Shear bond strength of metal brackets to ceramic surfaces using a universal bonding resin

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

Background

Universal adhesive systems used for restorative clinical procedures are like orthodontics and may be a viable option. This study evaluated the effectiveness of universal adhesive systems in enhancing the durability of the shear bond strength (SBS) and adhesive remnant index (ARI) of orthodontic brackets to enamel.

Material and Methods

100 bovine incisors were divided into five groups (n=20), according to the applied adhesive systems: Primer Transbond XT; Ambar; Ambar Universal; Single Bond Universal; Adper Single Bond 2. Bracket from each tooth were submitted to SBS test after 24 hours, and 12 months later. The amount of remaining adhesive was evaluated through ARI.

Results

After 24 hours, there was no difference in BS between the control and the other groups (p>0.05). However, there were difference between TOTALETCHING1 group and the Ambar Universal (p=0.015) and Single Bond Universal groups (p=0.011). After 12 months, Primer Transbond XT, Ambar, Ambar Universal and Adper Single Bond 2 showed no differences in the SBS (p>0.05). Nonetheless, Single Bond Universal presented superior result when compared to Primer Transbond XT (p=0.046) and Ambar (p=0.011) groups. The SBS of all groups reduced significantly after 12 months (p<0.05). There was no difference between ARI scores in each individually assessed group (p>0.05), for both periods. Following 24 hours, a difference was observed between the groups (p=0.043), fact that didn't occur after 12 months (p=0.109).

Conclusions

Adhesive systems, such as Ambar Universal and Single Bond Universal are efficient in bonding orthodontic brackets to enamel when associated with Transbond XT adhesive paste. Key words:Bond strength; Primer Transbond XT, orthodontic brackets, adhesive systems.

Comparison of shear bond strength of metallic brackets bonded to ceramic surfaces utilizing different adhesive systems: An in vitro study

OBJECTIVE

To compare the shear bond strength (SBS) of orthodontic brackets bonded to three different types of ceramic surfaces (feldspathic, lithium disilicate, and zirconium) using Assure® Plus All and Transbond™ XT adhesives.

MATERIALS AND METHODS

The sample comprised 72 monolithic computer-aided design and computer-aided manufacturing (CAD/CAM) ceramic samples that were randomly divided into six groups of 12 specimens each. Three groups (G1, feldspathic ceramic; G3, lithium disilicate ceramic; G5, zirconium surfaces) were bonded to metal brackets using Assure® Plus All adhesive, whereas the remaining three groups (G2, G4, G6; with the ceramic type in the same order as that in the previous groups) were bonded to metal brackets using Transbond™ XT. The samples were then subjected to 10,000 thermocycles. The SBS was calculated using the shear tests. The site of bonding failure was classified using the adhesive remnant index (ARI) score. One-way analysis of variance (ANOVA) and Kruskal-Wallis tests were used for statistical analyses at a 5% significance level.

RESULTS

Statistically significant differences were observed in the mean SBS values of the groups (P < 0.001). The mean SBS for G6 (zirconium plus Transbond™ XT) (2.52 MPa) was significantly lower than that for all other groups. Furthermore, statistically significant differences were found in the ARI score distribution among the groups (P < 0.001). Differences were identified between G6 and G3 (lithium disilicate Plus All Assure® Plus All) and G5 (zirconium plus Assure® Plus All).

CONCLUSIONS

The mean bonding strength of brackets with Assure® Plus All was higher than that with Transbond™ XT for all three types of ceramics. However, all groups, except the zirconium plus Transbond™ XT group, showed acceptable bonding strength for orthodontic purposes. The application of hydrofluoric acid followed by silane and finally the Assure® Plus All adhesive system is adequate for bonding brackets to any of the ceramic tested surfaces.

The Effects of Er,Cr:YSGG laser on shear bond strength of orthodontic lingual brackets to CAD/CAM ceramic systems

Purpose

The aim of this study is to compare the bond strength of lingual brackets bonded to resin-matrix and lithium disilicate based-ceramic crowns following various surface treatments.

Materials and methods

Sixty ceramic crowns (IPS Emax and Cerasmart) were fabricated by CAD/CAM. Er,Cr:YSGG laser, sandblasting with aluminium oxide and hydrofluoric acid treatment effects on ceramics was tested (n=10/group). A light-cure orthodontic adhesive was used to bond lingual brackets to the ceramic surfaces. Bond strengths of the brackets to ceramics were assessed by shear bond test. The remnant adhesive on bracket and ceramic surfaces was inspected with a light microscope and adhesive remnant index scores were recorded. The data were analyzed statistically using the Kruskal-Wallis test followed by the Mann-Whitney U-test.

Results

Cerasmart ceramic specimens showed lower shear bond strength values than IPS Emax ceramic specimens (p<0.05). The statistical analysis of the surface treatment groups regarding bond strength were ranked as follows: Laser ≤ Hydrofluoric acid ≤ Sandblasting (p=0.058). While laser-treated Cerasmart ceramic group displayed the lowest SBS (9.39 MPa), hydrofluoric acid-treated IPS Emax group had the highest (16.8 MPa) bond strength value.

Conclusion

The use of Er,Cr:YSGG lasers for etching of CAD-CAM ceramics could be a promising alternative to "conventional techniques", to improve bond strength of lingual brackets to IPS Emax and Cerasmart ceramics.

The effect of ceramic surface conditioning on bond strength of metallic brackets: An in vitro study

OBJECTIVE

To compare the shear bond strength (SBS) of brackets bonded to three different types of ceramic surfaces (feldspathic ceramic, lithium disilicate ceramic, and zirconia), conditioned with either hydrofluoric acid or sandblasting, using Assure® Plus All bonding agent.

MATERIALS AND METHODS

A total of 72 monolithic CAD/CAM ceramic specimens were divided into six groups of 12 samples. Three groups (G1: feldspathic ceramic, G3: lithium disilicate ceramic, G5: zirconia surfaces) were conditioned with 9.6% hydrofluoric acid, while the remaining three (G2, G4, G6; with ceramic type in the same order as the previous three groups) were prepared with 50 μm aluminum oxide sandblasting. Premolar brackets were bonded using light-cured Assure® Plus All. The SBS and adhesive remnant index (ARI) were recorded and submitted to inferential analysis using one-way analysis of variance and Kruskal-Wallis tests, respectively. The significance level was set at 5% (P ≤ 0.05).

RESULTS

The mean SBS values for the three different ceramic groups conditioned with hydrofluoric acid (G1: 7.2 ± 1.5 MPa, G3: 9.3 ± 2.3 MPa, G5: 8.5 ± 2.0 MPa) were significantly higher than those obtained for the groups prepared by sandblasting before bonding (G2: 7.5 ± 1.8 MPa, G4: 4.4 ± 2.0 MPa, G6: 4.3 ± 2.8 MPa).

CONCLUSIONS

The hydrofluoric acid treatment produced a favorable SBS for all three examined ceramic types before bracket bonding with Assure® Plus All. In comparison, sandblasting yielded a satisfactory SBS only with feldspathic surfaces. Furthermore, the ARI indicated a higher frequency of mixed-adhesive failures except for lithium disilicate conditioned with sandblasting. Therefore, using hydrofluoric acid is likely to be especially recommended when the clinician is not aware of the brand of ceramic restorative material.

Bracket Bonding to All-Ceramic Materials with Universal Adhesives

The need for bracket bonding to ceramic restorations is increasing. The aim of this study was to evaluate the effect of universal adhesives on bracket adhesion to polished or glazed lithium disilicate (LDS) and monolithic zirconia (MZ) surfaces. One hundred and twenty brackets (N = 10) were bonded to either polished or glazed LDS (e.max CAD B32, Ivoclar Vivadent, Schaan, Liechtenstein) and MZ (In-Ceram^® YZ, VITA, Bad Sackingen, Germany) blocks using three different adhesives combined with Transbond™ XT Paste (3M Unitek, Monrovia, CA, USA). Tested universal adhesives were Scotchbond™ Universal Adhesive (SU, 3M St. Paul, MN, USA) and Assure Plus (AP, Reliance, Itasca, IL, USA). Transbond™ XT Primer (XTP, 3M Unitek, Monrovia, CA, USA) served as a control adhesive. Bracket bond strength was measured in shear mode (SBS). Failure type was determined by the Modified Adhesive Remnant Index (ARI). Data were statistically analyzed. On polished LDS, SU yielded bracket SBS significantly superior to those of AP and XTP. On polished MZ, the use of SU and AP significantly enhanced bracket retention as compared with XTP. Low SBS values, below the threshold of clinical acceptability, were reached by all tested adhesives on glazed LDS and MZ specimens. SBS measurements corresponded with failure type observations. Universal adhesives SU and AP could be considered for use on polished LDS and MZ surfaces.

What Is the Most Effective Technique for Bonding Brackets on Ceramic-A Systematic Review and Meta-Analysis

Background: There has been an increase in demand for orthodontic treatment within the adult population, who likely receive restorative treatments using ceramic structures. The current state of the art regarding the most effective method to achieve an appropriate bond strength of brackets on ceramic surfaces isn’t consensual. This systematic review aims to compare the available surface treatments to ceramics and determine the one that allows to obtain the best bond strength. Methods: This systematic review followed the PRISMA guidelines and the PICO methodology was used, with the question “What is the most effective technique for bonding brackets on ceramic crowns or veneers?”. The research was carried out in PubMed, Web of Science, Embase and Cochrane Library databases. In vitro and ex vivo studies were included. The methodological quality was evaluated using the guidelines for reporting of preclinical studies on dental materials by Faggion Jr. Results: A total of 655 articles searched in various databases were initially scrutinized. Sevety one articles were chosen for quality analysis. The risk of bias was considered medium to high in most studies. The use of hydrofluoric acid (HF), silane and laser afforded the overall best results. HF and HF plus laser achieved significantly highest bond strength scores in felsdphatic porcelain, while laser was the best treatment in lithium disilicate ceramics. Conclusions: The most effective technique for bonding brackets on ceramic is dependent on the type of ceramic.

Orthodontic bonding to silicate ceramics: impact of different pretreatment methods on shear bond strength between ceramic restorations and ceramic brackets

Objective

The study aims to investigate the shear bond strength (SBS) between silicate ceramic restorations and ceramic brackets after different pretreatments and aging methods.

Material and methods

Leucite (LEU) and lithium disilicate (LiSi) specimens were pretreated with (i) 4% hydrofluoric acid + silane (HF), (ii) Monobond Etch&Prime (MEP), (iii) silicatization + silane (CoJet), and (iv) SiC grinder + silane (SiC). Molars etched (phosphoric acid) and conditioned acted as comparison group. SBS was measured after 24 h (distilled water, 37 °C), 500 × thermocycling (5/55 °C), and 90 days (distilled water, 37 °C). Data was analyzed using Shapiro–Wilk, Kruskal–Wallis with Dunn’s post hoc test and Bonferroni correction, Mann–Whitney U, and Chi² test (p < 0.05). The adhesive remnant index (ARI) was determined.

Results

LEU pretreated with MEP showed lower SBS than pretreated with HF, CoJet, or SiC. LiSi pretreated with MEP resulted in lower initial SBS than pretreated with HF or SiC. After thermocycling, pretreatment using MEP led to lower SBS than with CoJet. Within LiSi group, after 90 days, the pretreatment using SiC resulted in lowest SBS values. After HF and MEP pretreatment, LEU showed lower initial SBS than LiSi. After 90 days of water storage, within specimens pretreated using CoJet or SiC showed LEU higher SBS than LiSi. Enamel presented higher or comparable SBS values to LEU and LiSi. With exception of MEP pretreatment, ARI 3 was predominantly observed, regardless the substrate, pretreatment, and aging level.

Conclusions

MEP pretreatment presented the lowest SBS values, regardless the silicate ceramic and aging level. Further research is necessary.

Clinical relevance

There is no need for intraoral application of HF for orthodontic treatment.

Orthodontic Attachment Adhesion to Ceramic Surfaces

Ceramic materials are constantly evolving, achieving good functionality and aesthetics. Bonding to ceramics may be difficult because of high toxicity procedures and risk of surface damage. The review aims to answer several research questions: Is there a golden standard for bonding to ceramic? Are there adhesives or types of photopolymerization lamps that produce a higher bond strength on certain types of ceramics rather than others? Articles focusing on the bonding process of orthodontic attachments to ceramic surfaces searched in Pubmed, Medline and Embase, published between 1990 and 2018 were revised. Exclusions concerned bonding to non-ceramic surfaces, bonding to ceramic surfaces that are not destined for orthodontics or laser usage. Forty-nine articles that matched the inclusion criteria were researched. The following categories of original research articles were compared and discussed: metallic brackets bonding to ceramic surfaces, ceramic brackets to ceramic surfaces, bonding to new types of ceramics, such as zirconia, lithium disilicate, different photopolymerisation devices used on bonding to ceramics. Some types of adhesive may achieve minimal bond strength (6-8 MPa) even on glazed ceramic. Ceramic surface preparation may be done by sandblasting or hydrofluoric acid (60s application and 9.6%) with generally similar results. Studies rarely show any statistical difference and there are reduced number of samples in most studies. Ceramic brackets show better adhesion to ceramic surfaces and the same bonding protocol is advised. A higher bond strength may lead to ceramic surface. Few studies focus on newer types of ceramics; additional research is necessary. There is no clear evidence that a certain type of photopolymerization device produces higher shear bond strength values.

Analysing the potential of hydrophilic adhesive systems to optimise orthodontic bracket rebonding

Introduction

Bond failure during fixed orthodontic treatment is a frequently occurring problem. As bracket rebonding is associated with reduced shear bond strength, the aim of the present investigation is to analyse the effect of different innovative rebonding systems to identify optimised rebonding protocols for orthodontic patient care.

Methods

Metallic brackets were bonded to the frontal enamel surfaces of 240 bovine lower incisors embedded in resin bases. Teeth were randomly divided into two major experimental groups: in group 1 a hydrophilic primer (Assure™ PLUS) was compared to commonly used orthodontic adhesives (Transbond XT™, BrackFix®, Grengloo™) and a zero control. In group 2 different rebonding systems were analysed using a hydrophilic primer (Assure™ PLUS), a methyl methacrylate-consisting primer (Plastic Conditioner) and a conventional adhesive (Transbond XT™). All teeth were tested for shear bond strength according to the DIN-13990 standard, the Adhesive Remnant Index and enamel fracture rate.

Results

The hydrophilic primer enhanced shear bond strength at first bonding (Assure™ PLUS 20.29 ± 4.95 MPa vs. Transbond XT™ 18.45 ± 2.57 MPa; BrackFix® 17 ± 5.2 MPa; Grengloo™ 19.08 ± 3.19 MPa; Meron 8.7 ± 3.9 MPa) and second bonding (Assure™ PLUS 16.76 ± 3.71 MPa vs. Transbond XT™ 13.06 ± 3.19 MPa). Using Plastic Conditioner did not seem to improve shear bond strength at rebonding (13.57 ± 2.94). When enamel etching was left out, required shear bond strength could not be achieved (Plastic Conditioner + Assure™ PLUS 8.12 ± 3.34 MPa; Plastic Conditioner: 3.7 ± 1.95 MPa). Hydrophilic priming systems showed decreased ARI-scores (second bonding: 2.63) and increased enamel fracture rates (first bonding: 55%; second bonding 21,05%).

Conclusions

Based on the present study we found that rebonding strength could be compensated by the use of hydrophilic priming systems. The additional use of a methyl methacrylate-consisting primer does not seem to enhance shear bond strength. No etching approaches resulted in non-sufficient bond strength.

The effect of various mechanical and chemical surface conditioning on the bonding of orthodontic brackets to all ceramic materials

Background/purpose

Increasing the bond strength between the orthodontic brackets and all-ceramic materials is one of the challenges facing orthodontists. The purpose of this study is to assess the shear bond strength (SBS) of metal brackets to two types of all ceramic materials using various surface mechanical and chemical conditioning methods.

Materials and methods

Sixty ceramic blocks were prepared using two types of all ceramic materials (IPS e.max and VITA Suprinity® PC) and treated with 3 surface treatments; surface etching with 9.6% hydrofluoric acid (HFA) for 2 mins; surface roughening with Sof-Lex finishing discs; and surface roughening with Sof-Lex finishing discs and etching with HFA. Metal brackets were attached to the surface of the ceramic blocks using light cure orthodontic adhesive. Samples were subjected to 2000 thermo-cycles (5-50 °C) and the SBS was assessed using Instron machine. The adhesive remnant index (ARI) was evaluated under light microscope. Descriptive and group comparison were calculated using Two-way ANOVA, Post-hoc Tukey's and Chi-square tests and significance level set at (P < 0.05).Results: surface roughening of both ceramic materials with Sof-Lex discs and HFA resulted in a significant increase in SBS compared to other experimental groups (P < 0.05). However, VITA Suprinity ceramic prepared with Sof-Lex discs only showed the lowest SBS. The distribution of the ARI scores was significantly different between the groups (P < 0.05).

Conclusion

Surface preparation of all ceramic materials with Sof-Lex discs and hydrofluoric acid combination produces the highest SBS to metallic orthodontic brackets.

Shear bond strength of orthodontic brackets to porcelain surface using universal adhesive compared to conventional method

BACKGROUND

Considering the increase in demand for orthodontic treatment in adults, bracket bond to restored teeth is a clinical challenge. This study sought to compare the shear bond strength (SBS) of orthodontic brackets to feldspathic porcelain using universal adhesive and conventional adhesive with and without silane application.

MATERIALS AND METHODS

In this in vitro study Fifty-six feldspathic porcelain discs were roughened by bur, and 9.6% hydrofluoric acid was used for surface preparation. Samples were divided into the following four groups (n = 14): Group 1: universal adhesive, Group 2: universal adhesive/silane, Group 3: conventional adhesive, and Group 4: conventional adhesive/silane. Mandibular central incisor brackets were bonded, and SBS was measured by Instron^® machine. To assess the mode of failure, adhesive remnant index (ARI) score was determined. The data were analyzed using SPSS software and two-way ANOVA, Bonferroni test, and Kruskal-Wallis test (P < 0.05 considered significant).

RESULTS

The highest SBS was noted in the universal adhesive/silane group (12.7 MP) followed by conventional adhesive/silane (11.9 MP), conventional adhesive without silane (7.6 MP), and universal adhesive without silane (4.4 MP). In the absence of silane, the conventional adhesive yielded significantly higher SBS than universal adhesive (P = 0.03). In the presence of silane, the two adhesives showed SBS values significantly higher than the values obtained when silane was not applied, while the two adhesives were not significantly different in terms of SBS in the presence of silane (P = 0.53). Based on ARI score, there were statistically significant differences between Groups 1 and 4 (P = 0.00) and Groups 2 and 4 (P = 0.023).

CONCLUSION

Based on the current results, SBS of bracket to porcelain mainly depends on the use of silane rather than the type of adhesive. Both universal and conventional adhesives yield significantly higher SBS in the presence of silane compared to that in the absence of silane.