Had radiating pain on whole side of face/jaw. 1st dentist said it could be cracked filling, may need oral surgery, prescribed course of antibiotics. SECOND dentist AND endodontist tried hammering, cold spray, no response, said "no root canal necessary", possible cracked filling, needing crown to avoid leakage. THIRD dentist discovered a deep crack in the molar BEHIND the previously suspected tooth, and proved it by having me bite down on a Q-tip, with resulting pain. FOURTH dentist verified the finding. BOTH 3rd and 4th suggest root canal and crown may be inadequate, suggesting extraction and implant probably necessary. 4th wants to send me to a specialist with microscopic equipment adequate to make the call. Quotes are between 4,000 and 5,000 total. Sound about right?