Doppler ultrasound to detect pulpal blood flow changes during local anaesthesia.
OBJECTIVE
To examine whether Doppler ultrasound can detect changes in pulpal blood flow after infiltration anaesthesia.


METHODS
Changes in pulpal blood flow in maxillary central incisor teeth of 18 patients (mean age 26.7 years, 13 men, five women) after infiltration anaesthesia were examined. Before infiltration anaesthesia, the pulpal blood flow was measured using Doppler ultrasound. A local anaesthetic solution containing 2% lidocaine with 1:80,000 epinephrine was injected into the submucosa above the experimental tooth. The Doppler ultrasound test was carried out at 5, 10, 20, 30, 45 and 60 min after infiltration. The parameters were Vas (maximum linear velocity, cm s(-1) ), Vam (average linear velocity, cm s(-1) ) and Vakd (minimum linear velocity, cm s(-1) ), which are indicators of the level of blood flow. The mixed procedure at the 95% confidence interval was used to examine the changes in pulpal blood flow after the injection.


RESULTS
The linear velocity profiles (Vas, Vam, and Vakd) decreased sharply 5 min after anaesthesia and then reduced continuously for 30 min. The maximum degree of blood flow reduction in Vas, Vam and Vakd was 58%, 83% and 82%, respectively. After 30 min, the linear velocities increased gradually. The Vam returned to the pre-anaesthesia state at 60 minutes but the Vas and Vakd did not recover completely.


CONCLUSIONS
Doppler ultrasound can detect changes in pulpal blood flow after infiltration anaesthesia. In the future, Doppler ultrasound can be used as a tool for measuring pulpal blood flow.
Department of Operative Dentistry, College of Dentistry, Yonsei University, Seodaemun-gu, Seoul, Korea.
M J
MJ
Yoon
S J
SJ
Lee
E
E
Kim
S H
SH
Park
D000328:Adult; D000766:Anesthesia, Dental; D000772:Anesthesia, Local; D000779:Anesthetics, Local / Q000008:administration & dosage; D001160:Arterioles / Q000000981:diagnostic imaging; D003782:Dental Pulp / Q000098:blood supply*; D004837:Epinephrine / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor / Q000098:blood supply / Q000000981:diagnostic imaging; D007267:Injections; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D012039:Regional Blood Flow / Q000502:physiology; D013997:Time Factors; D019237:Tooth Cervix / Q000098:blood supply / Q000000981:diagnostic imaging; D018608:Ultrasonography, Doppler / Q000379:methods*; D014662:Vasoconstrictor Agents / Q000008:administration & dosage; D014699:Venules / Q000000981:diagnostic imaging
D000779:Anesthetics, Local; D014662:Vasoconstrictor Agents; D008012:Lidocaine; D004837:Epinephrine