The Study Aims to Compare the Effectiveness of Mesoporous Bioactive Glass-containing Adhesives vs Conventional Universal Adhesives on the Clinical Performance Composite Restorations Through Promoting Dentin Remineralization After Selective Caries Removal Over a Two-year Follow-up

Inclusion Criteria: * Adult patients aged 22 to 42 years. Presence of Class II carious lesions in posterior permanent teeth (ICDAS 5 \& 6). Radiographic evidence of caries extending to 50% of dentin with a radiopaque layer between the lesion and pulp chamber. Teeth with normal pulp vitality confirmed through cold pulp sensibility test. Teeth with no periapical pathosis on radiographic examination. Good oral hygiene as determined by the attending clinician. Willingness to sign the informed consent and comply with the 2-year follow-up protocol. Cooperative patients who can attend all follow-up visits. Exclusion Criteria: * Allergy to any of the restorative materials (OptiBond Universal or Hi-Bond Universal). Patients currently undergoing orthodontic treatment with fixed appliances. Pregnant women or those planning pregnancy during the study period. Patients with systemic diseases that could interfere with dental treatment (e.g., uncontrolled diabetes, cardiovascular diseases). Use of analgesics or medications that could mask postoperative sensitivity. Teeth with previous restorations or treatment in the target area. Teeth exhibiting spontaneous pain or lingering pain after sensitivity testing, indicating irreversible pulpitis. Negative response in cold pulp sensibility test, indicating pulp necrosis. Teeth with periapical radiolucencies or signs of infection. Mobile teeth due to periodontal disease or trauma. Teeth with extensive structural damage, such as c…