• Restorative Dentistry and Endodontics
• /
• v.21 no.1
• /
• pp.375-384
• /
• 1996

The purpose of this study was to investigate the functional involvement of sympathetic nerve in the control of the microcirculation in the dental pulp with the aim of elucidation of the involvement of neuropeptides and sympathetic nerve in neurogenic inflammation. Experiments were done on the 7 cats anesthetised with sodium pentobarbital, and sympathetic nerve to the' dental pulp was stimulated electrically (10 Hz, 4 V, 1.5 ms, 3.5 mins). Ana-adrenoceptor antagonist phentolamine and a neuropeptide Y antagonist D-myo-inositol-1,2,6-trisphosphate (PP56) were injected close intra-arterially into the dental pulp without changing the systemic blood pressure. The probe of laser Doppler flowmeter was placed on the buccal surface of ipsilateral canine teeth to the stimulation, and pulpal blood flow was measured. Stimulation of the sympathetic nerve decreased pulpal blood flow by $55.24{\pm}7.74\;%$ (mean${\pm}$SEM, n = 13). Stimulation of the sympathetic nerve following the injection of the ${\alpha}$-adrenoceptor antagonist phentolamine ($0.1{\mu}g$/kg) caused decrease of pulpal blood flow by $14.35{\pm}3.43%$ (mean${\pm}$SEM, n=5). Phentolamine attenuated the sympathetic nerve-induced pulpal blood flow decrease by $74.02{\pm}9.32%$ (mean${\pm}$SEM) Stimulation of the sympathetic nerve following the injection of the neuropeptide Y antagonist PP56 (2.3 mg/kg) caused decrease of pulpal blood flow by $30.64{\pm}7.92%$ (mean${\pm}$SEM, n=6). PP56 attenuated the sympathetic nerve-induced pulpal blood flow decrease by $44.37{\pm}11.01%$ (mean${\pm}$SEM). These data provide evidences of the co-contribution of nerepinephrine and neuropeptide Y on the sympathetic nerve-induced vasoconstriction in the feline dental pulp. In addition, they show functional evidences that sympathetic nerve plays an active role in controlling the microcirculation of the dental pulp.

• Restorative Dentistry and Endodontics
• /
• v.21 no.1
• /
• pp.366-374
• /
• 1996

The purpose of this study was to investigate whether D-myo-inositol-l,2,6-trisphosphate (PP56) can effectively antagonize vasoconstriction caused by neuropeptide Y in the dental pulp, and to understand involvement of neuropeptide Y in the regulation of microcirculation in the dental pulp with the aim of elucidating neurogenic inflammation. Experiments were performed on 7 cats anesthetised with sodium pentobarbital, and neuropeptide Y and a neuropeptide Y antagonist PP56 were injected close intra-arterially into the dental pulp. The probe of laser Doppler flowmeter was placed on the buccal surface of ipsilateral canine teeth to the drug administration and pulpal blood flow was measured. Intra-arterial injection of neuropeptide Y (1.3-$2.0\;{\mu}g$/kg) resulted in pulpal blood flow decrease of $37.73{\pm}5.73%$(mean${\pm}$SEM) (n=9). Intra-arterial injection of PP56(0.3 mg/kg) alone changed pulpal blood flow little by 1.03 % reduction. The effect of neuropeptide Y in the presence of PP56 resulted in significantly less decreases in pulpal blood flow ranging from $27.17{\pm}5.37$ to $16.63{\pm}3.48%$ from control as compared with neuropeptide Y alone(n = 13). In effect, PP56 attenuated pulpal blood flow caused by neuropeptide Y. Results of the present study have provided evidences that a non-peptide PP56 is capable of antagonizing vasoconstriction caused by neuropeptide Y in the feline dental pulp. In addition, they show functional evidences that neuropeptide Y plays an active role in modulating the microcirculation of the dental pulp.

• Restorative Dentistry and Endodontics
• /
• v.24 no.4
• /
• pp.560-569
• /
• 1999

Blood supply rather than nerve supply implies pulp vitality. To evaluate pulp vitality clinically, electric pulp test and thermal test which are based on sensory nerve response have been used in addition to many auxiliary data such as past dental history, visual inspection, radiographic examination, percussion, palpation and transillumination test. However, reactivity of the nerves to the stimulation is not synonymous with normalcy. Therefore measurement of pulpal blood flow using a laser Doppler flowmeter became a new trial to test the pulp vitality. The purpose of the present study was to evaluate normal pulpal blood flow level of maxillary teeth in adult to provide a guideline in determining the vitality of dental pulp. Pulpal blood flow was measured in maxillary central and lateral incisors, canines, first and second premolars and first molars of seventy nine adults of 22 - 30 years old using a laser Doppler flowmeter (PeriFlux 4001, Perimed Co., Stockholm, Sweden, 780 nm infrared laser, 1mW). For directly-made splints, silicone rubber impressions were taken directly from the mouth. For indirectly-made splints, alginate impressions were taken from the mouth and stone cast were made. After making depressions on the buccal surfaces of the cast teeth to indicate the hole positions, second impressions with vinyl polysyloxane putty were taken from the cast. Holes for the laser probes were made at the putty impressions 4mm above the gingival level. Laser probe (PF416 dental probe, 1.5mm) was inserted in the prepared hole and the splint was set in the mouth. After 10 minutes of patient relaxing, pulpal blood flow was recorded for 5 minutes on each tooth. The recorded flow was saved in the computer and calculated with a software 'Perisoft' version 5.1. Pulpal blood flow was also recorded in six teeth of five individuals with no response to electric pulp test and cold test, with periapical radiolucency, or with history of root canal treatment to compare with nonvital teeth. The difference between the mean flow values of each group of teeth were analyzed using one-way ANOVA and Duncan's Multiple Range test. The results were as follows: 1. The average pulpal blood flow values of all the tested teeth of each location were between 9 - 16 Perfusion Unit. Pulpal blood flow value was highest in maxillary lateral incisors, followed by first premolars, second premolars, canines, central incisors, and then first molars (p<0.01). 2. In six anterior teeth, indirectly-made splint group showed higher pulpal blood flow values than directly-made splint group (p<0.01). In posterior teeth, however, there was no significant flow value difference between directly-made splint group and indirectly-made splint one (p>0.05). 3. Teeth with vital pulps showed higher signal values than teeth with nonvital pulps (p<0.01), and the flow photographs showed heartbeat-synchronous fluctuations and vasomotions, while those were absent in non vital tooth.

• Proceedings of the KACD Conference
• /
• 2003.11a
• /
• pp.549-550
• /
• 2003

Pulpal inflammation is a kind of neurogenic inflammation and it shows vascular changes such as vasodilation and changes in vascular leakage. Various kinds of neuropeptides including substance P (SP) are known to be involved in the pulpal inflammation. The purpose of this study was to investigate the influence of NK1 receptor antagonists on the pulpal blood flow (PBF) when applied iontophoretically through the dentinal cavity of the teeth in order to understand whether iontophoretic ally applied NK1 receptor antagonists can control the pulpal inflammation.(omitted)

• Proceedings of the KACD Conference
• /
• 2003.11a
• /
• pp.596-596
• /
• 2003

The purpose of this study were to evaluate the effect of epinephrine-containing local anesthetics on pulpal blood flow (PBF) and to compare the change of pulpal blood flow after cavity preparation between in non-anesthetized teeth and in anesthetized ones in cats. Nine cats were initially anesthetized with intra-muscular injection of keramine(75mg/kg) and acepromazine(2.5mg/kg). Periapical radiographs of canine teeth were taken, followed by intra-venous injection of alpha-chloralose(40mg/kg) and urethane (500mg/kg) through the femoral vein for the general anesthesia.(중략)

• Restorative Dentistry and Endodontics
• /
• v.48 no.1
• /
• pp.9.1-9.11
• /
• 2023

Objectives: This study evaluated the effect of adjacent gingival blood flow on detection of pulpal blood flow (PBF) using ultrasound Doppler flowmetry (UDF) through animal study. Materials and Methods: The study included 36 right and left maxillary the third incisors and canines in 9 experimental dogs. The study included 2 main steps: In the first step, the pulse sound level (PSL) was recorded on the cervical part of each tooth without flap elevation (Group 1), with flap elevation (Group 2), and after it was repositioned in place (Group 3). In the second step, the PSL was recorded on the cervical part of each tooth (Group 4), after pulpotomy (Group 5), after partial pulp extirpation (Group 6), after complete extirpation (Group 7), and after canal filling (Group 8). In Groups 5-8, the study was performed with and without flap elevation in the left and right teeth, respectively. The PSL was graded as follows: 0, inaudible; 1, heard faintly; and 2, heard well. The difference between each group was analyzed using Friedman's test with Wilcoxon signed-rank tests (α = 0.05). Results: In step 1, the PSL results were Group 1 > 2 and 3. In step 2, there was no significant difference between the groups when the flap was not elevated, while PSL results were Group 4 > 5 ≥ 6 and 7 ≥ 8 when the flap was elevated. Conclusions: PBF is affected by gingival blood flow when measured with UDF. UDF measurements require isolation of gingiva from the tooth.

• Restorative Dentistry and Endodontics
• /
• v.29 no.3
• /
• pp.239-248
• /
• 2004

The purpose of this study was to investigate the influence of NK1 receptor antagonists on the pulpal blood flow (PBF) when applied iontophoretically through the dentinal cavity of the teeth in order to understand whether iontophoretically applied NK1 receptor antagonists can control the pulpal inflammation. Eleven cats were anesthetized with alpha-chloralose and urethane, and substance P (SP) was administered to the dental pulp through the catheterized lingual artery in doses that caused PBF change without the influence of systemic blood pressure. NK1 receptor antagonists were applied iontophoretically to the prepared dentinal cavity of ipsilateral canine teeth of the drug administration, and PBF was monitored. Data were analyzed statistically with paired t-test. PBF increase after iontophoretic application of the NK1 receptor antagonists followed by the intra-arterial administration of SP was significantly less than PBF increase after iontophoretic application of the 0.9% saline followed by the intra-arterial administration of SP as a control (p < 0.05). Iontophoretic application of the NK1 receptor antagonists (0.2~3.4 mM) following the intra-arterial administration of SP resulted in less increase of PBF than the iontophoretic application of the 0.9% saline following the intra-arterial administration of SP as a control (p < 0.05). Therefore. the results of the present study provide evidences that the iontophoretic application is an effective method to deliver drugs to the dental pulp. and that iontophoretically applied NK1 receptor antagonists block SP-induced vasodilation effectively. The above results show the possibility that the iontophoretical application of NK1 receptor antagonists can control the neurogenic inflammation in the dental pulp.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.12
• /
• pp.6340-6345
• /
• 2013

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 ($40-65^{\circ}C$) induced a significant increase in PBF. The application of histamine($5{\mu}g/kg/1ml$) followed by heat($45^{\circ}C$) 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.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.43 no.2
• /
• pp.158-165
• /
• 2016

The purpose of this study was to analyze photoplethysmographic waveforms from pulse oximeter using raw data of red and infrared light and investigate the reference values of parameters (Height, Width50, Maximum slope, Minimum slope, Area) for evaluating pulpal blood flow in maxillary central incisors with normal pulp vitality in children. The study was performed in 30 pediatric patients, aged 7-16 years old, using pulse oximeter (MEKICS Co., Ltd, Korea) combined with a custom-made sensor. The raw data was obtained and recorded by custom-made software and analyzed by LabChart (v.7.3, ADInstruments, Germany) offline. In this study, we analyzed photoplethysmographic waveforms from pulse oximeter applied to maxillary central incisor for assessment of pulpal blood flow and suggested several reference values of young permanent maxillary central incisor with normal pulp. On average, the waveform of red light was higher, stiffer and wider than that of infrared light. Future studies about reference values for other normal teeth and the teeth with impaired pulp vitality are needed.

• Proceedings of the KACD Conference
• /
• 2003.11a
• /
• pp.546.1-546
• /
• 2003

Laser doppler flowmeter (LDF) has been applied to the measurement of pulpal blood flow (PBF) in human teeth. As far as we searched, the detection area of the pulp in the blood flow measurement has not been clarified, yet. Therefore, the purpose of this study was to obtain information of the detection area in PBF measurement using LDF. The experiments were performed on the artificial blood circulation in extracted human upper central incisors. The apical portions of examined teeth (n=6) were severed and root canals were enlarged from the apical end to the 2mm incisal to the level of enamel-cement junction. An individual resin cap of each tooth was prepared and a hole was drilled 2mm incisal to enamel-cement junction of the labial side of the cap. The measurement probe of LDF (MBF3D, Moor Instrument, UK) was plugged into the hole of the cap. Heparinized human peripheral blood, which was in advance collected and diluted 3 times with physiological saline, was pumped through the apical foramen of the teeth via a silicone tube and a disposable needle (o.d. 0.7mm) and blood flow signals were monitored. The flux signal significantly increased with the enlargement of the root canal to incisal direction (p<0.01, Friedman analysis). The result indicates that the performance of LDF in PBF with human teeth is limited.