One of the most important aspects of endodontic practice is to abate pain during and post root canal treatment. An endodontist by all means should provide a painless endodontic treatment to their patients. This study is carried out to determine the effect of occlusal reduction on relief of pain and percussion in patients with irreversible pulpitis and symptomatic apical periodontitis treated in a single visit root canal treatment. Pain will be assessed preoperatively and then post operatively after completion of the root canal at 6 hours, 12 hours, 24 hours, 48 hours and 72 hours following obturation of root canal.

The objective of this randomized clinical trial is to evaluate the impact of occlusal reduction on the incidence of post obturation pain. 56 patients will be allocated randomly into 2 groups keeping 28 patients in each group which will meet the inclusion criteria of the study, patients diagnosed with symptomatic irreversible pulpitis and symptomatic apical periodontitis and requiring porcelain fused to metal crown with age ranging from 18 to 50 years. In the interventional group 2mm reduction will be done and assessment will be done to confirm the absence of occlusal contact while in control group no modification will be carried out on the occlusal surface. Single visit endodontic treatment will be carried out with 2.5% sodium hypochlorite for disinfection of the canal followed by crown down technique using rotary nickel titanium files for shaping the canals followed by obturating the canals with lateral condensation technique.

Pain will be assessed preoperatively and then post operatively at 6 hours, 12 hours, 24 hours, 48 hours and 72 hours following obturation of root canal. Visual Analogue Scale (VAS) will be used as a primary outcome measure.The VAS consists of a 10-cm line having two extremes NO PAIN and Extreme pain. Patients will be asked to choose the mark that represents their level of pain at the intervals mentioned above . Pain level are assigned to one of four categorical scores

1, None(0); 2, Mild (1-3) ; 3 Moderate (4-6); 4, Severe (7-10) 10. Tenderness to percussion will be evaluated postoperatively at 48 hour with readings either positive to tenderness or negative to tenderness Positive to tenderness will evaluate treatment not effective Negative to tenderness at 48 hour post obturation will evaluate treatment effectiveness Patients will be given placebo for administration in case severe pain and ibuprofen 400mg if the pain persisted. Documentation of intake of either placebo or analgesic will be done by the patient.

Inclusion Criteria:

• No medical history
• patients suffering from Symptomatic Irreversible Pulpitis
• patients suffering from Apical Periodontitis
• patients requiring porcelain fused to metal crown

Exclusion Criteria:

• Patients who were not suitable for conventional root canal treatment
• multirooted teeth