Segmented Indirect Versus Direct Bracket Bonding
Bond Failure of a Segmented Modified Indirect Bonding Technique Versus Direct Bonding: A Randomized Clinical Trial
This randomized clinical trial compared two methods of attaching orthodontic brackets to teeth: conventional direct bonding, in which each bracket is placed and bonded individually in the mouth, and a segmented modified indirect bonding technique, in which brackets are first positioned on a plaster model of the patient's teeth and then transferred to the mouth in segments using a hot-glue transfer tray. The purpose was to find out whether the two techniques differ in how often brackets come loose (bond failure) during treatment.
Eighteen patients receiving fixed orthodontic appliances at Riyadh Elm University, Riyadh, Saudi Arabia, were randomly assigned so that their brackets were placed by either the direct or the modified indirect technique. The same bracket type and adhesive were used in both groups. Patients were examined every four weeks for six months, and any bracket that debonded was recorded along with the tooth involved, the arch (upper or lower), the side (right or left), and the time from bonding to failure. The main outcome was the time from bonding to bracket failure; the investigators also compared failure rates and examined whether failure varied by tooth type, arch, or side.
Study Overview
Status
Conditions
Intervention / Treatment
Detailed Description
Background and rationale: Direct bonding, in which orthodontic brackets are positioned and light-cured individually on each tooth, remains the most common technique but depends heavily on operator visibility and isolation at the moment of placement, which is constrained on posterior teeth. Indirect bonding positions brackets on a working cast under direct vision and transfers them to the dentition in a tray, and has been proposed to improve placement and reduce chairside time. Whether indirect bonding reduces clinical bond failure compared with direct bonding is not established, and clinical failure data for low-cost analogue (hot-glue) transfer-tray methods are limited.
Objective: To compare time to bracket bond failure (primary outcome) and bond-failure rate (secondary outcome) between conventional direct bonding and a segmented modified indirect bonding technique, and to examine whether failure varied by tooth type, arch, or side.
Design: Prospective, parallel-arm, single-center randomized clinical trial. Participants were allocated by simple randomization from a computer-generated sequence to direct bonding or segmented modified indirect bonding. The trial was open-label, as the bonding technique could not be masked from the operator.
Setting: Orthodontic clinics, Riyadh Elm University, Riyadh, Saudi Arabia. Participants: Patients seeking fixed-appliance orthodontic treatment were screened against eligibility criteria. Patients with overbite greater than 3 mm; with crowns, bridges, veneers, restorations, or enamel hypoplasia on the teeth to be bonded; with severely rotated or blocked-out teeth; or with partially erupted teeth were excluded. Eighteen participants were enrolled after written informed consent.
Interventions: In the direct group, teeth were pumiced, etched with 37% phosphoric acid (Meta Etchant, Meta Biomed), rinsed thoroughly, and excess water was removed; Ortho Solo Universal Sealant and Bond Enhancer (Ormco) was applied, and brackets were bonded with Enlight light-cured adhesive (Ormco), then light-cured for 20 seconds occlusally and 20 seconds gingivally. In the modified indirect group, alginate impressions were poured in dental stone; brackets were fixed to the casts in planned positions; segmented transfer trays (separate segments for molars, premolar-canine, and lateral/central incisors per quadrant) were fabricated with thermal (hot) glue covering the occlusal and partial lingual surfaces, leaving the bracket exposed below the slot. Teeth were pumiced, etched with the same 37% phosphoric acid, rinsed thoroughly, and excess water was removed; Ortho Solo Universal Sealant and Bond Enhancer was applied to the etched teeth and Enlight adhesive to the bracket bases before tray insertion; the trays were then seated and light-cured for 20 seconds before removal. The same bracket type and adhesive system were used in both arms.
Outcomes: The primary outcome was time to bracket bond failure (days from bonding to first debonding); the secondary outcome was the bond-failure rate. Each event was recorded with the tooth, arch (maxilla/mandible), side (right/left), date, and time from bonding to failure in days. The unit of analysis was the individual bracket. Participants were reviewed every four weeks for six months; debonded brackets were re-bonded directly.
Analysis: Time to failure was analysed with Kaplan-Meier estimates, the log-rank test and Cox proportional-hazards regression. Failure rates were compared with chi-square and exact tests and Firth penalized logistic regression, with an exploratory Holm-corrected analysis of technique by tooth type and side.
Study Type
Enrollment (Actual)
Phase
- Not Applicable
Contacts and Locations
Study Locations
-
-
Riyadh Region
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Riyadh, Riyadh Region, Saudi Arabia, 12734
- Riyadh Elm university
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-
Participation Criteria
Eligibility Criteria
Ages Eligible for Study
- Child
- Adult
- Older Adult
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- Patients seeking fixed-appliance orthodontic treatment
- Permanent dentition
- Teeth to be bonded free of crowns, bridges, veneers, restorations, or enamel hypoplasia
Exclusion Criteria:
- Overbite greater than 3 mm
- Teeth with crowns, bridges, veneers, restorations, or enamel hypoplasia
- Severely rotated or blocked-out teeth
- Partially erupted teeth
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Treatment
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: None (Open Label)
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
|
Active Comparator: Direct bonding
Orthodontic brackets were bonded directly onto each tooth in the mouth. Teeth were pumiced, etched with 37% phosphoric acid (Meta Etchant, Meta Biomed), rinsed thoroughly, and excess water was removed. Ortho Solo Universal Sealant and Bond Enhancer (Ormco) was applied to the teeth, and each bracket was seated with Enlight light-cured adhesive (Ormco) along the tooth's long axis, vertical height, and mesiodistal midline, then light-cured for 20 seconds occlusally and 20 seconds gingivally. This arm comprised 160 brackets. |
Orthodontic brackets bonded individually onto each tooth intraorally. Teeth were pumiced, etched with 37% phosphoric acid (Meta Etchant, Meta Biomed), rinsed thoroughly, and excess water was removed; Ortho Solo Universal Sealant and Bond Enhancer (Ormco) was applied to the teeth, and each bracket was seated with Enlight light-cured adhesive (Ormco) along the tooth's long axis, vertical height, and mesiodistal midline, then light-cured for 20 seconds occlusally and 20 seconds gingivally. The same bracket type and adhesive system were used as in the experimental arm. |
|
Experimental: Segmented modified indirect bonding
Orthodontic brackets were first positioned on a dental stone cast in their planned locations, then transferred to the teeth using segmented hot-glue transfer trays (separate segments for molars, premolar-canine, and lateral and central incisors in each quadrant). Teeth were pumiced, etched with 37% phosphoric acid (Meta Etchant, Meta Biomed), rinsed thoroughly, and excess water was removed. Ortho Solo Universal Sealant and Bond Enhancer (Ormco) was applied to the etched teeth and Enlight light-cured adhesive (Ormco) to the bracket bases; the tray was then seated, light-cured for 20 seconds, and removed. This arm comprised 224 brackets. |
Orthodontic brackets positioned on a dental stone cast in their planned locations and transferred to the teeth using segmented hot-glue (thermal-glue) transfer trays, fabricated separately for molar, premolar-canine, and lateral and central incisor segments in each quadrant. Teeth were pumiced, etched with 37% phosphoric acid (Meta Etchant, Meta Biomed), rinsed thoroughly, and excess water was removed; Ortho Solo Universal Sealant and Bond Enhancer (Ormco) was applied to the etched teeth and Enlight light-cured adhesive (Ormco) to the bracket bases before tray insertion; the tray was then seated, light-cured for 20 seconds, and removed. The same bracket type and adhesive system were used as in the comparator arm. |
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Time to bracket bond failure (time to debond)
Time Frame: 6 months from bonding
|
For each bonded bracket, the number of days from bracket placement (bonding) to the first bond failure (debonding). A bracket still bonded at the end of follow-up is right-censored at the date of its last assessment. Only the first failure per bracket is the event; debonded brackets that were re-bonded are not re-entered. |
6 months from bonding
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Time to failure among debonded brackets
Time Frame: 6 months from bonding
|
For brackets that debonded, the time interval from initial bonding to the recorded failure, measured in days. |
6 months from bonding
|
|
Bracket bond failure rate
Time Frame: 6 months from bonding
|
Proportion of bonded brackets that debonded (bond failure) during the follow-up period. Each tooth was examined at four-weekly recall visits; a bracket was recorded as failed if it had detached from the tooth. Failure was assessed at the individual-bracket level and expressed as the percentage of brackets that debonded in each group. |
6 months from bonding
|
|
Bracket bond failure by tooth type, arch, and side
Time Frame: 6 months from bonding
|
Bracket bond-failure rate compared across tooth type (incisor, canine, premolar, molar), arch (maxilla, mandible), and side (right, left), to assess whether failure varied by bracket location. |
6 months from bonding
|
Collaborators and Investigators
Sponsor
Investigators
- Study Director: Omar H Alkadhi, Orthodontist, Riyadh Elm University
Publications and helpful links
General Publications
- Almosa N, Zafar H. Incidence of orthodontic brackets detachment during orthodontic treatment: A systematic review. Pak J Med Sci. 2018 May-Jun;34(3):744-750. doi: 10.12669/pjms.343.15012.
- Aguirre MJ, King GJ, Waldron JM. Assessment of bracket placement and bond strength when comparing direct bonding to indirect bonding techniques. Am J Orthod. 1982 Oct;82(4):269-76. doi: 10.1016/0002-9416(82)90461-4.
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Actual)
Study Completion (Actual)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Keywords
Other Study ID Numbers
- FPGRP/2020/525/334/328
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
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