Pulpal blood flow changes and pain scores related to using Superelastic 0. 018-inch Nickel Titanium as the first orthodontic alignment archwire: a prospective clinical trial

Abstract Background Optimal orthodontic force results in maximum rate of tooth movement without tissue damage. Even though starting orthodontic treatment with a thicker archwire may shorten treatment duration, the evidence on the effect of using 0.018-inch NiTi as the first alignment archwire on pulpal blood flow (PBF) status is still scarce. Objectives to record PBF changes and pain scores associated with using 0.018-inch NiTi as the first alignment archwire during fixed orthodontic treatment. Methodology Patients were selected from subjects attending postgraduate orthodontic teaching clinics at Jordan University of Science and Technology. In total, forty healthy patients who exhibited mild lower arch crowding were included. A split-mouth trial design was used. Each patient received two archwire sizes at one time joined in the midline by crimpable hook and applied in the lower arch. Patients were assigned into one of two groups based on archwire sizes used. Group 1: 0.014-inch and 0.018-inch NiTi (Six males, 14 females aged 19.4±1.33 years) and Group 2: 0.016-inch and 0.018-inch NiTi (Seven males, 13 females aged 19.6±1.45 years). The archwire size group was randomly allocated with a 1:1 allocation ratio. A Laser Doppler Flowmeter was used to measure PBF at different time intervals (T0-T5). Pain scores were recorded using a visual analogue scale (VAS). A repeated measures ANOVA and a post-hoc Bonferroni comparison tests were conducted to examine differences at the different time points before and during orthodontic alignment. Results For all studied archwire sizes, PBF decreased 20 minutes after their placement. Most PBF changes occurred within 24hours and continued to decrease until 72 hours after archwire placement where the maximum reduction was reached. Eventually, normal values were reverted within 1 month. PBF changes were similar between all alignment - groups. Conclusions Initial orthodontic alignment with 0.018-inch NiTi does not cause irreversible changes to pulpal vasculature or produces higher pain scores.

Dynamic changes of blood flow in frontal cortex of diabetic rats / 中国药理学通报

Aim To investigate the changes of cerebral blood flow in rats with diabetic cognitive impairment by two-channel laser Doppler flowmeter,and to explore the changes of cerebral blood flow in diabetic rats with cognitive impairment and to investigate the changes of cerebral blood flow lesions and the central nervous system function changes in the study to provide pre-foundation.Methods Thirty-four male Wistar rats were randomly divided into two groups:blank control group and diabetic model group.The rats in the model group were treated with streptozotocin (STZ) 60 mg · kg-1,and the glucose oxidase method was used to determine fasting blood glucose ≥ 16.7 mmol · L-1 as the standard of the model.The Water maze was used to observe the behavioral changes of diabetic rats.Dual-channel laser doppler flowmeter was used to measure cerebral blood flow in diabetic rats with cognitive impairment.Another 34 male Wistar rats were randomly divided into two groups:control group and diabetic model group.Dual-channel laser doppler flowmeter was used to dynamically monitor cerebral blood flow on 0 d,7 d,14 d,21 d,28 d,35 d,42 d,56 d and 75 d.ELISA was applied to detect the concentration of iNOS,eNOS and ET-1 in cerebrospinal fluid.Results Morris water maze test showed that the time of the platform (latency) was significantly longer than that of the blank control group(P ＜0.05).The cerebral blood flow/100 g of diabetic rats with cognitive impairment was significantly lower than that of the control group (P ＜ O.05),and the blood flow in the model group was significantly lower than that in the model group (P ＜ 0.05).Compared with control group,iNOS and eNOS concentrations were markedly elevated,while ET-1 concentration obviously decreased.Conclusions The decrease of blood flow in the frontal cortex of diabetic rats with cognitive impairment suggests that it may be one of the factors leading to cognitive impairment in diabetes mellitus.Cerebral blood flow reduction occurs in the early stages of diabetes,followed by no significant deterioration.Cerebral blood flow may not be related to the changes of NO and ET-1,but the trend of cerebral blood flow may be related to the change of the two.

Measurement of Vaginal Blood Flow using Laser Doppler Flowmetry in Rabbit / 대한남성과학회지

PURPOSE: One of the problems using laser doppler flowmetry is variability in the measurements. The purposes of this study were to investigate the regional differences of vaginal blood flow using laser Doppler flowmetry and to suggest a method to enhance the accuracy of measurement. MATERIALS AND METHODS: In New Zealand White female rabbits(3.0~3.5 kg, n=10), vaginal blood flow was measured by laser doppler flowmetry using a surface probe. Flow was measured at the anterior, posterior, left, and right side of vaginal wall in each vaginal introitus and proximal 2 cm of the vaginal wall. Each site was measured 3 times separately. The data were analyzed using two-way ANOVA and repeated measures ANOVA. RESULTS: Regional vaginal blood flows(ml/min/100 gm tissue) at the anterior, posterior, left, and right vaginal wall were 19.7+/-8.7, 19.6+/-7.3, 19.3+/-7.8, 18.8+/-7.2 at vaginal introitus and 27.3+/-8.8, 18.9+/-7.5, 22.6+/-7.1, 20.8+/-5.7 at the proximal 2 cm of vaginal introitus, respectively. Differences were not statistically significant(p> 0.05), as there was a wide range of variation. CONCLUSIONS: Vaginal blood flow did not show any regional differences in the distal part of the rabbit vagina. Repeated measurements may decrease the variation of vaginal blood flow by laser Doppler flowmetry.

The Predictive Value of Laser Doppler for Flap Survival

If we could predict the necrosis of the flap caused by reperfusion injury, we can minimize the necrosis of the flap by taking appropriate action before necrosis begins. In this study, we examined whether we can predict the survival of flap under reperfusion injury or not, by measuring laser doppler flow meter values. We divided the group into the control and experimental groups corresponding to 6, 8, 9, 10, and 12hours after reperfusion(hours after ligation of auricular central artery). In each group, we examined necrotic change, perfusion unit (PU), serum superoxide dismutase (SOD), glutathione peroxidase, angiography and pathologic findings. No necrosis was observed in the 6 and 8 hours group but 8, 18, 20 hours after ligation, necrosis was observed, Also in each of 9, 10 and 12 hours group (each group consisted of 20 flaps), necrosis were noted. According to the above data, the critical time of necrosis in the auricular skin flap model lies between about 8 to 9 hours. Comparing the PU between the necrosis and non-necrosis groups, the former group showed a mean 39.57 PU increase after 60 min of reperfusion, and the latter group showed a mean increase of 21.21 PU. We can conclude that better flow can dilute oxygen free radical into systemic circulation, and this means less injuries are caused on vessels. Our study implies that if blood flow increase is less than 30 PU, intensive care is needed to save the flap. Additionally, we found significant decrease of serum SOD and glutathione peroxidase in the necrotic group. Therefore, monitoring these serum markers will be helpful in predicting reperfusion injury and supplementing these enzymes could be helpful to save the flap. The laser doppler flow meter is thought to be helpful in clinical circumstances for evaluating the circulation of the flap after the operation. However, more accumulation of clinical studies should be necessary establishing useful clinical data.

Regulation of pulpal microcirculation by calcitonin gene-related peptide / 대한치과보존학회지

The purpose of this study was to investigate the function of calcitonin gene-related peptide (CGRP) in regulatory mechanism of pulpal microcirculation with the aim of elucidating neurogenic inflammation. Experiments were performed on twelve cats under general anesthesia. CGRP was administered through the femoral vein to see the systemic influence and through the external carotid artery to see the local effect. Sympathetic nerve to the dental pulp was stimulated electrically and pulpal blood flow (PBF) was measured with a laser Doppler flowmeter on the canine teeth to the drug administration. The paired variables of control and experimental data were compared by paired t-test and differences with p < 0.05 were considered statistically significant. Systemic administration of CGRP (0.3 microg/kg) exerted decreases in systemic blood pressure and caused changes in PBF with an initial increase followed by decrease and a more marked second increase and decrease. Close intra-arterial (i.a.) injection of CGRP (0.03 microg/kg) resulted in slight PBF increase. The effect of CGRP resulted in no significant increase in PBF in the presence of CGRP8-37. The electrical stimulation of the sympathetic nerve alone resulted in PBF decreases. The i.a. administration of CGRP following the electrical stimulation of the sympathetic nerve compensated the decreased PBF. Therefore, CGRP effectively blocked the sympathetic nerve stimulation-induced PBF decrease. Results of the present study have provided evidences that even though the local vasodilatory function of CGRP are weak, CGRP is effectively involved in blocking the vasoconstriction caused by sympathetic nerve stimulation in the feline dental pulp.

The influence of epinephrine concentration in local anesthetics on pulpal and gingival blood flows / 대한치과보존학회지

No abstract available.

Observation of the Effects of Sodium Sulfate Bathing on Digital Blood Flow by Laser Doppler Flowmeter / 日本温泉気候物理医学会雑誌

Change of digital blood flow during sodium sulfate bathing was studied using laser Doppler flowmeter. The 10 subjects were divided into two groups; group A and group B. In group A, digital bloood flow was measured in the following order; in the air→plain water→air→sodium sulfate bathing→air, while in group B, in the air→sodium sulfate bathing→air→plain water→air. The temperature of the water was kept at 40°C using thermostat. The 10g of sodium sulfate was dissolved in the 10L of water. In group A, the digital blood flow was 60.2±16.7 in the plain water and 70.6±35.0 in the sodium sulfate water, while in group B, 30.4±12.7 in the sodium sulfate water and 7.36±10.06 in the plain water (P<0.05).<br>Above results suggest an increase in digital blood flow in the sodium sulfate bathing, although there were great differences by individual and by the order of immersion.

Measurement of Vascular Corticosteroid Effect in Human using Laser Doppler Flowmeter / 대한피부과학회지

Vasoconstrictive effect of several topicsl corticosteroids was measured using laser Doppler flowmeter. Hydrophilic ointment base, 1% hydrocortisone cream, 0.1% clocortolone pivalate cream, and 0.25% desoxymethasone cream were applied on both forearms of 20 volunteers. To augment the vasoconstrictive effect of the corticosteroids, We had cut off the blood flow to forearms for 4 minutes by tourniquet. The reactive hyperemia was measured by laser Doppler flowmeter and the ares under the curve were calculated by digitizer aided by a computer. The mean areas of esch drugs were in the following order : hydrophilic ointment base, 0.1% clocortolone pivalate cream, 1% hydrocortisone crearn and 0.25% desoxymethasone cream. However, the standard deviations were too large for the difference to be statistically significant. We concluded that laser Doppler flowmeter is not suitable for the measurement of vasoconstrictive effect of corticosteroid.