Traditional vs. Minimally Invasive Decay Treatments in Primary Molars: An 18-month Split-mouth Randomized Study (MiCRO-PM)

February 26, 2026 updated by: Maria Paula Rueda Manjarres, TC Erciyes University

An 18-Month Split-Mouth Randomized Clinical Trial Comparing the Hall Technique, Silver Diamine Fluoride, and Compomer Restorations for the Management of Caries in Primary Molars in Children Aged 4-8 Years

The goal of this clinical trial is to compare the 18-month clinical success rates of three caries management approaches in primary molars of 60 healthy children aged 4-8 years attending the Department of Pediatric Dentistry at Erciyes University, using a randomized split-mouth design involving 180 treated teeth. The three approaches include the Hall Technique, Silver Diamine Fluoride, and the conventional "drill-and-fill" restorative approach using compomer material. The study will also evaluate pain perception during treatment, child behavior, and treatment acceptability from the perspectives of patients, parents, and dentists. The main questions it aims to answer are:

  • Do minimally invasive approaches (Hall Technique and Silver Diamine Fluoride) achieve comparable or superior 18-month clinical success rates compared to the conventional drill-and-fill restorative treatment?
  • Do minimally invasive approaches result in lower pain perception, improved child behavior, and greater treatment acceptability compared to the conventional drill-and-fill approach?

Researchers will compare the three treatment approaches applied to different teeth within the same child to see if minimally invasive methods provide similar or improved clinical outcomes and better patient-centered outcomes over 18 months compared to the conventional approach.

Participants will:

  • Contribute three eligible primary molars per child (180 teeth in total).
  • Have each tooth randomly assigned to one of the three treatment approaches following a split-mouth design.
  • Receive all three interventions within the same participant, with each treatment applied to a different tooth.
  • Attend scheduled follow-up visits at 1 month after completion of all interventions, and at 6, 12, and 18 months (final follow-up) for clinical and radiographic evaluation of each treated tooth.
  • Provide assessments of pain perception and treatment experience, with additional evaluations completed by parents and treating dentists.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

This randomized split-mouth clinical trial was designed to evaluate and compare the clinical performance and patient-centered outcomes of three different caries management approaches in primary molars of children.

Dental caries remains one of the most prevalent chronic diseases in childhood. Minimally invasive strategies such as the Hall Technique (HT) and Silver Diamine Fluoride (SDF) have gained increasing attention as alternatives to conventional restorative treatment, particularly in young or anxious pediatric patients. However, comparative clinical data evaluating long-term outcomes and patient-centered measures between these approaches and conventional restorative treatment remain limited.

A total of 60 healthy children aged 4-8 years requiring restorative treatment for at least three primary molars were included. Using a split-mouth design, each child contributed three eligible primary molars (total: 180 teeth). Within each participant, teeth were randomly allocated to receive one of the following interventions:

Hall Technique (placement of a preformed metal crown without caries removal or tooth preparation)

Silver Diamine Fluoride application

Conventional caries removal followed by restoration using compomer material (drill-and-fill approach)

The split-mouth design was selected to minimize inter-individual variability by allowing direct intra-patient comparison of the three treatment modalities.

Clinical and radiographic evaluations were performed at 1 month after completion of all interventions and at 6, 12, and 18 months. The primary outcome measure was 18-month clinical success of each treated tooth. Secondary outcomes included pain perception during treatment, child behavior, and treatment acceptability as assessed by patients, parents, and treating dentists.

This study aims to provide comparative evidence regarding the effectiveness and acceptability of minimally invasive versus conventional restorative approaches in pediatric dentistry.

Study Type

Interventional

Enrollment (Actual)

60

Phase

  • 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

  • Turkey (Türkiye)
    • Kayseri
      • Kayseri, Kayseri, Turkey (Türkiye), 38039
        • Erciyes University, Faculty of Dentistry, Department of Pediatric Dentistry

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

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Children aged 4 to 8 years.
  • Systemically healthy children without any medical or syndromic conditions.
  • Frankl Behavior Rating Scale score of 3 (positive) or 4 (definitely positive).
  • Presence of at least three unrestored, asymptomatic primary molars with active occluso-proximal dentine caries lesions (ICDAS codes 3, 4, or 5).
  • Written informed consent obtained from parents or legal guardians, with willingness to attend follow-up visits.

Exclusion Criteria:

  • Refusal to provide informed consent or unwillingness to participate.
  • Presence of systemic disease or chronic medical conditions requiring special care or antibiotic prophylaxis.
  • Teeth presenting mobility, symptoms, abscess, or tenderness to percussion.
  • Radiographic evidence of pulpal pathology.
  • Non-restorable teeth.
  • Children with severe lack of cooperation (Frankl score 1 or 2).
  • Refusal of treatment for aesthetic reasons by the parent or child.

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
Intervention / Treatment
Experimental: Hall Technique
Teeth randomly allocated to this arm were treated using the Hall Technique for the management of carious lesions in primary molars. The intervention consisted of cementation of a preformed stainless-steel crown (3M ESPE, USA) using glass ionomer luting cement, without caries removal, tooth preparation, or local anesthesia. In this split-mouth randomized design, eligible teeth within the same child were allocated to different treatment arms. Clinical evaluations were performed at 1, 6, 12, and 18 months after crown placement.
Procedure: Hall Technique
Placement of a preformed stainless-steel crown (3M ESPE, USA) cemented with glass ionomer luting cement without tooth preparation, local anesthesia, or caries removal.
Other Names:
  • SSC
  • Stainless Steel Crown
  • Preformed Stainless Steel Crown
Experimental: Silver Diamine Fluoride
Teeth randomly allocated to this arm were treated with 38% silver diamine fluoride for the management of carious lesions in primary molars. Unsupported enamel was removed and the cavity surface was cleaned using a rotary bristle brush prior to application. A 38% silver diamine fluoride solution with potassium iodide (Riva Star Aqua, SDI, Australia) was applied, followed by 22,600 ppm fluoride varnish (Duraphat, GABA, Germany). In this split-mouth randomized design, eligible teeth within the same child were allocated to different treatment arms. SDF applications were repeated at 6 and 12 months. Clinical evaluations were performed at 1, 6, 12, and 18 months.
Drug: Silver diamine Fluoride 38%
Topical application of a two-step protocol using 38% water-based silver diamine fluoride (step 1) followed by potassium iodide (step 2) (Riva Star Aqua, SDI, Australia) on active cavitated caries lesions extending into dentine. Prior to application, unsupported enamel margins are removed to allow plaque access. The procedure is completed with the application of 22,600 ppm fluoride varnish (Duraphat, GABA, Germany). Applications are repeated at 6- and 12-month follow-up visits.
Other Names:
  • SDF
  • 38% SDF
Experimental: Compomer Restoration
Teeth randomly allocated to this arm were treated with conventional caries removal and restoration using compomer material for the management of carious lesions in primary molars. Complete caries removal was performed under local anesthesia when clinically indicated, followed by restoration with a compomer material (Dyract, Dentsply, Germany) according to the manufacturer's instructions. In this split-mouth randomized design, eligible teeth within the same child were allocated to different treatment arms. Clinical evaluations were performed at 1, 6, 12, and 18 months.
Procedure: Compomer Restoration
Complete caries removal followed by restoration with compomer material (Dyract, Dentsply, Germany) under local anesthesia as needed.
Other Names:
  • Dyract
  • Polyacid-Modified Composite Resin

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Clinical success rate at 18 months
Time Frame: 18 months
Proportion of treated teeth without clinical or radiographic signs of failure, defined as absence of pain, abscess, fistula, pathological mobility, restoration or crown loss, or caries progression requiring further intervention. Outcomes are assessed through clinical and radiographic examination.
18 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pain perception during treatment
Time Frame: Periprocedural (Day 1)
Child-reported pain perception assessed immediately after treatment using the Visual Analogue Scale (VAS) of Faces. The scale ranges from 0 to 10, where 0 indicates no pain and 10 indicates worst possible pain. Higher scores indicate greater pain intensity.
Periprocedural (Day 1)
Child behavior during treatment
Time Frame: Periprocedural (Day 1)
Behavioral response assessed during treatment using the Frankl Behavior Rating Scale, a 4-point ordinal scale ranging from 1 (definitely negative) to 4 (definitely positive). Higher scores indicate more cooperative behavior. The treating dentist assigned the score based on observed cooperation during the procedure.
Periprocedural (Day 1)
Child treatment acceptability
Time Frame: Periprocedural (Day 1)
Child-reported treatment acceptability assessed immediately after treatment using a modified version of the Bell et al. (2010) questionnaire. The instrument consists of five items scored on a 5-point Likert scale ranging from strongly disagree (1) to strongly agree (5). Higher scores indicate greater treatment acceptability.
Periprocedural (Day 1)
Parental treatment acceptability
Time Frame: Periprocedural (Day 1)
Parent-reported treatment acceptability assessed immediately after treatment using a five-item questionnaire scored on a 5-point Likert scale ranging from strongly disagree (1) to strongly agree (5). Higher scores indicate greater treatment acceptability.
Periprocedural (Day 1)

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in occlusal vertical dimension (OVD) after Hall Technique
Time Frame: Baseline, immediately after treatment, and 1 month after crown placement
Occlusal vertical dimension (OVD) is assessed only in teeth treated with the Hall Technique. Measurements are performed using a digital vernier caliper to determine the vertical distance between the lowest point of the gingival margin of the lower canine and the tip of the corresponding upper canine on the treated side. If canines are absent, contralateral canines or first primary molars are used as reference. OVD is recorded before crown placement, immediately after treatment, and at 1-month follow-up to evaluate resolution of occlusal changes.
Baseline, immediately after treatment, and 1 month after crown placement

Collaborators and Investigators

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

Sponsor

TC Erciyes University

Investigators

  • Principal Investigator: Maria Paula Rueda Manjarres, DDS, Erciyes University, Faculty of Dentistry, Department of Pediatric Dentistry
  • Study Chair: Husniye Gumus, DDS, PhD, Erciyes University, Faculty of Dentistry, Department of Pediatric Dentistry

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)

August 1, 2024

Primary Completion (Actual)

August 30, 2024

Study Completion (Actual)

February 9, 2026

Study Registration Dates

First Submitted

February 20, 2026

First Submitted That Met QC Criteria

February 26, 2026

First Posted (Actual)

March 3, 2026

Study Record Updates

Last Update Posted (Actual)

March 3, 2026

Last Update Submitted That Met QC Criteria

February 26, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ERU-MiCROPM-2024-01
  • E-68869993-000-1538193 (Other Identifier: Turkish Medicines and Medical Devices Agency)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data underlying the results reported in publications (text, tables, figures).

IPD Sharing Time Frame

Beginning 6 months after publication of the primary results and ending 5 years after publication.

IPD Sharing Access Criteria

Access to de-identified individual participant data and supporting documents (study protocol and statistical analysis plan) will be granted to researchers who provide a methodologically sound research proposal. Proposals should include a clear description of the research objectives and planned statistical analyses.

Requests will be reviewed by the Principal Investigator and the research team to ensure scientific validity and compliance with ethical standards.

Data will be shared after approval of the proposal and execution of a signed data access agreement. Proposals should be submitted to the corresponding author via institutional email.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

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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