Endodontic retreatment of a maxillary first molar

History Presenting complaint – persistent dull pain arising from the upper right area of the mouth. History of complaint – Mr DS complained of a well localised, moderate, but constant dull ache arising from the right maxillary first molar (UR6). This started nine months ago following an acute episode that was managed by his GDP with antibiotics and is exacerbated only by masticatory forces with no sensitivity to thermal stimuli. The pain, which fortunately does not disturb his sleep, was being managed by overthe-counter analgesics. He recalls that the tooth in question had previously undergone root canal therapy approximately nine years ago as a result of extensive caries. This was allegedly completed over a single visit, with no recollection of rubber dam use and, upon completion, was coronally restored with a direct restoration. Relevant dental and social history – Mr DS regularly attends his GDP and has adopted an excellent oral hygiene regime, a low cariogenic diet, has never smoked and presents little to no anxiety or parafunction. Relevant medical history – no relevant medical history or known drug allergies. Examination – an extraoral assessment concluded a right submandibular lymphadenopathy.