CAD/CAM Fixed Retainers vs. Conventional Multistranded Fixed Retainers in Orthodontic Patients. Comparison of Stability Retainer Failure Rate Adverse Effects Cost-effectiveness and Patient Satisfaction. A Randomized Controlled Clinical Trial

STATUS

Recruiting
End date

Dec 5, 2025
participants needed

126
sponsor

University of Aarhus

Updated on 19 February 2024

See if I qualify

Summary

Show definitions

Introduction

Orthodontic retainers are used after the completion of orthodontic treatment to assure dental occlusal stability and to maintain the achieved end-result. However, without retention teeth could go back to their initial dental malposition or could even take a different unpredicted position resulting once again in dental malocclusion (a deviation from normal occlusion).

There are different types of retainers, some are fixed (glued to the back of the front teeth), and others are removable (can be removed and replaced into the mouth by the patient).

While there are various retainers used for retention (stability), there is no perfect method. Fixed retainers (FRs) are used worldwide. On the one hand, FRs focus on preventing relapse. On the other hand, there are sometimes some adverse effects of retainers; they could fail at a certain point (break/get loose), or cause unwanted tooth movements. Until now, the choice of a retention method is based solely on clinicians' experience as there is no substantial evidence regarding the best retention method or the duration of the retention period. Some clinicians prolong the retention period while others prefer to keep the retainers for an indefinite time.

As the world is advancing, so is the orthodontic science. New FR fabricated by CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing), are assumed to have greater accuracy, better fit, and most importantly, might offer a passive positioning of the retainer. However, the evidence about CAD/CAM FRs is very limited.

Purpose

To investigate and compare the clinical effectiveness of two types of FRs; CAD/CAM vs. multistranded wire, in terms of stability (primary outcome), failure rate, adverse effects, cost-effectiveness, and patient satisfaction (secondary outcomes), substantial up to 5 years after retainer placement.

Hypotheses

Compared to traditional multistranded FRs, CAD/CAM FRs have:

Better long term stability,
Similar failure rate,
Fewer adverse effects,
Similar cost-effectiveness and patient satisfaction.

Description

Material and Methods

Setting: Section of Orthodontics, Department of Dentistry and Oral Health, Aarhus University, Denmark and Department of Orthodontics, Faculty of Dentistry, University of Oslo, Norway.

Sample size: 126 participants are needed for this study.

Randomization: After oral and written consent is obtained, allocation to groups, either conventional multistranded Stainless Steel fixed retainers, or CAD/CAM custom-cut Nickel Titanium fixed retainers, will take place at the last appointment before debonding. Subjects will be allocated 1:1 into one of the two groups.

Intervention protocol: After completing a full active orthodontic treatment, at both centers. The achieved treatment end result has to be maintained in the long term in order to prevent relapse (movement of teeth to the initial malocclusion). One of either two different fixed retainers will be bonded (to the upper and lower anterior teeth) by one operator in each center.

This study follows a standard retention protocol procedure carried at both centers and has a long term posttreatment follow-up of 5 years. Patients will be recalled for follow-up appointments after 1, 3, 6, 12, 24, 36 and 60 months. At follow-up visits, we will perform the following: at 1, and 3 months - a clinical examination. At 6, 12, 24, 36, and 60 months - a clinical examination, a digital impression of the teeth known as "an intraoral scan" (Trios 3, 3Shape, Copenhagen, Denmark) and intraoral photographs. In addition, at 1, 6, and 12 months patients will be asked to fill out a Visual Analogue Scale (VAS) form regarding patient satisfaction Furthermore, we will investigate stability by superimposition (Orthoanalyzer, 3Shape, Copenhagen, Denmark) together with recording of adverse effects (i.e. any changes in torque and/or rotations of the teeth).

Details

Condition	Relapse
Age	12years - 25years
Treatment	Bonding of either CAD/CAM or conventional multistranded stainless steel fixed retainer
Clinical Study Identifier	NCT04389879
Sponsor	University of Aarhus
Last Modified on	19 February 2024

How understandable was the trial content above?

Hard to understand

Easy to understand

Eligibility		Yes	No	Not Sure
Inclusion Criteria
	Healthy patients
	Age: 12-25 years old (at time of debonding)
	Presence of all maxillary and mandibular anterior teeth, with normal shape and size
	Completion of a course of fixed appliance therapy involving both dental arches
	Subjects willing to consent to the trial and comply with the trial regime
	No restriction to presenting initial malocclusion, type of active orthodontic
	treatment undertaken provided that it included full fixed appliances
	(functional/removable appliances in combination with fixed appliances -
	extraction or non-extraction)
Exclusion Criteria
	Patients with cleft lip or palate, or both or any other craniofacial syndrome
	Patients who had surgical correction of the jaws: Le fort I (2- or 3-piece maxilla) or SARPE (surgically assisted rapid palatal expansion)
	Lingual appliance treatments
	Periodontal disease
	Hypoplasia of enamel
	Fluorosis
	Active caries, restorations or fractures in the anterior teeth
	Patients who have had separate debonding appointments for each jaw, with a difference of more than 2 months in between
	Re-treated patients

How to participate?

Step 1 Connect with a study center

Send a message

Enter your contact details to connect with study team

First name*

Last name*

Email*

Phone number*

Other language

I am at least 18 years old.

By sending a message, I agree to share my information with the study team for the selected site and consent to receive emails and text messages for trial updates, notifications, and related communication. TrialX values your privacy; your information will be handled in accordance with our Privacy Policy

Step 2 Get screened

Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more

Step 3 Enroll in the clinical study

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more

Step 4 Get your study results

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider

Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

CAD/CAM Fixed Retainers vs. Conventional Multistranded Fixed Retainers in Orthodontic Patients. Comparison of Stability Retainer Failure Rate Adverse Effects Cost-effectiveness and Patient Satisfaction. A Randomized Controlled Clinical Trial