Improvement of the detection of human pulpal blood flow using a laser Doppler flowmeter modified for low flow velocity

Measurement of pulp blood flow rates in maxillary anterior teeth using ultrasound Doppler flowmetry

“…In the present study, the blood flow velocities ranged from 0.44 to 0.67 cm s À1 . These findings are consistent with results reported in previous studies of 0.27-0.79 cm s À1 (Yoon et al 2010(Yoon et al , 2012 and 0.18-0.56 cm s À1 (Qu et al 2014). In this study, there were no significant differences in the mean blood flow velocities of the maxillary central incisors, lateral incisors and canines; however, the measured data had a relatively large standard deviation, which is consistent with other studies (Norer et al 1999, Roy et al 2008.…”

Laser Doppler Flowmetry Evaluation of the Microcirculation in Dentistry

“…Additionally, oral LDFRs have demonstrated considerable intra-and inter-individual variability [94,95]. A part of the limitations is being solved by the fact that the velocity of PBF in humans is very low and that LDF modified for the measurement of slow blood flow is appropriate for PBF measurement in humans [96]. One of the most important limitations of the LDF is that each patient presents variation of blood flow because the measurement is influenced by the thickness of the connective tissue and local distribution of the vessels and also the recording site (free gingivae, inter-dental gingivae, attached gingivae or alveolar mucosae) [35][36][37]40].…”

Pulpal blood flow recorded from exposed dentine with a laser Doppler flow meter using red or infrared light

“…The higher resolution of the records from dentine compared with those from enamel, did not reveal any additional details of fluctuations in blood flow synchronised to the heart-beat, such as a dicrotic notch, which might have been present due to the very low compliance of the pulp (Matthews & Andrew, 1995). In recordings from enamel, Qu et al (2014) found that blood flow in the pulpal circulation was characterized by a lack of high velocity components.…”

“…This would apply particularly in elderly individuals since pulpal blood flow tends to decrease with age (Ikawa, Komatsu, Ikawa, Mayanagi & Shimauchi, 2003). Another method of improving the signal:noise ratio in recordings of pulpal blood flow would be to reduce the upper limit of the bandwidth of the system that measures the Doppler shift in frequency of the light when it is scattered by moving blood cells, from the usual 24 kHz or 20 kHz (as in the present experiments) to 5 kHz (Qu, Ikawa & Shimauchi, 2014). This optimises the detection system to match the relatively slow peak blood velocities in a tooth.…”