Patient is experiencing severe pain on upper left side and is seen on an emergency basis. The first molar is having a necrotic pulp and an acute periapical inflamation. Tooth is having a complete stenosis of canal system. Patient is taking per os bisphosphonate and does not want to remove the tooth, thus extraction with an implant surgery is not an option. All canals were located with the assistance of a dental operative microscope. Canals were shaped, cleaned and filled with Calcium hydroxyde. Symptomes subsided in the following hours. Endodontic treatment has been completed after 8 days. Post and amalgam build up done in our office and patient returned to his dentist for crowning.