Diagnostic Tests

Most of our job is done by the time we have finished taking the history and the clinical examination. These following diagnostic tests further take us to the proper diagnosis and help us to formulate our treatment plan.

Electric Pulp Tester (EPT)

The EPT uses electric current to stimulate the sensory nerves of the dental pulp. Measurement of electric voltage in teeth may be inconsistent due to thickness of enamel and dentin, dryness and electrical resistance of enamel, infractions, restorations, pits, fissures and caries. Where the electric pulp tester is placed on the tooth crown is critical. It has been shown that the incisal edge on anterior teeth and the mesio-buccal incisal edge on lower teeth is the optimal placement site for the EPT to determine the lowest response threshold. This is true of the cold tests as well.

Pulp testers should only be used to assess vital or non-vital pulps; they do not quantify disease, nor do they measure health and should not be used to judge the degree of pulpal disease. Pulp testing gives no indication of the state of the vascular supply, which would more accurately indicate the degree of pulp vitality.

The only way pulpal blood-flow may be measured is by using a Laser-Doppler Flow Meter, not usually available in general practice!

Heat: The tip of a gutta-percha stick may be heated in a flame and applied to a tooth. Take great note that hot gutta-percha may stick fast to enamel.

Cold: Different methods may be used to apply a cold stimulus to a tooth. The most effective is the use of a –50°C spray( Pulpofluorane , Septodont), which may be applied using a cotton pledget. This test is a simple and efficient test for most clinical situations though not necessarily conclusive.

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.

Radiographic Examination

a) Intra-oral views of affected teeth: At least two views should be taken from different angulation to see if there is any fracture line present and occlusal films should be taken to check for the signs of trauma to teeth.

b) Extra-oral views as necessary.

c) Panoramic view: Facial bone projection or CAT scan should be done to see for any fracture lines.