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.

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.

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.

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.

Anaesthetic efficacy of bupivacaine 2-hydroxypropyl-ß-cyclodextrin for dental anaesthesia after inferior alveolar nerve block in rats.

Bupivacaine is a long-acting local anaesthetic that is widely used in medicine and dentistry. The duration and intensity of its sensory blockade in animal models is increased by its inclusion in complexes with cyclodextrins. The aim of the present study was to evaluate the anaesthetic efficacy of bupivacaine 2-hydroxypropyl-ß-cyclodextrin (HPßCD) inclusion complex for dental anaesthesia after inferior alveolar nerve block in rats. Thirty rats were each given an injection close to the mandibular foramen of 0.2ml of one of the following formulations: 0.5% bupivacaine alone; 0.5% bupivacaine with 1:200,000 epinephrine; and 0.5% bupivacaine-HPßCD inclusion complex (bupivacaine-HPßCD). The other sides were used as controls, with either 0.9% saline or anaesthetic-free HPßCD solution being injected. The onset, success, and duration of pulpal anaesthesia were assessed by electrical stimulation ("pulp tester") on inferior molars. Results were analysed using ANOVA (Tukey), log rank, and chi square tests (α=5%). There were no differences among the formulations in onset of anaesthesia (p=0.59) or between the bupivacaine plus epinephrine and bupivacaine plus HPßCD in duration of anaesthesia, but bupivacaine plus epinephrine gave significantly higher values than bupivacaine alone (p=0.007). Bupivacaine plus epinephrine was a better anaesthetic than bupivacaine alone (p=0.02), while Bupi-HPßCD gave intermediate results, and therefore did not differ significantly from the other 2 groups (p=0.18 with bupivacaine alone; and p=0.44 with bupivacaine plus epinephrine). The bupivacaine-HPßCD complex showed similar anaesthetic properties to those of bupivacaine with epinephrine.

Evaluation of dental pulp sensibility tests in a clinical setting.

INTRODUCTION: The goal of this project was to evaluate the performance of dental pulp sensibility testing with Endo Ice (1,1,1,2-tetrafluoroethane) and an electric pulp tester (EPT) and to determine the effect of several variables on the reliability of these tests. METHODS: Data were collected from 656 patients seen in the University of Iowa College of Dentistry Endodontic graduate clinic. The results of pulpal sensibility tests, along with the tooth number, age, sex, number of restored surfaces, presence or absence of clinical or radiographic caries, and reported recent use of analgesic medications, were recorded. The presence of vital tissue within the pulp chamber was used to verify the diagnosis. RESULTS: The Endo Ice results showed accuracy, 0.904; sensitivity, 0.916; specificity, 0.896; positive predictive value, 0.862; and negative predictive value, 0.937. The EPT results showed accuracy, 0.75; sensitivity, 0.84; specificity, 0.74; positive predictive value, 0.58; and negative predictive value, 0.90. Patients aged 21-50 years exhibited a more accurate response to cold testing (P = .0043). Vital teeth with caries responded more accurately to cold testing (P = .0077). There was no statistically significant difference noted with any other variable examined. CONCLUSION: Pulpal sensibility testing with Endo Ice and EPT are accurate and reliable methods of determining pulpal vitality. Patients aged 21-50 exhibited a more accurate response to cold. Sex, tooth type, number of restored surfaces, presence of caries, and recent analgesic use did not significantly alter the results of pulpal sensibility testing in this study.

Predictive values of thermal and electrical dental pulp tests: a clinical study.

INTRODUCTION: For a diagnostic test to be useful, it is necessary to determine the probability that the test will provide the correct diagnosis. Therefore, it is necessary to calculate the predictive value of diagnostics. The aim of the present study was to identify the sensitivity, specificity, positive and negative predictive values, accuracy, and reproducibility of thermal and electrical tests of pulp sensitivity. METHODS: The thermal tests studied were the 1, 1, 1, 2-tetrafluoroethane (cold) and hot gutta-percha (hot) tests. For the electrical test, the Analytic Technology Pulp Tester (Analytic Technology, Redmond, WA) was used. A total of 110 teeth were tested: 60 teeth with vital pulp and 50 teeth with necrotic pulps (disease prevalence of 45%). The ideal standard was established by direct pulp inspection. RESULTS: The sensitivities of the diagnostic tests were 0.88 for the cold test, 0.86 for the heat test, and 0.76 for the electrical test, and the specificity was 1.0 for all 3 tests. The negative predictive value was 0.90 for the cold test, 0.89 for the heat test, and 0.83 for the electrical test, and the positive predictive value was 1.0 for all 3 tests. The highest accuracy (0.94) and reproducibility (0.88) were observed for the cold test. CONCLUSIONS: The cold test was the most accurate method for diagnostic testing.

Anesthetic efficacy of the inferior alveolar nerve block in red-haired women.

INTRODUCTION: The exact reasons for failure of the inferior alveolar nerve (IAN) block are not completely known, but red hair could play a role. The genetic basis for red hair involves specific mutations, red hair color (RHC) alleles, in the melanocortin-1 receptor (MC1R) gene. The purpose of this prospective randomized study was to investigate a possible link between certain variant alleles of the MC1R gene or its phenotypic expression of red hair and the anesthetic efficacy of the IAN block in women. MATERIALS: One-hundred twenty-four adult female subjects (62 red haired and 62 dark haired) participated in this study. Dental anxiety was determined in each subject using the Corah Dental Anxiety Questionnaire. The subjects were given 2 cartridges of 2% lidocaine with 1:100,000 epinephrine via the IAN block. Pulpal anesthesia was measured in the posterior and anterior teeth in 4-minute cycles for 60 minutes using an electric pulp tester. The MC1R alleles were genotyped for each subject from cheek cells containing DNA collected using buccal swabs. RESULTS: Women with red hair and women with 2 RHC alleles reported significantly higher levels of dental anxiety compared with women with dark hair or women with 0 RHC alleles. No significant differences in anesthetic success were found between any of the groups for any of the teeth. CONCLUSIONS: Red hair and the MC1R gene were significantly linked to higher levels of dental anxiety but were unrelated to success rates of the IAN block in women with healthy pulps.

Comparison of the efficacy of a custom-made pulse oximeter probe with digital electric pulp tester, cold spray, and rubber cup for assessing pulp vitality.

INTRODUCTION: The ideal technique for the evaluation of pulp vitality should be noninvasive, painless, objective, reliable, and reproducible. To achieve this, the most routine tests are sensitivity tests. However, a major shortcoming with these tests is that they indirectly indicate pulp vitality by measuring a neural response. Pulse oximetry is a well-established oxygen saturation monitoring technique broadly used in medicine. However, its efficacy as the pulp vitality test should be evaluated. The aim of this study was to design and build a custom-made pulse oximeter dental probe and to evaluate its efficacy in comparison with electric pulp tester, cold spray, and a rubber cup in pulp vitality testing. METHODS: Twenty-four single-canal mandibular premolars needing endodontic treatment were selected. The patients did not have systemic disease and did not consume drugs. Also, they had no clinically relevant signs of necrosis. The selected teeth were pulpally tested with 4 kinds of tests including pulse oximetry, the electric test, cold spray, and the rubber cup. After endodontic treatment of these teeth, which revealed the actual status of the pulp, the results were analyzed by the kappa test to show the efficacy of these tests. RESULTS: When comparing electric, cold, heat, and pulse oximeter tests with the gold standard, the kappa agreement coefficient was 18%, 18%, 14%, and 91%, respectively. The sensitivity of pulse oximetry, a rubber cup, electric test, and cold spray was 0.93, 0.60, 0.60, and 0.53, respectively. The specificity of these tests was 1.00, 0.55, 0.22, and 0.66, respectively. CONCLUSIONS: Pulp testing by using pulse oximetry is more reliable than the electric test, rubber cup, and cold spray. The custom-made pulse oximeter dental probe is an effective and objective method for pulp vitality assessment.

Comparison of heat-testing methodology.

INTRODUCTION: Patients with irreversible pulpitis occasionally present with a chief complaint of sensitivity to heat. To appropriately diagnose the offending tooth, a variety of techniques have been developed to reproduce this chief complaint. Such techniques cause temperature increases that are potentially damaging to the pulp. Newer electronic instruments control the temperature of a heat-testing tip that is placed directly against a tooth. The aim of this study was to determine which method produced the most consistent and safe temperature increase within the pulp. This consistency facilitates the clinician's ability to differentiate between a normal pulp and irreversible pulpitis. METHODS: Four operators applied the following methods to each of 4 extracted maxillary premolars (for a total of 16 trials per method): heated gutta-percha, heated ball burnisher, hot water, and a System B unit or Elements unit with a heat-testing tip. Each test was performed for 60 seconds, and the temperatures were recorded via a thermocouple in the pulp chamber. Analysis of the data was performed by using the intraclass correlation coefficient. RESULTS: The least consistent warming was found with hot water. The heat-testing tip also demonstrated greater consistency between operators compared with the other methods. Hot water and the heated ball burnisher caused temperature increases high enough to damage pulp tissue. CONCLUSIONS: The Elements unit with a heat-testing tip provides the most consistent warming of the dental pulp.

Pulsed Nd: YAG laser induces pulpal analgesia: a randomized clinical trial.

This double-blind, randomized, clinical trial investigated the effectiveness and underlying mechanism of neural inhibition of pulsed Nd:YAG laser induction of pulpal analgesia compared with 5% EMLA anesthetic cream. Forty-four paired premolars from 44 orthodontic patients requiring bilateral premolar extraction from either dental arch were randomly assigned to the 'Laser plus Sham-EMLA' or 'EMLA plus Sham-Laser' treatment group. Analgesia was tested by an Electric Pulp Tester (EPT) and the cutting of a standardized cavity, which was terminated when participants reported sensitivity, and Visual Analogue Scale (VAS) and numbness were recorded. Statistical analyses were done by paired t test, McNemar's test, and a chi-squared test (p < 0.05). Sixty-eight percent of laser- and 59% of EMLA-treated teeth had completed cavities with statistically significant EPT increases above baseline. No significant within-patient differences were found for either group. No laser-treated participants reported numbness. The trial confirmed that the pulsed Nd:YAG laser effectively induced pulpal analgesia, by suppression of intradental nerve responses to electrical and mechanical stimuli. Such a laser provides an alternative for dental pain management (ANZ-Clinical Trial Registry: N12611001099910).

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.

Appropriate electrode placement site for electric pulp testing of anterior teeth in Nigerian adults: a clinical study.

Electric pulp testing is one of the pulp vitality tests which aid dentists in diagnosis of the pulp status. This test is technique sensitive and hence may elicit false responses. There are some concerns regarding the optimal placement of the probe tip. The threshold value (the lowest electric current at which sensation is perceived) is reached when an adequate number of nerve fibers are stimulated, so the sensation would be greatest where the density of neural distribution is the highest. The purpose of this study was to identify the optimum site for electrode placement in anterior teeth of adults, the threshold values of these teeth using an electric pulp test, and to determine the influence of sex, age, and arch on the outcome. The optimum electrode placement sites and threshold values varied with type of tooth and arch. The maxillary teeth, canines, male gender and increasing age required higher electric current to evoke a sensation, while incisal edges required lower current to evoke a sensation.

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.

Interference of cardiac pacemaker and implantable cardioverter-defibrillator activity during electronic dental device use.

BACKGROUND: The authors conducted a study to determine if electromagnetic interference of cardiac pacemaker and implantable cardioverter-defibrillator (ICD) activity occurs during the operation of electronic dental devices. METHODS: The authors tested nine electronic dental devices in vitro to assess their ability to interfere with the function of two pacemakers and two ICDs as determined by electrocardiographic telemetry. RESULTS: The pacing activity of both pacemakers and the dual-chamber ICD were inhibited during operation of the battery-operated composite curing light at between 2 and 10 centimeters from the generator or leads. The use of the ultrasonic scaler interfered with the pacing activity of the dual-chamber pacemaker at between 17 and 23 cm from the generator or leads, the single-chamber pacemaker at 15 cm from the generator or leads and both ICDs at 7 cm from the leads. The operation of the ultrasonic cleaning system interfered with the activity of the dual-chamber pacemaker at between 15 and 23 cm from the generator or leads, and of the single-chamber pacemaker at 12 cm. Operation of the electric toothbrush, electrosurgical unit, electric pulp tester, high- and low-speed handpieces, and an amalgamator did not alter pacing function. CONCLUSION: Select electronic dental devices interfere with pacemakers' and ICDs' sensing and pacing activity in vitro. CLINICAL IMPLICATIONS: Use of the ultrasonic scaler, ultrasonic cleaning system and battery-operated composite curing light may produce deleterious effects in patients who have pacemakers or ICDs.