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Comparison of Bonding Failure Rates of Fixed Lingual Mandibular Retainers in a French Sample Aged 11 or Older, Comparing Prior Enamel Sandblasting With Conventional Pumice Polishing

Comparison of Bonding Failure Rates of Fixed Mandibular Lingual Retainers in a French Sample Aged 11 or Older Comparing Prior Enamel Sandblasting With Conventional Pumice Polishing

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03954145
Acronym
CONTORTHO
Enrollment
88
Registered
2019-05-17
Start date
2019-10-08
Completion date
2021-05-21
Last updated
2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Detachment of Glued Mandibular Post-orthodontic Restraints

Brief summary

At the completion of orthodontic treatment, the position of the mandibular canines and incisors is being maintained on a routine basis by bonding a multi-braided wire retainer onto their lingual surfaces. One of the adverse events that might occur with time is the debonding of the wire from one or several lower anterior teeth . This event which can unfortunately get unnoticed by the patient can lead to unwanted tooth displacement. When the practionner detects such a debonding, he has to go through a laborious and lengthy procedure to rebond the wire. When on the other hand the patient notices himself such a debonding, he is to call in emergency his practitioner to get his retainer repaired. This leads to emergency visits that are susceptible to affect adversely his timetable. The prevalence of these bonding failures is estimated at 37% at 18 month follow-ups. It has been reported that with prior enamel sandblasting, bonding failure rate is reduced to 8% at 24 month follow-ups. However, no study has reported yet the debonding rate of lower fixed, comparing wires that have been bonded after prior enamel pumicing to those that were put in place after prior enamel sandblasting. The expected result of this trial is a significantly decrease in bonding failure rate of mandibular lingual retainer when enamel surfaces are initially sandblasted compared to the ones which are pumiced. This reduction would lower the risk of unwanted tooth movement of mandibular incisors and canines after orthodontic treatment and decrease the number of emergency appointments for the patient and the practitioner.

Interventions

PROCEDUREEnamel pumicing before bonding the lingual retainer.

Lingual surfaces of the lower incisors and canines are pumiced before bonding the lingual retainer. Teeth are being cleaned using a brush loaded with pumice and mounted on a low speed contra-angle. Teeth are then etched and the multi-braided retainer wire is being bonded with composite onto the lingual surfaces of the lower canines and incisors.

PROCEDUREEnamel sandblasting before bonding the lingual retainer.

Enamel is being initially prepared through sandblasting the lingual surfaces of the mandibular canines and incisors. Sandblasting is performed with the help of a MicroEtcher IIATM (Danville) which is projecting 50 μm Al2O3 particles onto the enamel surfaces. Teeth are subsequently etched and the retainer is then being bonded with composite onto the lingual surfaces of the mandibular incisors and canines.

Sponsors

University Hospital, Strasbourg, France
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
DOUBLE (Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
11 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Minimum of 11 years of age * At completion of fixed orthodontic therapy * Presence of all 6 mandibular canines and incisors

Exclusion criteria

* Active decay * Presence of dental restorations * Tooth fracture * Periodontal disease * Structural anomalies affecting the lingual side of the mandibular incisors and canines * Cleft lip and palate * Cranio-facial syndrome * Inability to obtain the patient informed consent

Design outcomes

Primary

MeasureTime frameDescription
Number of Participants With at Least One Bonding Failure at 18 Months18 months after bonding of the fixed mandibular lingual retainerParticipants presenting at least one debonding event of the fixed mandibular lingual retainer during the 18-month follow-up period. A retainer was considered failed if at least one bonded tooth became detached.

Countries

France

Baseline characteristics

Characteristic
Age, Continuous16.0 years
Race and Ethnicity Not Collected0 Participants
Sex: Female, Male
Female
28 Participants
Sex: Female, Male
Male
36 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 00 / 0
other
Total, other adverse events
0 / 00 / 0
serious
Total, serious adverse events
0 / 00 / 0

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 30, 2026