Electrical Pulp Testing: Sources of Error

INTRODUCTION

Accurate identification and assessment of an inflamed or necrotic tooth is essentialfor endodontic treatment. The purpose of this research was to investigate possible sources of error associated with the use of the electric pulp tester (EPT).

METHODS

Forty-six intact teeth (23 tooth pairs) in 22 patients were evaluated in vivo. For the tooth pairs, one tooth had to have been previously endodontically treated and restored with a class II amalgam restoration. The restoration was required to have proximal contact with a class II amalgam of another vital posterior tooth. EPT was performed on pulpless and vital teeth for experimental groups (enamel, restoration, contacting, or isolated).

RESULTS

The highest rate of false positive responses (82%) was found in the pulpless restored contacting group, suggesting that EPT impulses are able to travel through proximal metallic contacts and stimulate teeth distant from the EPT probe. All vital tooth groups had a high rate of positive responses with no significant diferences.

CONCLUSIONS

If a tested tooth contains an interproximal restoration contacting adjacent restorations or the gingival, the teeth must be isolated (rubber dam) and the EPT probe should be placed in a region suspected to have uninterrupted tubule paths to the pulp.

Effect of repeated refrigerant spray applications using various carriers on pulpal temperature change

This study sought to determine how repeated applications of a refrigerant spray on various cotton carriers affected the change in pulpal temperature. A thermocouple was placed at the roof of the pulp chamber of a human maxillary canine and connected to a thermometer logging at one-second intervals while the root was immersed in a water bath at 37 degrees C. Four different carrier types were used: large cotton pellets, small cotton pellets, cotton-tip applicators, and cotton rolls. Each carrier was sprayed with 1,1,1,2-tetrafluoroethane and placed on the crown for five seconds. Pulpal temperature change was recorded after each five second application of the same carrier to the tooth until a total of six consecutive sprays and applications of the carrier were applied. Each carrier group consisted of 10 performances of the six sets of readings (n = 10). The difference between baseline and the low temperature reading was calculated to determine the temperature change (in degrees C) in the pulp chamber per application. When the refrigerant spray was used, the large cotton pellet carrier generally produced the largest decrease in pulpal temperature at each repeated application compared to the other types of carriers. However, the same large cotton pellet should not be sprayed with the refrigerant more than two times before it is replaced.

Dental pulp neurophysiology: part 2. Current diagnostic tests to assess pulp vitality

In this second part of our 2-part review, we discuss recent research about pulp tests that determine the vitality of the tooth and clinically accepted pulp testers. A pain response to hot, cold or an electric pulp tester indicates the vitality of only a tooth's pulpal sensory supply; the response does not give any idea about the state of the pulp. Although the sensitivity of these tests is high, when false-positive and false-negative results occur, they may affect the treatment of the tooth. A tooth falsely diagnosed as nonvital with an electric pulp tester may undergo an unnecessary root canal, whereas one falsely diagnosed as vital may be left untreated, causing the necrotic tissue to destroy the supporting tissues (resorption). The vascular supply is more important to the determination of the health of the pulp than the sensory supply. Pulp death is caused by cessation of blood flow and may result in a necrotic pulp, even though the pulpal sensory supply may still be viable. The pulp can be healed only if the circulating blood flow is healthy. Although still under investigation, diagnostic devices that examine pulpal blood flow, such as the pulse oximeter and laser Doppler flowmetry, show promising results for the assessment of pulp vitality.

The anesthetic efficacy of articaine in buccal infiltration of mandibular posterior teeth

BACKGROUND

The authors conducted a prospective, randomized, double-blind, crossover study comparing the degree of pulpal anesthesia achieved by means of mandibular first molar buccal infiltrations of two anesthetic solutions: 4 percent articaine with 1:100,000 epinephrine and 2 percent lidocaine with 1:100,000 epinephrine.

METHODS

Each of 60 blinded adult subjects randomly received two buccal infiltrations at the first molar site: one cartridge of 4 percent articaine with 1:100,000 epinephrine at one appointment and one cartridge of 2 percent lidocaine with 1:100,000 epinephrine at another appointment. The injections were administered during two separate appointments spaced at least one week apart. The authors used an electric pulp tester to assess the first and second molars and the first and second premolars for pulpal anesthesia in three-minute cycles for 60 minutes. They considered anesthesia to be successful when they obtained two consecutive pulp test readings of 80 (meaning the subject evidenced no response at the maximum output on the pulp tester).

RESULTS

With the lidocaine formulation, successful pulpal anesthesia ranged from 45 to 67 percent. With the articaine formulation, successful pulpal anesthesia ranged from 75 to 92 percent. There was a significant difference (P < .05) in anesthetic success between the lidocaine and articaine formulations for each of the four teeth. Pulpal anesthesia declined slowly over 60 minutes with both formulations.

CONCLUSION AND CLINICAL IMPLICATIONS

For a mandibular buccal infiltration of the first molar, 4 percent articaine with 1:100,000 epinephrine will result in a higher success rate than will 2 percent lidocaine with 1:100,000 epinephrine, but the duration of pulpal anesthesia will decline over 60 minutes with either formulation.

Comparison of Electrical, Thermal, and Pulse Oximetry Methods for Assessing Pulp Vitality in Recently Traumatized Teeth

Pulse oximeter is a well-established and noninvasive method for measuring vascular health by evaluating oxygen saturation. This study compared the efficacy of a custom-made pulse oximeter dental probe with the electric pulp testing and thermal testing for measuring pulp vitality status of recently traumatized permanent teeth. Readings for pulp vitality for 17 recently traumatized maxillary incisors were taken with custom-made pulse oximeter dental probe (group 1), electrical pulp tester (group 2), and thermal testing (group 3) over a 6-month period. The proportion of recently traumatized teeth showing a positive responsiveness in thermal/electric pulp tests increased from no teeth showing responsiveness on day 0 to 29.4% teeth on the 28th day, 82.35% of teeth at 2 months, and 94.11% teeth at 3 months. However, pulse oximeter gave positive vitality readings that remained constant over the study period from day 0 to 6 months in all patients.

Evaluation of Efficacy of a New Custom-Made Pulse Oximeter Dental Probe in Comparison With the Electrical and Thermal Tests for Assessing Pulp Vitality

Pulse oximetry is a noninvasive method of measuring vascular health by evaluating oxygen saturation. This study evaluated the efficacy of a new custom-made pulse oximeter dental probe in comparison with the electrical and thermal tests for assessing pulp vitality. Sensitivity, specificity, negative predictive value, and positive predictive value for each test were calculated by comparing the test results with the actual pulpal status, as evaluated by direct visual inspection. The sensitivity of the pulse oximeter was found to be 1.00, as compared to 0.81 with the cold test and 0.71 with the electrical test. The specificity of the pulse oximeter was 0.95, as compared to 0.92 with the cold and electrical pulp tests. Thus, the custom-made pulse oximeter dental probe is an effective, accurate, and objective method of evaluating pulp vitality.

Safety of electronic apex locators and pulp testers in patients with implanted cardiac pacemakers or cardioverter/defibrillators

The purpose of this study was to determine if electronic apex locators (EAL) or electric pulp testers (EPT) interfere with the function of implanted cardiac pacemakers (ICP) or cardioverter/defibrillators (ICD). Twenty-seven patients with ICPs or ICDs had continuous electrocardiogram monitoring and device interrogation to detect interferences during the use of two types of EALs and one EPT. No interferences were detected by any ICP or ICD. In six patients, with intermittent pacing, a significant increase in pacing was observed during EAL/EPT stimulation (p < 0.05). Examination of RR intervals (a measure of intrinsic heart rate) demonstrated significantly longer RR intervals (slower intrinsic heart rate) during EAL/EPT stimulation (p < 0.05). Evaluation of the electrocardiograms for each patient failed to show any abnormalities in pacing during testing. These findings led us to conclude that the increased pacing frequency observed was related to a slower intrinsic heart rate and not electrical interference with the cardiac devices. In conclusion, the two EALs and one EPT used in this study did not interfere with the functioning of any of the cardiac devices tested.

Assessment of the efficacy of an indigeniously developed pulse oximeter dental sensor holder for pulp vitality testing

Current routine methods of assessment of pulp vitality rely on stimulation of nerve fibres and give no direct indication of blood flow within the pulp. Pulse oximeter is a proven, atraumatic method of measuring vascular status, by evaluating oxygen saturation. This study explores the use of customized dental pulse oximeter sensor holder to assess pulpal vascular oxygen saturation in permanent teeth. Pulse oximeter readily differentiated between known vital and nonvital teeth. Vital teeth consistently provided oxygen saturation values that were lower than the values recorded on the patient's fingers. Pulse oximeter is an accurate, atraumatic clinical alternative to the present electrical and thermal methods of assessing pulp vitality in teeth.

Reduction of excessive electrical stimulus during electric pulp testing

AIM

To measure excessive electrical stimulus time during pulp testing via electromyography (EMG) in the anterior belly of the digastric muscle, voice and finger movement, and to determine whether excessive stimulus time could be attenuated by a specially designed automatic circuit breaker on the basis of the EMG signal.

METHODOLOGY

The signals from three human responses (EMG, finger and voice), induced by the Digitest (Parkell Inc., Farmingdale, NY, USA) electric pulp tester, were captured using a MP100 (Biopac System Inc., Goleta, CA, USA) and recorded into a personal computer. The excessive stimulus time from activation to the end of electrical stimulation was calculated for each of these three responses. The automatic circuit breaker was designed to disconnect the electrical output of the electric pulp testing (EPT) unit immediately after detecting the preset EMG level (100 mV). Each of the right central incisors and first premolars of 23 healthy individuals (16 males and seven females) was tested to see whether there was a difference in tooth type or gender. This was analysed by Wilcoxon signed rank test (nonparametric paired t-test) and Mann-Whitney test (nonparametric independent t-test), respectively.

RESULTS

Amongst three human responses, the electrical onset occurred in the order of EMG, finger and voice. Excessive stimulus time was 347.8 +/- 78.3 ms when observed by the EMG, 264.9 +/- 63.9 ms when observed by finger span and 229.4 +/- 41.8 ms when observed by the voice, which were all found to be significantly different (P < 0.05). When the automatic circuit breaker was used, the excessive stimulus time was 61.0 ms, which was 286.8 ms shorter than that measured from EMG onset when using the conventional EPT.

CONCLUSIONS

When the automatic circuit breaker was used, excessive stimulus time on the basis of EMG was attenuated on average by 286.8 ms.

[LASER applications in endodontics]

Since the development of the ruby laser by Maiman in 1960 and the application of the laser for endodontics by Weichman in 1971, a variety of lasers with a wide range of characteristics are now being used in endodontic therapy. In the past two decades much experience and knowledge has been gained The first purpose of the present paper is to provide an understanding of the essential physical science behind laser technology and information on the effects of laser beams on tissue (tissue interaction). A second purpose is to summarize laser applications in endodontics, including their use in pulp diagnosis, dentinal hypersensitivity, pulp capping and pulpotomy, modification of the root canal walls, sterilization of the root canal system, cleaning--shaping--obturation of the root canal, and endodontic surgery. It will be clear that a number of endodontic procedures with conventional treatments cannot provide comparable results or are less effective.

Anesthetic efficacy of the palatal–anterior superior alveolar injection

BACKGROUND

A single palatal-anterior superior alveolar, or P-ASA, injection has been reported to provide pulpal anesthesia of the four maxillary incisors and usually the canines. The authors conducted a prospective, randomized, double-blind study to compare the anesthetic efficacy of 2 percent lidocaine with 1:100,000 epinephrine and 3 percent mepivacaine using a computer-assisted injection system to administer the P-ASA injection.

MATERIALS AND METHODS

In a double-blind manner, the authors used a crossover design to administer randomly P-ASA injections of 1.4 milliliters of the lidocaine solution and 1.4 mL of the mepivacaine solution using the computer-assisted injection system at two appointments to 40 subjects. They used a pulp tester to test for anesthesia of the central incisors, lateral incisors and canines in four-minute cycles for 72 minutes. Anesthesia was considered successful when two consecutive maximum readings (80 readings) with the pulp tester were obtained.

RESULTS

For the lidocaine solution, successful pulpal anesthesia ranged from 32 to 58 percent for the six anterior teeth. For the mepivacaine solution, successful pulpal anesthesia ranged from 22 to 38 percent. Except for the left canine, the lidocaine solution was significantly more likely to result in pulpal anesthesia than the use of the mepivacaine solution. The duration of pulpal anesthesia, for both solutions, declined steadily over 72 minutes.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Using the computer-assisted injection system for the P-ASA injection, we concluded that the rather modest-to-low success rates of the lidocaine and mepivacaine solutions would not ensure predictable pulpal anesthesia of the four maxillary incisors and the canines.

The effect of electrical dental equipment on a vagus nerve stimulator's function

BACKGROUND

Dental patients who have epilepsy with pharmacologically refractory seizures may be treated with an implanted pulse generator that electrically stimulates the left vagus nerve. The pulse generator functions like a cardiac pacemaker. Some electrical dental devices have been shown to cause electromagnetic interference with the function of cardiac pacemakers. The potential effect of similar dental equipment on vagus nerve stimulators is unknown.

METHODS

Common electrical dental devices were operated at maximum power settings in close proximity to a representative vagus nerve stimulator. The author assessed any interference of the dental devices with the nerve stimulator function by observing oscilloscope tracings.

RESULTS

Under the conditions of this evaluation, none of the dental devices tested altered the function of the vagus nerve stimulator.

CONCLUSIONS

Some commonly used electrical dental devices may be used in close proximity to patients who have implanted vagus nerve stimulators without adverse effects on the nerve stimulator function.

CLINICAL IMPLICATIONS

Dentists and dental hygienists may encounter patients with implanted vagus nerve stimulators, and they need to be cognizant of developments in the treatment of epilepsy. Under the conditions of this study, use of common dental electrical devices did not alter the function of a vagus nerve stimulator. The findings of this study, however, should not be generalized to all types of electrical dental or medical devices, as a recent report indicates that treatment with diathermy devices is contraindicated for patients with implanted nerve stimulators.

Impact of dental devices on cochlear implants

A cochlear implant (CI) converts mechanical sound energy into electrical signals that can be delivered to the cochlear nerve of profoundly deaf patients. The purpose of this study was to investigate whether electromagnetic interference with the CI occurs during the operation of the electric pulp tester, apex locator, electrocautery unit, electrosurgery unit, or panoramic radiograph machine. A mastoidectomy and cochleostomy were performed on a cadaver, and a CI was implanted. The dental devices were used intraorally, and the implant's circuitry was tested after each trial. A second CI was implanted in a human skull, which was then exposed to 50 panoramic radiographs, testing the implant's circuitry after each exposure. The probability of damage to the CI by any of the devices was negligible, except for the electrosurgery unit operated at level 7, which destroyed the CI's circuitry. Therefore, although the other devices seem safe, it is recommended that the electrosurgery unit not be used on a CI patient.

Lasers in endodontics

The first application of lasers in dentistry was the surgical treatment of tumors in the oral cavity, and various lasers, including semiconductor diode, carbon dioxide, helium-neon, neodymium:yttrium-aluminum-garnet, argon, erbium, and erbium chromium, have been developed since and applied in dentistry. This article describes the current and possible future clinical indications, laser devices, techniques, assessment methods, and mechanics.

Effect of transcutaneous electrical nerve stimulation on pain perception threshold of human teeth: a double-blind, placebo-controlled study

In this double-blind, placebo-controlled study, we studied the effect of three different transcutaneous electrical nerve stimulation (TENS) devices with extra- and intraoral electrodes on the pain perception thresholds of 234 unrestored, caries-free human teeth of 66 healthy individuals subjected to stimulation with an electric pulp tester. A placebo control collective of 64 healthy subjects received no electrical stimulation, since an inactive TENS device was used. In all tooth types tested (maxillary and mandibular incisors and premolars), the use of the active TENS devices resulted in an increase of 16.3-32.5% versus baseline in the pain perception threshold. The differences between active TENS and baseline were statistically significant for both TENS devices using extraoral electrodes (P < 0.05). No statistically significant differences were found between the different devices tested (P > 0.05). In the placebo collective, the increase in the pain perception threshold ranged between 6.4% and 10.3% versus baseline. There were no significant differences between placebo TENS and baseline on the one hand and between placebo TENS and the active TENS devices on the other hand (P > 0.05). The findings suggest that, as an alternative to local anesthetics, TENS seems not to be useful in the case of painful dental interventions, since it offered only minor advantages over a placebo.

Effect of the type carrier used on the results of dichlorodifluoromethane application to teeth

Thermal testing, especially cold, is an important part of diagnosing pulpal vitality. It was the purpose of this study to determine (i) if a difference exists in temperature when Endo ice is used with four different applicators, and (ii) if there is one applicator device that provides the greatest thermal change for a tooth. Endo ice was used with the following applicators: a #2 standard size large cotton pellet, a #4 standard size small cotton pellet, a wood stick cotton tip applicator, and a cotton roll. The temperature of a mandibular incisor pulp chamber was measured in degree C 10 s after the application of the dichlorodifluoromethane (DDM) to the midfacial surface of the crown. Also, the DDM was applied to each applicator either by direct spray or by submergence in DDM liquid. This study found that the greatest temperature change was recorded by Endo Ice (DDM) sprayed directly onto a large cotton pellet. There was no significant difference between directly spraying or submerging the applicator in DDM liquid.

Evaluation of the ability of thermal and electrical tests to register pulp vitality

The aim of the present study was to evaluate the ability of thermal and electrical tests to register pulp vitality. Sensitivity, specificity, negative predictive value and positive predictive value were calculated by comparing the test results with a "gold standard". The thermal tests studied were a cold test (ethyl chloride) and a heat test (hot gutta-percha). For the electrical test, the Analytic Technology Pulp Tester was used. The examined teeth were 59 teeth with unknown pulpal status in need of endodontic treatment and 16 intact teeth, all with radiographically normal periapical bone structures. In total 46 teeth with vital pulps and 29 teeth with necrotic pulps were tested. This gave a disease prevalence of 39%. The gold standard was established by direct pulp inspection of the 59 teeth in need of endodontic treatment. In the 16 intact teeth the pulp was judged as vital. The number of true positive (TP), false positive (FP), true negative (TN) and false negative (FN) test results was calculated for each method as compared to the gold standard. Based on this, the sensitivity, specificity, positive predictive value and negative predictive value were calculated for each method. The sensitivity was 0.83 for the cold test, 0.86 for the heat test and 0.72 for the electrical test. The specificity was 0.93 for the cold test, 0.41 for the heat test and 0.93 for the electrical test. The positive predictive value was 0.89 for the cold test, 0.48 for the heat test and 0.88 for the electrical test, and the negative predictive value was 0.90 for the cold test, 0.83 for the heat test and 0.84 for the electrical test. This indicated that the probability of a non-sensitive reaction representing a necrotic pulp was 89% with the cold test, 48% with the heat test and 88% with the electrical test. It also indicated that the probability of a sensitive reaction representing a vital pulp was 90% with the cold test, 83% with the heat test and 84% with the electrical test.

Pulse oximetry evaluation of vitality in primary and immature permanent teeth

Present methods of assessing pulp vitality (electric and thermal testing) are of limited use with children, often resulting in false positive or false negative results. Pulse oximetry is a proven, atraumatic method of measuring vascular health by evaluating oxygen saturation (SaO2). This pilot study explores the use of a modified pulse oximetry ear probe to assess pulpal vascular oxygen saturation in primary and immature permanent teeth. Pulse oximetry readily differentiated between known vital and nonvital teeth. Vital teeth consistently provided SaO2 values that were lower than the values recorded on the patients' fingers. Further study of the SaO2 changes in traumatized teeth, with a probe designed specifically for teeth, is warranted by these initial results. Although additional research is indicated, pulse oximetry is already an objective, atraumatic clinical alternative to the present electrical and thermal methods of assessing pulp vitality in children's teeth.

Evaluation of a laser Doppler flowmeter to assess blood flow in human primary incisor teeth

PURPOSE

This study determined whether the portable Advance Laser Flowmeter Model 21, a clinical instrument, would indicate significant values when pulpal blood flow was present or absent; whether the analog output of the flowmeter was time-linked to the heart rate; and whether labial and lingual crown surfaces produced different flow values.

METHODS

Teeth were tested under two conditions: with the teeth in situ and extracted, or with the pulp present and removed.

RESULTS

Values before and after the teeth were extracted, and those before and after pulpectomy with the tooth in situ were significantly different. These findings verified that the flowmeter measured the presence of bloodflow. Peaks of the electrocardiogram waves and the regular signal fluctuations of the flowmeter were time-linked and verified the measurement of the heart rate from the dental pulp. Differences in the values for the lingual and labial surfaces of individual teeth were not significant.

CONCLUSIONS

This instrument proved a valid means of determining the presence of pulpal blood flow in primary incisors.

Demonstration of a possible source of error with an electric pulp tester

The purpose of this study was to determine whether electrical current can travel between adjacent teeth through contacting interproximal amalgam restorations. Twenty-two extracted human premolars were restored with class II amalgam restorations. They were then mounted in pairs in self-curing resin, simulating adjacent teeth. Only their restorations were allowed to contact. An electrical multimeter was used to supply electrical current and to measure any current passing through the mounted teeth. One current measurement was made from the buccal enamel of a tooth to the occlusal surface of the filling in that tooth. A second measurement was made from the buccal enamel of the same tooth to the occlusal surface of the adjacent filling. These two measurements were made for all 11 trials. Statistically, all current that entered the first tooth passed to the adjacent tooth. This finding suggests a potential source of error when using an electric pulp tester.

Information of circulation from soft tissue and dental pulp by means of pulsatile reflected light: further development of optical pulp vitalometry

OBJECTIVES

To show experimentally and clinically that information of blood circulation patterns can be obtained through dentin and enamel by means of reflected light.

STUDY DESIGN

Several different experimental techniques were developed in vitro leading up to in vivo tests.

RESULTS

Pulsatile information of back-scattered light at 560 nm was obtained in an experiment in which a thread with white and red sections was pulled through the empty pulp cavum. The pulsatile information of back-scattered light of 560 nm wavelength was detected from a forefinger of a volunteer through dental hard tissue plates. There was a difference in the radiant flux of back-scattered light in extracted teeth filled with various materials. Photoplethysmograms obtained from the vital pulp of a 24-year-old woman were analyzed with Fast Fourier Transformation (FFT). The analyzed data showed a dominant amplitude of heart rate near 1 Hz.

CONCLUSIONS

Tests indicated that reliable information of circulation can be obtained from the dental pulp chamber by means of the optical reflection method. This could serve as a model for a new type of pulp vitalometer.

Possible application of transmitted laser light for the assessment of human pulpal vitality

The purpose of this study was to determine whether use of transmitted laser light would enable a better assessment of human pulpal vitality than back-scattered light does (LDF: laser Doppler flowmetry). The experiments were carried out on ten upper central incisors in six subjects aged 23-28 years; five of the teeth were vital with no restoration, and five were non-vital. For use with transmitted laser light, the fibers within the probe of a conventional LDF apparatus were used, one for transmitting light onto the buccal surface, the other for receiving it at the palatal surface of the same tooth. For LDF, the probe was fixed at the buccal surface. Blood flow was measured at three different locations on each experimental tooth: the incisal third, the center and the cervical third of the tooth crown. In non-vital teeth, 1) output signals with transmitted laser light all registered zero, and no oscillation could be seen in recordings from any location on the tooth, but 2) LDF signals were above zero, there were regular oscillations related to heart rate, and passive increases in blood flow (corresponding to blood pressure increases) were recorded from both the center and the cervical third of the tooth, indicating that LDF registered blood flow of non-pulpal origin. In vital teeth, LDF signals were significantly higher than in non-vital teeth at each location on the tooth. At the central site on vital teeth, the output signals for transmitted laser light were about twice those seen with LDF, and passive blood flow changes corresponding to blood pressure increases were more clearly observed. These results indicated that transmitted laser light would be useful for the assessment of tooth pulp vitality both because the blood flow signals did not include flow of non-pulpal origin, and because its output signals and response to blood flow changes were clear and could easily be monitored.

Use of the dental pulp tester in veterinary dentistry

Personal experience with a manually set electronic dental pulp tester is described. The small battery-operated hand-held unit is used in awake dogs and cats, and can rapidly indicate absence of vitality or increased or decreased responsiveness of the pulp tissue.

Evaluation of a pulse oximeter and customized probe for pulp vitality testing

Current routine methods for assessment of pulp vitality rely on stimulation of A-delta nerve fibers and give no direct indication of blood flow within the pulp. Recent papers have suggested that pulse oximeters may be used to diagnose pulp vitality by detection of blood flow. In this study, an optimized pulse oximeter probe for teeth was designed, built and tested using the Biox 3740 Oximeter (Ohmeda, Louisville, CO). Following preliminary in vitro tests, the probe was tested clinically. Pulse waveforms from maxillary and mandibular anterior teeth were noted. Simultaneous readings from the subjects' finger were used as controls. Pulse wave readings from the teeth were found to be synchronous with the finger probe, but not consistently. It was easier to maintain continuous readings from mandibular incisors than from maxillary incisors. The average percentage synchronization with the pulse was 28.95% for maxillary incisors and 50.28% for mandibular incisors. This difference was significant (p = 0.05). The overall accuracy of the commercial instrument was disappointing, and in its present form it was not considered to have clinical value.

A clinical evaluation of the electric pulp tester as an indicator of local anesthesia

Local anesthesia is the primary method in dentistry to control patients' pain. However, several studies have shown that profound anesthesia is not always achieved. The electric pulp tester has been used to measure the level of local dental anesthesia during endodontic therapy. However, no study has been performed that evaluates the ability of the electric pulp tester to predict the efficacy of local anesthesia prior to as operative procedure. If ineffective anesthesia could be predicted, supplemental injections could be administered to alleviate the anesthetic problem. The purpose of this study was to evaluate the ability of the electric pulp tester to measure the level of local anesthesia prior to operative treatment. The study was performed in vivo on patients requiring operative therapy. All teeth were pulp tested preoperatively for vitality using the electric pulp tester. After injection of local anesthetic, traditional parameters of dental anesthesia were verified (lip numbness, mucosal sticks). Teeth were then retested with the electric pulp tester and the results recorded. The teeth were them prepared for restoration using conventional instrumentation, and the patient's level of anesthesia evaluated using a visual analog scale. The electric pulp tester readings were compared to the patient's responses using Fisher's Exact test (two-tail). The results indicate that the electric pulp tester can be a valuable tool in predicting potential anesthetic problems in operative (restorative) dentistry.

Simplified approach to use of electrical pulp tester

The routine use of gloves as a barrier technique is recommended by the American Dental Association and the Centers for Disease Control. The use of the electrical pulp tester necessitates that the dentist contact the patient's skin or mucosa to complete the circuit. A technique is presented that simplifies the operation of the electrical pulp tester by the dentist wearing gloves. Advantages of this method include a sound barrier technique, an enhanced psychological benefit to the dentist, and an abatement in discomfort for the patient.

Reliability of laser Doppler flowmetry in testing vitality of human teeth

The aim of this investigation was to study the reliability of the laser Doppler flowmetry (LDF) output signals when testing from 4 different positions on the buccal surface of human teeth. Recordings were made from 10 intact anterior teeth in 10 patients, mean age 27.4 years. Five types of probes were used. Each probe had 3 fibers arranged in a triangle, one lighted fiber and 2 receiving ones. The separation of the fibers was 1500, 1000, 800, 500 and 250 microns. The diameter of the fibers was 200 microns in all probes except the one with the smallest separation of fibers where it was 125 microns. A rubber base splint was used to position the probe on the buccal surface of the teeth tested. The first recording was made with the ingoing light in a gingival position. Then 3 additional recordings were made turning the probe 90 degrees each time consequently changing the position of the ingoing light accordingly. Thus, gingival, mesial, incisal and distal recordings were obtained. The output signals were fed into a lap-top computer upon which all calculations were done. The output signals from the incisalmost position of the teeth were significantly lower than the output signals from the other 3 positions with all probes except one. The turning of the probes into the 4 different positions affected the output signals from the probe with the smallest separation of fibers significantly more than the output signals from the other probes.

Electric pulp tester and apex locator barrier technique

Use of the electric pulp tester and the apex locator during assessments of pulp vitality and root length determination involves bacterial cross-contamination of the metal surfaces of the probe tip and lip clip inserts which contact the oral hard and soft tissues. Reuse of these endodontic aids necessitates the sterilization or disinfection of the metal insert or the acquisition of extra attachments. A barrier technique that protects the electric pulp tester probe tip and the apex locator lip clip from bacterial contamination and employs the principle of electric conductive bridging is presented.

Effect of probe design on the suitability of laser Doppler flowmetry in vitality testing of human teeth

The aim of this investigation was to study the influence of probe design on the signal output from the dental pulp in experiments with laser Doppler flowmetry (LDF). Eighteen patients 14 to 39 years of age were examined. Recordings were made from a maxillary and a mandibular central incisor and a maxillary canine with an infrared laser Doppler flowmeter. The radiographic appearance of the tested teeth was within normal limits and all teeth responded normally to electric pulp testing (EPT). Five configurations of probes were used. Each probe had 3 fibers arranged in a triangle. One fiber carried the laser light to the pulp tissue and 2 fibers carried the backscattered light to the detector giving the signal output. The diameter of each of the 3 fibers in the probe was 200 microns except in 1 probe where the diameter of the fibers was 125 microns. The distance between the 3 fibers in the triangular arrangement in each probe was 250, 500, 800, 1000, and 1500 microns. A special rubber base splint was used to hold the probe in place on the buccal surface of the tested teeth. The output signals from the LDF were fed into an analog printer and a lap top computer where all calculations were done. The probe with the largest separation of the fibers produced significantly higher output signals from the maxillary and mandibular incisors than the other probes. The same probe also produced significantly higher output signals than the smaller probes from the maxillary canine with the exception of the 200/800 probe.(ABSTRACT TRUNCATED AT 250 WORDS)

Dual wavelength spectrophotometry as a diagnostic test of the pulp chamber contents

The purpose of this in vitro study was to determine the feasibility of using dual wavelength spectrophotometry to identify teeth with pulp chambers that are either empty, filled with fixed pulp tissue, or filled with oxygenated blood. In phase I of the experiment, a human third molar was prepared so that its pulp space could be filled with oxygenated blood and later emptied. In phase II, the lower jaw of a beagle dog was removed and placed in formalin, thereby fixing the pulps of the teeth. The pulp of the right canine was removed via an apical approach, and attachments were placed in a similar position to those on the human tooth, to allow filling and emptying of the pulp space. Cavit was placed over the exposed fixed pulp in the left canine. Ten readings, which were separated by light source and detector removal and replacement, were taken of the right canine pulp space when it was empty or filled with oxygenated blood, or the left canine pulp space when it was filled with fixed tissue. Distinct and reproducible changes were measured for pulp spaces filled with air, tissue, or oxygenated blood. In phase III, simulated pulp testing on a dog tooth model was performed. Blood was introduced into the root canal space, the chamber was rinsed with water and replaced with air, according to a predetermined code. Spectrophotometer readings were recorded. The identification of pulpal contents was correctly determined in all 20 of the predetermined conditions. The findings indicate that continuous wave spectrophotometry may become a useful pulp testing method.

Use of dental instruments for bridging during electric pulp testing

It has been suggested that dental instruments can be used as bridging instruments to facilitate electric pulp testing of teeth with extensive restorations. This study reports a clinical investigation to evaluate the effectiveness of this procedure. One hundred seventeen vital teeth in 20 volunteers were tested. Ten endodontically treated teeth functioned as controls. Following appropriate isolation and asepsis technique, baseline recordings of the threshold response with the electric pulp tester were taken. With the use of dental explorers and endodontic files to bridge between the probe tip and the tooth surface, recordings were made of the threshold responses. Findings indicate that electrically conductive dental instruments can be reliably used as bridging instruments with the electric pulp tester.

Reproducibility of data from a hand-held digital pulp tester used on teeth and oral soft tissue

Controlled studies of the reproducibility of data from electronic pulp testing instruments are limited and contain few statistical analyses. The reproducibility of these readings is important if the instrument is to be used for determining differences in sensitivity. Twenty human subjects (16 male) were used in this study. One incisor, one premolar, one molar tooth with small or no restorations, and two gingival soft tissue positions from each upper and lower arch of each subject were stimulated with the Analytic Technology vitality scanner. This procedure was repeated twice with a 5-minute rest between each trial, for a total of three trials. Each subject was then seen again after a period of at least 3 days, at which time the trials were repeated. The collected data were grouped by trial, tooth position, and day. Paired t test analysis of both the absolute difference between any two trials on the same day and the average of the absolute differences between corresponding trials on days 1 and 2 showed no statistically significant differences (p greater than 0.05). Accommodation to the stimulus was evaluated by examining differences in the mean values between the three same-day trials. The Analytic Technology vitality scanner was found to be reproducible both for consecutive same-day trials and for corresponding trials on different days. No same-day trends in meter readings were noted.

[Vitality tests of the tooth pulp using laser Doppler flowmetry]

Laser-Doppler flowmetry allows a non-invasive assessment of the microcirculation in circumscribed tissue areas. However, measurements in intact human teeth prove to be extensive, as far as instrumental equipment and time requirements are concerned. Therefore we developed an application system which allows us to transfer the principle of measurement under clinical conditions. Thus we were able to prove that the signal recorded can be regarded as a specific expression of pulpal microcirculation. A comparison between vital teeth and root-filled teeth shows that the signal to noise ratio is sufficiently high to allow a definite assessment of pulp vitality.

[Measuring of thresholds of the periodontal diseased teeth by electric pulp tester]

Studying of influence of periodontal disease on vitality of pulp, the response thresholds of 421 teeth (250 normal teeth, 171 periodontal diseased teeth) were examined electronically by means of an automatic pulptester. (ANALYTIC TECHNOLOGY CO.) The pulp tester values of three experiments were averaged. The average value of normal teeth was 36.3 and that of periodontal diseased teeth 31.4. The response thresholds of periodontal diseased teeth were lower than those of normal teeth. This indicated that pulp was inflamed by periodontal disease and pulp vitality became weak.

A comparison of pulpal and tactile detection threshold levels in young adults

Pulpal and tactile sensory detection threshold (SDT) values of the maxillary and mandibular incisor and canine teeth were determined and recorded for young adult subjects at three test sessions. A commercially available monopolar pulp-testing device was used to determine pulpal SDT values, and von Frey hairs were used to determine the tactile SDT values. Statistical analysis of the data indicated that the pulpal and tactile test procedures were sufficiently reliable in identifying what is defined as the true SDT value for both parameters. The study confirmed the constancy of these SDT values over days and the independence of the values for jaw, side, and sex. SDT values were influenced, however, by tooth type, with canine teeth displaying higher tactile and pulpal values than the central and lateral incisor teeth. These data should provide a suitable baseline for a longitudinal study to identify the SDT fluctuations known to occur in tooth pulp and dental supporting tissues in a growing human population.

Capacitance effect of rubber gloves on electric pulp testers

Electric pulp testers (EPTs) are widely used to assess tooth pulp vitality. With many unipolar EPTs the electrical circuit is completed through the operator. Since dentists now routinely wear rubber gloves, these might be expected to provide electrical insulation, and therefore to break the circuit. The objective of this investigation was to define the electrical effect of wearing rubber gloves. Two battery-powered unipolar EPTs were examined using a digital storage oscilloscope with an input impedance of 1 M omega. The probe tip was connected directly to the positive input lead of the oscilloscope. Three conditions were tested: (i) with the conductive handle connected directly to the negative input lead; (ii) with the ungloved operator holding the negative input lead in one hand and the conductive handle of the EPT in the other; and (iii) holding the conductive handle in a gloved hand. While the two EPTs produced different patterns of voltage spike, for each there was no difference between conditions (i) and (ii). However, when the conductive handle was held in a gloved hand (condition iii), there was a reduction in peak negative voltage and a change in wave form with positive overshoot. The alteration in wave form could be reproduced by substitution of the operator's gloved hand with a capacitance of 47 pF. These results support the hypothesis that a rubber glove acts partly as a capacitor in series with the electric pulp tester, and will alter the performance of EPTs unless the glove is bypassed electrically.

The optimum placement-site of the electrode in electric pulp testing of the 12 anterior teeth

The present study of 2,387 recordings of 12 anterior teeth in 53 patients indicates that the incisal edge is the optimal placement-site for the electric pulp tester to determine the lowest response threshold. The results show significant individual variations in the lowest threshold responses of the cervical-third, middle-third, incisal one-third, and incisal edge sites on a tooth, with a confidence level of 99%, according to the analysis of variance. The maxillary teeth gave a higher response threshold than the mandibular teeth and different types of teeth (canines and incisors) had statistically significant different response thresholds. The application of the electric pulp tester to the incisal-edge region with exposed dentin produced the most significant decrease in the threshold response.

Using the electric pulp tester with gloves: a simplified approach

A method is presented which simplifies the use of the electric pulp tester for the dentist who routinely wears gloves in practice. Advantages of this method include a reduction in patient apprehension as well as a possible decrease in discomfort for the patient.

Pulp test response of the maxillary anterior teeth in cleft palate patients

The relative pulpal responsiveness of the six maxillary incisors to electrical and cold thermal stimuli was tested in patients with complete unilateral and bilateral clefts. The six maxillary anterior teeth were tested at random to electrical stimuli. After a 5-minute interval, the same teeth were tested at random to cold stimuli with an ice pencil. Unilateral and bilateral cleft palate patients had statistically significant higher mean electrical pulp test thresholds for the maxillary anterior teeth than the noncleft palate patients. No statistically significant difference between unilateral and bilateral cleft palate patients was found in electric pulp test responses of the maxillary anterior teeth. No statistically differences in electric pulp test responses and cold test responses of the maxillary anterior teeth in both cleft palate and noncleft palate individuals based on differences in sex were observed. No statistically significant difference in cold test responses were observed between cleft palate and noncleft palate patients. Cleft palate patients who completed orthodontic treatment within 1 year of testing showed elevated mean electrical pulp test thresholds as did noncleft palate patients who received orthodontic treatment within 1 year of testing.