Pulpal Blood Flow Research Articles

The Effect of Exercise on Pulpal and Gingival Blood Flow in Physically Active and Inactive Subjects as Assessed by Laser Doppler

The effects of exercise on pulpal and gingival blood flow are undefined. The autonomic nervous system response suggests that they could increase or decrease with exercise, and they may be independent of each other. This study attempts to answer these questions.Materials and Methods:15 “physically active” subjects and 15 “physically inactive” subjects exercised on a treadmill. Laser Doppler recordings of pulpal and gingival blood flow were taken before and after exercise.Results:There was a mean increase of approximately 50% in both pulpal (range -66%-+509%) and gingival (-72%- +1022%) blood flow after exercise, with wide variations, with no significant differences between the two groups of subjects.Conclusion:Exercise could increase pulpal and/or gingival blood flow as part of the overall increase in cardiac output with exercise, or could decrease pulpal and/or gingival blood flow due to diversion of blood to the somatic muscles during exercise. This study suggests that the former physiological phenomenon usually takes place at both sites,though there were some contradictory results.

Spectroscopic Study of Human Teeth and Blood from Visible to Terahertz Frequencies for Clinical Diagnosis of Dental Pulp Vitality

Transmission spectra of wet human teeth and dentin slices, together with blood of different flow rates were investigated. The measurements carried out over a wide spectral range, from visible light down to terahertz radiation. The results make it possible to find the optimum light frequency for an all-optical determination of pulpal blood flow and, consequently, for clinically diagnosis of tooth vitality.

Assessment of pulp blood flow in primary and permanent teeth using pulse oximetry

Abstract – Pulse oximetry (PO) is a well-accepted non-invasive method for assessing vascular health, based on oxygen saturation (SaO2) measurements. The objectives of this study were to design and build a custom-made PO dental sensor holder, to evaluate the effectiveness of PO in determining pulp blood flow in primary and permanent teeth, and to compare the SaO2 levels obtained in teeth and on the little finger of patients. The PO sensor adapted to the custom-made sensor holder is termed as a device to position and hold the PO sensor. This study evaluated SaO2 readings obtained in the pulp of 123 teeth of 84 children aged 4–13 years. The teeth were divided into three groups: group I – primary teeth: 23 central incisors and 28 canines; group II – permanent teeth: 25 central incisors and 28 canines; and group III – endodontically treated teeth (control): 12 permanent central incisors and seven primary central incisors. The pulp blood flow and SaO2 were measured and were compared with readings of the patient’s finger. Data were analyzed by paired t-tests and Pearson’s analysis method. The PO was able to identify all the clinically normal pulps contained in the sample, and all the endodontically treated teeth (controls) showed no response. The mean SaO2 values were 85.27% in the teeth and 92.85% in the fingers. In conclusion, PO readings were effective in determining pulp blood flow in primary and permanent teeth. However, there was no correlation between the SaO2 values in the fingers and in the teeth of the patients (P < 0.05).

Evaluation of Pulpal Blood Flow Changes in Primary Molars with Physiological Root Resorption by Laser Doppler Flowmetry and Pulse Oximetry

The aim of this study was to undertake a comprehensive quantitative investigation ofpulpal bloodflow (PBF) changes in human non-carious primary molar teeth with variable degrees of root resorption by Laser Doppler Flowmetry (LDF) and Pulse Oximetry (PO) methods. Data was collected from clinically and radiographically healthy 86 mandibular primary molars which have different physiological root resorption levels (PRRLs). PRRLs for each of the teeth were assessed using periapical radiographs and teeth were subdivided into three groups. The LDF values demonstrated a significant diference (p = 0.0001) between all groups although PO did not demonstrate any difference (p = 0.109). Statistical analysis of LDF values demonstrated significant differences between Groups A and C (p = 0.0001) and Groups B and C (p = 0.008). Furthermore, positive correlations were determined between LDF values and PRRL groups (p = 0.0001) and patients' ages (p = 0.0001). In our study, it was observed that the PBF values of human primary molars measured by LDF tended to increase with the progress of physiological root resorption and age. LDF was found to be a more effective method than PO to assess the pulpal vascularity changes of human primary molars.

Doppler ultrasound to detect pulpal blood flow changes during local anaesthesia

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

Monitoring dental pulp sensibility and blood flow in patients receiving mandibular orthognathic surgery

To investigate the effect of orthognathic surgery, in particular genioplasty, on pulp sensibility and pulp blood flow (PBF). Pulp blood flow monitoring and CO(2) pulp sensibility testing were performed on 101 mandibular anterior teeth from 17 subjects who received mandibular bilateral sagittal split osteotomy (BSSO) with or without genioplasty and other maxillary surgical procedures combined with orthodontic treatment. A laser Doppler flowmeter was used to monitor PBF using customized acrylic splints for each subject. Preoperative baseline scores were recorded from up to 1 week preoperatively, and subsequently monitored for up to 18-28 weeks postoperatively. The data were analysed by RMANOVA and pairwise comparisons. Statistical significance was defined as P < 0.05. The average PBF in subjects who received genioplasty was not significantly different to those who received no genioplasty (F = 0.076, P = 0.784). In both groups, PBF decreased significantly postoperatively (F = 23.323, P = 0.000) and remained significantly lower (P = 0.000) than preoperative values at all times. PBF decreased markedly for 1-2 weeks postoperatively in patients who received genioplasty. However, there were no statistical differences between the PBF values at any time postoperatively for either group (P > 0.05). All teeth in both groups responded to CO(2) preoperatively. The average number of teeth that responded to CO(2) postoperatively in the genioplasty group was lower without significant difference when compared to the group without genioplasty (binomial distribution F = 2.63, P = 0.1256, normal distribution F = 2.98, P = 0.1048). At each progressive period after 1-2 weeks following surgery, the number of teeth responding to CO(2) increased significantly (P < 0.001) in both groups. At the end of the study, in the genioplasty group 81.1% of teeth responded to CO(2) compared to all teeth in the group without genioplasty. Pulp blood flow decreased and remained significantly lower than preoperative values in mandibular anterior teeth postoperatively with or without genioplasty. At no time was the absence of PBF recorded. The number of teeth that responded to CO(2) decreased markedly postoperatively but recovered significantly over time. All teeth regained sensibility in the group without genioplasty at the end of the study. There were neither common trends nor coincidence in the recovery of PBF and pulp sensibility.

Evaluation of Accuracy, Reliability, and Repeatability of Five Dental Pulp Tests

Introduction The aim of this study was to compare the clinical accuracy, reliability, and repeatability of laser Doppler flowmetry (LDF), an electric pulp test (EPT), and various thermal pulp sensibility tests. Methods Pulp tests were done on 121 teeth in 20 subjects by using LDF, EPT, and thermal pulp testing (CO 2, Endo Frost [EF], Ice) during 2 or 3 test sessions with at least 1-week intervals. The order of testing was reversed on the second visit. A laser Doppler flowmeter was used to measure mean pulp blood flow (Flux) calibrated against a brownian motion medium and zeroed against a static reflector. The laser source was 780 nm, with 0.5-mm fiber separation in the probe, 3.1 kHz as the primary bandwidth for filter set to 0.1-second time output constant. Customized polyvinylsiloxane splints were fabricated for each participant, and a minimum of 90-second recording time was used for each tooth. Raw data were analyzed by using repeated measure analysis of variance, pairwise comparisons, and interclass correlations (ICC). Results The accuracy of EPT, CO 2, and LDF tests was 97.7%, 97.0%, and 96.3%, respectively, without significant differences ( P > .3). Accuracy of EF and Ice was 90.7% and 84.8%, respectively. EPT ( P = .015) and CO 2 ( P = .022) were significantly more accurate than EF. LDF was more accurate than EF, but this was not statistically significant ( P = .063). Ice was significantly less accurate than EPT ( P = .004), CO 2 ( P = .005), LDF ( P = .006), and EF ( P = .019). With the exception of Ice (effect of visit: F 2,38 = 5.67, mean squared error = 0.01, P = .007, η 2 p = 0.23), all tests were reliable. Ice (ICC = 0.677) and LDF (ICC = 0.654) were the most repeatable of the tests, whereas EPT (ICC = 0.434) and CO 2 (ICC = 0.432) were less repeatable. Conclusions CO 2, EPT, and LDF were reliable and the most accurate tests, but CO 2 and EPT were less repeatable yet less time-consuming than LDF. EF was reliable but not as accurate as EPT and CO 2 and less repeatable than Ice and LDF. Ice was the most repeatable but the least accurate and least reliable test.

The use of laser Doppler flowmetry in paediatric dentistry

An early determination of pulpal vitality is crucial with respect to a correct differential diagnosis of revascularisation or necrosis and its treatment. Sensibility tests (cold, heat, electrical pulp test) in combination with radiographs are commonly promoted. However these tests are arbitrary, based on sensations and therefore not always reliable. In such situations registration of pulpal blood flow will be advantageous. The most studied and well documented method for registration of blood circulation is laser Doppler flowmetry (LDF) which is typified as a non-invasive technique with direct and objective registrations. In this article blood flow, LDF and its characteristics, the advantages and disadvantages of the methods and the latest developments regarding LDF is described. Despite there being a low implementation of LDF in dentistry to date, this should become one of the basic techniques for clinical use in paediatric dentistry.

A comparison between red and infrared light for recording pulpal blood flow from human anterior teeth with a laser Doppler flow meter

ObjectiveTo compare red (635nm) and infrared (780nm) light for recording pulpal blood flow from human anterior teeth with a laser Doppler flow meter. DesignRecordings were made from 7 healthy teeth in 5 subjects (aged 22–55 years) using a laser Doppler flow meter (Periflux 4001) equipped with both red and infrared lasers. Average blood flow signals were obtained with both light sources alternately from each tooth under five conditions: intact tooth without opaque rubber dam, intact tooth with dam, after injecting local anaesthetic (3% Mepivacaine) (LA) over the apex of the tooth and cavity preparation to almost expose the pulp, after removal and replacement of the pulp, and with the root canal empty. ResultsWith infrared light, because of technical limitations, data were obtained for the first three conditions only. The dam significantly decreased the mean blood flow by 82%. Injecting LA and cavity preparation had no significant effect. With red light, dam produced a decrease of 56%, and the resulting signal was reduced by 33% after LA and cavity preparation. The remaining signal fell by 46% after pulp removal and replacement. This contribution of the pulp is similar to that recorded previously with infrared light. There was no significant further change when the pulp was finally removed. ConclusionsThe importance of using opaque rubber dam is confirmed. With dam, there is no advantage to using red rather than infrared light, and in each case the pulp contributes less than 50% to the blood flow signal.

Assessment of pulp blood flow in primary and permanent teeth using pulse oximetry

Pulse oximetry (PO) is a well-accepted non-invasive method for assessing vascular health, based on oxygen saturation (SaO(2) ) measurements. The objectives of this study were to design and build a custom-made PO dental sensor holder, to evaluate the effectiveness of PO in determining pulp blood flow in primary and permanent teeth, and to compare the SaO(2) levels obtained in teeth and on the little finger of patients. The PO sensor adapted to the custom-made sensor holder is termed as a device to position and hold the PO sensor. This study evaluated SaO(2) readings obtained in the pulp of 123 teeth of 84 children aged 4-13years. The teeth were divided into three groups: group I - primary teeth: 23 central incisors and 28 canines; group II - permanent teeth: 25 central incisors and 28 canines; and group III - endodontically treated teeth (control): 12 permanent central incisors and seven primary central incisors. The pulp blood flow and SaO(2) were measured and were compared with readings of the patient's finger. Data were analyzed by paired t-tests and Pearson's analysis method. The PO was able to identify all the clinically normal pulps contained in the sample, and all the endodontically treated teeth (controls) showed no response. The mean SaO(2) values were 85.27% in the teeth and 92.85% in the fingers. In conclusion, PO readings were effective in determining pulp blood flow in primary and permanent teeth. However, there was no correlation between the SaO(2) values in the fingers and in the teeth of the patients (P<0.05).

Sensory Transduction in Human Teeth with Inflamed Pulps

The effects of pulpal inflammation on the sensitivity of dentin to cold (5°C) and negative hydrostatic pressure (−300 mm Hg) stimuli in man were compared, since recent evidence suggests that these stimuli excite different classes of sensory receptors. Dentin was exposed in premolars in 14 participants aged 15-25 years. Stimuli were applied to etched dentin immediately after cavity preparation and after the cavity had been filled with gutta percha for 7 days. This treatment increased significantly the intensity of pain produced by cold, and at the same time decreased that evoked by negative pressure stimuli. Pulpal blood flow was increased in the treated teeth, indicating that their pulps were inflamed. It is concluded that the sensory receptors responsible for the response to cold were probably sensitive to some change other than an outward flow of fluid in dentinal tubules, which would be caused by both forms of stimulus.

Pulpal blood flow recorded from human premolar teeth with a laser Doppler flow meter using either red or infrared light

ObjectiveTo compare red (635nm) and infrared (780nm) light for recording pulpal blood flow from human premolar teeth. DesignRecordings were made from 11 healthy teeth in 9 subjects (aged 16–30 years) using a laser Doppler flow meter (Periflux 4001) equipped with both red and infrared lasers. Average blood flow signals were obtained with both light sources alternately from each tooth under five conditions: intact tooth without opaque rubber dam, intact tooth with dam, after injecting local anaesthetic (3% Mepivacaine) (LA) over the apex of the tooth and cavity preparation to almost expose the pulp, after removal and replacement of the pulp, and with the root canal empty. ResultsWith infrared light, the dam significantly decreased the mean blood flow by 80%. Injecting LA and cavity preparation had no significant effect. Removal and replacement of the pulp reduced the mean blood flow by 58%. There was no further change when the pulp was removed. With red light, the dam reduced the signal from intact teeth by 60%. Injecting LA and cavity preparation had no significant effect. The signal fell by 67% after pulp removal and replacement and did not change significantly when the pulp was removed. ConclusionsOpaque rubber dam minimises the contribution of non-pulpal tissues to the laser Doppler signal recorded from premolars. Using dam, the pulp contributed about 60% to the blood flow signal with both red and infrared light. The difference between them in this respect was not significant.

Partial pulp necrosis caused by excessive orthodontic force

As the dental pulp is encased with a rigid, noncompliant shell, changes in pulpal blood flow or vascular tissue pressure can have serious implication for the health of pulp. Numerous studies have demonstrated that orthodontic force application may influence both blood flow and cellular metabolism, leading degenerative and/or inflammatory responses in the dental pulp. The aim of this case report is to present a case about tooth with chronic periapical abscess which showed normal vital responses. Excessive orthodontic force is thought to be the prime cause of partial pulp necrosis. Owing to remaining vital tissue, wrong dianosis can be made, and tooth falsely diagnosed as vital may be left untreated, causing the necrotic tissue to destroy the supporting tissuses. Clinician should be able to utilize various diagnostic tools for the precise diagnosis, and be aware of the endodontic-orthodontic inter-relationship. [J Kor Acad Cons Dent 2011;36(2):149-153.]

Pulpal blood flow changes due to rapid maxillary expansion

To determine the pulpal blood flow (PBF) changes in anchorage teeth associated with the high forces of a rapid maxillary expansion (RME) appliance. The study was performed with 14 girls and 7 boys for a total of 21 patients between 10 and 15 years of age (mean, 13.1 +/- 1.39 years). A modified acrylic bonded RME appliance was used as an expansion appliance. Laser Doppler flowmetry was used for the pulpal perfusion measurements. Records were taken from 42 upper central incisors, 28 canines, and 42 first molars at the following time intervals: just before expansion (T1); at the first week of expansion (T2); at the end of the expansion process (T3); and at the third (T4), seventh (T5), and 12th weeks of retention (T6). The data gained were statistically evaluated by parametric tests. PBF values of the anchorage teeth were doubled at the first week of expansion; however, these values began to decrease because of separation of the median palatal suture. PBF values tended to reach their initial values during the retention period. Pulpal perfusion changes of all examined anchorage teeth were similar to each other from the beginning to the end of the evaluation. PBF changes that occur with RME are reversible.

Effective Human Pulpal Blood Flow Changes During Brief Intrusive Force Application and Continuous Orthodontic Force Application using Laser Doppler Flowmetry

Effective Human Pulpal Blood Flow Changes During Brief Intrusive Force Application and Continuous Orthodontic Force Application using Laser Doppler Flowmetry

Amount of Bone Lengthening Affects Blood Flow Recovery and Bone Mineralization after Distraction Osteogenesis in a Canine Cleft Palate Model

Distraction osteogenesis has been applied to the craniofacial region. To reduce the cleft width of patients with cleft lip and palate, alveolar bones are distracted toward the cleft. However, no reports have described limitations to the amount of lengthening that can be achieved by distraction osteogenesis in this area. Therefore, we investigated the healing process following different extents of distraction osteogenesis using a canine cleft palate model. A 10-mm bone defect was made in the palates. A bony segment including the canine was prepared and translocated into the defect area at a rate of 1 mm/d for 6 or 10 days, resulting in two groups (6- and 10-mm groups). Canine pulpal blood flow was monitored for 100 days with Doppler flowmetry. Then, the animals were sacrificed and the regenerated bone area was evaluated radiologically and histologically. Statistical significance was confirmed with the Mann-Whitney rank test. Pulpal blood flow in the 6-mm group recovered to original levels earlier than in the 10-mm group. Cortical bone density in the regenerated bone, measured by peripheral quantitative computed tomography, was significantly greater in the 6-mm group than in the 10-mm group. The amount of regenerated bone in histologic sections was also significantly greater in the 6-mm group. We clearly showed that healing progress depends on the extent of distraction osteogenesis, highlighting the importance of limited distraction osteogenesis in the alveolar area.

Pulpal Blood Flow Measurement with Ultrasound Doppler Imaging

Introduction This study compared the difference in pulpal blood flow between vital and root-filled teeth by using ultrasound Doppler imaging. Methods To compare the difference in pulpal blood flow between vital and root-filled teeth, 11 patients (mean age, 32.06 years; 3 male, 8 female) who had undergone root canal treatment on the anterior tooth of the maxilla or mandible and had a vital contralateral tooth were examined. Pulpal blood flow measurements were performed on the vital and root canal–treated teeth by using ultrasound Doppler imaging. The parameters examined were the maximum linear velocity (Vas), average linear velocity (Vam), minimum linear velocity (Vakd), pulsation index (PI), and circulation resistance (RI), which are indicators of the pulpal blood flow. The differences between the vital and root-filled teeth were examined by using a paired t test at the 95% confidence interval. Results There were significant differences in the Vas, Vam, Vakd, and RI between the vital and root-filled teeth ( P < .05). With the root-filled teeth, ultrasound Doppler imaging revealed a linear and nonpulsed waveform, whereas the vital teeth showed a pulsed waveform that is characteristic of an arteriole. Conclusions Ultrasound Doppler imaging can detect pulpal blood flow in vital tooth through indicators such as Vas, Vam, Vakd, PI, and RI.

The use of likelihood ratio methodology to find predictors of treatment outcome in patients with dental injury diagnoses

The purpose of this prospective, cohort study of patients with dental injuries was to develop prediction rules to predict treatment response related to the management of dental injuries. The study comprised of 130 patients with a single permanent incisor affected by a dental displacement (n = 100) or fracture injury (n = 30). Laser Doppler flowmetry (LDF) measurements of pulpal blood flow (PBF) were taken 6 and 18 weeks after dental injury Treatment response (success or failure) was categorized based on findings of clinical and radiographical evaluation after 9 months. Forty-four (34%) subjects were categorized as treatment success (absence of loss of sensitivity, periapical radiolucency and grey discolouration of crown), 43 (33%) as treatment failures (loss of sensitivity, and periapical radiolucency and/or grey discolouration of crown) and 43 (33%) as acceptable outcome (loss of sensitivity). After using univariate analysis to determine the association between potential clinical and LDF predictor variables and treatment response status, preliminary prediction rules were developed for prediction of success [positive likelihood ratio (LR), 29.0; 95% confidence interval (CI), 1.7-496.4] and failure (negative LR, 0.55; CI, 0.4-0.7). The most important variables were subluxation, root fracture, baseline PBF level and change in PBF level at 3-month follow-up. Outcome following the management of dental injuries may be predicted from variables collected from LDF and physical examination. Predictive modelling may provide clinicians with the opportunity to identify 'at-risk' patients early and initiate specific treatment approaches.

Pulpal Blood Flow Measurement of Traumatized Deciduous and Young Permanent Teeth by Transmitted-light Plethysmography

Pulpal Blood Flow Measurement of Traumatized Deciduous and Young Permanent Teeth by Transmitted-light Plethysmography

Effect of restorations on pulpal blood flow in molars measured by laser Doppler flowmetry

To: (i) compare laser Doppler pulpal blood flow (PBF) signals from restored and unrestored first molar teeth, (ii) investigate PBF in teeth with large and small restorations, and (iii) to relate PBF to pulp chamber dimensions on radiographs. Bitewing radiographs of young adults with restored first molars were obtained and pulp chamber dimensions measured. Subjects were divided into 2 groups: group A with a restored tooth and an unrestored contralateral (43 subjects) and group B, those with a molar with a small (usually occlusal) restoration whilst the contralateral tooth had an extensive occlusal restoration (or restorations) or restored proximal surface(s) and/or cuspal overlay (31 subjects). The 148 teeth responded to electric pulp testing, and their PBF was recorded using a laser Doppler flowmeter. Data were analysed using Student's t-test. In group A the PBF in the restored teeth was significantly lower than in unrestored contralaterals (P = 0.028) and the total pulp chamber area and that in the clinical crown were smaller (P = 0.039 and 0.021 respectively). The group B molars with large restorations had significantly lower PBF than contralaterals with small restorations (P = 0.001), and their total pulp chamber area and pulp chamber width at cervix were reduced significantly (P = 0.003 and 0.032 respectively). In molars the size of the pulp chamber was influenced by the presence of restorations and the PBF was reduced when restorations were present. Size and extent of restorations had a significant effect on PBF.