Clinical Performance and Wear Resistance of Two Nano Ceramic Resin Composite in Class I Cavities

Inclusion Criteria: * • Male or female gender. * Only co-operative patients approving to participate in the trial. * Good oral hygiene. * Medically free adult patients. * The age range of the patients is 20 to 54 years * Vital first and second molars, with Class I lesion. * Functioning tooth with presence of an opposing. * Healthy periodontium Exclusion Criteria: * Patients with disabilities. * Patients having systemic diseases or severe medically compromised. * Individuals with full dentures or crowns and bridges in occlusal contact with teeth indicated for the restorative treatment * Pregnant or lactating subjects, or intending to become pregnant during the course of the study * Poor oral hygiene. * Teeth with pulpal pain. * Teeth with periapical lesions. * Endodontically treated teeth * Teeth with mobility. * Non-functioning tooth with no opposing tooth. * Heavy occlusion or signs of severe attrition. * Severe periodontal affection