|Year : 2020 | Volume
| Issue : 2 | Page : 158-163
A clinical evaluation of two electronic apex locators and conventional radiography in working length determination in primary molar and its influence on children's behavioral responses
Krithi Nellamakkada, Sandya S Patil, Madhu Kakanur, Ravi S Kumar, Rachna Thakur
Department of Pediatric and Preventive Dentistry, KLE Society's Institute of Dental Sciences and Hospital, Bengaluru, Karnataka, India
|Date of Submission||17-Jan-2020|
|Date of Decision||21-Feb-2020|
|Date of Acceptance||18-Apr-2020|
|Date of Web Publication||28-Jun-2020|
Dr. Madhu Kakanur
Department of Pediatric and Preventive Dentistry, KLE Societyfs Institute of Dental Sciences and Hospital, No. 20, Yeshwanthpur Suburb, Thumkur Road, Bengaluru - 560 022, Karnataka, India
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Accurate root canal length determination, simplicity of the procedure, and patient's cooperation are important determinants in the success of endodontic treatment in primary teeth. Aim: The aim of the study was to clinically compare the accuracy of Propex Pixi and Formatron D10 apex locators with conventional radiography in determining working length in mandibular primary second molars with and without varying degrees of physiological root resorption. Design: A nonrandomized clinical trial was conducted in 115 mandibular primary second molars indicated for pulpectomy in 90 pediatric dental patients. A single calibrated examiner determined the working length by conventional radiographic method and electronic apex locator (EAL) methods in a total of 376 canals. Behavior of the children during execution of each method in each tooth was recorded using the Frankl's behavior rating scale. The data obtained were tabulated and subjected to statistical analysis. Results: Significant correlation (intraclass correlation = 0.80 and 0.81, P < 0.001) could be detected between working length measurements obtained using Propex Pixi and Formatron D10 and measurements obtained using conventional radiography. Higher percentage of negative behaviors (negative and definitely negative) was observed during the conventional radiographic method (68.6%) as opposed to the Propex Pixi (16.5%) and Formatron D10 (20.8%) methods. Conclusions: Both the apex locators were as accurate as conventional radiography in determining working length in primary teeth; Formatron D10 being more accurate than Propex Pixi. The EALs were far better accepted by children than conventional radiography.
Keywords: Apex locator, behavior, conventional radiography, pulpectomy, working length
|How to cite this article:|
Nellamakkada K, Patil SS, Kakanur M, Kumar RS, Thakur R. A clinical evaluation of two electronic apex locators and conventional radiography in working length determination in primary molar and its influence on children's behavioral responses. J Indian Soc Pedod Prev Dent 2020;38:158-63
|How to cite this URL:|
Nellamakkada K, Patil SS, Kakanur M, Kumar RS, Thakur R. A clinical evaluation of two electronic apex locators and conventional radiography in working length determination in primary molar and its influence on children's behavioral responses. J Indian Soc Pedod Prev Dent [serial online] 2020 [cited 2021 May 18];38:158-63. Available from: https://www.jisppd.com/text.asp?2020/38/2/158/288224
| Introduction|| |
The tortuous and bizarre morphology of primary molar root canal systems, as a result of the balance of resorption and hard tissue deposition, makes pulpectomy treatment in these teeth distinctly challenging., The size of the root canals as well as position of the apical foramen is continually altered making it difficult to determine the exact location of apical foramen., Working length determination during pulpectomy aims to prevent over instrumentation and overfilling of primary teeth beyond the apex, thereby preventing harm to both periradicular tissues and the succeeding permanent tooth germ.,
Conventional radiography, having a major role in preoperative assessment, is also the most widely used method for measuring the working length in primary teeth. Over the years, attempts to minimize the need for exposing children to radiation have led to electronic apex locators (EALs) becoming popular as adjunct measurement tools. Formatron D10 (Parkell Inc., NY, USA) is a third generation apex locator that uses multiple frequencies to determine the distance from the end of the canal and has powerful microprocessors which are able to process the mathematical quotient and algorithm calculations required to give accurate readings, regardless of fluid electrolytes being present within the canal. Propex Pixi (Dentsply Maillefer, Ballaigues, Switzerland), a fifth generation multi-frequency technology-based apex locator calculates the root mean square values of the electric signals., It is claimed to be less affected by electrical noises affecting other physical parameters, such as amplitude or phase of electrical signal. The accuracy of these two EALs in permanent teeth has been investigated ex vivo,,,,,,, with one study done to evaluate Formatron D10 in primary teeth. However,in vivo studies to evaluate their accuracy in the primary dentition are limited.
Behavior management, as we know, is the cornerstone of pediatric dentistry. Moreover, having an anxiety free, relaxed child not only leads to an uneventful treatment procedure but also improves operator efficiency. Observation and accurate interpretation of child behavior, by the dentist, can serve as a valuable aid to evaluate the success of the technique he/she decides to use in a particular child during the clinical experience. Therefore, the present study aimed to clinically assess the accuracy of Propex Pixi and Formatron D10 apex locators by comparing with conventional radiography, using paralleling technique as the standard, in determining the working length in mandibular primary second molars with and without varying degrees of physiological root resorption and to evaluate the behavioral responses of the children during each method.
| Materials and Methods|| |
This nonrandomized clinical trial was conducted in children aged between 4 and 9 years with mandibular primary second molars scheduled for pulpectomy and accompanying their parents to the department of pediatric and preventive dentistry. The study was reviewed and approved by the Institutional Ethics Committee (KIDS/IEC/03-2015/11). This study has been carried out in accordance with the Code of Ethics of the World Medical Association (Declaration of Helsinki). Informed consent was obtained from the parents/guardians of participating children prior to the treatment. The size of the sample was derived using G*Power 3.0.10 software (Institute for Experimental Psychology in Dusseldorf, Germany), with an effect size of 0.215, α value at 0.05, and power (1− β) of the study set at 0.95 (95%), and a sample size of 115 mandibular primary second molars was determined.
Mandibular primary second molars with nonrestorable crown structure, intracanal calcifications, extensive periapical/furcation radiolucency, mobility, twothird of the root resorption, and children with any underlying systemic disorders were excluded from the study. A preoperative radiograph was taken using paralleling technique to confirm the selection criteria. The exposure factors and distance between the source and the tooth and the tooth and the film (Kodak-E speed, Carestream Dental, Atlanta, USA) were standardized with the help of a film positioner (FPS 3000-Film positioning system complete, TPC Advanced Technology Inc., California, USA).
After administration of local anesthesia (Lignox 2% A, Kilitch Drugs India Ltd., Navi Mumbai, India), the tooth was isolated with rubber dam. Access cavity was prepared and the coronal pulp tissue was amputated using a sharp discoid spoon excavator. Barbed broaches (Dentsply Maillefer, Ballaigues, Switzerland) and headstrom (H) files (Dentsply Maillefer, Ballaigues, Switzerland) were used to extirpate the pulp tissue from each root canal. Care was taken not to penetrate the apex. The root canals were then irrigated with 1% sodium hypochlorite followed by sterile saline solution. The pulp chamber was dried using sterile cotton pellets.
Working length was then determined by conventional radiography and EALs in all the selected teeth.
Working length determination by radiographic method
Measurements were made from the preoperative radiograph using ISO 08-20 size files (Dentsply Maillefer, Ballaigues, Switzerland) with rubber stoppers. With these measurements, files were inserted into the canals. In case of more than one canal on the same side, for example, mesiobuccal and mesiolingual canals of mandibular primary second molars, different types of files were inserted in each canal for easy identification, for example, K-files in mesiobuccal canals and H-files in mesiolingual canals. Conventional intraoral periapical radiograph was taken with the endo FPS 3000 film positioner using the paralleling technique. Cusp adjacent to the canal was taken as the occlusal reference. The files were removed and file length was determined using a digital Vernier caliper, as in the study by Chougule et al. Ingle's method was followed for working length determination (file 1 mm shorter than the radiographic apex).
Working length determination using electronic apex locators
Working length was determined clinically using Propex Pixi (Dentsply Maillefer, Ballaigues, Switzerland) and Formatron D10 (Parkell Inc., NY, USA) apex locators as per the manufacturer's instructions. The EAL to be used first was chosen randomly.
Working length determination using Propex Pixi Apex Locator
The same K-file used in the radiographic method was attached to the file holder and the ground electrode was secured to the patient's labial commissure. The pulp chamber was dried using sterile cotton pellets. The file was advanced into the canal till the Propex Pixi showed the 0.5 marking, indicating that the file was in the apical zone. The rubber stopper was adjusted at the same occlusal reference point as the radiographic method. The file was carefully withdrawn from the canal and the measurement was recorded using a digital Vernier caliper. This procedure was followed for each canal.
Working length determination by using Formatron D10 Apex Locator
A similar procedure was followed for working length determination using the Formatron D10 apex locator except that the file was advanced into the canal till the apex locator indicated that the file was close to the apical constriction.
Pulpectomy treatment was completed in subsequent appointments.
During the execution of the conventional radiography and Propex Pixi and Formatron D10 apex locator methods of working length determination for each tooth, behavioral responses of the child to each method were assessed and rated using the Frankl's Behavior Rating Scale and classified as definitely negative, negative, positive, or definitely positive.
The data collected were statistically analyzed using the SPSS version 18.0 software (SPSS Inc., Chicago, IL, USA). One-way analyses of variance were used to test the difference between the EALs (Propex Pixi and Formatron D10) and conventional radiography groups. If ANOVA was significant, further pairwise comparison between the methods was carried using Tukey test (Post hoc test). Pearson correlation coefficient test was used to determine whether there was any correlation between the three measurements. The behavioral responses of the children to the three methods of working length determination were assessed using the Chi-square test. In all the above tests, P < 0.05 was taken to be statistically significant.
| Results|| |
A total of 376 canals in 115 mandibular primary second molars among 90 children were assessed in this study. [Figure 1] shows the age distribution of the study population. Twenty-three mandibular primary second molars included for working length determination were in 4–5-year-old children, 25 in 5–6-year–old children, 18 in 6–7-year-old children, 17 in 7–8-year-old children, and 32 were in 8–9-year-old children.
[Table 1] shows the means and standard deviations of working length determination obtained by conventional radiography and Propex Pixi and Formatron D10 apex locators. No statistically significant difference was detected between the three methods (P > 0.05). Pearson correlation test showed the highest correlation between Formatron D10 measurements and conventional radiography (intraclass correlation [ICC] = 0.81, P < 0.001) [Figure 2]. Propex Pixi showed a strong correlation to conventional radiography (ICC = 0.80, P < 0.001) [Figure 3]. ICC between Propex Pixi and Formatron D10 was 0.89 (P < 0.001).
|Table 1: Working length determined in mandibular second primary molars using different methods|
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|Figure 2: Intraclass correlation between working length determination by conventional radiography and Formatron D10 apex locator|
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|Figure 3: Intraclass correlation between working length determination by conventional radiography and Propex Pixi apex locator|
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Higher percentage of negative behaviors (negative and definitely negative) was observed during the conventional radiographic method (68.6%) as opposed to the Propex Pixi (16.5%) and Formatron D10 (20.8%) apex locator methods. Statistically significant differences were observed between the behavioral responses of the children to working length determination by conventional radiography and Propex Pixi and Formatron D10 apex locator methods (P < 0.001) [Table 2].
|Table 2: Age group.wise distribution of the children displaying various behaviors toward the different methods of working length determination|
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| Discussion|| |
Working length determination is one of the most important steps in root canal treatment in both primary and permanent teeth. Conventional radiography has been traditionally used to determine the working length. Forsberg, upon extensive research, has reported that the working length determined by bisecting angle technique was less accurate than the paralleling technique and the latter was better for radiographic reproduction of the apical anatomy., Hence, the paralleling technique was followed in this study. Error in the placement of radiographic film, and X-ray cone was eliminated using the FPS 3000 film positioning system.
Although numerous ex vivo studies have been performed to evaluate the accuracy of working length determination in primary teeth,, precise simulation of the oral environment is not possible in ex vivo conditions and as such cannot be a true representative of clinical situations in which the entire treatment is done in the mouth. Only a few studies have been performed exclusively inin vivo conditions in the primary teeth., In this study, an attempt was made to reproduce what occurs during a routine endodontic treatment. To the best of our knowledge, noin vivo study has been done to evaluate the accuracy of Propex Pixi and Formatron D10 apex locators in working length determination in primary teeth.
In the present study, children in the age group of 4–9 years were considered as they represented the population in which the mandibular primary second molars showed physiological root resorption ranging from none to varying degrees. Thus, the effectiveness of the apex locators could be tested in these teeth. According to the results of our study, there were no statistically significant differences between the working lengths determined by conventional radiography and apex locators. This result is consistent with those obtained by previous studies using different apex locators.,,,,,, Supporting these results, Angwaravong and Panitvisai have reported that the EAL was capable of functioning accurately in primary molars with root resorption because though the apical foramen was resorbed and enlarged, the conical shape of the canal was still maintained and the root canal typically has a decreasing taper toward the defect. Our study showed that Formatron D10 (ICC = 0.81) was more accurate than Propex Pixi (ICC = 0.80) when compared with the standard of conventional radiography.
A child's behavioral assessment can be an important factor in evaluating the success of the clinical technique decided on by the dentist. Greater the cooperation elicited from the patient, more is the operator efficiency and consequently, better are the chances for success of the treatment rendered. Therefore, an attempt was made in our study to assess the behavioral responses of the children to the conventional radiographic method and apex locator methods of working length determination using the Frankl's Behavior Rating Scale, as it is a more reliable and commonly used behavior rating scale in pediatric dentistry., As observed in our study, overall, a higher percentage of children displayed negative or definitely negative behavior during conventional radiographic method as opposed to the EAL methods where majority of the children displayed positive or definitely positive behaviors. The placement of the film positioner was problematic in children with small mouth openings which could attribute to them finding the procedure uncomfortable and to some extent the negative behaviors, i.e., (--) and (-). Children in the 4–5 year [n = 13 (--), 9 (-)] and 5–6 year [n = 13 (--), 10 (-)] age groups were seen to display more negative behaviors during conventional radiographic method. A reason could be that children in these age groups are known to be more prone to anxiety and temper tantrums and less willing to cooperate with procedures causing some amount of discomfort. One surprising observation in our study was the Propex Pixi functioning as an audiovisual distraction device for the children. As the device is small and compact, most children were able to hold the device in their hands. The children in the present study were told to look for the “yellow” light coming “on” on the display screen and to notice the beep sound. This task tended to distract the children.
| Conclusion|| |
Both Formatron D10 and Propex Pixi apex locators were as accurate as conventional radiography in determining working length in primary teeth with and without varying degrees of physiological root resorption. Formatron D10 was found to have better accuracy in working length determination than Propex Pixi. The EALs were much better accepted by the children than conventional radiography. Pediatric dentistry may therefore benefit from using these apex locators which are not only easy to use but have also been proven to elicit better cooperation from children.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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