restoring posterior teeth by bulk fll and nanofill composite and clinical evaluation of performance and durability of both restorations during one year follow up

The treated cavities will be divided into 2 groups, cavities will be incrementally layered with resin composite and each increment will be cured as directed by the manufacturer with the light curing unit (XL 3000; 3M/eSPe), with an energy higher than 450 mW/cm² (±50 mw/cm²) and other group of cavities will be restored by bulk fill composite (3M ESPE) as one increment then will be cured as directed by the manufacturer with the light curing unit.

Articulation will be checked carefully with an articulating paper and occlusal adjustments will be performed using flame shaped carbide and diamond finishing burs (DENTSPLY) using water spray, restorations will be finished occlusally with finishing burs and finally polished with aluminium oxide polishing paste and a rubber cup (DENTSPLY).

Inclusion Criteria:

• Good oral hygiene.Patients must show no signs of orofacial pain. The presence of molar teeth requiring composite restorations for the treatment of primary carious lesions

Exclusion Criteria:

• Teeth with abnormal periapical anatomy or caries that will be likely to result in very deep restorations. Teeth with old restorations or severely destructed dental crowns.Tempro-mandibular joint problems involving symptomatic pain.Pregnancy or breast feeding, acute and chronic systemic diseases, immune-compromised patients