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

Relapse Clinical Trial

— Retention  

Official title:

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.

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT04389879
• Other study ID #: 01286
• Status: Active, not recruiting
• Phase: N/A
• Start date: September 1, 2018
• Est. completion date: December 2025

Study information

• Verified date: November 2022
• Source: University of Aarhus
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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).

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 126
• Est. completion date: December 2025
• Est. primary completion date: November 2025
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 12 Years to 25 Years

Eligibility

Inclusion Criteria:

1. Healthy patients.

2. Age: 12-25 years old (at time of debonding).

3. Presence of all maxillary and mandibular anterior teeth, with normal shape and size.

4. Completion of a course of fixed appliance therapy involving both dental arches.

5. 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:

1. Patients with cleft lip or palate, or both or any other craniofacial syndrome.

2. Patients who had surgical correction of the jaws: Le fort I (2- or 3-piece maxilla) or SARPE (surgically assisted rapid palatal expansion).

3. Lingual appliance treatments.

4. Periodontal disease.

5. Hypoplasia of enamel.

6. Fluorosis.

7. Active caries, restorations or fractures in the anterior teeth.

8. Patients who have had separate debonding appointments for each jaw, with a difference of more than 2 months in between.

9. Re-treated patients.

Related Conditions & MeSH terms

• Recurrence
• Relapse

Intervention

Other:
• Bonding of either CAD/CAM or conventional multistranded stainless steel fixed retainer
Investigate and compare the clinical effectiveness of two types of fixed retainers; CAD/CAM vs. multistranded wire.

Locations

Country	Name	City	State
Denmark	Marie Anne Michele Cornelis	Aarhus
Norway	University of Oslo	Oslo

Sponsors (2)

Lead Sponsor	Collaborator
University of Aarhus	University of Oslo

Countries where clinical trial is conducted

Denmark,  Norway, 

References & Publications (24)

Al Yami EA, Kuijpers-Jagtman AM, van 't Hof MA. Stability of orthodontic treatment outcome: follow-up until 10 years postretention. Am J Orthod Dentofacial Orthop. 1999 Mar;115(3):300-4. — View Citation

Artun J, Spadafora AT, Shapiro PA. A 3-year follow-up study of various types of orthodontic canine-to-canine retainers. Eur J Orthod. 1997 Oct;19(5):501-9. — View Citation

Artun J, Zachrisson B. Improving the handling properties of a composite resin for direct bonding. Am J Orthod. 1982 Apr;81(4):269-76. — View Citation

Bjering R, Sandvik L, Midtbø M, Vandevska-Radunovic V. Stability of anterior tooth alignment 10 years out of retention. J Orofac Orthop. 2017 Jul;78(4):275-283. doi: 10.1007/s00056-017-0084-2. Epub 2017 Apr 13. — View Citation

Bolla E, Cozzani M, Doldo T, Fontana M. Failure evaluation after a 6-year retention period: a comparison between glass fiber-reinforced (GFR) and multistranded bonded retainers. Int Orthod. 2012 Mar;10(1):16-28. doi: 10.1016/j.ortho.2011.12.005. Epub 2012 Jan 11. English, French. — View Citation

Forde K, Storey M, Littlewood SJ, Scott P, Luther F, Kang J. Bonded versus vacuum-formed retainers: a randomized controlled trial. Part 1: stability, retainer survival, and patient satisfaction outcomes after 12 months. Eur J Orthod. 2018 Jul 27;40(4):387-398. doi: 10.1093/ejo/cjx058. — View Citation

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Hichens L, Rowland H, Williams A, Hollinghurst S, Ewings P, Clark S, Ireland A, Sandy J. Cost-effectiveness and patient satisfaction: Hawley and vacuum-formed retainers. Eur J Orthod. 2007 Aug;29(4):372-8. — View Citation

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Katsaros C, Livas C, Renkema AM. Unexpected complications of bonded mandibular lingual retainers. Am J Orthod Dentofacial Orthop. 2007 Dec;132(6):838-41. — View Citation

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Littlewood SJ, Millett DT, Doubleday B, Bearn DR, Worthington HV. Orthodontic retention: a systematic review. J Orthod. 2006 Sep;33(3):205-12. Review. — View Citation

Littlewood SJ, Millett DT, Doubleday B, Bearn DR, Worthington HV. Retention procedures for stabilising tooth position after treatment with orthodontic braces. Cochrane Database Syst Rev. 2004;(1):CD002283. Review. Update in: Cochrane Database Syst Rev. 2006;(1):CD002283. — View Citation

Owman G, Bjerklin K, Kurol J. Mandibular incisor stability after orthodontic treatment in the upper arch. Eur J Orthod. 1989 Nov;11(4):341-50. — View Citation

Pazera P, Fudalej P, Katsaros C. Severe complication of a bonded mandibular lingual retainer. Am J Orthod Dentofacial Orthop. 2012 Sep;142(3):406-9. doi: 10.1016/j.ajodo.2012.01.019. — View Citation

Reitan K. Clinical and histologic observations on tooth movement during and after orthodontic treatment. Am J Orthod. 1967 Oct;53(10):721-45. — View Citation

Renkema AM, Renkema A, Bronkhorst E, Katsaros C. Long-term effectiveness of canine-to-canine bonded flexible spiral wire lingual retainers. Am J Orthod Dentofacial Orthop. 2011 May;139(5):614-21. doi: 10.1016/j.ajodo.2009.06.041. — View Citation

Rose E, Frucht S, Jonas IE. Clinical comparison of a multistranded wire and a direct-bonded polyethylene ribbon-reinforced resin composite used for lingual retention. Quintessence Int. 2002 Sep;33(8):579-83. — View Citation

Saleh M, Hajeer MY, Muessig D. Acceptability comparison between Hawley retainers and vacuum-formed retainers in orthodontic adult patients: a single-centre, randomized controlled trial. Eur J Orthod. 2017 Aug 1;39(4):453-461. doi: 10.1093/ejo/cjx024. — View Citation

Salehi P, Zarif Najafi H, Roeinpeikar SM. Comparison of survival time between two types of orthodontic fixed retainer: a prospective randomized clinical trial. Prog Orthod. 2013 Sep 11;14:25. doi: 10.1186/2196-1042-14-25. — View Citation

Tynelius GE, Lilja-Karlander E, Petrén S. A cost-minimization analysis of an RCT of three retention methods. Eur J Orthod. 2014 Aug;36(4):436-41. doi: 10.1093/ejo/cjt070. Epub 2013 Oct 1. — View Citation

Wolf M, Schumacher P, Jäger F, Wego J, Fritz U, Korbmacher-Steiner H, Jäger A, Schauseil M. Novel lingual retainer created using CAD/CAM technology: evaluation of its positioning accuracy. J Orofac Orthop. 2015 Mar;76(2):164-74. doi: 10.1007/s00056-014-0279-8. English, German. — View Citation

* Note: There are 24 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Stability	Change in lower incisor crowding will be assessed using Little's Irregularity Index (LII). Change in overall occlusal stability will be assessed by the Peer Assessment Rating (PAR) index. In addition, changes in arch dimensions, occlusal relationships, and re-opening of extraction spaces will be recorded.	From debonding (T1), and after 6, 12, 24, 36 and 60 months in retention phase (T4, T5, T6, T7, and T8 respectively)
Secondary	Failure rate and survival time	Calculated from the first day of retainer's bonding to the day of the first failure episode	From the time of retainer bonding to the first failure episode: From debonding, and up to 60 months later
Secondary	Adverse effects	Screen for unexpected posttreatment changes in the mandibular anterior region associated with the use of both types of fixed retainers	From debonding, and up to 60 months later
Secondary	Cost-effectiveness	Unit costs in euros (€) will be used to value the resources included	From debonding, and up to 60 months later
Secondary	Patient satisfaction	Visual Analogue Scale (VAS)	From debonding, and after 1, 6 and 12 months in retention phase