Pulpal Blood Flow Research Articles

Comparative evaluation of pulpal blood flow during incisor intrusion

AbstractAimThe aim of the present study was to evaluate and compare changes in pulpal blood flow (PBF) as a result of maxillary incisor intrusion achieved by one of two methods (utility arches or mini-implants).Materials and methodsThirty subjects were divided into three groups, the first of which underwent maxillary incisor intrusion using utility arches (UA) and a second group, intrusion via mini-implants (MI). The third group acted as a control. An intrusive force of 100 g was applied to the upper incisors in the treatment groups, whereas no force was applied to the anterior teeth in the control group. A laser Doppler flowmeter (LDF) was used to measure PBF at baseline (T0) and during incisor intrusion at 24 hours (T1), three days (T2), seven days (T3) and three weeks (T4). Statistical changes in PBF were assessed by the Wilcoxon Signed Rank and Mann-Whitney U tests, with significance set atp< 0.05.ResultsThe mean PBF in the UA and MI groups decreased significantly from T0 to T1 (p< 0.001), slightly increased at T2 and continued to increase gradually at T3. PBF attained levels similar to those measured prior to intrusion at T4. No significant changes in PBF were observed in the control group over the course of the study. The only statistically significant difference between the UA and MI groups were at T1 and T2, at which time the MI group had lower PBF values (p< 0.001).ConclusionsDespite slight regressive changes in pulpal tissue observed over the short term, PBF values tended to return to initial levels within three weeks, indicating that changes observed in PBF with the UA and MI intrusion methods are reversible. Although the changes in PBF could not be directly related to the method of intrusion employed, in general, a more severe drop in PBF was observed in the MI group during the first three days of intrusion.

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

To measure pulp blood flow rates of clinically normal maxillary anterior teeth of healthy adults using ultrasound Doppler flowmetry (UDF). A total of 359 anterior teeth from 63 patients (mean age, 29.8 years; range, 22-52 years; 26 females and 36 males) were included. The data were collected according to tooth type (three groups: central incisors, lateral incisors and canines). An MM-D-K (Minimax, Moscow, Russia) ultrasound Doppler imaging instrument was used to measure pulp blood flow. Differences between the tooth types were analysed with one-way anova and a Bonferroni correction at the 95% confidence level. The mean average linear velocities during the systolic period (Vams) of the central incisors, lateral incisors and canines were 0.58, 0.58 and 0.52 cm s(-1) , respectively. There were no significant differences in the mean Vams between the tooth types (P > 0.05). Within the limitations of this study, the pulp blood velocities of clinically normal, maxillary anterior teeth of healthy adults were between 0.5 and 0.6 cm s(-1) . There were no significant differences in mean blood flow rates between maxillary central incisors, lateral incisors and canines.

Changes in maxillary molar pulp blood flow during orthodontic intrusion

Abstract Introduction/Objective: The aim of this prospective study was to evaluate the effects of maxillary first molar intrusion on pulpal blood flow (PBF) in humans as recorded by laser Doppler flowmetry (LDF). Materials and methods: Maxillary first molars of 16 participants were divided into two groups. In the study group, 20 teeth in 10 participants were subjected to an intrusive force of 100 g delivered from mini-implants for 6 months. A control group of 6 subjects (12 teeth) received no orthodontic treatment. LDF measurements were recorded at baseline and at 3 days, 3 weeks, 3 months and 6 months during intrusion. Data was analysed using the Wilcoxon Signed Rank and Mann-Whitney U tests, with a level of p < 0.05 considered statistically significant. Results: No significant changes in PBF perfusion units (PU) were observed in the control group over the course of the study. However, PBF in the study group was significantly higher at T0 (8.7 ± 0.9 PU) when compared with T1 (6.1 ± 0.6 PU, p < 0.001) and T2 (6.0 ± 0.6 PU, p < 0.001). PBF did not vary significantly between T1 and T2 (p = 0.073) or between T3 and T4 (p = 0.262). Moreover, PBF at the end of the study (T4) was similar to baseline PBF values for both groups (study group: p = 0.687; control group: p = 0.525). Conclusions: Despite significant short-term regressive changes in pulpal tissue during continuous molar intrusion with mini-implants and an applied force of 100 g, blood vessel function was maintained throughout intrusion, as indicated by LDF measurements of PBF, which tended to return to baseline values by the end of the observation period. These results highlight the changes that can occur in molar vascularity, especially during six months of intrusion.

Characterization of blood flow rate in dental pulp by speckle patterns of backscattered light from an in vivo tooth.

Experimental data on the hemodynamics of dental pulp at different stages of caries treatment are given. Observations of speckle patterns in backscattered laser light are used as a measurement method to qualitatively characterize changes in blood flow rate through the dental pulp. The measurements were made by the author-designed experimental setup. Theoretical estimations showed that stationary reflected light from an in vivo tooth contains a negligibly small information body on changes in the pulpal blood flow due to the shadowing of the pulp by optically thick enamel and dentin. Therefore, the temporal variations in the speckle patterns are the only possible way that can provide monitoring of blood conditions in the pulp by using backscattered light. Various statistical characteristics of the random reflected light fields are studied as indicators of blood flow rate changes. There were selected five statistical parameters of backscattered speckle images that give self-consistent data on these changes. The parameters include four combinations of integrals of the Fourier transforms of the observed temporal variations as well as the speckle image contrast. The selected parameters are shown to qualitatively agree with general considerations on the effects of reduced or increased blood flow rates on the selected integral quantities.

Changes in dental pulp blood flow of different maxillary tooth types after Le Fort I osteotomy.

This study examined the effects of Le Fort I (LF-I) osteotomy on pulpal blood flow (PBF) in maxillary teeth during a 12-month postsurgical period. A laser Doppler flowmeter was used to measure PBF in maxillary incisors, canines, and first premolars of 14 patients undergoing LF-I osteotomy (study group), 7 patients undergoing mandibular osteotomy (surgical control group), and 7 nonsurgical controls. The PBF was measured at baseline (preoperatively) and at 1 week and 1, 3, 6, and 12 months postoperatively and at similar intervals in nonsurgical control subjects. Data were evaluated using Kruskal-Wallis and post hoc Mann-Whitney tests. Changes in PBF over time for each tooth type were evaluated using the Wilcoxon signed-rank test. The level of significance was set at P < 0.05. Study findings showed that baseline PBF values did not differ significantly between groups. Maxillary PBF in the control group did not vary over time; however, an initial decrease in PBF was observed in all tooth types immediately after surgery in the study group. A gradual increase to near-preoperative levels was then observed during a 12-month healing period. Although dramatic reductions in maxillary perfusion of the first premolar and canine pulps were observed at 1 week and 1 month after LF-I osteotomy when compared with baseline (P < 0.001), PBF significantly recovered over time. Moreover, hyperemia was observed in lateral incisors 3 months postoperatively, demonstrating a tooth type-specific effect of LF-I osteotomy on PBF.

Laser light passage through restored and carious posterior teeth.

Laser Doppler flowmetry (LDF) has been used to investigate pulpal blood flow as a means of pulp vitality testing. Transmission of laser light from the tooth surface to the pulp space may be influenced by caries and restorations. One hundred and twenty-two first and second molars that had caries into dentine, restorations or significant loss of coronal tissue were sectioned in half axio-bucco-lingually. The two sections were illuminated with a laser from their buccal and lingual aspects 2 mm coronal to the amelocemental junction. Light reaching the pulp space was recorded. Buccal and lingual illumination sites were equally effective for 67 teeth (55%). Buccal sites alone were effective for 35 teeth (29%), despite over one-third of these surfaces being restored or featuring enamel or dentine caries. A lingual position alone was effective for 20 teeth (16%). Caries affected light transmission, but for over half the teeth, the pulp could be illuminated from all four probe positions. No effect was found when the influence of mesial and distal restorations on transmission into the corresponding tooth section was examined. The pulp spaces of most (84%) restored, and carious posterior teeth could be illuminated by laser light from their buccal aspect and these teeth could potentially be vitality tested using LDF.

Changes in maxillary incisor dental pulp blood flow during intrusion by mini-implants

Aim. The aim of this clinical study was to identify changes in pulpal blood flow (PBF) in human central incisors resulting from short- and long-term intrusive orthodontic forces from mini-implants. Materials and methods. A total of 40 sound upper central and lateral incisors in 20 patients scheduled for intrusion for orthodontic reasons were divided into two groups. From each group, 20 teeth were subjected to intrusive force from mini-implants (Group 1 = Light Force: 40 g; Group 2 = Heavy Force: 120 g), whereas the remaining 20 contralateral teeth were not subjected to forces from mini-implants and served as controls. Laser-Doppler flowmetry (LDF) measurements were recorded at baseline and at 3 days and 3 weeks following intrusion. Results. PBF decreased significantly at 3 days (Light Force Group: 7.72 ± 0.50; Heavy Force Group: 7.72 ± 0.52) and then increased towards baseline at 3 weeks (Light Force Group: 10.37 ± 0.58; Heavy Force Group: 10.31 ± 0.45) following intrusion. Conclusions. In other words, despite slight regressive changes in pulpal tissue in the short-term, PBF improved after 3 weeks following intrusion by mini-implants, indicating that the changes observed in PBF is reversible, even following radical incisor intrusion.

Iloprost Up-regulates Vascular Endothelial Growth Factor Expression in Human Dental Pulp Cells In Vitro and Enhances Pulpal Blood Flow In Vivo

IntroductionProstacyclin (PGI2) is a biomolecule capable of enhancing angiogenesis and cellular proliferation. MethodsWe investigated the influence of a PGI2 analogue (iloprost) on dental pulp revascularization in vitro and in vivo by using human dental pulp cells (HDPCs) and a rat tooth injury model, respectively. Iloprost stimulated the human dental pulp cell mRNA expression of vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), and platelet-derived growth factor (PDGF) in a significant dose-dependent manner. This mRNA up-regulation was significantly inhibited by pretreatment with a PGI2 receptor antagonist and forskolin (a protein kinase A activator). In contrast, a protein kinase A inhibitor significantly enhanced the iloprost-induced mRNA expression of VEGF, FGF-2, and PDGF. Pretreatment with a fibroblast growth factor receptor inhibitor attenuated the VEGF, FGF-2, and PDGF mRNA expression, indicating opposing regulatory mechanisms. ResultsThe effect of iloprost on the dental pulp was investigated in vivo by using a rat molar pulp injury model. The iloprost-treated group exhibited a significant increase in pulpal blood flow at 72 hours compared with control. ConclusionsThe present study indicates that iloprost may be a candidate agent to promote neovascularization in dental pulp tissue, suggesting the potential clinical use of iloprost in vital pulp therapy.

LEDを利用した透過型光電脈波法（TLP）の歯髄診断への応用

Transmitted-light plethysmography (TLP) is an optical technique to detect circulatory changes in pulp tissue. It has been reported as overcoming the disadvantages of electrical pulp testing in terms of objectivity and invasiveness. In a previous study, we reported the applicability of the TLP system with a 525 nm light-emitting diode (LED) to traumatized young permanent and deciduous teeth. The system works by detecting the pulsation intensity of light transmitted through a tooth and visualizing the pulpal blood flow synchronized with the heartbeat. During the clinical follow-up, we found that TLP pulse amplitudes and pulse shape characteristics change gradually due to the pathological condition. However, the origins of tooth plethysmograms were not fully understood because of the structural specificity of teeth. In this study, multiwavelength optical plethysmography was used to examine the light transmission properties of teeth to clarify the effects of physiological parameters such as the blood volume and SO2 on the pulsation of TLP pulse waves. The results indicated that the optical process in teeth mainly depended on the blood cell concentration (Hctp), light attenuation by the hard tissues, and the light source wavelength. Clinically, it was assumed that the changes in blood vessel density, pulpal blood volume, and pulp chamber size associated with subjects' ages or pathological conditions might affect TLP pulse waves. We also demonstrated the applicability of pulse oximetry to dental pulp using an in vitro blood circulation model. The LEDs with 470 nm and 590 nm wavelengths showed high sensitivity to the blood SO2 level. R values calculated from pulsatile/nonpulsatile component ratios of two different wavelengths were significantly correlated with the pulpal SO2, indicating the possibility of pulpal blood SO2 measurement. The present results indicate that TLP pulse waves potentially provide additional information to diagnose the circulatory status of the pulp in relation to pathological conditions of the dental pulp.

オトガイ部におけるNd:YAGレーザー照射によるヒト歯髄血流量および歯髄温度感覚閾値への影響

オトガイ部におけるNd:YAGレーザー照射によるヒト歯髄血流量および歯髄温度感覚閾値への影響

고양이 치수에서 열 자극으로 유도된 신경병증 염증에서 치수 혈류량 변화

본 연구는 열 자극으로 유도된 신경성 염증 상태에서 혈류량의 변화와 histamine의 치수혈류 조절에 관해 유기적 관계를 연구함으로써 치수혈류 조절기전을 밝히고자 하였다. 연구방법은 열 마리의 고양이를 전신마취 하에 사용되었으며, 치수혈류의 변화는 레이저 도플러 측정계(Periflux 4001, Stockholm, Sweden)을 사용하여 측정 하였다. 레이저 도플러 측정하는 프로브는 하악 견치의 치면에 위치하였다. 열 자극은 입력/출력 장치와 열 자극 제어 스크립트 파일을 사용하여 치아에 적용하였다. 열(<TEX>$40-65^{\circ}C$</TEX>)에 따라 치수 혈류량이 증가를 확인하였으며, <TEX>$55^{\circ}C$</TEX>에서 가장 큰 변화가 나타났다. 열 자극의 변화가 없는 <TEX>$45^{\circ}C$</TEX>에서 Histamine(<TEX>$5{\mu}g/kg/1ml$</TEX>)를 치아와 가까운 설 동맥으로 주입 시 열 자극만 처치한 그룹보다 현저한 증가가 나타났다. 본 연구는 열적 자극에 의해 발생된 신경성 염증상태에서 치수혈류 변화와 이에 히스타민의 기능적으로 관여함을 나타내주며, 치아 염증 상태의 기전을 밝힐 수 있는 가능성을 보여준다. This study examined the involvement of histamine in heat-induced changes in pulpal blood flow(PBF) to determine the mechanism of neurogenic inflammation in feline dental pulp. The experiments were carried out in 10 felines anesthetized with sodium pentobartial and histamine injected into the dental pulp through the external carotid artery. The change in the pulpal PBF was measured using a laser Doppler flowmeter(Periflux 4001, Stockholm, Sweden). The probe of laser Doppler flowmeter was placed on the buccal surface of the ipsilateral canine teeth. Heat was applied to the tooth using a heat stimulator controlled script file with an input/output device. The application of heat (<TEX>$40-65^{\circ}C$</TEX>) induced a significant increase in PBF. The application of histamine(<TEX>$5{\mu}g/kg/1ml$</TEX>) followed by heat(<TEX>$45^{\circ}C$</TEX>) resulted in an increase in PBF. Therefore, the results of the present study showed that heat and histamine are capable of vasoconstriction caused by neurogenic inflammation in feline dental pulp. In addition, neurogenic inflammation plays an active role in modulating the microcirculation of the dental pulp.

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

ObjectiveHuman pulpal blood flow (PBF) signals as measured by laser Doppler flowmeter (LDF) decrease with age. Although this decrease is considered to be due in part to slow blood flow, information regarding this velocity in humans has been lacking. The aims of the present study were to estimate the blood flow velocity in human dental pulp and to evaluate the validity of LDF modified for the measurement of slow blood flow. DesignMean blood flow velocities at the upper central incisor, gingiva, fingertip and forearm of 28 volunteers (mean age: 38.6 years old) were estimated using LDF with a frequency analyser. Blood flow signals at these measurement areas were recorded using two different LDFs: (a) one with a standard blood flow range; and (b) one modified for low blood flow velocity. ResultsThe frequency range of the Doppler shift measured at the teeth with an opaque rubber dam was the narrowest (median: 4.3kHz) among all of the measurement areas. The estimated mean blood flow velocity was the slowest at the teeth with a dam (median: 0.18mm/s). LDF for low blood flow velocity detected larger and clearer pulsatile blood flow signals from the teeth with dams than did standard LDF. ConclusionsThe present results indicate 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.

In vitro optical detection of simulated blood pulse in a human tooth pulp model

Noninvasive optical methods such as photoplethysmography, established for blood pulse detection in organs, have been proposed for vitality testing of human dental pulp. However, no information is available on the mechanism of action in a closed pulp chamber and on the impairing influence of other than pulpal blood flow sources. Therefore, the aim of the present in vitro study was to develop a device for the optical detection of pulpal blood pulse and to investigate the influence of different parameters (including gingival blood flow [GBF] simulation) on the derived signals. Air, Millipore water, human erythrocyte suspensions (HES), non-particulate hemoglobin suspension (NPHS), and lysed hemoglobin suspension (LHES) were pulsed through a flexible (silicone) or a rigid (glass) tube placed within an extracted human molar in a tooth-gingiva model. HES was additionally pulsed through a rigid tube around the tooth, simulating GBF alone or combined with the flow through the tooth by two separate peristaltic pumps. Light from high-power light-emitting diodes (625 nm (red) and 940 nm (infrared [IR]); Golden Dragon, Osram, Germany) was introduced to the coronal/buccal part of the tooth, and the signal amplitude [∆U, in volts] of transmitted light was detected by a sensor at the opposite side of the tooth. Signal processing was carried out by means of a newly developed blood pulse detector. Finally, experiments were repeated with the application of rubber dam (blue, purple, pink, and black), aluminum foil, and black antistatic plastic foil. Nonparametric statistical analysis was applied (n = 5; α = 0.05). Signals were obtained for HES and LHES, but not with air, Millipore water, or NPHS. Using a flexible tube, signals for HES were higher for IR compared to red light, whereas for the rigid tube, the signals were significantly higher for red light than for IR. In general, significantly less signal amplitude was recorded for HES with the rigid glass tube than with the flexible tube, but it was still enough to be detected. ∆U from gingiva compared to tooth was significantly lower for red light and higher for IR. Shielding the gingiva was effective for 940 nm light and negligible for 625 nm light. Pulpal blood pulse can be optically detected in a rigid environment such as a pulp chamber, but GBF may interfere with the signal and the shielding effect of the rubber dam depends on the light wavelength used. The optically based recording of blood pulse may be a suitable method for pulp vitality testing, if improvements in the differentiation between different sources of blood pulse are possible.

Levobupivacaine vs. bupivacaine for third molar surgery: quality of anaesthesia, postoperative analgesia and local vascular effects

The main purpose of this prospective, double-blind, randomized study was to evaluate anaesthetic parameters, postoperative analgesia and vasoactive properties of levobupivacaine and bupivacaine for lower third molar surgery. Sixty patients (ASA I) were scheduled for lower third molar surgery under inferior alveolar nerve block, lingual nerve block and buccal nerve block (mandibular nerve blocks) obtained with 3 ml of 0.5 % levobupivacaine and 3 ml of 0.5 % bupivacaine. Success rate, onset and duration of three nerve bocks were evaluated by electrical pulp testing, pinprick testing and signs of soft tissue anaesthesia (patient-reported numbness). Intensity of intraoperative anaesthesia and postoperative analgesia were measured with visual analogue scale (VAS) and numeric rating scale (NRS). The time of first postoperative pain reported and analgesic consumption were also recorded. The laser Doppler flowmetry was used for the measurement of the first premolar pulpal blood flow. There were no differences between levobupivacaine and bupivacaine regarding the success rate, onset and duration of mandibular nerve blocks as well as intensity of postoperative analgesia and analgesic consumption. Intensity of intraoperative anaesthesia and duration of postoperative analgesia were significantly higher in the levobupivacaine than in the bupivacaine group. Both anaesthetics showed similar biphasic vasoactive effect. Levobupivacaine 0.5 % achieved superiority over bupivacaine 0.5 % in the intensity of intraoperative anaesthesia and duration of postoperative analgesia for lower third molar surgery under the mandibular nerve blocks. It seems that the plain levobupivacaine (0.5 %) could be an effective alternative to plain bupivacaine (0.5 %) in those dental procedures which require profound bone and soft tissue anaesthesia.

Effects of enamel and dentine thickness on laser doppler blood-flow signals recorded from the underlying pulp cavity in human teeth in vitro

ObjectiveTo determine the effect of enamel and dentine thickness on laser Doppler blood-flow (LDF) signals recorded from dental pulp. DesignObservations were made on 18 human premolars that had been extracted from young patients during orthodontic treatment. The apical 2/3 of the root was cut off and the remaining pulp removed. Blood flow signals were recorded from the buccal surface of the crown with a laser Doppler flow metre while dilute blood was pumped at 10ml/min. through a cannula inserted into the pulp cavity. Recordings were made from the enamel surface and at 0.5mm steps through the enamel and dentine. ResultsThe blood flow signal increased significantly as the cavity depth increased and at 2.0mm, the median flux signal was more than ten times greater than that obtained on the enamel surface. The backscattered light intensity did not change with cavity depth. ConclusionWhen recording pulpal blood flow from a human tooth with a laser Doppler flow metre, a substantially better signal-to-noise ratio should be obtained by placing the probe on dentine in the floor of a cavity than on the enamel surface.

Effect of tooth isolation on laser Doppler readings

To measure differences between single (STI) and multiple teeth isolation (MTI), pulpal blood flow (PBF) was assessed using laser Doppler flowmetry (LDF). Pulpal blood flow of twenty maxillary incisors with no restorations or abnormal responses to sensitivity tests in healthy patients between 24 and 42years of age was measured in perfusion units (PU). STI (isolation of only the tooth undergoing blood flow assessment) and MTI (isolation including the maxillary right to the maxillary left canine) recordings were taken with regular blood flow (RBF) and with local infiltration (LI) with vasoconstrictor. anova and Tukey HSD tests were used for statistical analysis. The mean PBF with regular blood flow conditions was significantly different between single tooth isolation [5.53 PU (SD±2.98)] and multiple tooth isolation [2.85 PU (SD±2.13)] (P<0.01). When local anaesthesia was administered (LI), the PBF was significantly different between single tooth isolation [2.95 PU (SD±2.48)] and multiple tooth isolation [1.32 PU (SD±0.70)] (P<0.05). Significant differences in PBF also existed between single tooth isolation under regular blood flow conditions and with local anaesthesia (P<0.01), between single tooth isolation under regular blood flow conditions and multiple tooth isolation with local anaesthesia (P<0.01), and between multiple tooth isolation under regular blood flow conditions and with local anaesthesia (P<0.05). Pulpal blood flow measurements could be obtained with multiple teeth isolation and single tooth isolation. Multiple teeth isolation blocked signal contamination better. Single tooth isolation provided significantly different readings for regular blood flow and LI conditions and may therefore provide an option for pulpal blood flow assessment with LDF.

The Postural Autonomic Regulation of Pulpal Blood Flow

Evidence suggests that postural changes in systemic blood pressure may significantly affect blood flow in the dental pulp. This in vivo study examined the responses of pulpal perfusion, systemic blood pressure, and heart rate to postural changes in humans. The experiments were done on 21 premolars in 16 participants aged 20-31 yrs. Pulpal blood flow recordings were measured by means of a laser Doppler Flowmeter. A blood pressure monitor was used to record blood pressure and heart rate. All measurements were simultaneously recorded for 1 min, 5 min after participants made postural changes. Changing from supine to standing caused a significant reduction in pulpal perfusion, while heart rate and diastolic blood pressure increased significantly. A significant non-linear relationship was found between percentage changes in pulpal perfusion and heart rate resulting from standing up. We speculate that when patients arise from the supine position, the shift in venous blood to the legs transiently (2-10 sec) lowers venous return and cardiac output, causing less inhibition of the vasomotor center, which, in turn, results in increased heart rate and blood pressure, but a decrease in pulpal blood flow. These results suggest that pulpal blood flow is affected by postural change, presumably via the autonomic nervous system.

Glutamate control of pulpal blood flow in the incisor dental pulp of the rat

Glutamate is present in primary sensory afferents innervating the dental pulp and is known to exert vasoactive effects. The aims of this study were (i) to assess pulpal blood flow (PBF) after glutamate infusion in the dental pulp and (ii) to observe the distribution of glutamatergic nerve fibers expressing the vesicular transporters of glutamate (VGluT). The PBF was monitored with laser Doppler flowmetry before and after glutamate (0.5 M) infusion in the dental pulp vs. saline infusion. Immunochemistry for VGluT1, 2, and 3 was performed in addition to immunochemistry for the vascular and neuronal markers smooth-muscle actin (SMA), isolectin B4 (IB4), and calcitonin gene-related peptide (CGRP). Glutamate infusion resulted in a PBF increase that lasted for 60 s. Positive immunolabeling was observed for the three glutamate transporters, but was more pronounced for VGluT3. Moreover, VGluT3 immunoreactivity was observed within nerve fibers entering the dental pulp and terminating at the periphery and at the vicinity of odontoblasts. Also, VGluT3 was colocalized with the vascular marker SMA, and in some nerve fibers with IB4, but not with CGRP. This study provides support for a control of dental pulp microcirculation by neurons expressing VGluT3.

치수혈류 측정을 위한 광 프로브 개발

To diagnose dental pulp vitality, electric pulp tester has been widely used, which is a method to test condition of nerve. However, especially in the case of patients with trauma, nerve desensitization could temporarily occur even though nerve might be recovered by blood flow within the pulp later, which implies that blood flow in dental pulp is also an important factor for diagnosing vitality. This paper described the development of a probe that relatively measured blood flow in dental pulp using photoplethysmography (PPG). The probe emits four different wavelength light sources including three visible and an infrared light. We tested which light source detect sensitively the blood flow in dental pulp. As a result, green light had the largest peak to peak voltage and the power spectrum among different wavelengths.

Dental Pulp Blood Flow and Its Oscillations in Women with Different Estrogen Status

IntroductionThe skin microcirculation is significantly affected by serum estrogen levels. The objective of this study was to investigate the effects of estrogen serum level changes associated with the menstrual cycle and postmenopause on dental pulp blood flow (PBF) as well as its dynamics. MethodsYoung women at the menstrual phase (low serum estrogen levels) and in the mid-cycle phase of the menstrual cycle (high serum estrogen levels) and postmenopausal women were enrolled in the study. PBF and its oscillations were measured by laser Doppler flowmetry and analyzed by using wavelet transform. Serum levels of estradiol-17β were measured by immunoassay. ResultsPBFs of young women in the menstrual phase and postmenopausal women were mutually similar and significantly lower than those of young women in the mid-cycle period. With respect to the mid-cycle phase, relative amplitude and power were significantly increased in the interval 0.0095–0.02 Hz and decreased in the intervals 0.02–0.06 and 0.06–0.2 Hz in the menstrual phase. A significant decrease in 0.0095–0.02 Hz and increase in 0.02–0.06, 0.06–0.2, 0.2–0.6, and 0.6–1.6 Hz intervals were observed in postmenopause. ConclusionsThe study has shown that the menstrual phase of the menstrual cycle and postmenopause have similar PBF decrease, but PBF oscillations are differently affected in the mid-cycle phase.