To achieve an optimal contact area is essential to avoid tooth migration, food impaction, and the occurrence of secondary caries. However, proximal restorations constitute challenge for the professional and tight contact points are difficult to obtain depending not only on tools used, but also on type of restorative material. Current tooth-colored restorative materials are not condensable and there is shrinkage with setting. The aim of this study is to compare the proximal contact tightness of zirconia reinforced glass ionomer versus conventional nanohybrid resin composite when used in class II cavities.

Eligibility Criteria of participants:

Inclusion Criteria of participants:

• Patients with occlusoproximal caries in molars classified as ICDAS III or IV.
• 19-35 years.
• Males or Females.
• Co-operative patients approving to participate in the trial.

Exclusion criteria of participants:

• Pregnancy.

• Disabilities.

• Systemic disease or severe medical complications.

• Allergic history concerning methacrylate.

• Rampant caries.

• Heavy smoking.

• Xerostomia.

• Lack of compliance.

• Evidence of severe bruxism, clenching, or temporomandibular joint disorders.

  b- Eligibility Criteria of teeth:

Inclusion Criteria of teeth:

• Occlusoproximal caries in molars classified as ICDAS III or IV.
• Vital upper or lower posterior teeth with no signs of irreversible pulpitis.
• Intact contact with opposing teeth.
• Teeth with no previous restorations in other surfaces.

Exclusion criteria of the teeth:

• Extensive carious lesions
• Periapical pathology or signs of pulpal pathology.
• Tooth hypersensitivity.
• Possible prosthodontic restoration of teeth.
• Heavy occlusion and occlusal contacts or history of bruxism.
• Sever periodontal affection.