The above picture is a radiograph of a patient who attends your surgery with a toothache.She complained of dull aching pain on the upper right, with some tenderness in the upper buccal sulcus. The pain is unaffected by thermal stimuli. Describe your assessment and likely diagnosis.

Clinical features

Obtain a complete history first. How long has the pain been present? Have there been previous episodes or is this the first? Carry out a complete examination. Test each tooth for sensitivity with a cotton wool pledget soaked in ethyl chloride. Use gentle finger pressure on each tooth, followed up by percussion if there is no abnormal response. Record the responses and note if you manage to reproduce the pain the patient is complaining of.

Radiology

The radiograph shows a large restoration in the molar and a post crown on the first premolar. In the premolar, the root filling looks insubstantial and there is a periapical granuloma present. At the level of the end of the post, there is radio-opaque material overlying the tooth and bone. Also at this level and further coronally, lamina dura is lost along the root surface.

Likely diagnosis

The lack of any aggravation of the pain by thermal stimuli suggests that this is not pulpitis. The dull aching pain, along with the tenderness in the buccal sulcus, suggests chronic periapical periodontitis is a likelier diagnosis. On radiological grounds, there is only one likely tooth with problems: the first premolar. The apical granuloma suggests chronic inflammation, but you should bear in mind that the radiograph is a snapshot in time and that the lesion could be healing (although the poor root filling suggests otherwise). The interesting finding is the collection of signs around the end of the post. The radio-opaque material overlying the root here is probably extruded cement from when the post was cemented. This at least suggests a perforation and may indicate a fracture of the root at this level. Clinical examination might reveal mobility of the crown if a fracture were present