In-vivo compatibility between pacemakers and dental equipment.

In-vitro studies suggest that electromagnetic interference can occur under specific conditions involving proximity between electronic dental equipment and pacemakers. At present, in-vivo investigations to verify the effect of using electronic dental equipment in clinical conditions on patients with pacemakers are scarce. This study aimed to evaluate, in vivo, the effect of three commonly used electronic dental instruments - ultrasonic dental scaler, electric pulp tester, and electronic apex locator - on patients with different pacemaker brands and configurations. Sixty-six consecutive non-pacemaker-dependent patients were enrolled during regular electrophysiology follow-up visits. Electronic dental tools were operated while the pacemaker was interrogated, and the intracardiac electrogram and electrocardiogram were recorded. No interferences were detected in the intracardiac electrogram of any patient during the tests with dental equipment. No abnormalities in pacemaker pacing and sensing function were observed, and no differences were found with respect to the variables, pacemaker brands, pacemaker configuration, or mode of application of the dental equipment. Electromagnetic interferences affecting the surface electrocardiogram, but not the intracardiac electrogram, were found in 25 (37.9%) patients, especially while using the ultrasonic dental scaler; the intrinsic function of the pacemakers was not affected. Under real clinical conditions, none of the electronic dental instruments tested interfered with pacemaker function.

[Endodontic treatment efficacy enhancement by means of instrumental physiotherapy]. / Povyshenie éffektivnosti éndodonticheskogo lecheniia s pomoshch'iu apparaturnykh metodov.

The article describes in detail and examines the prospects of such methods as electroodontodiagnosis, diathermocoagulation and apex-phoresis. It proves the necessity of development and standardization of devices for the mentioned treatment modalities that will improve the effectiveness an quality of caries complications treatment.

Oxygen saturation and perfusion index from pulse oximetry in adult volunteers with viable incisors.

OBJECTIVE: Evaluation of pulp vitality is an important diagnostic procedure in dentistry. Conventional techniques for measurement of pulp vitality, including thermal stimulation, electrical stimulation, or direct dentin stimulation, are frequently associated with false positive or false negative results. Recently, oxygen saturation from pulse oximetry has been utilized in the evaluation of pulp vitality. Perfusion index (PI) data calculated from photoplethysmography have been widely used to evaluate peripheral perfusion. The combination of oxygen saturation and PI may aid in the accurate measurement of pulp vitality. We aimed to investigate the baseline values of oxygen saturation and PI using pulse oximetry in adult volunteers. MATERIAL AND METHODS: Fifteen adult volunteers with viable incisors were tested. To measure PI, a fabricated oxygen sensor was applied to an incisor without a pulp lesion while oxygen saturation was simultaneously measured in the finger. Oxygen saturation and PI were continuously measured with customized software. The normal reference values of oxygen saturation and PI were obtained by analyzing the recorded data. RESULTS: Pulse oximetry showed relatively stable, objective, and accurate oxygen saturation results. The tooth oxygen saturation ranged from 97% to 100%. The PI ranged from 0.3% to 0.5%, and PI and oxygen saturation showed relatively consistent values across subjects. CONCLUSIONS: Although there are some limitations to our study, these results may prove useful for detecting teeth with impaired vitality and non-invasively differentiating between necrotic and vital pulp.

The use of pulse oximetry in evaluation of pulp vitality in immature permanent teeth.

BACKGROUND AND AIM: The current methods of pulp vitality assessment, either electric or thermal, are of limited use in children. Recently, traumatized and immature teeth may not respond to such methods and because such methods require subjective responses, it may not provide accurate results particularly in children. Pulse oximetry, an atraumatic approach, is used to measure oxygen saturation in vascular system. The aim of this study was to investigate the use of pulse oximetry to evaluate pulp vitality status in immature permanent teeth. METHODS AND MATERIALS: The study was conducted on 329 maxillary central and lateral incisors in children. The negative control group consisted of 10 root filled teeth. Systemic oxygen saturation was first measured on the thumb of the individual using a custom-made sensor. Oxygen saturation values of the teeth were then evaluated. The correlation between oxygen saturation measurement obtained from finger and tooth, and the correlation between oxygen saturation values and stage of root development were analyzed. A further comparison was made between the teeth with open and closed apex. RESULTS: Mean oxygen values recorded in the patient's finger were 97.17%, and mean oxygen values in the maxillary central and lateral incisors were 86.77% and 83/92%, respectively. There was no significant correlation between blood oxygen levels in the finger and in the teeth. (P > 0.05) There was a significant negative correlation between the stage of root development and the blood oxygen levels in the patients' teeth. (P < 0.05) Mean oxygen values in the teeth with open apex were significantly higher than the teeth with closed apex. (P < 0.001). CONCLUSION: Vital teeth provided consistent oxygen saturation readings, and non-vital teeth recorded no oxygen saturation values. During tooth development, the oxygen saturation values decreased. These findings confirm that the pulse oximetry is capable of detecting the pulpal blood flow and oxygen saturation.

Capacity of dental equipment to interfere with cardiac implantable electrical devices.

Patients with cardiac implantable electrical devices should take precautions when exposed to electromagnetic fields. Possible interference as a result of proximity to electromagnets or electricity flow from electronic tools employed in clinical odontology remains controversial. The objective of this study was to examine in vitro the capacity of dental equipment to provoke electromagnetic interference in pacemakers and implantable cardioverter defibrillators. Six electronic dental instruments were tested on three implantable cardioverter defibrillators and three pacemakers from different manufacturers. A simulator model, submerged in physiological saline, with elements that reproduced life-size anatomic structures was used. The instruments were analyzed at differing distances and for different time periods of application. The dental instruments studied displayed significant differences in their capacity to trigger electromagnetic interference. Significant differences in the quantity of registered interference were observed with respect to the variables manufacturer, type of cardiac implant, and application distance but not with the variable time of application. The electronic dental equipment tested at a clinical application distance (20 cm) provoked only slight interference in the pacemakers and implantable cardioverter defibrillators employed, irrespective of manufacturer.

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.

Responses of pulp sensibility tests during orthodontic treatment and retention.

AIM: To investigate the effect of orthodontic tooth movement involving the six maxillary anterior teeth on the pulp response to both thermal and electric stimuli during active orthodontic treatment and retention. METHODOLOGY: Forty-seven subjects who required fixed orthodontic appliances were used as a study group with 23 non-orthodontic subjects recruited as a control group. Cold and electrical stimuli were applied to the maxillary incisors and canines immediately before and after the placement of fixed appliances and at regular intervals for both groups during active treatment and 12 months into retention. The numbers of negative responses for each tooth at each time interval were recorded for both groups. The data were collected and tabulated, and chi-square tests were used to determine significant difference between the numbers of negative responses for the two types of tests used on the same tooth and between different teeth. The mean values of the electric pulp testing (EPT) thresholds were also obtained and used to assist in analysing the results. RESULTS: In the control group, all teeth tested positively to the EPT and thermal pulp tests at all time intervals. In the orthodontic group, two teeth failed to respond to EPT and only one tooth to thermal testing at baseline (Time 0). After that, the number of negative responses to both tests increased gradually at each time interval reaching a peak after 2 months of active treatment (Time 3) and then declined gradually towards the end of observation period (Time 14). At baseline, response thresholds to electric testing were typically higher for orthodontic subjects, particularly for the maxillary lateral incisor tooth. For the control group, the response threshold over the study period was relatively constant. For the orthodontic group, application of force immediately increased the response threshold to EPT (Time 1), which peaked after 2 months (Time 3) and then gradually reduced. At the end of the active treatment, response thresholds remained elevated, but they returned to pre-treatment values towards the end of the retention phase. CONCLUSION: Dental practitioners should interpret responses to electrical pulp testing cautiously in orthodontic patients; thermal testing may be more reliable.

Review of pulp sensibility tests. Part II: electric pulp tests and test cavities.

The electric pulp test (EPT) is one type of pulp sensibility test that can be used as an aid in the diagnosis of the status of the dental pulp. However, like thermal pulp sensibility tests, it does not provide any direct information about the vitality (blood supply) of the pulp or whether the pulp is necrotic. The relevant literature on pulp sensibility tests in the context of endodontics up to January 2009 was reviewed using PubMed and MEDLINE database searches. This search identified articles published between November 1964 and January 2009 in all languages. The EPT is technique sensitive, and false responses may occur. Various factors can affect the test results, and therefore it is important that dental practitioners understand the nature of these tests and how to interpret them. Test cavities have been suggested as another method for assessing the pulp status; however, the use of this technique needs careful consideration because of its invasive and irreversible nature. In addition, it is unlikely to be useful in apprehensive patients and should not be required because it provides no further information beyond what thermal and electric pulp sensibility tests provide - that is, whether the pulp is able to respond to a stimulus. A review of the literature and a discussion of the important points regarding these two tests are presented.

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.

Laser Doppler flowmetry in endodontics: a review.

Vascular supply is the most accurate marker of pulp vitality. Tests for assessing vascular supply that rely on the passage of light through a tooth have been considered as possible methods for detecting pulp vitality. Laser Doppler flowmetry (LDF), which is a noninvasive, objective, painless, semi-quantitative method, has been shown to be reliable for measuring pulpal blood flow. The relevant literature on LDF in the context of endodontics up to March 2008 was reviewed using PubMed and MEDLINE database searches. This search identified papers published between June 1983 and March 2008. Laser light is transmitted to the pulp by means of a fibre optic probe. Scattered light from moving red blood cells will be frequency-shifted whilst that from the static tissue remains unshifted. The reflected light, composed of Doppler-shifted and unshifted light, is returned by afferent fibres and a signal is produced. This technique has been successfully employed for estimating pulpal vitality in adults and children, differential diagnosis of apical radiolucencies (on the basis of pulp vitality), examining the reactions to pharmacological agents or electrical and thermal stimulation, and monitoring of pulpal responses to orthodontic procedures and traumatic injuries. Assessments may be highly susceptible to environmental and technique-related factors. Nonpulpal signals, principally from periodontal blood flow, may contaminate the signal. Because this test produces no noxious stimuli, apprehensive or distressed patients accept it more readily than current methods of pulp vitality assessment. A review of the literature and a discussion of the application of this system in endodontics are presented.

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.

Appropriate electrode placement site for electric pulp testing first molar teeth.

Twenty volunteers with first molars free of restorations and caries were recruited. One molar from each arch was selected, and rubber dam was applied. Seven sites on each crown were electric pulp tested 4 times with an Elements Diagnostic Unit, and lowest threshold responses were recorded. Data were analyzed with one-way analysis of variance and the Tukey test at the .01 level. The lowest response for both the maxillary and mandibular teeth was with the probe on the mesiobuccal cusp tip. Other sites showed an increase in level from the mesiobuccal cuspal surface, mesiobuccal gingival surface, and the center of the supporting cusps (palatal of maxillary molar, buccal of mandibular molar). No significant difference in responses was found between male and female subjects; however, male subjects responded at higher thresholds than female subjects on all test sites except the mesiobuccal cusp tip. The optimum site for pulp testing first molars is the mesiobuccal cusp tip.

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.

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.

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.

Appropriate electrode placement site of electric pulp tester for the premolars: a clinical study.

CONTEXT: Electric pulp testers (EPTs) are widely used as diagnostic aid in dentistry for dental pulp. This delivers enough current to overcome enamel and dentin resistance and to stimulate the myelinated sensory fibers at the junction of pulp and dentin. Such testing requires the electrode to be in contact with the surface of the tooth, with optimal positions identified for anterior teeth, premolars, and molars. AIMS: To determine the best site position of EPT on premolars. The objective of electric pulp testing was to determine the sensibility of each premolar at the lowest sensory response threshold. SETTINGS AND DESIGN: Clinical study Materials and Methods: The premolars of 20 patients between 13 and 15 years accompanied with parents, free of restorations, and caries were selected. Five sites on the crown were tested with EPT for minimum of four times. STATISTICAL ANALYSIS USED: One-way analysis of variance test and the Tukey's honestly significant difference test. RESULTS: The lowest threshold response was noted at the incisal edge of the tooth; the middle third had a higher threshold among all the different placement of electrode. Statistically significant difference was observed for occlusal surface in terms of region of placement of electrode. CONCLUSIONS: This experiment found the best electrode site for pulp testing in premolars. The appropriate EPT site was on the occlusal surface of maxillary and mandibular premolars.

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.