IJSR International Journal of Scientific Research 2277 - 8179 Indian Society for Health and Advanced Research ijsr-10-1-33001 Original Research Paper Surgical management of a large periapical lesion using Tricalcium Silicate Cement and Platelet Rich Fibrin followed by Walking Bleach of discoloured tooth- A Case Report with 2 Year followup SHILPI TIWARI Dr. January 2021 10 1 01 02