Clinical Performance of Orthodontic Bands in the Restorative Treatment of Hypomineralised Primary Second Molars: a Randomised Clinical Trial

This randomised clinical trial will compare the clinical performance and acceptability of orthodontic bands and preformed stainless steel crowns for the restorative management of hypomineralised second primary molars. Thirty children aged 5-10 years will be randomly allocated in a 1:1 ratio to receive either an orthodontic band or a stainless steel crown. One index tooth per participant will be evaluated immediately after treatment and at 6, 12, and 18 months. The primary outcomes will be marginal adaptation, retention, and the presence of carious lesions. Secondary outcomes will include biofilm accumulation and treatment acceptability among children and their caregivers.

Study Overview

• Status: Recruiting
• Conditions: Enamel Hypomineralization
• Intervention / Treatment: Procedure: Orthodontic band restorative treatment; Procedure: Hall Technique with preformed stainless steel crown

Detailed Description

Hypomineralised second primary molars are more susceptible to post-eruptive enamel breakdown, carious lesions, hypersensitivity, and premature tooth loss. Although preformed stainless steel crowns have demonstrated favourable clinical performance in primary molars, orthodontic bands may represent a less invasive restorative approach for maintaining affected teeth until physiological exfoliation. However, their clinical performance in hypomineralised primary teeth has not been investigated.

This parallel-group randomised clinical trial will include 30 children presenting at least one hypomineralised second primary molar with extensive post-eruptive enamel breakdown or a cavitated carious lesion requiring restorative treatment. Participants will be randomly allocated to receive either an orthodontic band cemented with glass ionomer luting cement after restoration of the cavitated lesion or a preformed stainless steel crown placed using the Hall technique. When more than one tooth is eligible, one index tooth will be randomly selected for the primary analysis.

Clinical assessments will be performed immediately after treatment and at 6, 12, and 18 months. Marginal adaptation, retention, and carious lesions adjacent to the restoration margins will be assessed using modified United States Public Health Service criteria. Biofilm accumulation will be assessed using the Silness and Löe Plaque Index. Treatment acceptability will be evaluated immediately after treatment using separate questionnaires for children and caregivers. Physiological exfoliation during follow-up will be recorded separately and will not be considered treatment failure.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Brazil
  • Rio Grande do Norte
    • Natal, Rio Grande do Norte, Brazil, 59056-000
      • Recruiting
      • Federal University of Rio Grande do Norte
      • Contact: Lavínia L. Costa, Master's; Phone Number: +55 84 998987405; Email: lavinialourencocosta@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Children aged 5-10 years.
• Presence of at least one second primary molar affected by hypomineralised second primary molars requiring restorative treatment.
• Hypomineralisation associated with post-eruptive enamel breakdown involving more than one tooth surface or a cavitated carious lesion involving more than one surface and classified as code 5 or 6 according to the International Caries Detection and Assessment System.

Exclusion Criteria:

• Extensive carious lesion with subgingival margins.
• Clinical or radiographic signs of pulpal inflammation or necrosis.
• Advanced physiological root resorption indicating imminent exfoliation of the eligible tooth.
• Previous restorative treatment of the eligible tooth.
• Presence of bruxism.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Bands; Participants allocated to this arm will receive selective removal of softened carious dentine when carious tissue is present, followed by restoration of the cavity with conventional glass ionomer restorative cement (GC Gold Label 9). A prefabricated stainless steel orthodontic band will then be adapted to the index tooth and cemented with glass ionomer luting cement (Meron).	Procedure: Orthodontic band restorative treatment; Selective removal of softened carious dentine, when present, followed by restoration with conventional glass ionomer cement and placement of a prefabricated stainless steel orthodontic band cemented with glass ionomer luting cement.
Active Comparator: Crowns; articipants allocated to this arm will receive a preformed stainless steel crown placed using the Hall technique, without caries removal, local anaesthesia, or tooth preparation. When a large cavity is present, glass ionomer restorative cement (GC Gold Label 9) will be placed at its base without prior caries removal. The crown will be cemented with glass ionomer luting cement (Meron).	Procedure: Hall Technique with preformed stainless steel crown; Placement of a preformed stainless steel crown using the Hall technique, without caries removal, local anaesthesia, or tooth preparation. The crown will be cemented with glass ionomer luting cement.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Marginal adaptation	Marginal adaptation will be assessed using modified United States Public Health Service criteria: Alpha, continuous margin without a detectable gap; Bravo, minor discontinuity not requiring clinical intervention; and Charlie, marginal defect requiring repair or replacement. Alpha and Bravo will be considered clinically satisfactory, whereas Charlie will be considered a failure.	18 months after treatment
Retention	Retention will be classified as Alpha when the orthodontic band or stainless steel crown remains firmly cemented and functional, or Charlie when it is lost or dislodged and requires recementation or replacement. Alpha will be considered successful retention and Charlie a failure.	18 months after treatment
Presence of carious lesions	Carious lesions adjacent to the restoration margins will be assessed clinically and classified as Alpha when absent or Charlie when present. Alpha will be considered clinically satisfactory and Charlie a failure.	18 months after treatment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Biofilm accumulation	Biofilm accumulation will be assessed using the Silness and Löe Plaque Index, ranging from 0 to 3: 0, absence of biofilm; 1, thin biofilm film along the free gingival margin; 2, moderate accumulation within the gingival sulcus; and 3, abundant accumulation within the gingival sulcus. Lower scores indicate less biofilm accumulation.	Immediately after treatment and at 6, 12, and 18 months
Child-reported treatment acceptability	Acceptability will be assessed using a five-item questionnaire. Each item will be scored from 0 to 4, resulting in a total score ranging from 0 to 20. The negatively worded item will be reverse-scored. Higher total scores indicate greater treatment acceptability.	Immediately after treatment
Caregiver-reported treatment acceptability	Acceptability will be assessed using a five-item questionnaire. Each item will be scored from 0 to 4, resulting in a total score ranging from 0 to 20. Higher total scores indicate greater treatment acceptability.	Immediately after treatment

Collaborators and Investigators

• Sponsor: Universidade Federal do Rio Grande do Norte

Publications and helpful links

General Publications

• Bekes K, Steffen R, Kramer N. Hypomineralised second primary molars: the Wurzburg concept. Eur Arch Paediatr Dent. 2024 Aug;25(4):597-602. doi: 10.1007/s40368-024-00913-7. Epub 2024 May 28.
• Talekar AL, Waggoner WF, Silotry TMH, Musale PK, Chaudhari GS. Prospective, Randomized, Clinical Evaluation of Preformed Zirconia Crowns and Stainless Steel Crowns on Permanent First Molars: 12-Month Results. Pediatr Dent. 2023 May 15;45(3):232-239.
• Bagattoni S, Gozzi I, Lunardon C, Gatto MR, Piana G, Lardani L. Orthodontic Bands for Preventing Post-Eruptive Breakdown in Molars Affected by Molar Incisor Hypomineralisation. Eur J Paediatr Dent. 2025 Sep 1;26(3):212-217. doi: 10.23804/ejpd.2025.2380. Epub 2025 Apr 1.

Study record dates

Study Major Dates

• Study Start (Actual): November 3, 2025
• Primary Completion (Estimated): August 1, 2028
• Study Completion (Estimated): July 1, 2029

Study Registration Dates

• First Submitted: September 5, 2026
• First Submitted That Met QC Criteria: September 5, 2026
• First Posted (Actual): September 11, 2026

Study Record Updates

• Last Update Posted (Actual): September 11, 2026
• Last Update Submitted That Met QC Criteria: September 5, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: stainless steel crowns; enamel defects; orthodontic bands; hspm
• Additional Relevant MeSH Terms: Developmental Defects of Enamel; Stomatognathic Diseases; Tooth Diseases; Stomatognathic System Abnormalities; Congenital Abnormalities; Tooth Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Dental Enamel Hypomineralization
• Other Study ID Numbers: 8.054.527

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