Zirconomer-P Versus RMGI for Proximal Restorations in Primary Molars

This randomized clinical trial will evaluate the clinical performance of zirconia-fortified glass ionomer (Zirconomer-P capsules) compared with resin-modified glass ionomer (FX-Ultra) for restoring proximal cavities in primary molars.

The study will include children aged 4 to 7 years with posterior primary molars having proximal carious lesions classified as International Caries Detection and Assessment System (ICDAS) 3 or 4, with no clinical or radiographic signs of pulpal involvement. Eligible participants will be randomly allocated to receive either zirconia-fortified glass ionomer or resin-modified glass ionomer as the restorative material.

The restorative procedure will include dental prophylaxis, isolation of the operative field, selective removal of carious tissue, cavity preparation, placement of a matrix and wedge, and restoration using the assigned material. Local anesthesia will not be routinely administered according to the study protocol.

The primary outcome will assess the biological properties of the restorations, including caries at the restoration margin, dental hard tissue defects at the restoration margin, and postoperative hypersensitivity or pulp status. Secondary outcomes will assess functional properties, including marginal adaptation, proximal contact point, form and contour, occlusion and occlusal wear, fracture of the restorative material, and retention.

Clinical outcomes will be assessed using the revised Fédération Dentaire Internationale (FDI) criteria. Participants will be evaluated at baseline and during follow-up visits at 3, 6, 12, and 18 months after restoration. Outcome assessment will be performed by the study assessors, with calibration and assessment of inter- and intra-observer agreement before the study begins.

The study is designed to determine whether zirconia-fortified glass ionomer provides comparable or superior clinical performance to resin-modified glass ionomer for proximal restorations in primary molars over an 18-month follow-up period.

Inclusion criteria

• Generally cooperative children who can be managed by the operators.
• Parent/legal guardian willing to sign the informed consent.
• Acceptance of the required follow-up period.
• Moderate to low caries risk according to the Cariogram application.
• Posterior primary molar with a proximal carious lesion and no signs or symptoms of pulpal involvement.
• Bitewing radiograph showing the lesion extending to the outer one-third of dentin.
• Carious lesion classified as International Caries Detection and Assessment System (ICDAS) 3 or ICDAS 4.

Exclusion criteria

• Allergy to any restorative material.
• Patients undergoing orthodontic treatment with fixed appliances.
• Patients with debilitating systemic diseases.
• Children with special needs.
• Teeth with previous restorations.
• Periapical radiolucencies.
• Sensitivity to axial or lateral percussion.
• Mobile teeth.
• External or internal resorption.