|Year : 2022 | Volume
| Issue : 1 | Page : 2-15
Assessment of actual pulp status using pulp sensibility tests and pulp vascularity tests: A systematic review
Krishnamachari Janani1, Kavalipurapu Venkata Teja2, Jerry Jose2
1 Department of Conservative Dentistry and Endodontics, SRM Dental College, SRM Institute of Science and Technology, Chennai, Tamil Nadu, India
2 Department of Conservative Dentistry and Endodontics, Saveetha Dental College, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, India
|Date of Submission||06-Sep-2021|
|Date of Decision||01-Nov-2021|
|Date of Acceptance||26-Dec-2021|
|Date of Web Publication||25-Mar-2022|
Dr. Kavalipurapu Venkata Teja
Department of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil nadu
Source of Support: None, Conflict of Interest: None
Pulp vitality plays an important role in endodontic diagnosis as it has an integral role in primary care. In routine practice, the clinicians rely on pulp sensibility tests. Unfortunately, the major drawback with pulp sensibility tests is that these tests rely on the patient's response to pain and it is subjective in nature. Therefore, the actual status of pulp can be assessed by the vascular response of the tooth. The aim of the systematic review is to evaluate the diagnostic accuracy of pulp sensibility test and pulp vascularity test in identifying the actual status of pulp. The databases of PubMed, Medline, Cochrane Database of Systematic Review, Science Direct, and SCOPUS were searched up to January 2021. Only clinical studies assessing the status of pulp with pulp sensibility test and pulp vascularity test were recruited in this systematic review. The studies considered were based on the data extraction and analysis of the studies for the quality and publication bias. The data collection form was customized. The primary outcome measure was assessing the status of pulp sensibility test and pulp vascularity test. Only clinical study articles were recruited for the systematic review. The search identified 120 articles, out of which 13 duplicate articles and 107 articles were screened. Sixty-seven articles were excluded during the initial screening. Forty full-text articles were retrieved to assess for eligibility. Twenty articles were excluded as it did not fulfil the criteria of the research question. Finally, 20 articles were included for the systematic review. From this systematic review, it can be concluded that pulse oximeter and laser Doppler flowmetry accurately assessed the actual pulp status when compared to pulp sensibility test.
Keywords: Endodontic diagnosis, pulp sensibility, pulp vascularity, pulse oximeter, thermal test
|How to cite this article:|
Janani K, Teja KV, Jose J. Assessment of actual pulp status using pulp sensibility tests and pulp vascularity tests: A systematic review. Endodontology 2022;34:2-15
| Introduction|| |
The criteria for an ideal pulp test are that it should be reliable, noninvasive, less techniques sensitive, easy to use, simple, objective, reproducible, standardized, and accurate., The tests which are used to identify the status of pulp in routine dental practice are the pulp sensibility test.
Pulp sensibility test records the neural response of the tooth upon the stimulation of nerve fibers. The pulp sensibility test includes thermal test (heat test and cold test) and electric pulp tester (EPT). These tests are based on the patient's subjective response to stimuli. The actual status of the pulp will not be revealed by recording the neural response when a stimulus is administered. Moreover, as a result of trauma, the sensory function of the teeth will be temporarily or permanently lost and the tooth will be unresponsive to these tests.
The nervous tissue, being highly resistant to inflammation, may remain reactive long after the surrounding tissues have degenerated. Therefore, if only the pulp vasculature is damaged, thermal and electric tests may give false-positive responses. The conditions which affect pulp are infectious and inflammatory in origin. In both the cases, microcirculation initiates the inflammatory response that occurs within the pulp as a defense mechanism; hence, the blood supply of the tooth is the actual and reliable indicator of pulp status. There are several devices which are used to assess the vascular response of the tooth. Invasive methods include hydrogen gas desaturation and radioisotope clearance, whereas noninvasive methods include pulse oximetry, laser Doppler flowmetry, transmitted light photoplethysmography, and crown surface temperature.
The present systematic review investigates the diagnostic accuracy of the pulp vitality tests in assessing the actual status of the pulp.
The aim of this systematic review is to investigate the diagnostic accuracy of pulp sensibility tests (heat, cold, and EPT) and pulp vascularity test (pulse oximeter and laser Doppler flowmetry) in identifying the actual status of the pulp.
| Materials and Methods|| |
Preferred reporting items for systematic review and meta-analysis guidelines were followed for reporting this systematic review. PICOS were defined as Population: Single and multi-rooted teeth, Intervention: Pulse Oximeter, Laser Doppler flowmetry (pulse vascularity test), Comparison: Heat test, cold test, and EPT (pulp sensibility tests), Outcome: Identification of actual pulp status, study type: Clinical studies.
For the identification of studies included or considered for this review, detailed search strategies were developed for the database searched. The PubMed search was performed using the combination of controlled vocabulary and free text term from January 1990 to January 2021, MEDLINE, Cochrane Database of Systematic Review, Science Direct, SCOPUS databases were used. Full text articles in English were only applied during the electronic search to include all the possible clinical trials in the potentially relevant article search phase of the systematic review. Reference list of the reviews and of identified randomized controlled trials was also checked for possible additional studies.
Clinical study, patients aged between 14 and 58 years and teeth without development abnormalities, and calcification were included for the assessment. Both single and multi-rooted teeth were recruited with varied preoperative status.
Patients unable to respond to pulp testing, case reports/case series, animal studies, in vitro studies, and review articles were excluded from the study.
Selection of studies
Based on the inclusion and exclusion criteria, the studies selected were analyzed and were imported to reference managing software. The records were independently reviewed by two reviewers (K.J., K.V.T.) and in case of disagreement, a third reviewer (J.J.) reviewed to sort the consensus.
Extraction of data
The data were extracted by (K.J., K.V.T.) from the studies which was eligible following the full text extraction. The data were extracted based on the sensitivity, specificity, predictive values, overall diagnostic accuracy, and oxygen saturation reading for different teeth at different clinical condition. All three authors provided risk of bias data for the evaluation.
| Results|| |
Only clinical study articles were included for the systematic review. The search identified 120 articles, out of which 13 duplicate articles and 107 articles were screened. Sixty-seven articles were excluded during the initial screening. Forty full-text articles were retrieved to assess for eligibility. Twenty articles were excluded as it did not fulfil the criteria of the research question. Finally, 20 articles were included for the systematic review.,,,,,,,,,,,,,,,,,,, [Figure 1] shows the PRISMA flow diagram. [Table 1], [Table 2] shows the search methodology and the list of excluded articles respectively. General information of included articles is described in [Table 3] and summation of results in [Table 4].
Risk of bias assessment for 20 included studies was performed using Quality Assessment for Diagnostic Accuracy Studies -2 (QUADAS-2) tool depicted in [Table 5]. The quality of the studies has been assessed under four categories, namely patient selection, index test, reference test, flow, and timing. All the included studies except Chen and Abbott had discussed the method of patient selection that matched the inclusion criteria and had a low risk of bias. The method of sampling patients was also mentioned. Eight studies had high risk of bias in performing the index test.,,,,,,, Eleven studies showed low risk of bias in performing the reference test.,,,,,,,,,, Appropriate time interval between the index test and reference test had been mentioned,,,,,,,,,,,,,,,,,, and all the patients received the same reference standard.
A meta-analysis is a more precise approach to combine the data derived from a systematic-review. The results obtained from a meta-analysis are reported to have strong evidence. However, meta-analysis was not possible for the present systematic review due to heterogeneity among the included studies such as difference in sample size, effect size, and time interval between each test and difference in order of testing device.
| Discussion|| |
The present systematic review focused to identify the actual pulp status comparing pulp sensibility test with pulse oximeter and laser Doppler flowmetry in various clinical conditions. Although there have been three systematic reviews published, it has assessed the diagnostic accuracy of three pulp sensibility tests with pulse oximeter alone.,, Considering this, the present systematic review aimed to identify the diagnostic accuracy of thermal tests, EPT, pulse oximeter, and laser Doppler flowmetry at different clinical scenario. Among the pulp vascularity tests, pulse oximeter is comparatively procurable and can be used in practice when compared to Laser Doppler flowmetry which is expensive, even though it provides accurate results. Twenty articles which matched the inclusion criteria were recruited for the discussion.
Two studies assessed the diagnostic accuracy of pulse oximeter with cold test and EPT., Caldeira et al. reported the oxygen saturation level on luxated teeth with irreversible pulpitis and pulpal necrosis at three different time periods. Saturation values were compared with the index finger and also on healthy teeth taken as positive control for reference standard. Sensitivity, specificity, and predictive values showed pulse oximeter to be accurate in determining the actual pulp status. Direct visualization of the access cavity was performed which was considered to be the reference standard.
Two studies evaluated the pulpal status in compromised systematic conditions., de Fátima Carvalho Souza et al. evaluated the oxygen saturation levels in patients with sickle cell anemia compared with normal hemoglobin. There was no difference in the saturation level in patients with sickle cell anemia compared to healthy individual except for maxillary central and lateral incisors which showed reduced saturation level. The another study by Kataoka et al. reported that there is no difference in patients undergoing radiotherapy compared healthy individual in all the teeth.
Kosturkov, solda reported the spo2 levels in the maxillary anterior to be ranging between 83 and 85., Calil et al. reported the spo2 level in the range of 90–91 for maxillary incisors. Whereas Kahan et al. showed contradictory results, the difference could be due to the type of probe used. Kong et al. reported to show 97%–100% of spo2 level in maxillary incisors. When comparing the oxygen saturation level in molars, maxillary second molar showed 81% while the maxillary first molar and the mandibular molars reported to range between 85% and 88%.
In teeth with reversible pulpitis, the spo2 level ranged between 85 and 87, irreversible pulpitis ranged between 81 and 83.,, The oxygen saturation level decreased and ranged between 70% and 74% in case of pulpal necrosis.,, In the healthy teeth that were taken as positive control, two studies showed spo2 levels ranging between 94% and 96%., whereas 88% was reported by Janani et al.
Previous study assessed the sensitivity and specificity of cold test, EPT and pulse oximeter. In evaluating the diagnostic accuracy, assessment of sensitivity and specificity is necessarily important. The sensitivity implies the ability of the test to identify that the tooth is nonvital, whereas specificity of the pulp test implies the ability to identify that the tooth is vital. This is especially important in case of a traumatized tooth, where the specificity of the test is of utmost importance as this will prevent unnecessary endodontic intervention.
Dastmalchi et al. compared electric, cold, heat, and pulse oximeter tests with the gold standard. The sensitivity was the highest for pulse oximeter and the least was cold test, whereas the most specificity was related to cold test and the least specific was seen in pulse oximeter. In another study by Gopikrishna et al. where he evaluated the diagnostic accuracy of cold test, EPT and pulse oximeter in a traumatized tooth. The results of these tests showed that pulse oximeter is effective and accurate in assessing the pulp condition as it is an objective test based on oxygen saturation. Moreover, sensibility tests in such conditions do not respond due to transient paresthesia of nerve fibers.
On comparing the accuracy of EPT and pulse oximeter in teeth with complete endodontic fillings, Karayilmaz and Kirzioğlu reported that sensitivity was higher in EPT than pulse oximeter, whereas specificity was accurately diagnosed by pulse oximeter than EPT. The results of this study could not be compared to other studies as there are no studies done on endodontic filing teeth with the help of pulse oximeter. Other studies, reported pulse oximeter to have higher sensitivity and specificity followed by cold test, EPT, and heat test. Chen and Abbott reported no difference in overall diagnostic accuracy between EPT, cold test with carbon dioxide snow, and laser Doppler flowmetry.
In the present systematic review, participants were included who are above the age of 14 years as the eruption of permanent teeth gets complete.,,, Age advances there is progressive change that happens in regard to the pulp. There occurs reduction in the size of pulp chamber with the constriction of blood vessels. Eventually, the blood flow to the pulp gets decreased with reduction in oxygen saturation. In such instances, the oxygen saturation levels get reduced in older individuals, which should not misinterpret.
From the above studies, the most accurate was found to be pulse oximeter, whereas the other studies showed contradictory results with cold test and EPT.,, There might be various reasons for these results such as age of the patients, type of the teeth included in the study, sample size, decrease in pulp volume, changes in interstitial tissues, extensive restoration, and calcification. When discussing the Laser Doppler flowmetry, Ghouth et al. reported the latter to have highest diagnostic accuracy when compared to the other pulp test. There is very limited evidence comparing LDF with pulse oximeter in assessing the actual pulpal status.
Although pulp vascularity tests are clinically more reliable in diagnosing the actual clinical condition, more clinical trials are required on LDF to assess the diagnostic accuracy when compared with pulse oximeter.
| Conclusion|| |
From this systematic review, it can be concluded that pulse oximeter and laser Doppler flowmetry accurately assessed the actual pulp status when compared to pulp sensibility test. However, from the available evidence, modern endodontics is becoming influenced by novel biological, genetic, and metabolic approaches toward new strategies for regeneration of dental pulp, the technology with which pulse oximeter and laser Doppler flowmetry works can be adapted for the true objective evaluation of the progress of regeneration, which could be a leap into the future of endodontics.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]