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.

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.

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.

Single-blind