Clinical Evaluation of Different Bulk-Fill Restorative Materials in Primary Molars

The goal of this clinical trial is to compare the clinical performance of chemically-cured and light-cured bulk-fill composite materials used for Class II restorations in children aged 4 to 9 years with primary second molars. The main questions it aims to answer are: What are the clinical success rates of the restorations at 12 months based on modified FDI criteria? How do the two materials compare regarding application times, clinician ease of use, and patient satisfaction? Researchers will compare the chemically-cured bulk-fill composite (Stela Capsule) to the light-cured bulk-fill composite (Filtek One) using a split-mouth design to see which material provides better long-term clinical performance and survival rates. Participants will: Receive two different bulk-fill composite restorations in matched primary second molars within the same dental arch Visit the clinic for routine checkups and evaluations at 1 week, 3 months, 6 months, 12 months, 24 months, and 36 months

Inclusion Criteria: * Cooperative pediatric patients aged between 4 and 9 years. * Presence of bilateral primary second molars with Class II dentin caries requiring restoration. * Teeth with positive response to vitality tests (where applicable) and no clinical signs or symptoms of irreversible pulpitis, periapical pathology, or spontaneous pain. * Teeth restorable with direct restorative techniques. * Parents or legal guardians providing signed informed consent. Exclusion Criteria: * Patients with systemic diseases, bleeding disorders, or physical/mental disabilities that prevent cooperation during dental treatment. * Teeth with excessive loss of tooth structure that cannot be restored with a direct restoration or requiring crown coverage. * Teeth with clinical or radiographic signs of pulp exposure, pulp involvement, internal/external resorption, or periapical/furcation involvement. * Teeth with poor oral hygiene or high caries risk where isolation is compromised. * Known allergy or hypersensitivity to the components of the tested materials (e.g., resin composites, primers, adhesives).