A Randomized Clinical Trial Comparing Hall vs. Conventional Technique in Primary Molars.

September 24, 2025 updated by: Hanan Mohamed, Primary Health Care Corporation, Qatar

Comparative Analysis of Hall Technique and Conventional Method for Stainless Steel Crown Placement in Primary Molars With Approximal Caries: A Randomized Controlled Trial at Primary Healthcare Corporation, Qatar

This study aims to assess the comparative effectiveness of the Hall technique (HT) and the conventional technique (CT) for placing Stainless Steel Crowns (SSCs) in primary molars with approximal caries.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Background:

The most common chronic disease in children and adolescents (6-19 years old) is dental caries. The conventional approach to treating carious lesions involves cavity preparation with rotary instruments, followed by restoration using composite resin, amalgam, or stainless steel crowns (SSCs).

Retrospective studies have shown that SSCs have a higher success rate compared to amalgam or resin-based restorations when used for multi-surface caries in primary teeth. Accordingly, the American Academy of Paediatric Dentistry (AAPD) recommends the use of SSCs as the treatment of choice for carious lesions involving more than one surface in high-risk children.

Recently, the Hall Technique (HT) has been used to seal caries in primary molars. This contemporary technique was first introduced in the literature in 2006 by Dr Norna Hall, while working in a high caries-risk area in rural Scotland. The technique is based on straightforward biological principles: the most important layer for caries progression- the superficial plaque layer- is left intact and sealed along with the carious lesion. This leads to the development of a less cariogenic flora within the plaque biofilm, thereby arresting or slowing the caries progression in primary teeth.

The Hall Technique involves cementing an SSC over a carious primary tooth without the use of rotary instruments or local anaesthesia, thus reducing discomfort and improving the child's behaviour during treatment.

Aim:

The study aims to compare the Hall Technique (HT) and Conventional Restoration (CR) using stainless steel crowns (SSCs) in terms of clinical effectiveness, changes in occlusal vertical dimension (OVD), procedural time, child pain perception and cooperation, as well as parental acceptability of both techniques.

Methods/Design:

Approximal dental caries (ICDAS 3-5) in primary molars of children aged 3 to 9 years will be managed using two treatment techniques: conventional restorations (CR) with stainless steel crowns (SSCs) and the Hall Technique (HT). The study will be a binary outcome, non-inferiority randomised trial conducted in a primary care dental clinic setting. The study protocol will follow the Consolidated Standards of Reporting Trials (CONSORT) guidelines for randomised trials of non-pharmacologic treatments. Participants will be randomly allocated to receive SSCs placed using either the conventional technique (CT, control group) or the Hall Technique (HT, experimental group), in order to compare different approaches for managing occluso-proximal caries lesions in primary molars.

Discussion:

This clinical trial aims to determine whether the Hall Technique (HT) provides clinical outcomes that are not inferior to those of conventional restorations (CR) using stainless steel crowns (SSCs) in the management of approximal caries in primary molars. The study will also assess child pain perception, cooperation, and parental acceptability, to support the use of minimally invasive techniques in paediatric dental care.

Study Type

Interventional

Enrollment (Actual)

80

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

  • Qatar
      • Doha, Qatar
        • Primary Healthcare Corporation

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:

  • Participant inclusion criteria:

PHCC paediatric dental patients:

  1. Whose parents or legal guardians accept and sign the consent form
  2. Who assent to participation.
  3. Who aged 3-9 years old.
  4. Who exhibit generally cooperative behavior.
  5. Who exhibit good general health conditions.
  6. Who are presenting at least one occluso-proximal lesion in a primary molar.

Tooth/ carious lesion inclusion criteria:

1. From clinical and radiographic examination, caries limited to the occluso-proximal surfaces and extending to enamel or dentine, cavitated or non cavitated.

Exclusion Criteria:

  1. Uncooperative children who do not understand the procedure or tolerate biting the crown into its position without local anesthesia.
  2. Children with special health care needs (SHCN) will be excluded.
  3. Children with nickel allergies and sensitivity.

Tooth/ caries lesion exclusion criteria:

  1. Tooth with signs or symptoms of dental infection or irreversible pulpitis such as:

    A history of spontaneous unprovoked pain, a sinus tract, soft tissue inflammation not resulting from gingivitis or periodontitis, excessive mobility not associated with trauma or exfoliation, furcation/ apical radiolucency, or radiographic evidence of internal/ external resorption (Camp JH 2011).

  2. Crowns severely destructed with caries, which considered non-restorable (Innes, N.P 2009).
  3. Teeth with single surface (occlusal) caries.

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: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Hall Crown Technique
HT is a conservative restorative technique used for primary molars with single- or multi-surface carious lesions. This technique involves cementing a SSC directly over the affected primary molar without any caries removal or tooth reduction.
Procedure: Hall Crown Technique
The Hall technique (HT) involves cementing Stainless Steel Crowns SSC on carious primary teeth without using rotary instruments nor local anaesthesia, thus eliminating discomfort, and increasing child's behavior.
Active Comparator: Conventional SSC Technique
CT is the traditional restorative technique often used for primary molars with multi-surface carious lesions. This technique involves caries removal and occlusal-proximal tooth surface reduction before crown cementation.
Procedure: Conventional SSC Technique
The conventional technique involves complete removal of the carious lesion using rotary instruments and local anesthesia, then restoring the tooth with Stainless Steel Crown SSC.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Restoration survival over 12 months
Time Frame: At 1 month, 6 months, 9 months, and 12 months post-treatment

Success:

  • Satisfactory restoration/crown, no intervention required
  • No clinical or radiographic signs or symptoms of pulp pathology
  • Tooth exfoliated

Minor Failures:

  • Secondary caries or new lesions detected clinically
  • Crown presents perforation
  • Restoration fracture or wear - intervention required
  • Loss of restoration - tooth that can be re-restored
  • Crown loss - tooth able to be re-treated
  • Reversible pulpitis, which could be treated without the need for extraction or pulpotomy

Major Failures:

  • Irreversible pulpitis or dental fistula/abscess requiring pulpotomy or extraction
  • Loss of restoration/crown - tooth not capable of being re-restored
  • Periradicular and/or furcation radiolucency
At 1 month, 6 months, 9 months, and 12 months post-treatment
Occlusal Vertical Dimension (OVD) resolution
Time Frame: Assessments will be conducted at baseline (before treatment), immediately after crown placement, and at follow-up visits at 1, 6, 9, and 12 months post-treatment, with particular emphasis on the 1-month follow-up.
Will be assessed only in the HT group using a millimetre dental probe.
Assessments will be conducted at baseline (before treatment), immediately after crown placement, and at follow-up visits at 1, 6, 9, and 12 months post-treatment, with particular emphasis on the 1-month follow-up.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Tooth survival over 12 months
Time Frame: At 1 month, 6 months, 9 months, and 12 months post-treatment
Teeth with treatments scored as satisfactory or with minor failures will be classified as "successful," while teeth presenting major failures will be considered as "failure for tooth." Data related to the treated tooth will be collected for both groups.
At 1 month, 6 months, 9 months, and 12 months post-treatment
Procedural Time
Time Frame: At the time of treatment visit
Will be recorded during the treatment visit using a stopwatch for both the Hall Technique and the Conventional Technique.
At the time of treatment visit
Participant's cooperation
Time Frame: At the time of treatment visit
Participant cooperation will be assessed and compared between the two intervention groups using the Frankl Behaviour Rating Scale.
At the time of treatment visit
Participant's pain perception
Time Frame: At the time of treatment visit
Pain perception will be assessed and compared between the two intervention groups using the Wong-Baker Faces Pain Scale (WBFPS).
At the time of treatment visit
Parents' perceptions and opinions regarding treatment
Time Frame: At the time of treatment visit

A five-point Likert scale will be used to assess the following:

  • Child's behaviour during treatment
  • Comfort during treatment
  • Satisfaction with treatment undertaken
  • Dentist's ease of treatment provision
  • Perceived duration of the procedure
  • Willingness to choose the same treatment option again
At the time of treatment visit

Collaborators and Investigators

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

Sponsor

Primary Health Care Corporation, Qatar

Investigators

  • Principal Investigator: Hanan A Mohamed, Primary Health Care Corporation (PHCC) of Qatar

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

Helpful Links

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)

December 6, 2023

Primary Completion (Actual)

July 27, 2025

Study Completion (Actual)

August 1, 2025

Study Registration Dates

First Submitted

March 24, 2024

First Submitted That Met QC Criteria

April 1, 2024

First Posted (Actual)

April 5, 2024

Study Record Updates

Last Update Posted (Estimated)

September 25, 2025

Last Update Submitted That Met QC Criteria

September 24, 2025

Last Verified

March 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • BUHOOTH-D-23-00073

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

A password protected computer system is used to assure secure data storage. Only encrypted systems are used for storing research data on laptops. A locked file cabinet is used to store research related paper forms. Access to study data is limited to only a few members of the study team. Plans are set to destroy all research generated data after 3 years according to PHCC regulations.

The study report / publication will show only aggregate results with no identifiers.

Only deidentified study data is stored. A code number is used instead of the participant's real name on study data.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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