets were bonded to porcelain surfaces with a composite resin and then subjected to thermocycling 2500× between 5°C and 55°C. The shear bond strength test was carried out using a universal testing device at a crosshead speed of 0.5 mm/min. Failure types were classified according to the adhesive remnant index. Analysis of variance and Tukey tests were used for statistical analysis (α = 0.05). Microstructure of untreated and surface-treated specimens was investigated by scanning electron microscopy. Using G-Abrasion specimens resulted in the highest shear bond strength value of 8.58 MPa for feldspathic porcelain. However, the other specimens showed lower values: G-Grinding (6.51 MPa), G-Nd:YAG laser (3.37 MPa), G-HF (2.71 MPa), G-H3PO4 (1.17 MPa), and G-Untreated (0.93 MPa). Airborne-particle abrasion and grinding can be used as surface treatment techniques on the porcelain surface for a durable bond strength. Hydrofluoric acid and phosphoric acid etching methods were not convenient as surface treatment methods for the feldspathic porcelain.

Shear bond strength of ceramic bracket bonded to different surface-treated ceramic materials

BackgroundThis study evaluated the effect of ceramic surface treatments on bond strength of ceramic brackets to machine-able ceramics and ceramic veneering metal.Material and MethodsMachined ceramic specimens (10x10x1.5 mm) were prepared from Empress® CAD (EP), and e.max® CAD (EM). Ceramic veneering metal specimens (PF) were fabricated from sintered d.Sign® porcelain (1.27 mm thickness) over d.Sign®10 metal (0.23 mm thickness). Each ceramic was divided into 3-groups and treated surface by Er-YAG laser (LE) or etching with 9.6% HF acid for 5 seconds (A5) or 15 seconds (A15). Resin adhesive (Transbond™-XT) was used for attaching ceramic brackets for each group (n=15) and cured with LED (Bluephase®) for 50 seconds. Specimens were immersed in distilled water for 24 hours before testing for shear bond at crosshead speed of 1.0 mm/min. The data were analyzed for the differences in bond strength with ANOVA and Tukey’s multiple comparisons (α = 0.05). De-bond surfaces were microscopically examined.ResultsBond strength (MPa) were 12.65±1.14 for EMA5, 14.50±2.21 for EMA15, 13.97±1.17 for EMLE, 12.40±1.95 for PFA5, 15.85±3.13 for PFA15, 14.06±2.17 for PFLE, 12.12±1.54 for EPA5, 15.65±1.57 for EPA15, 12.89±1.17 for EPLE. Significant differences in bond strength among groups were found related to surface treatment (p<0.05), but not significant difference upon type of ceramics (p>0.05). A15 provided higher bond strength than LE and A5 (P<0.05). No damage of ceramic surface upon de-bonding was indicated except for A15 tends to exhibit ditching. LE showed more uniform treated surface for bonding and no surface destruction upon de-bond compared to others.ConclusionsBond strength was affected by surface treatment. Both LE and A15 treated surface provided higher bond strength than A5. Considering possibly inducing defect on ceramic surface, LE seems to provide better favorable surface preparation than others. Treated ceramic surface with Er-YAG prior to bracket bonding is recommended. Key words:Ceramic, ceramic bracket, Er-YAG, laser, shear bond strength, surface treatment.

Influence of adhesive and thermal cycling on the bond strength of ceramic brackets to dental ceramic

Aim: This in vitro study investigated the effect of the application of an adhesive, silane and thermal cycling (TC) on the shear bond strength (SBS) of ceramic brackets to feldspathic ceramic. Methods: 16 cylinders of feldspathic ceramic were etched with hydrofluoric acid and divided into four groups (n=4): G1 - silane, without TC; G2 – silane, with TC; G3 - adhesive, without TC; G4 - adhesive, with TC. One layer of silane was applied on the surface of cylinders in G1 and G2 e one layer of photo-activated adhesive Single Bond Universal was used in G3 and G4. Ceramic brackets were bonded using Transbond XT. The SBS data were subjected to two-way ANOVA and Tukey’s post hoc test (α=0.05). The Adhesive Remnant Index (ARI) was evaluated at 40× magnification. Results: Silane was more effective than adhesive on the SBS of the brackets to ceramic (p&lt;0.05). TC decreased significantly the SBS values compared with the groups without TC (p&lt;0.05). The ARI results showed predominance of score 0. Conclusions: Groups with silane showed higher SBS than groups with adhesive. TC influence significantly on the bond strength. Regarding ARI, score 0 predominated in all groups.

Effect of different intracoronal bleaching methods on shear bond strength of ceramic brackets bonded to bleached enamel: An in-vitro study.

OBJECTIVE:To investigate the effect of different intracoronal bleaching methods on the shear bond strength and site of failure of ceramic brackets.MATERIALS AND METHODS:Sixty freshly extracted human maxillary incisors were randomly divided into four groups (n = 15). Endodontic access cavity was prepared and root canals were filled, root fillings were removed 2mm apical to the cementoenamel junction, and a 2-mmthick layer of glass ionomer cement base was applied. Group 1 served as the control. Intracoronal bleaching was performed with 35% carbamide peroxide in group 2, sodium perborate in group 3, and 37.5% hydrogen peroxide in group 4. The teeth were immersed in artificial saliva for 4 weeks before bracket bonding. Ceramic brackets were bonded with composite resin and cured with LED light. After bonding, the shear bond strength of the brackets was tested with a universal testing machine. The site of bond failure was determined by modified ARI (Adhesive Remnant Index).RESULTS:The highest value of shear bond strength was measured in control group (18.67 ± 1.59 MPa), which was statistically significant from groups 2,3, and 4. There was no significant difference between groups 2 and 4. The lowest shear bond strength was measured in group 3. ARI scores were not significant from each other.CONCLUSIONS:Intracoronal bleaching significantly affected the shear bond strength of ceramic brackets even after 4 weeks of bleaching. Bleaching with sodium perborate affects shear bond strength more adversely than does bleaching with other agents like hydrogen peroxide and carbamide peroxide.