Diagnostic Accuracy of Cold, Heat, and Electric Pulp Tests

Diagnostic Accuracy of Cold, Heat, and Electric Pulp Tests: An In Vivo Study

The goal of this observational study is to evaluate the diagnostic accuracy of cold, heat, and electrical pulp tests in adults with teeth suspected of requiring endodontic treatment. The main questions it aims to answer are:

1. How accurately do cold, heat, and electrical pulp tests identify pulp vitality?
2. How do these tests compare with direct visual inspection of pulp bleeding during endodontic access (reference standard)? Participants attending The University Endodontics Clinic with at least one tooth indicated for endodontic access will receive cold, heat, and electrical pulp testing as part of the clinical examination. The test responses will be recorded and compared with the presence or absence of pulp bleeding observed directly after access cavity preparation.

Study Overview

• Status: Completed
• Conditions: Pulp Necrosis; Pulpitis - Irreversible; Dental Pulp Disease
• Intervention / Treatment: Diagnostic test: Pulp Sensibility Tests

Detailed Description

This is a prospective, in vivo, observational diagnostic accuracy study conducted at the Endodontics Clinic of Istanbul University Faculty of Dentistry. The protocol was approved by the Ethical Committee of Istanbul University Faculty of Dentistry (Ref. 2024/48 Rev-2) and registered in the Turkish Medicines and Medical Devices Agency (Protocol No. 2023/38). The study was performed in accordance with the Declaration of Helsinki, and written informed consent was obtained prior to study procedures. Before study initiation, the research team was trained and calibrated for the testing protocol and data collection.

Eligible adult participants presenting with at least one tooth indicated for root canal treatment were recruited during routine clinical care. One tooth per participant was included. Eligibility criteria and exclusions were defined a priori and are described in the Eligibility module.

Index Tests (Pulp Sensibility Tests) All index tests were performed by a single operator who was blinded to the participants' clinical signs/symptoms, dental history, and radiographic findings. Participants were instructed to raise their hand immediately when they perceived pain, discomfort, or tingling.

To establish an individual baseline response, testing was first performed on an asymptomatic, functional contralateral tooth without prior endodontic treatment; if unavailable, an adjacent tooth meeting these criteria was used. The study (index) tooth was tested last. Teeth were isolated with cotton rolls and dried with an air syringe before each test. Tests were applied to standardized anatomical sites (incisors/canines: middle third of buccal surface; premolars: occlusal third; molars: mesiobuccal cusp tip area or the closest available site). Responses were recorded dichotomously as "response present" or "response absent" (response time and intensity were not measured). The three tests were performed in the following order, with a 5-minute interval between tests to minimize carryover effects:

Cold test: Refrigerant spray containing propane-butane (Endo-Frost; Roeko, Coltene Whaledent, Germany) was applied to a size 2 cotton pellet. Once frosting was visible, the pellet was placed on the standardized site for up to 15 seconds or until the participant responded.

Heat test (frictional heat): A sterile rubber cup (NAIS, Sofia, Bulgaria) mounted on a low-speed contra-angle handpiece at a constant speed setting was applied with light, consistent contact without water cooling. The stimulus was stopped when the participant responded or after a maximum of 7 seconds.

Electric pulp test (EPT): An apex locator with integrated pulp tester (Ai-Pex; Woodpecker, Guilin, P.R. China) was used with toothpaste as a conducting medium on a 2-mm electrode tip. The current was increased at the lowest ramp setting, and the numeric value at first perception was recorded. The contralateral tooth served as the control. If the response for the index tooth occurred at a value equal to or lower than the control, the result was recorded as "response present"; if a higher value was required or no response occurred up to the maximum value (80), the result was recorded as "response absent."

Reference Standard (Pulpal Bleeding) Immediately after completion of the index tests, local anesthesia (Ultracain D-S Forte; Sanofi, Paris, France) was administered and rubber dam isolation was applied. A standard endodontic access cavity was prepared by a second researcher who was blinded to the pulp test results. The presence or absence of pulpal bleeding in the pulp chamber was assessed by direct visual inspection under 3.5× magnification (dental loupes) and recorded as present/absent. Teeth were classified as vital when bleeding was observed within the pulp chamber. Teeth were classified as non-vital when no bleeding was present in the pulp chamber. Cases with bleeding limited to root canal(s) without pulp chamber bleeding, or bleeding not present in all canals of multi-rooted teeth, were classified as partially necrotic and recorded as non-vital. Teeth with uncertain pulp status were excluded. Following reference standard assessment, root canal treatment was performed as planned.

Statistical Approach For each index test, true-positive, false-positive, true-negative, and false-negative values were determined against the reference standard. Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were calculated and reported with 95% confidence intervals (Wilson score method). Agreement between each test and the reference standard was assessed using Cohen's kappa. Differences among the three tests were evaluated using Cochran's Q test, and pairwise comparisons were performed using Bonferroni-adjusted Z tests. Analyses were conducted using IBM SPSS Statistics (Version 23; IBM Corp., Armonk, NY, USA), with statistical significance set at p<0.05.

• Study Type: Observational
• Enrollment (Actual): 175

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Fatih
    • Istanbul, Fatih, Turkey (Türkiye), 34116
      • Istanbul University Faculty of Dentistry

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Participants were selected from patients who presented to the Endodontics Clinic at Istanbul University Faculty of Dentistry (Istanbul, Türkiye), including patients referred from the Department of Oral and Maxillofacial Radiology, and who were evaluated in routine care and determined by clinicians to require endodontic treatment for at least one tooth.

Description

Inclusion Criteria:

• Age ≥ 18 years
• At least one tooth indicated for root canal treatment confirmed at the Endodontics initial examination unit
• Able and willing to provide written informed consent

Exclusion Criteria:

Tooth-related

• Full-coverage crown
• Extensive restoration affecting testing area
• History of dental trauma (for the study tooth)
• Root resorption
• Incomplete root development (open apex)
• Tooth fracture or crack
• Regressed pulp chamber / pulp canal obliteration or calcified root canals Patient-related
• Severe or uncontrolled systemic disease: ASA physical status 3-6

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Teeth Indicated for Root Canal Treatment (Adults); Adults (≥18 years) with at least one tooth indicated for root canal treatment (one tooth per participant). Each included tooth undergoes cold, heat, and electric pulp testing; pulp status is classified by the reference standard (presence/absence of pulpal bleeding during access cavity preparation). The cohort includes teeth ultimately classified as vital and non-vital by the reference standard; no separate comparison cohort is enrolled.

Diagnostic test: Pulp Sensibility Tests; Cold Pulp Sensibility Test (Refrigerant Spray) Refrigerant spray (propane-butane) is applied to a cotton pellet and placed on the tooth surface for up to 15 seconds (or stopped when the patient responds). Response is recorded as present/absent. 2) Heat Pulp Sensibility Test (Frictional Heat) A sterile rubber cup on a low-speed handpiece is applied to the tooth surface without water cooling for up to 7 seconds (or stopped when the patient responds). Response is recorded as present/absent. 3) Electric Pulp Test (EPT) An electric pulp tester is applied with toothpaste as a conducting medium to the tooth surface. Current is increased gradually; the perception threshold value is recorded and compared with a contralateral control tooth. Response is recorded as present/absent per the predefined rule.; Other Names: Heat Pulp Sensibility Test (Frictional Heat); Electric Pulp Test (EPT); Cold Pulp Sensibility Test (Refrigerant Spray)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Predictive values of pulp sensibility tests for pulp vitality	Positive predictive value (PPV) and negative predictive value (NPV) of cold, heat, and electric pulp tests for identifying pulp vitality, calculated against the reference standard (presence/absence of pulpal bleeding during access cavity preparation). PPV/NPV are derived from the observed false-positive and false-negative results for each test.	Periprocedural (during pulp testing and access cavity preparation on Day 1)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
False-positive and false-negative responses	Number and proportion of false-positive and false-negative responses for each pulp test compared with the reference standard (pulpal bleeding).	Periprocedural (during pulp testing and access cavity preparation on Day 1)
Sensitivity and specificity	Sensitivity and specificity of each pulp test versus the reference standard (pulpal bleeding) based on 2×2 contingency tables.	Periprocedural (during pulp testing and access cavity preparation on Day 1)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall diagnostic accuracy	Overall accuracy (proportion correctly classified) for each pulp test compared with the reference standard.	Periprocedural (during pulp testing and access cavity preparation on Day 1)
Agreement with reference standard	Agreement between each pulp test and the reference standard assessed using Cohen's kappa coefficient.	Periprocedural (during access cavity preparation on Day 1)

Collaborators and Investigators

• Sponsor: Istanbul University
• Investigators: Study Director: Ayca Yilmaz, Assoc. Prof., Istanbul University; Principal Investigator: Ecem Erden Bozdağ, Istanbul University

Publications and helpful links

General Publications

• Chen E, Abbott PV. Evaluation of accuracy, reliability, and repeatability of five dental pulp tests. J Endod. 2011 Dec;37(12):1619-23. doi: 10.1016/j.joen.2011.07.004. Epub 2011 Sep 9.
• Jespersen JJ, Hellstein J, Williamson A, Johnson WT, Qian F. Evaluation of dental pulp sensibility tests in a clinical setting. J Endod. 2014 Mar;40(3):351-4. doi: 10.1016/j.joen.2013.11.009. Epub 2013 Dec 15.
• Mejare IA, Bergenholtz G, Petersson K, Tranaeus S. Estimates of sensitivity and specificity of electric pulp testing depend on pulp disease spectrum: a modelling study. Int Endod J. 2015 Jan;48(1):74-8. doi: 10.1111/iej.12277. Epub 2014 Apr 2.
• Salgar AR, Singh SH, Podar RS, Kulkarni GP, Babel SN. Determining predictability and accuracy of thermal and electrical dental pulp tests: An in vivo study. J Conserv Dent. 2017 Jan-Feb;20(1):46-49. doi: 10.4103/0972-0707.209067.
• Villa-Chavez CE, Patino-Marin N, Loyola-Rodriguez JP, Zavala-Alonso NV, Martinez-Castanon GA, Medina-Solis CE. Predictive values of thermal and electrical dental pulp tests: a clinical study. J Endod. 2013 Aug;39(8):965-9. doi: 10.1016/j.joen.2013.04.019. Epub 2013 May 21.
• Weisleder R, Yamauchi S, Caplan DJ, Trope M, Teixeira FB. The validity of pulp testing: a clinical study. J Am Dent Assoc. 2009 Aug;140(8):1013-7. doi: 10.14219/jada.archive.2009.0312.
• Gopikrishna V, Tinagupta K, Kandaswamy D. Evaluation of efficacy of a new custom-made pulse oximeter dental probe in comparison with the electrical and thermal tests for assessing pulp vitality. J Endod. 2007 Apr;33(4):411-4. doi: 10.1016/j.joen.2006.12.003. Epub 2007 Feb 23.
• Peters DD, Baumgartner JC, Lorton L. Adult pulpal diagnosis. I. Evaluation of the positive and negative responses to cold and electrical pulp tests. J Endod. 1994 Oct;20(10):506-11. doi: 10.1016/S0099-2399(06)80048-8.
• Petersson K, Soderstrom C, Kiani-Anaraki M, Levy G. Evaluation of the ability of thermal and electrical tests to register pulp vitality. Endod Dent Traumatol. 1999 Jun;15(3):127-31. doi: 10.1111/j.1600-9657.1999.tb00769.x.

Study record dates

Study Major Dates

• Study Start (Actual): June 30, 2024
• Primary Completion (Actual): December 30, 2024
• Study Completion (Actual): February 28, 2025

Study Registration Dates

• First Submitted: February 13, 2026
• First Submitted That Met QC Criteria: February 20, 2026
• First Posted (Actual): February 25, 2026

Study Record Updates

• Last Update Posted (Actual): February 27, 2026
• Last Update Submitted That Met QC Criteria: February 25, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Sensitivity; Predictive values; False responses; Pulp sensibility test; Specificty
• Additional Relevant MeSH Terms: Stomatognathic Diseases; Pathologic Processes; Immune System Diseases; Tooth Diseases; Necrosis; Pathological Conditions, Signs and Symptoms; Dental Pulp Necrosis; Hypersensitivity; Dental Pulp Diseases
• Other Study ID Numbers: 2024/48 Rev-2; TITCK (Other Identifier: Turkish Medicines and Medical Devices Agency)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared because the informed consent and ethics approval did not include public data sharing, and the dataset contains potentially identifiable clinical information.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes