|Year : 2006 | Volume
| Issue : 4 | Page : 182-185
Accuracy of electronic apex locator in length determination in the presence of different irrigants: An in vitro study
Soujanya, MS Muthu, N Sivakumar
Department of Pedodontics and Preventive Dentistry, Meenakshi Ammal Dental College, Chennai, India
M S Muthu
Department of Pedodontics and Preventive Dentistry, Meenakshi Ammal Dental College, Alapakkam Main Road, Maduravoyil, Chennai - 600 095
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Determining the root canal length accurately had been a challenge in endodontics. Introduction of apex locators have definitely served as an effective adjuvant to radiographs. This in vitro study had attempted to compare the effectiveness of electronic apex locator in the presence of various canal contents. Comparison of the length determined by apex locators with the radiographic length was also made. The results of the study had shown that the length of root canals can be accurately made irrespective of the canal contents.
Keywords: Apex locator, hydrogen peroxide, radiographic length, saline, sodium hypochlorite
|How to cite this article:|
Soujanya, Muthu M S, Sivakumar N. Accuracy of electronic apex locator in length determination in the presence of different irrigants: An in vitro study. J Indian Soc Pedod Prev Dent 2006;24:182-5
|How to cite this URL:|
Soujanya, Muthu M S, Sivakumar N. Accuracy of electronic apex locator in length determination in the presence of different irrigants: An in vitro study. J Indian Soc Pedod Prev Dent [serial online] 2006 [cited 2020 Jul 10];24:182-5. Available from: http://www.jisppd.com/text.asp?2006/24/4/182/28074
| Introduction|| |
Locating the appropriate apical position always has been a challenge in clinical endodontics. The Cemento Dentinal Junction (CDJ) where the pulp tissue changes into the apical tissue is the most ideal physiologic apical limit of the working length. It is also referred to as the minor diameter or the apical constrictors. However, the CDJ and apical constrictors do not always coincide particularly in senile teeth as a result of cementum deposition, which alters the position of the minor diameter. Therefore, setting the apical contracture as the apical limit of the working length, where it is easy to clean and shape or obturate the canal is recommended.
Working arbitrarily short of radiographic terminus encourages the accumulation and retention of debris, which may result in apical blocks that predispose the point to ledges and perforations. Working short has led to many frustrations, interappointment flare-ups, unexplained failures and even extractions.
The requirements of an ideal method for determining working length might include:
- Rapid location of the apical constrictors in all pulpal conditions and all canal contents.
- Easy measurement, even when the relationship between the apical constrictors and radiographic apex is unusual.
- Rapid periodic monitoring and conformation of patient and clinician comfort.
- Minimal radiation to the patient.
- Ease of use in special patients such as those with severe gag reflex.
- Ease of use in patients with reduced mouth opening.
- Usefulness in pregnant patient.
- Cost effectiveness of the procedure.
Electronic apex locator has fulfilled most of these above-mentioned criteria. This study was planned and carried out with the following aims and objectives:
- To compare the radiographic length with the length determined by the apex locator.
- To assess the influence of various irrigant solutions in length determination by apex locator.
| Materials and Methods|| |
A total number of 30 extracted single rooted teeth with closed apices were used for the study. The selected teeth were extracted for periodontal reasons. These teeth were divided into 3 groups
- Group A - Central incisors ( n =10)
- Group B - Premolars ( n =10)
- Group C - Canines ( n =10).
Access opening was done in all the extracted teeth. An endodontic reamer or file was placed inside the canal and a radiograph was taken. The radiographic length was measured by Ingle's method. All the radiographs were taken in a standardized manner [Figure - 1]. The object (tooth with endodontic instrument) was at a distance of 14 cm from the X-ray tube end, while taking radiographs. After radiographic length determination, all the samples were embedded in alginate blocks [Figure - 2]. Electronic measurements were recorded using Neo-Sono copilot (Satelec, USA) which is of frequency dependent type. The measurements were recorded by the following steps.
- In each central incisor, electronic root length was first measured in dry mode [Figure - 3].
- Then few drops of saline were injected into the canal. Mode of the apex locator was changed into wet mode and lengths were recorded following the manufacturer's instructions.
- Water from three - way syringe was used to washout saline from the canal and the canal was dried completely. Sodium hypochlorite (3.25%) was injected into the canal and the lengths were recorded.
- Water from the three-way syringe was used to washout sodium hypochlorite from the canal and the canal was dried completely. Hydrogen peroxide (5%) was injected into the canal subsequently and the lengths were recorded.
The same procedure was followed for premolars and canines. All the readings recorded were subjected to statistical analysis.
| Results|| |
The radiographic length, length of the root canal without any canal contents (dry mode), electronic length obtained with different irrigants inside the canal for incisors, premolars and canines were given in [Table - 1][Table - 3][Table - 5], respectively. This data, which was subjected to one-way anova for incisors, premolars and canines were given in [Table - 2][Table - 4][Table - 6], respectively. Turkey HSD procedure was employed to identify the significance at 5% level. The mean, standard deviation and test of significance of mean value of absolute change from radiographic length for all groups combined was given in [Table - 7].
| Discussion|| |
Third generation apex locators (frequency dependant) are more accurate in determining the length in the presence of electro conductive fluids inside the canal than the Impedance and resistance type apex locators (3, 4, 5, 6). The objective of this study was to test the accuracy of the apex locator named Neo Sono Co pilot (Satelec, USA). Comparisons were made between electronic and radiographic measurements. The radiographs were taken in a standardized manner with the object and source distance of 14 cm for all the three groups of teeth.
In Group A (Incisors) the difference between the radiographic length and the electronic length was ranging between 0 and 0.9 mm. The mean difference was ranging from 0.31 to 0.36 mm when the radiographic length was compared with the electronic length in the presence of different irrigants inside the canal. Statistical analysis revealed that there was no significant difference in mean values between the different groups.
In Group B (Premolars), the difference between the radiographic length and the electronic length was ranging from 0 to 0.6 mm. The Mean difference was ranging from 0.17 to 0.33 mm when the radiographic length was compared with the electronic length in the presence of different irrigants inside the canal. Statistical analysis revealed that there was no significant difference in mean values among the different groups.
In Group C (Canines) the difference between the radiographic length and the electronic length was ranging from 0 to 0.6 mm. The mean difference was ranging from 0.12 to 0.31 mm when the radiographic length was compared with the electronic length in the presence of different irrigants inside the canal. Statistical analysis revealed that there was no significant difference in mean values between the different groups.
When the data for the entire study was statistically analyzed using one-way anova a significant difference in Mean values between different groups was found. However, the multiple range test by Turkey HSD procedure showed that there was no significant difference in Mean values between different study groups ( P >0.05).
In this study 40 readings (10 readings each - dry mode, with saline, with hydrogen peroxide, with sodium hypo chlorite) were recorded for each group. Out of the 120 readings, 87.5% of the electronic measurements were within the clinically accepted tolerance of ±0.5 mm when compared with the radiographic measurements. Only 12.5% of the readings were between ±0.5 and ±1 mm. If ±1 mm was taken as accepted clinical tolerance the accuracy of the present study was 100%. Kaufman studied the accuracy of Bingo 1020 (Forum Engineering Technologies, Israel), a third generation apex locator in the presence of different irrigants and concluded that the influence of the canal contents was not significant. Oliver Pommer in his study using Apex Finder (Analytic Endodontics orange, CA) with Sodium hypochlorite as the irrigant had concluded that the Apex Finder was highly accurate in vital canals. Kim in his recent article had summarized the different studies with apex locators in the last decade.
| Conclusion|| |
In routine endodontic practice, there is a need for 3-4 radiographs to complete endodontic treatment successfully. If accurate use of apex locator can avoid one radiograph for 85% of our patients, we feel that the equipment can be added to our armamentarium for regular use. Though in vitro situations are different from the in vivo conditions, similar studies in both primary and permanent teeth are being carried out in our department with clinically acceptable results. Apex locators are user friendly, less time consuming and reliable in most of the clinical situations. Though at this stage apex locators cannot replace radiographs, but will definitely serve as an effective adjuvant. Hence, it can be concluded that the newer apex locators can be very useful in endodontic practice for length determination.
| References|| |
|1.||Kim E, Lee SJ. Electronic apex locator. Dent Clin North Am 2004;48:35-54. [PUBMED] [FULLTEXT]|
|2.||Ingle JI, Bakland LK. Endodontics. 5th ed. Elsevier: New Delhi; 2003. p. 513-25. |
|3.||Kaufman AY, Keila S, Yoshpe M, Accuracy of a new apex locator: An in-vitro study. Int Endod J 2002;35:186-92. |
|4.||Pommer O, Stamm O, Attin T. Influence of the canal contents on the electrical assisted determination of the length of the Root canals. J Endod 2002;28:83-5. [PUBMED] [FULLTEXT]|
|5.||Arora RK, Gulabivala K. An in vivo evaluation of ENDEX and RCM Mark II electronic apex locators in not canals with different contents. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1995;79:497-503. [PUBMED] |
|6.||Oshi A, Yoshioka T, Kobayashi C. Electronic detection of root canal constructions. J Endod 2002;28:361-4. |
|7.||Kobayashi C. Electric canal length measurement. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1995;79:226-31. [PUBMED] |
[Figure - 1], [Figure - 2], [Figure - 3]
[Table - 1], [Table - 2], [Table - 3], [Table - 4], [Table - 5], [Table - 6], [Table - 7]
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