To minimize the effects of polymerization shrinkage in the restorative treatment, there are new composites called Bulk- Fill which the companies has developed this composites for example Tetric N Ceram(Ivoclar-Vivadent) and Filtek ( 3M ESPE). Its decreased polymerization shrinkage and properties allow the material to be inserted in one layer being quickly than traditional composite. This clinical study is designed to compare the clinical performance of the bulk fill composite resin in Class I (one-surface posterior), II (two-surface posterior) and V (cervical-surface posterior) fillings.

A patients with 3 caries lesions class one either two or five will be divided into 3 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 (Bluephase Style Ivoclar-Vivadent), with an energy 1,100 mW/cm² (±50 mw/cm²) and others group of cavities will be restored by bulk fill composite (3M ESPE) and other bulk fill composite ( IVOCLAR-VIVADENT) as one increment then will be cured as directed by the manufacturer with the light curing unit.

The study will investigate the clinical performance and efficacy of a bulk-filled composite resin restorative material for a period of 5 years

Inclusion Criteria:

• must have given written informed consent to participate in the trial
• need at least three posterior restorations
• must be available for the required post-operative follow-up visits
• have a buccal to lingual/palatal width no greater than 1/3 the distance from buccal to lingual/palatal cusp tips
• At least one occlusal and proximal contact on a natural tooth
• Cavities depth > 2 mm in cervico-occlusal

Exclusion Criteria:

• have severe medical complications (organ transplants, long term antibiotic or steroid treatment, cancer or immunocompromised) and disabilities who may not be able to tolerate the time required to complete the restorations
• have xerostomia either by taking medications known to produce xerostomia or those with radiation induced or Sjogren's syndrome patients
• chronic periodontitis
• present with any systemic or local disorders that contra-indicate the dental procedures included in this study
• an unstable occlusion
• severe bruxing
• teeth with periapical pathology or expected pulp exposures
• are pregnant.
• Endodontically treated teeth