Segmented Indirect Versus Direct Bracket Bonding

September 30, 2026 updated by: Omar Alkadhi, Riyadh Elm University

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

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
18

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Saudi Arabia
    • Riyadh Region
      • Riyadh, Riyadh Region, Saudi Arabia, 12734
        • Riyadh Elm university

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

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

This section provides details of the study plan, including how the study is designed and what the study is measuring.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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.
Procedure: Direct bonding

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.
Procedure: Segmented modified indirect bonding

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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
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

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
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

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Riyadh Elm University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Omar H Alkadhi, Orthodontist, Riyadh Elm University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 22, 2020

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 19, 2021

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 19, 2021

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 31, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 30, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 6, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
October 6, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 30, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • FPGRP/2020/525/334/328

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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