Use of ultrasound Doppler to determine tooth vitality in a discolored tooth after traumatic injury: its prospects and limitations
A 30-year-old female patient visited our clinic for further treatment of traumatized anterior teeth. She had sustained an injury from a fall 2 weeks ago, and had visited a local clinic immediately after the trauma. The subluxated tooth #21 was splinted with composite resin and wire from tooth #13 to tooth #23, and then the local dentist referred her to our clinic. In the periapical radiographic view, the root and periapical area were normal (). Tooth #21 showed negative responses to the thermal test and EPT, a positive response to the percussion test, and pinkish discoloration (). The other teeth showed normal responses to all of the tests. In the ultrasound Doppler test, tooth #21 produced a normal pulsated response like those of the other teeth, and we were also able to hear the beat of the pulsation from the speaker (). At 4 weeks after the injury, tooth #21 showed normal response to percussion, again. In the other tests, the results were also the same as in the previous visit. At 6 weeks after the injury, tooth #21 still showed pinkish discoloration and negative responses to the thermal test and EPT. At 10 weeks after the injury, the shade of tooth #21 returned to normal (). At 12, 16, 20, and 24 weeks after the injury, the patient did not feel any discomfort at all. In the ultrasound Doppler test, tooth #21 showed a vital response, but it did not respond to the cold test or EPT. In the periapical view, the root and periapical area were within the normal range. The negative response continued throughout the follow-up period for 9 months. At that time, she was pregnant and wanted to delay her next visit until after her delivery.