This study aims to investigate the influence of desensitizing agents on reducing post-operative sensitivity in posterior composite.

Inclusion Criteria:

• Patients having active primary class I carious lesions on vital molar teeth either in the middle or the inner third of dentin in the three quadrants of each patients.
• Teeth having a positive reaction to vitality test (cold test), no signs of pulp inflammation, or spontaneous pain before treatment.
• Preoperative radiographic record of the carious lesions.
• Buccolingual width is no more than half the inter-cuspal distance

Exclusion Criteria:

• Excessive tooth wear due to clenching or abnormal habits.
• Patients with direct occlusal contact by antagonist cusp (traumatic occlusion).
• Patients with periodontal or gingival disease.
• Patients using analgesics and/or anti-inflammatory medicine.