Retrospective study of orthodontic bonding without liquid resin

Comparative evaluation of bracket bond failure rates of a novel non-primer adhesive with a conventional primer-based orthodontic adhesive - a pilot study

Background

Bonding is an important step in fixed orthodontic therapy and evaluation of bracket bond failures while using different bonding systems is required. The aim of the present study was to evaluate and compare bracket failure rates of a novel no primer adhesive with conventional primer-based orthodontic adhesives.

Methods

This split mouth study was conducted among fifteen patients who underwent therapy with fixed orthodontic appliances using metal brackets. Total of 300 brackets were bonded and the bracket bond failure rates were assessed at the end of 3 months. The difference in bond failure rates between the two groups were assessed in different teeth. Descriptive statistics and chi-square test was performed.

Results

Evaluation of bracket bond failure rates showed a higher incidence of bond failures in the group bonded with the primerless adhesive (6.3%) compared to conventional adhesive (2.3%) but there was no statistically significant difference (P>0.05). No intergroup difference was found in the bracket failure rates of individual teeth (P>0.05).

Conclusion

Higher incidence of bond failures were noted with brackets bonded with primerless adhesive when compared to primer-based adhesive but no significant difference was noted over a period of 3 months. Mandibular canine and premolars had a higher bracket failure rate with no significant difference between the adhesives.

Evaluation of Shear Bond Strength of a Primer Incorporated Orthodontic Composite Resin: An In-Vitro Study

Introduction

Newer adhesive systems are available eliminating the separate priming step during the bonding procedure thereby reducing the chances of introduction of error during bonding. The purpose of this study was to compare the shear bond strength of a primer-incorporated adhesive with that of a self-etching primer system and conventional bonding system.

Materials and method

Sixty-six extracted human premolars were cleaned, mounted, and randomly divided into three groups. In group A (control), 22 teeth were bonded with stainless steel orthodontic brackets using the conventional bonding system; in group B, 22 teeth were bonded using a self-etching primer system (Transbond Plus SEP, 3M Unitek, Monrovia, CA) and in group C, 22 teeth were bonded using the new primer-incorporated adhesive system (GC Ortho Connect, GC Orthodontics, Breckerfeld, Germany). After bonding, the teeth were stored in artificial saliva at 37^ºC for 24 hours and debonded with a universal testing machine. The adhesive remnant index (ARI) was also evaluated. Statistical analysis was done using one-way ANOVA to compare the shear bond strength values among the three groups and Kruskal Wallis test was used for comparison of ARI scores.

Results

The SBS values in group A (11.60 ± 2.95 MPa), group B (9.44 ± 4.46 MPa) and group C (12.68 ± 6.25 MPa) were found to be comparable with no statistically significant difference. The ARI scores were also similar among the tested groups with the predominant site of bond failure being the bracket-adhesive interface indicating a safe bond-failure site.

Conclusion

GC Ortho Connect was found have clinically acceptable shear bond strength values that are comparable with that of self-etching primer and conventional bonding system. Therefore, it can be used effectively for saving the clinician’s chairside time by reduction in the number of steps during bonding without compromising on the bond strength.

Bracket Failure in Orthodontic Patients: The Incidence and the Influence of Different Factors

Failure of brackets is a common problem in orthodontics. This affects the treatment time, cost, and compliance of the patient. This study was conducted to estimate the bracket failure rate and the related factors for the long term. Methodology. This ambidirectional cohort study included 150 nonsyndromic orthodontic patients undergoing fixed appliance therapy for the last two years. The same patients were followed for 7 months. Different variables related to bracket failure were evaluated. The available data were analyzed descriptively, and the Kaplan-Meier estimate was used to measure the bracket survival rate from the date of bonding to failure. Results. A total of 180 bracket bond failures in the 150 included patients (52.2% males and 47.8% females) with a median age of 17 years (range 10-25 years). 69% of brackets failures were reported within the first 6 months after bonding. About 58.3% of bracket failure was noticed in adolescent patients before the age of 18 years. The majority of the cohort (81.1%) has good oral hygiene. The failure rate in patients with normal overbite was 41.1%, in decreased overbite cases was 15%, while in deep bite cases the failure rate was 43.9% with a statistically significant difference. Adults show less bracket failure (41.7%) than adolescent patients (58.3%). More bracket failure was noted in the lower arch (55%) than the upper arch (45%), and there were more bond failures posteriorly (61%) than on the anterior teeth (39%). Majority (41.1%) of the bracket failed on round NiTi wires. Conclusion. The bracket failure rate was 6.4%, with most bracket failure occurring in the first 6 months after bonding with individual difference. There was more incidence of bond failure in an increased overbite, adolescents, lower arch, posterior teeth, and lighter alignment wires.

Comparison of bond strength of metal and ceramic brackets with or without primer

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Single-component orthodontic adhesives: comparison of the clinical and in vitro performance

OBJECTIVES

To investigate the clinical and in vitro performance of single-component orthodontic adhesives under metal brackets.

MATERIALS AND METHODS

Bimaxillary orthodontic treatment was required for sixty patients and 60 premolar teeth were divided into three groups (n: 20). The single-component orthodontic adhesives Biofix and GC Ortho Connect (GC) that did not require primers were compared to the control group using Transbond XT, which was applied with a primer. For each patient, total bonding time was measured. The Adhesive Remnant Index (ARI_(Bracket)) score was noted over 12 months. In vitro tests were used to evaluate specimens, shear bond strength (SBS), ARI_(Bracket), and Enamel Surface Index (ESI). After in vitro debonding, the enamel surface and bracket base were analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX).

RESULTS

Clinical failure rate with primer was 9.0%, while it was 8.0 and 10.0 for GC and Biofix, respectively. The mean in vitro SBS values of the Biofix, GC, and Transbond XT groups were 8.21, 8.07, and 7.37 MPa, respectively. There were no statistically differences in clinical failure (p = 0.160) and SBS values (p = 0.158). Mean differences in bond-up time per jaw were 9.65, 10.51, and 11.97 min, which were statistically significant (p = 0.0001).

CONCLUSION

Single-component adhesives had acceptable SBS values and enamel effects according to SEM-EDX analysis. Clinically, bonding failure was not shown statistically inferior to bonding with primer. There was also a significant difference in bond-up times.

CLINICAL RELEVANCE

Considering an intensely working clinic with bonding processes for at least two jaws per day, this means a saving of the chair time of 1 patient per week. However, better saliva contamination and moisture control with lack of the primer stage and, thereby, an acceptable bracket failure rate will bring clinically significant results with less chair time for clinicians.

Enamel shear bond strength of different primers combined with an orthodontic adhesive paste

AIM

The aim of this study was a comparison of shear bond strength (SBS) on tooth enamel of different primers combined with the adhesive paste Transbond XT.

MATERIALS AND METHODS

Forty bovine teeth were used in order to create 40 test blocks. The blocks were divided into four groups of 10 blocks each: group A - sample primer (SP); group B - Opal Seal (OS); group C - Transbond Plus SEP (TSEP); group D - Transbond XT Primer (TXT). After surface preparation and application of the primer, respectively, two stainless steel brackets were fixed on each tooth by using Transbond XT. Accordingly, 80 brackets were debonded (n=20). Shear bond strength and adhesive remnant index (ARI) scores were evaluated. Statistical analyses were performed by using the Student's t-test and Mann-Whitney U test.

RESULTS

All tested groups revealed high shear bond strength in a similar size range. There were no significant differences between the groups concerning shear bond strength. The ARI scores of group C showed significantly lower ARI scores (0 and 1) than that of group D. Apart from that there was no statistical difference.

CONCLUSION

In combination with the adhesive paste Transbond XT, all tested primers were suitable for fixing orthodontic brackets. The primers could be changed according to the clinical situation.

Orthodontic bonding with and without primer: a randomized controlled trial

OBJECTIVE

To evaluate the incidence of failure of brackets bonded with and without primer.

DESIGN

A single-operator, cross-mouth, randomized controlled trial (RCT).

SETTING

The Orthodontic Department at the Postgraduate Dental Education Centre, Örebro, Sweden.

ETHICAL APPROVAL

Ethical approval was granted by the Regional Ethical Review Board, Uppsala, Sweden.

PROTOCOL

The protocol was not published before trial commencement.

SUBJECTS AND METHODS

Fifty consecutive patients requiring bimaxillary orthodontic treatment with fixed appliances and with an equal number of teeth on each side of the dental arch, were included in this RCT. A cross-mouth methodology was applied. In each patient, two diagonal quadrants (i.e. upper right and lower left, or vice versa) were randomly assigned to the primer group (control group) and the contralateral diagonal quadrants to the non-primer group (experimental group). The randomization process was as follows: A computer-manufactured block-randomization list was acquired and stored with a research secretary at the Postgraduate Dental Education Centre. Each time a patient gave consent, the secretary was contacted by e-mail, and information about which quadrants were to be bonded with and without primer was obtained. All incidents of bracket failure and debonding noted in patient records during the 2012-14 observation period were compiled by the other co-author, whom was blinded to the study and did not perform any orthodontic treatment on the study patients.

MAIN OUTCOME MEASURES

Number of bracket failures over 18 months.

RESULTS

Failure rate without primer was 5.5 per cent and with primer 3.1 per cent; P = 0.063, odds ratio (OR) 1.89 [95% confidence interval (CI) 0.97-3.68] in the adjusted model. Younger ages (10-13 years), boys, and mandible were significantly associated with higher failure rates. Interaction tests indicated that younger patients had significantly higher failure rates without (12.1 per cent) than with primer (4.1 per cent), P < 0.001, OR 3.51 (95% CI 1.93-6.38) in the adjusted model. No failure rate differences between study settings were found for older patients (14-18 years).

LIMITATIONS

The difference between two groups was powered at 5 per cent. Some clinicians may consider a difference less than 5 per cent clinically significant.

CONCLUSION

Bonding Victory Series™ brackets with Transbond™ XT with or without Transbond™ MIP primer seems overall to work equally well in a clinical setting, except in younger children where lower failure rate was found in the primer setting.

Do we need primer for orthodontic bonding? A randomized controlled trial

OBJECTIVE

To evaluate the clinical performance of APC™II Victory Series™ (3M Unitek) brackets in direct orthodontic bonding with and without the use of primer.

DESIGN

A single-operator, two-centre prospective, non-inferiority randomized controlled clinical trial.

SETTING

The Orthodontic departments at the Leeds Dental Institute and St Luke's Hospital, Bradford, UK.

ETHICAL APPROVAL

Ethical approval was granted by Leeds (East) Research Ethics Committee on 18th of December 2009 (Reference 09/H1306/102).

PROTOCOL

The protocol was not published prior to trial commencement.

SUBJECTS AND METHODS

Ninety-two patients requiring orthodontic treatment with fixed appliances were randomly allocated to the control (bonded with primer) or test groups (bonded without primer). Patients were randomly allocated to either the control or experimental group. This was performed by preparing opaque numbered sealed envelopes in advance using a random numbers table generated by a computer by an independent third party . Once the envelopes were opened, blinding of the operator and the patient was no longer possible due to the nature of the intervention. Patients were approached for inclusion in the trial if they qualified for NHS orthodontic treatment requiring fixed appliances and had no previous orthodontic treatment.

MAIN OUTCOME MEASURES

Number of bracket failures, time to bond-up appliances, and the adhesive remnant index (ARI) when bracket failure occurred, over a 12-month period

RESULTS

Failure rate with primer was 11.1 per cent and without primer was 15.8 per cent. Bonding without primer was shown statistically to be non-inferior to bonding with primer odds ratio 0.95-2.25 (P = 0.08). Mean difference in bond-up time per bracket was 0.068 minutes (4 seconds), which was not statistically significant (P = 0.402). There was a statistically significant difference in the Adhesive Remnant Index - ARI 0 with primer 49.4 per cent, no primer 76.5 per cent, (P < 0.0001).

LIMITATIONS

As the study was only performed by one operator, the results can therefore only be truly be applied to their practice. Also this study was powered to ascertain if there was no difference between the 2 groups up to 5%, however orthodontists may consider a change in the bracket failure rate of 2% to be clinically significant.

CONCLUSION

When bonding with APC™II Victory Series™ brackets without primer was shown statistically to be non-inferior to bonding with primer (P =0.08). There was no significant difference in bond-up times. Bond failure was more likely to happen at the composite-enamel interface when bonded without a primer.

CONFLICT OF INTEREST

No conflict of interest for all authors.

FUNDING

No funding sources were used.

REGISTRATION

Study was not registered on external databases.

A comparative evaluation of lingual retainer failure bonded with or without liquid resin

OBJECTIVE

To prospectively evaluate and compare the effect of liquid resin on lingual retainer failure after a 2-year follow-up.

MATERIALS AND METHODS

Fifty-two patients (26 males, 26 females) with a mean age of 18.3 ± 1.3 years at follow-up, were randomized into two groups: the resin group and the nonresin group. The lingual retainers in the resin group were bonded to the enamel surfaces with two-step bonding resin, Optibond FL, and Tetric EvoFlow. The nonresin group followed the same procedure of bonding retainers but without applying the Optibond FL. Retainer failure, calculus accumulation, and discoloration of composite pads adjacent to the retainers during the 2-year observation period were registered, compared, and statistically analyzed with a Fisher's exact test and chi-square test.

RESULTS

In the resin group, the incidence of retainer failure was 4% and occurred at the composite-wire interface; in the nonresin group, the incidence was 27% and occurred at the enamel-composite interface. The difference between the groups was statistically significant (P  =  .049). The incidences of calculus accumulation and discoloration adjacent to the composite pads were 27% and 69% (P  =  .003 and P < .001) higher in the nonresin group, respectively.

CONCLUSION

Application of resin in bonding of lingual retainers appears to reduce the incidence of retainer failure as well as the incidence of calculus accumulation and discoloration adjacent to the composite pads.

A randomized control clinical trial investigating orthodontic bond failure rates when using Orthosolo universal bond enhancer compared to a conventional bonding primer

OBJECTIVE

This study assessed the in vivo bond failure rates of orthodontic brackets bonded using Orthosolo universal bond enhancer and compared it with the conventional bonding primer, Transbond XT.

DESIGN

This was a single centre randomized controlled clinical study.

SETTING

Department of Child Dental Health, Bristol Dental Hospital, Bristol, UK.

MATERIALS AND METHODS

Thirty-three consecutive patients undergoing fixed orthodontic appliance therapy were included in this study. Using a split-mouth design, diagonally opposite quadrants were randomly allocated a primer, either Orthosolo universal bond enhancer (Ormco, Orange, CA, USA) or Transbond XT primer (3M Unitek, Monrovia, CA, USA). A total of 555 teeth were bonded using a conventional acid-etch technique. 277 received Orthosolo as their primer and 278 received the Transbond XT primer. Bond failures and their positions were recorded at six months.

RESULTS

There was an overall bond failure rate of 1.26%. Four brackets failed in the Orthosolo group (0.72%) and three failed in the Transbond XT group (0.54%).

CONCLUSION

There was no clinical or statistically significant difference in the in vivo bond failure rates between orthodontic brackets bonded using either Orthosolo universal bond enhancer or the conventional Transbond XT primer.

Effect of primer precuring on the shear bond strength of orthodontic brackets

Two adhesive systems, Transbond APC II (3M Unitek, Monrovia, Calif) and Quick Cure (Reliance Orthodontic Products, Itasca, Ill), were used to determine the efficacy of precuring the liquid resin primer phase of the systems to increase shear bond strength. One hundred sixty bovine incisors were divided into groups of 20 specimens. In 1 group, the primer was cured before placement of the bracket with the filled adhesive material, and, in the other group, the primer was not precured. The shear-peel bond strength was tested with a testing machine at 30 minutes and 24 hours. No statistically significant difference in bond strength was found between the groups that had or had not been precured. More adhesive remained on the teeth with the Transbond when the primer was not precured. There is no advantage or disadvantage in bracket bond strength by precuring the primer before placing the bracket and filled component of the adhesive.

Clinical comparison between a modified light-curing denture base resin and a conventional composite resin for orthodontic bonding

The purpose of this in vivo study was to evaluate and compare the bond failure rate of a modified visible light-cured denture base resin (Triad VLC Provisional Material; Dentsply International Inc., York, PA) with that of a conventional visible light-cured composite resin (Transbond XT; 3M/Unitek, Monrovia, CA) for the bonding of orthodontic brackets. Both adhesives were used in each patient following a split-mouth design. Thirty-five consecutive patients with fixed appliances were included in the study, and the performance of 655 stainless steel brackets was evaluated: 325 brackets were bonded with the modified Triad VLC resin and 330 were bonded with Transbond XT resin. The incidence and site of bond failures were recorded over a period of 12 months. The overall failure rate of Triad VLC (4.3%) was not significantly different (p>0.05) from that of Transbond XT (3.6%). No significant differences in the failure rates of upper and lower arches within each material or between the two materials were found (p>0.05). Transbond XT showed a significantly higher failure rate (p<0.05) in the anterior (4.8%) than in the posterior teeth (1.6%). The present findings demonstrate that Triad VLC could be used as an alternative bonding material for direct bonding of orthodontic brackets.