Cracked Tooth or Irreversible Pulpitis in a Heavily Restored Molar
A 47-year-old man presents with sharp pain on biting on the upper right first molar for 3 months. The pain lasts seconds after release and is provoked by hard foods. He had a large amalgam 6 years ago and a composite repair 1 year ago. The tooth is not tender to percussion, probing depths are 3 mm or less, and there is no mobility. Cold testing produces a sharp response that resolves in about 5 seconds; the adjacent second molar responds similarly. A periapical radiograph shows a deep restoration close to the pulp with no periapical radiolucency. Bite test with a wooden stick reproduces pain on release on the mesiobuccal cusp. He wants the tooth extracted because he is anxious about repeated visits.
1. What is your working diagnosis, and how do the special tests discriminate between the main possibilities?
Read the worked answer
The working diagnosis is a cracked tooth syndrome affecting the restored first molar, with a reversible pulpal state. The key discriminator is the bite test: pain reproduced on release of biting on the mesiobuccal cusp, with a sharp, brief cold response that settles, points to a incomplete cusp fracture rather than irreversible pulpitis. Irreversible pulpitis typically gives prolonged, spontaneous or lingering pain after cold removal, which is absent here. Periapical pathology is unlikely because there is no percussion tenderness or radiolucency. The normal adjacent tooth response confirms the cold test is valid. Probing depths exclude a periodontal crack extending to the root. A fracture line may not be visible radiographically, so diagnosis is clinical; transillumination or staining can help localise it. I would explain that the tooth is likely salvageable and that extraction is not the first option.
2. Outline a conservative management plan and the criteria for escalating to root canal treatment or extraction.
Read the worked answer
First, remove the cracked cusp or place a protective band or provisional crown to splint the tooth and redistribute occlusal load, then reassess symptoms in 2 to 4 weeks. If pain settles, place a definitive adhesive restoration or full-coverage crown, which reduces flexure and prevents crack propagation; advise avoiding hard foods on that side. Escalate to root canal treatment if pain becomes spontaneous or lingering, if cold response becomes prolonged, or if the pulp becomes necrotic, because irreversible pulpitis indicates pulp involvement. Extract if the fracture line extends subgingivally, is mobile, or reaches the root, or if symptoms persist despite splinting and the tooth is unrestorable. Address his anxiety with a clear staged plan, written information, and a review appointment, since a predictable conservative pathway is more acceptable than immediate extraction and preserves the tooth.