If a patient complains of pain on chewing and there is no evidence of periapical inflammation, an incomplete fracture of the tooth may be suspected. Biting on a wood stick in these cases can elicit pain, usually on release of biting pressure.
Fibre-optic light
A powerful light can be used for transilluminating teeth to show interproximal caries, fracture, opacity or discoloration. To carry out the test, the dental light should be turned off and the fibre-optic light placed against the tooth at the gingival margin with the beam directed through the tooth. If the crown of the tooth is fractured, the light will pass through the tooth until it strikes the stain lying in the fracture line; the tooth beyond the fracture will appear darker.Cutting a test cavity
When other tests have given an indeterminate result, a test cavity may be cut in a tooth which is believed to be pulpless. In the author’s opinion, this test can be unreliable as the patient may give a positive response although the pulp is necrotic. This is because nerve tissues can continue to conduct impulses for some time in the absence of a blood supply.