This randomized controlled trial aims to compare the effectiveness of supra periosteal injection of dexamethasone versus placebo in reducing post operative pain in teeth diagnosed with symptomatic irreversible pulpitis. A total of 44 patients will be randomly assigned into two groups: Group A will receive a supra periosteal injection of dexamethasone(4mg/ml), and Group B will receive a similar injection of normal saline as placebo. post operative pain will be assessed at 6hr,24hr and 48hr using a VAS Analogue Scale, with the final outcome measured at 24hrs. the study will help determine whether local dexamethasone injection is effective in minimizing postoperative pain

Inclusion Criteria:

• Patients age 18 or above 18 year old (to have complete apex formation)
• Patient with normal periapical area (no pain on percussion).
• Patient who have not received any preoperative analgesic and antibiotic in last one month.

Exclusion Criteria:

• Pregnancy and Lactation because radiographs are contraindicated.
• Moderate to severe periodontal disease because teeth are not salvageable.
• Patient with nonvital teeth diagnose via cold test and EPT.
• Patient with known sensitivity to dexamethasone by history.
• Patients whose medical history include a history of certain illnesses, such as HIV, heart disease, or epilepsy (conditions that can affect a patient's rate of healing).