|Year : 2019 | Volume
| Issue : 1 | Page : 68-71
Apical microleakage in root canal-treated teeth containing broken hand files obturated with two different obturating materials: An in vitro study
Shailendra Mashalkar, Gladson Selvakumar, Pawan Diwanji, Shreeshail Indi, Jyoti Warad
Department of Conservative Dentistry and Endodontics, Al Badar Dental College and Hospital, Gulbarga, Karnataka, India
|Date of Web Publication||19-Jun-2019|
Dr. Jyoti Warad
Department of Conservative Dentistry and Endodontics, Al Badar Dental College and Hospital Gulbarga, Karnataka
Source of Support: None, Conflict of Interest: None
Introduction: Separated instruments in root canals complicate routine endodontic treatment. This study aimed to compare apical microleakage in root canals containing separated hand stainless steel K-files obturated with gutta-percha and Portland cement.
Materials and Methods: In this in vitro, experimental study, forty single-rooted freshly extracted teeth were decoronated and then the roots were randomly divided into four groups (n = 40). The biomechanical preparation was done according to the step-back technique. The K-file of 25 size was intentionally broken in apical third and obturation was done with gutta-percha and AH Plus sealer using lateral compaction technique and with Portland cement. Apical microleakage was measured using dye penetration method; teeth were immersed in Indian ink for 48 h. The roots were rinsed and sectioned by a cutting saw. The sections were evaluated under a stereomicroscope under ×50 magnification by two observers. Data were analyzed using ANOVA test.
Results: Root canals filled with Portland cement have shown lowest microleakage when compared to laterally compacted gutta-percha according to dye penetration depth. Statistical results with ANOVA have showed a significant difference in microleakage among the four groups (P < 0.001, significant).
Conclusion: The results of this study have shown that apical microleakage is less in instrument-separated teeth obturated with Portland cement than in instrument-separated teeth obturated with gutta-percha.
Keywords: Apical microleakage, gutta-percha, lateral compaction, Portland cement
|How to cite this article:|
Mashalkar S, Selvakumar G, Diwanji P, Indi S, Warad J. Apical microleakage in root canal-treated teeth containing broken hand files obturated with two different obturating materials: An in vitro study. Endodontology 2019;31:68-71
|How to cite this URL:|
Mashalkar S, Selvakumar G, Diwanji P, Indi S, Warad J. Apical microleakage in root canal-treated teeth containing broken hand files obturated with two different obturating materials: An in vitro study. Endodontology [serial online] 2019 [cited 2019 Nov 12];31:68-71. Available from: http://www.endodontologyonweb.org/text.asp?2019/31/1/68/260538
| Introduction|| |
The success of endodontic treatment relies on proper diagnosis, thorough biomechanical preparation and three-dimensional (3D) obturation. The chemomechanical preparation is accomplished by stainless steel files and different chemicals. Separation of the instrument is one of the procedural accident during root canal treatment, which could compromise the clinical outcome in terms of failure of the root canal treatment. Most of the stainless steel instruments fail due to excessive torque, whereas NiTi rotary files usually fracture due to torsional stress and cyclic loading.
Fractured instrument itself may not cause treatment failure. However, the remaining fragment in the root canal can hinder the complete preparation of root canal space. In a situation where broken instrument cannot be retrieved, then achieving a proper 3D obturation becomes difficult and can lead to failure in the long run.
Traditionally, gutta-percha has been used in lateral compaction technique to give hermetic seal which guarantees the success of root canal treatment. However, it does not bond to dentin and has poor flexibility.
Lateral compaction technique is commonly practiced for root canal obturation with gutta-percha due to relative simplicity and low cost. However, this technique has certain drawbacks such as risk of void formation and difficult application in curved canals.
Hence, mineral trioxide aggregate (MTA) has been suggested as a root canal filling material due to its optimal sealing ability. Successful use of MTA for apical seal, apical plug, and root perforation repair has been reported in many previous studies.,
It is biocompatible and nontoxic and has a bactericidal effect. Long setting time, difficult handling, and high cost are the drawbacks of MTA.
Microleakage testing is often performed to assess the quality of root filling using dye penetration method, microbial leakage model, radioisotope tracing, or fluid filtration a technique. Dye penetration technique is among the most commonly used methods for this purpose.
To overcome the drawback of MTA in cost-effectiveness, Portland cement which is suggested as an alternative material choice for obturation. Therefore, the aim of this study was to investigate “apical microleakage in root canal tooth with two obturating materials over apically separated hand files using dye penetration method.”
| Materials and Methods|| |
In this in vitro experimental study, forty human single-rooted teeth (n = 40) extracted for orthodontic or periodontal reasons were selected. To ensure the reliability of results, 15 teeth were included in Group 1 and 2 and 5 teeth in Group 3 and 4 (control groups).
After collection, the teeth were cleaned and disinfected by immersion in 5.25% sodium hypochlorite for 1 h. They were then stored in 0.9% saline at room temperature until the experiment.
All the teeth were decoronated at cementoenamel junction using a diamond bur and high-speed handpiece under water irrigation and then roots were divided into four groups for root canal filling with gutta-percha (Gapadent, Korea) using lateral compaction technique, Portland cement, and two control groups (positive control and negative control group); first, roots were radiographed in buccolingual direction after mounting in acrylic blocks.
Working length was determined, and the root canals were instrumented with hand K-files (Dentsply Maillefer, Ballaigues, Switzerland), followed by Mtwo rotary files (VDW, Munich, Germany) up to size 25/0.06 to the working length and 30/0.06–1.5 mm short of the working length.
Recapitulation was performed between files, and root canals were irrigated with 5.25% sodium hypochlorite. A final rinse with 1.25% sodium hypochlorite was also performed followed by 17% ethylenediaminetetraacetic acid and 5 mL of saline.
A #30 rotary file was scratched at 3 mm from its tip by a high-speed handpiece and was intentionally broken in the canal in the apical region. The middle and coronal sections of the canals were filled with the above-mentioned root canal filling materials/techniques. The roots were radiographed after file fracture and after filling [Figure 1].
|Figure 1: Radiographic image of root canal filling material over broken file|
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For assessment of microleakage using dye penetration technique, the roots were coated with nail varnish to 2 mm around the root apex. The coronal orifice was sealed with glass ionomer (GC, Gold Label, GC Corp., Tokyo, Japan). The roots were then immersed in Indian ink for 48 h.
The roots were rinsed and mesiodistally sectioned by a cutting saw. The sections were evaluated under a stereomicroscope under ×50 magnification by two observers.
Dye penetration depth was measured by Image J software (LOCI, University of Wisconsin). Data were analyzed using descriptive and analytical statistics. The mean and standard deviation of dye penetration depth were reported. One-way ANOVA was used to compare microleakage among the groups.
Tukey's test was applied for pairwise comparisons. Interclass correlation coefficient was calculated to assess the agreement between the two observers. All statistical analyses were performed using SPSS software (SPSS version 18, SPSS, Chicago, IL, USA) at 0.001 level of significance.
| Results|| |
The interclass correlation coefficient was found to be 0.950 between two observers' excellent agreement. [Table 1] shows the mean and standard deviation of dye penetration depth (indicative of microleakage) and differences in this regard among the four groups and shows Mean values of dye penetration among two groups (Group 1 and 2).
|Table 1: Effect of separated file on the dye microleakage of obturated tooth|
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As shown in [Table 1], the depth of penetration is more in Group 1 (root canal obturated with gutta-percha using AH Plus sealer with intentional file breakage in the apical one third) when compared with other groups. Statistical results with ANOVA have shown a significant difference in microleakage among the four groups (P < 0.001 Significant).
| Discussion|| |
The results of this study have shown that apical microleakage is less in instrument-separated teeth obturated with Portland cement than in instrument separated teeth obturated with gutta-percha, thus accepting the alternative hypothesis.
The overall prevalence of instrument separation during root canal preparation by postgraduate students was 1.83% and by clinicians was 7.41%. The prevalence of instrument separation in the apical third (52.5%) was significantly higher when compared with coronal (12.5%) and middle thirds (27.5%). The frequency of fracture of stainless steel hand instruments is relatively low ranging between 0.25% and 6% compared to that of NiTi rotary instruments (1.3%–10%). Although the prevalence is low, it is of prime importance when considering the prognosis of the teeth over long term.
Evidence shows that a broken instrument that remained in the root canal does not have a significant adverse effect on the quality of root canal seal by filling materials and success of endodontic treatment mainly depends on coronal seal and cleaning of the middle and coronal thirds.
There are a variety of obturation techniques, which can be divided into two basic groups: cold lateral compaction and warm vertical compaction. Lateral compaction is widely used and is a proven clinically effective filling technique; it serves as a standard to which all other obturation techniques are compared. However, it has been shown that type of broken instrument also affects the quality of seal provided by restorative materials.
Saunders et al. showed that microleakage in canals containing a broken instrument was higher than those without it, but after filling of root canals with gutta-percha, no significant difference in microleakage was found.
Studies showed lesser microleakage in instrument-separated teeth obturated with MTA and calcium-enriched mixture than laterally compacted gutta-perch, but the cost-effectiveness and longer setting time of these materials are still a drawback. To overcome the drawback of MTA in cost-effectiveness, Portland cement which is suggested as an alternative material of choice for obturation. Thus, in this study, we aimed to evaluate the microleakage with Portland cement obturation.
Dye penetration technique is a simple and affordable technique for the evaluation of microleakage. Several dyes are used for the assessment of microleakage such as Indian ink, methylene blue, silver nitrate, and Rhodamine B.
Godiny et al. compared the apical microleakage in root canals containing broken instruments rotary which was obturated using MTA, CEM cement, and gutta-percha with lateral compaction technique and injected gutta-percha using dye penetration techniques and reported superior results with MTA and CEM cement which was in agreement with our results.
Another treatment modality for a broken instrument in root canal is apical respective surgery and retrograde application of filling material to obtain apical seal. However, isolation of area is difficult, and if not well achieved, contamination of the area with blood and fluids may compromise the quality of apical seal. Thus, considering the result of our study, Portland cement can be used as an obturating material in instrument-separated teeth.
| Conclusion|| |
Within the limitations of this study, It can apically separate instruments may play a significant role in leakage as teeth separated with hand instruments. Apical microleakage is less in instrument-separated teeth obturated with Portland cement than in instrument-separated teeth obturated with gutta-percha.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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