|Year : 2015 | Volume
| Issue : 2 | Page : 138-142
Appropriate electrode placement site of electric pulp tester for the premolars: A clinical study
Seema Dinesh Bargale1, Shital Kiran Davangere Padmanabh2
1 Department of Pedodontics and Preventive Dentistry, Sumandeep Vidyapeeth, Kanjibhai Manjibhai Shah Dental College and Hospital, Vadodara, Gujarat, India
2 Department of Pedodontics and Preventive Dentistry, Karnavathi School of Dentistry, Adalaj Uvarsad Road, Gandinagar, Gujarat, India
|Date of Web Publication||15-Apr-2015|
Dr. Seema Dinesh Bargale
Professor, K. M. Shah Dental College and Hospital, Vadodara - 390 001, Gujarat
Source of Support: None, Conflict of Interest: None
| Abstract|| |
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.
Keywords: Dental pulp innervations, electrodiagnosis, pulp vitality test
|How to cite this article:|
Bargale SD, Davangere Padmanabh SK. Appropriate electrode placement site of electric pulp tester for the premolars: A clinical study. J Indian Soc Pedod Prev Dent 2015;33:138-42
|How to cite this URL:|
Bargale SD, Davangere Padmanabh SK. Appropriate electrode placement site of electric pulp tester for the premolars: A clinical study. J Indian Soc Pedod Prev Dent [serial online] 2015 [cited 2019 Jul 21];33:138-42. Available from: http://www.jisppd.com/text.asp?2015/33/2/138/155128
| Introduction|| |
The best pulp test technique should deliver a simple, inexpensive, accurate, standardized, and objective way of diagnosis of the vital and nonvital pulp tissue. Electric pulp testing is based on stimulus of sensory nerves which requires subjective assessments from the patient. Electric pulp tester (EPT) remains an important aid, which is an innocuous clinical test which can provide useful evidence about healthy and diseased pulp tissue. ,
EPT is aimed to deliver an electric current to stimulate the nearby myelinated A-delta fibers; however, the device usually does not excite the unmyelinated C fibers due to their higher threshold. EPT directs the neural transmission which confirms the presence of vital nerve fibers. Any pulp tester requires the electrode to be in connection with surface of the tooth with optimum sites. Incorrect location of the probe may lead to false-negative response in a vital tooth. Electric pulp testing is intended to determine the sensitivity of each tooth at the lowermost threshold for sensory reaction. 
Jacobson  and Lin et al.,  have reported the optimum positions of the electrode for anterior teeth and first molars, respectively. Bender and coworkers  have determined that placing the electrode at the incisal edge of anterior teeth aroused a response with the slightest amount of electrical current. So far no studies have been conducted to determine optimum electrode positioning, and comparative data for different sites on premolars. Therefore, this experiment was designed to determine the best electrode placement site on premolars as there is no such study that has been conducted. The objective of electric pulp testing was to determine the sensibility of maxillary and mandibular premolars at the lowest sensory response threshold.
| Materials and Methods|| |
Twenty dental patients (12 male and eight female) aged between 13 and 15 years were recruited from the dental department, after the ethical committee approval for the study. Participants gave their informed consent after providing the written details of the procedure.
Inclusion criteria included all the first and second premolars which were free of restorations or caries, and also no recent history of orthodontic treatment or dental trauma. Bitewing radiographs were taken for the all participants to confirm absence of disease.
One premolar from each arch was selected followed by rubber dam application without clamps. The pulp vitality tester (Parkell Inc, Edgewood, New York) was used in accordance with the manufacturer's instructions. The machine reads from 0 to 8 units, and the rate of electric current was increased by 2 units to allow accurate determination of the first perception of the stimulus.
Fluoride gel (topical APF Gel) was slightly coated on the electrode tip of the pulp tester and then positioned on the intended testing site. Subjects used their thumb and forefinger on the lip clip to complete the circuit who were also instructed to release the clip on first detection of a warm, tingling, or painful sensation.
Five electric pulp testing sites on each first and second maxillary and mandibular premolar crown were tested. They were incisal, middle and gingival buccal surface, palatal of maxillary, lingual of mandibular premolar, and center of occlusal cusps [Figure 1] and [Figure 2]. The subjects picked numbered balls from a bag to decide electric pulp testing site for each premolar. Four electric pulp testing readings were made at each site and the average was calculated. Between the tests, the teeth were air dried, and a recovery period of at least 1 min was allowed to eliminate the phenomenon of nerve accommodation as per the Cooley and Robison.  The principal investigator carried out the reading in the maxillary arch and the coinvestigator in mandibular arch; in order to eliminate inter examiner differences. Data were analyzed with Statistical Package for the Social Sciences (SPSS) software (SPSS 18.0; SPSS Inc, Chicago, IL) by using a one-way analysis of variance test and Tukey's honestly significant difference test at five electric pulp testing readings were made at each site.
| Results|| |
Mean age of the study subject was 14.4 ± 0.50 years. In this study population, the male subjects were 12 (60%) and females were eight (40%).
Males reported a slightly higher test values as compared to females. The mean threshold electric pulp testing values were higher in maxillary second premolar (7.00 ± 1.78) among males and lower in mandibular first premolar (3.70 ± 0.75) in females. However, the differences observed were statistically not significant (P > 0.05) in [Table 1]. Only mandibular second premolar showed statistically significant difference in relation to gender (P < 0.05).
Mean values were calculated for each site, and these ranged from 1 to 7. Values for the different electrode placement sites for maxillary and mandibular premolars are shown in [Table 2]. The mean threshold electric pulp testing values were higher in the second premolars in both the maxillary and mandibular arches, with incisal (6.90 ± 1.97) and palatal/lingual regions (5.40 ± 2.37), respectively. When all the premolars were compared with the different regions of placement of electrode, a statistically significant difference was observed only for occlusal surface of premolars (P < 0.05) [Table 3].
|Table 3: The mean optimum electrode placement site for maxilla and mandible premolars|
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The mean threshold value for mandibular teeth was lower than the values for the maxillary teeth at all placement sites. In maxillary arch, the electric pulp testing values were higher in the middle (5.37 ± 0.81), lower in incisal and gingival site (5.27 ± 1.34), with lowest at the occlusal (4.52 ± 1.08) sites. In mandibular arch, it was higher in lingual surface (4.75 ± 1.51) and gingival (4.70 ± 1.15), lower in incisal (4.58 ± 1.62), with lowest at middle (4.50 ± 0.51) and occlusal (4.50 ± 1.19) sites. Also, the difference between the groups was statistically significant for all sites (P < 0.05), except the occlusal site electric pulp testingvalue (P > 0.05).
| Discussion|| |
Pulp testing is indicated where pulp health may be in question or in situations where restorative or orthodontic interventions are required. The radiographic changes or symptoms only may not be considered as definite signal of pulp vitality, since pulpal degeneration can happen without associated symptoms. The cause of most oral pain is connected to pulp inflammation, but pain localization may be challenging which requires various tests as well as a careful history and examination. Few studies have quantified the worth of pulp testing in recognizing pulpal pain from other conditions such as referred pain and myofascial pain dysfunction syndrome.  On the contrary, a usual response to pulp testing may rule out the diagnosis of pulpal pathology in the orofacial pain of anonymous etiology. The main objective of EPT is to excite intact A-delta nerves in the pulp-dentine complex by application of an electric current on the tooth surface. An encouraging result curtails from an ionic swing in the dentinal ﬂuid within the tubules causing local depolarization and later generation of an action potential together from A-delta fibers of nerves. 
A slender range of subject age was chosen in this study to avoid sensitivity disparity produced by occlusal wear, pulp size reduction, and dentin deposition in relation to premolars. The dimension of the pulp chamber was the significant factor in influential thermal response, with smaller pulp chambers creation of thermal stimulation of the pulp was difficult. 
Lin et al.,  had studied on optimum electrode pulp testing in relation to first permanent molar; whereas, Johnsen  and Bender et al.,  had checked optimal site for permanent anterior teeth. In our study, optimal electrode placement site of the premolar have been considered because so far the study regarding optimum electric site placement on premolar has not been conducted.
Petersson et al.,  described a 'gold standard' method wherein accuracy was 81% for the EPT, 71% for heat, and 86% for the cold test which indicated that cold and the EPT are trustworthy to a similar extent in the diagnosis of vital and nonvital pulp. The Parkell electric vitalometer showed better accuracy in diagnosing vitality or nonvitality, but could not distinguish the specific state of vitality.  In this study a current model of EPT, the electronics of which are identical to those used in previous machines has been used.
Tooth isolation during electric pulp testing is essential, in our experiment rubber dam was used to isolate the teeth from the gingivae in order to maintain isolation and to prevent gingival conduction which was in accordance to previous study by Lin et al.  Cooley and Robison  had used cotton rolls to dry teeth for isolation. The electric pulp testing is procedure sensitive and has a number of limitations. Drying the enamel as well as placement of rubber dam, and interproximal plastic strip can prevent the blowout of electrical impulses to neighboring teeth or gingival tissue. ,
According to Staller,  some or the other electrolyte should be used as an interface material between electrode tip and enamel as this has the highest index of surface roughness of the crown. A popular conducting medium topical fluoride gel was used in our study; it was also used by Martin et al.,  who have concluded that the medium made no appreciable difference in readings after application of interface material.
A recent study specifically designed to determine the best site fort heplacement of the electrode on the molar tooth surface found no significant difference between maxillary and mandibular molars in male and female subjects.  In our study there was highest test values of electric pulp testing response present with premolars in males compared to female subjects.
The location of the electrode on the buccal surface was tested in other studies. Cooley and Robison  and Bender et al.,  found that the best placement of the electrode is theincisal third of anterior teeth where the least amount of electric current provoked a response. In other studies, the electrode were placed on the occlusal third of the buccal surface, centred between the gingival margin and the occlusal edge of the buccal surface or on the gingival third of the buccal surface. ,, In our study the best electrode placement site was on the occlusal surfaces which reported lowest threshold response on maxillary and mandibular premolars.
Lin et al.,  elicited the lowest response of the electrode placement on the mesiobuccal cusp tip of permanent first molars; whereas, placing the electrode more apically and to the center of the supporting cusps showed an increase in the threshold response level. These results were related to the presence of pulp horns, where there is a high concentration of neural elements. , In permanent teeth the highest concentration of neural elements is in the pulp horns, with progressively fewer in the cervical and radicular regions of the pulp. Similar results were seen in this study as the electrode placement on premolars showed occlusal surface with lower threshold and gingival margin with higher threshold values.
An in vitro study by Jacobson  determined electrode placement by using extracted incisors and premolars with measurements from an oscilloscope. He suggested the best locations for probe placement are the incisal two-thirds of the labial surfaces of maxillary incisors and the occlusal two thirds of the buccal surface of maxillary premolars. But our study differed from above and showed maxillary premolars with higher response in the middle and lower at the occlusal sites, whereas in mandibular arch it was higher in lingual, lower at middle, and occlusal surface of the premolars.
There are numerous thoughts about optimal location of the tester electrode. The utmost desired area of valuation in incisor teeth is at the incisal edge, where the enamel is thinnestor absent. The pulp tester should be placed on the tooth surface nearby to a pulp horn, as this obtains the highest nerve concreteness with in the pulp. , This site parallels to theincisal third region of anterior teeth and the mid-third region of posterior teeth. The threshold for reaction may be inﬂuenced by the chunkiness of the enamel and dentine covering the pulp.  The response threshold for healthy teeth may be lowest in incisors, some what greater in premolars, and greatest in molar teeth. Lin et al.,  have shown that the optimum site for electrode placement on molars was on the tip of the mesiobuccal cusp. Our study revealed best tested optimum electrode placement site of EPT on the occlusal surface of premolars.
| Conclusion|| |
- The present study found the best electrode site for pulp testing in premolars for diagnostic purposes.
- Males reported a slightly higher response threshold as compared to females.
- In maxillary premolars, occlusal surface showed lower threshold electric pulp testing value.
- In mandibular premolars, incisal and occlusal surface showed lower electric pulp testing value.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3]