Evaluation of Apically Extruded Debris during Root Canal Filling Material Removal in Teeth with External Apical Root Resorption: A Comparison of Different Obturation Techniques

doi:10.21203/rs.3.rs-3590423/v1

Download PDF

Research Article

Evaluation of Apically Extruded Debris during Root Canal Filling Material Removal in Teeth with External Apical Root Resorption: A Comparison of Different Obturation Techniques

https://doi.org/10.21203/rs.3.rs-3590423/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

Aim

Root canal retreatment is required when the initial procedure fails. While NiTi systems aid in filling material removal, some preparation methods can extrude canal contents, leading to inflammation, pain, and delayed healing due to the design and kinematics of endodontic files. This study seeks to mitigate complications and promote healing by limiting the dispersion of materials to periradicular tissues. It also investigates the impact of preparation techniques and endodontic file systems on apical debris volume to identify the optimal method for minimizing extrusion during filling removal.

Material and Method:

Ninety extracted maxillary incisor teeth were studied. Simulated apical root resorption was created by removing the apical 2 mm of the root with a fissure bur. The teeth were divided into two groups: one filled with a single cone and the other with cold lateral compaction. These were further split into three subgroups (n = 15 each). Subgroup 1 used Reciproc R25 for removal and R50 for final preparation. Subgroup 2 employed PTUR files D1, D2, D3 for removal and ProTaper Next X5 for finalization. Subgroup 3 utilized VDW.RotateR for removal and VDW.Rotate 50.04 for completion. Debris from retreatment was collected in pre-weighed eppendorf tubes to determine the amount. The apical extrusion data underwent a two-way analysis of variance.

Results

The Reciproc group had a mean weight of extruded debris of 0.54 ± 0.24 mg, significantly higher than the PTUR (0.28 ± 0.15 mg) and VDW.RotateR (0.39 ± 0.29 mg) groups (p < 0.05). The single-cone technique (SCT) resulted in a mean debris weight of 0.34 ± 0.23 mg, statistically lower than the cold lateral compaction (CLC) technique, which had a mean of 0.46 ± 0.27 mg (p < 0.05). While there was no significant difference in retreatment time between file systems (p > 0.05), the SCT group had a mean retreatment duration of 111.12 ± 33.46 seconds, shorter than the CLC group's 176.26 ± 52.26 seconds (p < 0.05).

Conclusion

The Reciproc file system and the CLC obturation technique resulted in greater apical debris extrusion than other methods. Although retreatment time remained consistent across file systems, the SCT had a quicker duration than the CLC method. The Reciproc groups are more susceptible to extrusion from the apex during retreatment.

Clinical Relevance:

This study is crucial for dental practitioners, offering insights into minimizing complications during root canal retreatment, enhancing patient outcomes by guiding the selection of optimal techniques and file systems.

apical debris extrusion

simulated apical root resorption

endodontic

retreatment

obturation

Reciproc

PTUR

VDW.RotateR

The endodontic treatment eliminates bacterial components and toxins by mechanically shaping the root canal system and filling it with materials to establish a three-dimensional seal from its coronal to apical aspects [1]. However, challenges arise when there's no apical constriction due to incomplete root development or external apical root resorption [2]. In cases where the cementum layer is compromised, whether due to periradicular inflammation, orthodontic treatment, or trauma, infections in dentinal tubules or bacterial mediators can induce inflammation in the periodontal ligament, potentially leading to root resorption. Often, such resorption goes unnoticed in radiographs [3]. In addition, a significant proportion of teeth with apical periodontitis have been found to exhibit some level of root resorption [4].

Root canal retreatment becomes necessary when the initial treatment does not succeed [5]. Several tools and techniques, ranging from nickel-titanium (NiTi) instruments, ultrasonic systems, and laser systems to chemical solvents, are available to remove root canal filling material [6]. Among the NiTi systems, the ProTaper Universal retreatment system, the VDW Rotate retreatment system, and the Reciproc single-file system are notable for their effectiveness in gutta-percha removal [7]. However, during the root canal preparation and removal of the root canal filling material, elements like dentine chips, pulp tissue, microorganisms, or irrigants can be extruded into the periradicular tissues [8]. Such extrusion can lead to consequences like inflammation, postoperative pain, flare-ups, and delayed periapical healing [9]. Research has indicated that all methods used for root canal preparation might cause the extrusion of varying amounts of canal contents beyond the apical foramen [10], with the design and kinematics of the endodontic files playing a role in this extrusion [11].

The primary objective of this study was to evaluate the quantity of apically extruded debris in teeth with simulated apical root resorption during retreatment using different NiTi systems, as well as to ascertain the time needed for the removal of gutta-percha and sealer. The study was grounded in the null hypothesis that no significant differences would be observed in the amount of apically extruded debris following retreatment, irrespective of the Ni-Ti systems and obturation techniques.

This study was supported by the …… University Research Fund (PYO.DIS.1904.20.007). Informed consent was obtained in written form from all study participants, and the local ethics committee approved this procedure. Participants were informed about the study's purpose, procedures, and potential risks, and their written consent was obtained before their inclusion. Following approval from the Clinical Research Ethics Committee of …… University (2020/341), 90 straight, single-rooted human maxillary incisor teeth (central and lateral), extracted due to periodontal reasons, were chosen for the study. Each specimen's external resorption, calcifications, cracks, fractures, caries, or previous root canal treatment was examined using an x2.5 loupe (Eyemag Pro S, Zeiss, Oberkochen, Germany). Teeth exhibiting these features were excluded. Only teeth with a single canal in each root and a curvature less than 5⁰ were included, as determined by Schneider’s method [12]. Before experimentation, teeth were stored in distilled water.

To simulate apical root resorption, the apical 2 mm of the root was removed using a fissure bur [13]. Endodontic access cavities were prepared with a high-speed carbide bur (Dentsply Sirona, Ballaigues, Switzerland) with cooling water. Canals with a diameter larger than ISO size 25 were excluded. All crowns were trimmed using a high-speed bur with water cooling to achieve a consistent 13 mm tooth length. The working length (WL) was defined by reducing 1 mm from the actual root length, determined by a number 10 K-file (Dentsply Maillefer) introduced until visible at the apical foramen.

Chemomechanical preparation of the root canals was executed using the ProTaper Next System (Dentsply Maillefer, Ballaigues, Switzerland) with an X4 file at the established WL, following the manufacturer's guidelines. During preparation, root canals were irrigated with 2 mL of 2.5% sodium hypochlorite (NaOCl) after using each file. Final irrigation consisted of 5 mL each of 17% EDTA, 2.5% NaOCl, and distilled water. The prepared samples were then divided randomly into two groups: one utilized a single cone filling method, while the other employed the cold lateral compaction technique. Post-filling, specimens were stored at 37°C in 100% humidity for two weeks to ensure a complete sealer setting.

For the collection of apically extruded debris, an opening was made in an Eppendorf tube lid to accommodate a tooth up to its cementoenamel junction. A 27-gauge needle was positioned alongside the tube's stopper to equilibrate internal and external pressures. Each tube, fitted with a tooth and needle, was then secured within a plastic cap, obscuring the operator's view during debris extrusion. Before the root canal filling material removal, the weight of each Eppendorf tube was determined with an analytical balance (AUW-220D, Shimadzu, Tokyo, Japan) to a precision of 10^-5 g, averaging three consecutive measurements. Finally, specimens were assorted into three random subgroups (n = 15 per subgroup) based on the root canal filling material removal method.

Reciproc group:

Using the Reciproc R25 file (size 25,08 taper) in RECIPROC mode of the VDW.Gold Reciproc endomotor (VDW, Münih, Germany) eliminated the root canal filling material. The Reciproc R25 file, employed in a slow in-and-out pecking movement with a 3-mm amplitude, was combined with a gentle apical pressure and brushing motion against the canal's lateral walls. After every third pecking movement, the file was extracted for flute cleaning. The procedure continued until the working length (WL) was achieved. Subsequently, an apical preparation was executed using the R50 file (size 50,05 taper).

PTUR group: ProTaper Universal Retreatment (PTUR)

Removal of the root canal filling material was accomplished using PTUR files D1 (size 30,09 taper), D2 (size 25,08 taper), and D3 (size 20,07 taper), operating at a torque of 2-Ncm and a speed of 500-rpm. To reach the WL, the files were maneuvered with a brushing action in a crown-down orientation. Specifically, the D1 file addressed the cervical third, D2 was utilized in the middle third, and D3 covered the entire WL. The final apical preparation incorporated the ProTaper X5 file (size 50,06 taper) operating at 2-Ncm torque and 300 rpm.

VDW.RotateR group: VDW.Rotate Retreatment (VDW.RotateR)

Using the VDW.Rotate retreatment file (size R25.05 taper) set at 3.5-Ncm torque and 400-rpm speed; the root canal filling material was effectively removed up to the WL. The concluding apical preparation employed the VDW. Rotate 50.04 file, working at 2-Ncm torque and 350 rpm.

A single operator executed all procedures to ensure consistency and eliminate interoperator variability. While root canal filling material was removed, each canal was irrigated with 15 mL of distilled water and delivered through a 30-gauge double-sided port needle (Medical Brokers, Zgierz, Poland). After each use, the file flutes were meticulously cleaned. The removal process was determined to be complete once the following criteria were met: the final file had attained the new working length (WL), no root canal filling material remained on the file, and the canal walls appeared clean and devoid of any visible debris.

Upon completion of the retreatment procedures, the tooth's apical region was rinsed with 1 mL of distilled water to gather the debris that had extruded and adhered to the root apex, which was then collected in Eppendorf tubes. These tubes were subsequently placed in a 70°C incubator for five days, allowing for the evaporation of any remaining distilled water. Following this, the dry weight of the extruded debris was measured. Utilizing the same analytical balance from earlier stages, each tube containing the debris was weighed thrice, from which an average value was derived. The net dry weight of the debris was then ascertained by subtracting the weight of an empty tube from that of a tube containing debris.

The time to remove the root canal filling material was diligently recorded using a chronometer. This duration encapsulated the period from the initial insertion of the instruments into the canal to reach the original WL. Pauses, such as when the instrument was removed from the canal, were accounted for by stopping and restarting the chronometer.

The study aimed to assess and quantify the extent of apically extruded debris during the retreatment procedure using different file systems and obturation techniques. This was pivotal to understanding the efficacy and relative cleanliness of the tested techniques.

Extrusion of Debris by Different File Systems

Table 1 presents the data on the weight of apically extruded debris produced during retreatment across three file systems. The Reciproc file system recorded a mean value of 0.54 ± 0.24 mg, ranging from 0.11 mg to 1.21 mg. This was markedly higher, confirming that the Reciproc group significantly extruded more debris than its counterparts (p < 0.05). In contrast, the PTUR and VDW.RotateR systems demonstrated lower mean values of 0.28 ± 0.15 mg and 0.39 ± 0.29 mg, respectively. The extent of variability within each file system can be understood from the reported standard deviations with the VDW. The RotateR system has the highest variability. It is crucial to note that, based on the statistical annotations, the PTUR and VDW.RotateR groups were not significantly different regarding debris extrusion at the p = 0.05 level.

Table 1

Weight of apically extruded debris (mg)
File System	N	Min.	Max.	Mean ± S.D.
Reciproc	30	0,11	1,21	0,54 ± 0,24^a
PTUR	30	0,03	0,63	0,28 ± 0,15^b
VDW.RotateR	30	0,05	1,02	0,39 ± 0,29^b
SD, standard deviation; Values with the same letters were not statistically different at p = 0 .05.

Extrusion of Debris by Different Obturation Techniques: Table 2 provides an overview of the amount of apically extruded debris in retreatment for two obturation techniques: the Single-Cone Technique (SCT) and Cold Lateral Compaction (CLC). The SCT exhibited a mean extrusion of 0.34 ± 0.23 mg, which was statistically lesser than the CLC technique, which had a mean of 0.46 ± 0.27 mg (p < 0.05). This indicates that the SCT is more conservative regarding debris extrusion than the CLC during retreatment.

Table 2

Weight of apically extruded debris (mg)
Obturation Technique	N	Min.	Max.	Mean ± S.D.
SCT	45	0,03	0,96	0,34 ± 0,23^A
CLC	45	0,07	1,21	0,46 ± 0,27^B
CLC, cold lateral compaction; SD, standard deviation; SCT, single-cone technique;
Values with the same letters were not statistically different at p = 0.05

Retreatment Time for Different Obturation Techniques

The duration required for retreatment across the obturation techniques was compared in Table 3. The findings suggest that the Single-Cone Technique (SCT) required a significantly shorter time, with a mean duration of 111.12 ± 33.46 seconds, ranging between 56.47 and 166.12 seconds. In contrast, the Cold Lateral Compaction (CLC) technique took an average of 176.26 ± 52.26 seconds, with the durations spanning from 95.88 seconds to as high as 305.36 seconds (p < 0.05). This highlights the efficiency of the SCT over the CLC in terms of time consumption during retreatment.

Table 3

Retreatment time (s)
Obturation Technique	N	Min.	Max.	Mean ± S.D.
SCT	45	56,47	166,12	111,12 ± 33,46^a
CLC	45	95,88	305,36	176,26 ± 52,26^b
CLC, cold lateral compaction; SD, standard deviation; SCT, single-cone technique;
Values with the same letters were not statistically different at p = 0.05

The primary objective of endodontic retreatment is the complete removal of the root canal filling material, followed by thorough cleaning and shaping of the root canal in preparation for final obturation [14]. Unfortunately, during the process of canal preparation and retreatment, there is a tendency for debris to be apically extruded, resulting in potential postoperative discomfort, including pain and swelling [15]. This phenomenon of apical extrusion has been documented in primary root canal treatments involving various canal preparation techniques [16].

This study compared the extent of apically extruded debris during endodontic retreatment, employing three different Ni-Ti file systems in teeth with external apical root resorption that had been filled using distinct root canal filling techniques.

External inflammatory resorption typically presents as an orthodontic problem and primarily affects the apical region of the tooth [17]. It has been reported that 42.3% of maxillary central incisors, 38.5% of maxillary lateral incisors, and 17.4% of mandibular incisors are susceptible to this condition [18]. Therefore, in our study, we selected maxillary central and lateral incisors as our subjects, considering their relatively higher incidence of external apical root resorption.

Da Silveira et al. [19] emphasized the irregular nature of the natural root resorption process, which results in the formation of lesions with varying characteristics. To address this irregularity, they suggested the use of acid demineralization as a method for creating irregular resorption cavities. This approach led to the development of resorption lesions with differing diameters and depths. However, in our current study, we opted for a different methodology to create simulated apical root resorption lesions. We achieved standardization by removing the apical 2 mm of the root using burs, similar to the approach followed in Topcuoglu's study [20].

In previous investigations, researchers have employed materials like floral foam and agar gel to simulate the resistance of periapical tissues [21]. While these materials have been valuable for experimental purposes, they have limitations. Floral foam, when used as a barrier, has the drawback of potentially absorbing irrigant solutions and debris [22]. On the other hand, the agar gel model, though useful, fails to capture the full spectrum of periapical conditions. This is because the thickness of the agar gel around the apex is standardized, while the density of periapical tissues can vary in different cases [21]. In our study, we consciously chose not to simulate periapical tissue resistance and instead adopted the method outlined by Myers and Montgomery [23].

In clinical practice, retreatment procedures typically involve using files with apical diameters larger than the apical diameter of the master apical file used in the initial canal preparation, ensuring comprehensive removal of root canal filling material [24]. A previous study has highlighted the influence of the number of files on the amount of apically extruded debris [25]. In the present study, additional instrumentation was introduced using size 50 files and one file to replicate clinical conditions, especially since the apical diameter of the master apical file in the initial canal preparation was size 40. However, a potential limitation in the study is the variability in the taper of the final instruments among the groups due to standardized produced files in the systems used, which may introduce inconsistency in the experimental design. The current study chose distilled water as the irrigation solution during canal preparation. This decision was made to prevent any possible crystallization of NaOCl, which has the potential to alter the weight of dentine debris and compromise the reliability of the results [22].

The study revealed that the Reciproc file system caused significantly more extruded debris than the PTUR and VDW.RotateR systems (p < 0.05). In contrast, the amount of debris extrusion was significantly lower with the single-cone technique than the cold lateral compaction technique (p < 0.05). The total retreatment time did not show a significant difference between the file systems (p > 0.05). However, it is important to note that the total retreatment time was significantly shorter in the single-cone technique group compared to the cold lateral compaction technique group (p < 0.05).

In light of these findings, the null hypothesis was rejected, underscoring the significance of the choice of file system and obturation technique in influencing the amount of apically extruded debris during retreatment. These results align with a previous study that emphasized how reciprocating movements push debris toward the apex, supporting the validity of the study's findings [22].

In a study conducted by Dinçer et al. [26], a comparison was made among the ProTaper Universal Retreatment (PTUR), Reciproc, and MtwoR file systems, revealing that the Reciproc system exhibited the lowest apical extrusion of debris. This finding contrasts with the results of our study and may be attributed to variations in the number of files employed in the respective studies. Topçuoğlu et al. [20] conducted a similar comparative analysis, where they assessed hand files, ProTaper Universal Retreatment (PTUR), Reciproc, and D-Race file systems in teeth with simulated apical root resorption. They reported that the Reciproc system resulted in significantly less debris extrusion than the PTUR group. However, this contradictory outcome might be linked to operator-related variables. Çanakçı et al. [27] extended the comparative examination to include the PTUR, MTwoR, D-Race, R-Endo, and Reciproc file systems. Their findings indicated that the Reciproc system extruded significantly more debris than the other groups, a result in line with our current study's outcomes. In a separate investigation, Topçuoğlu et al. [28] evaluated the amount of apically extruded debris during the retreatment of root canals filled by three different filling techniques (CLC, WVC, and SCT), using two distinct sealers (AH Plus and MTA Fillapex). They determined that the SCT group exhibited significantly less debris extrusion than the CLC group, consistent with our study.

Rödig et al. [7] compared the total time required for retreatment using hand files, Reciproc, and PTUR, finding no statistically significant difference between Reciproc and PTUR. Similarly, Akbulut et al. [29] compared the total time required for retreatment using hand files, Twisted File (TF) Adaptive, Reciproc, and PTUR, yielding no statistically significant difference between Reciproc and PTUR. Our study's results align with the findings of these studies. However, Özyürek et al. [30] investigated the total time required for retreatment using Twisted File (TF) Adaptive, Protaper Next, Reciproc, and PTUR, revealing that PTUR was significantly faster than the other groups. Operator-related variables may explain this discrepancy.

Summarily, the implication of these diverse study outcomes underscores the multifaceted nature of factors influencing apical extrusion and total retreatment time. Operator-related variables, the number of files used, and the specific characteristics of the file systems may contribute to the variations observed in different research studies. Clinicians must consider these variables and choose the most appropriate techniques based on the clinical context. Further research and standardization of protocols are warranted to better guide clinical decision-making in endodontic retreatment procedures. For future research, a deeper exploration of the specific factors contributing to the observed differences and their clinical implications could provide valuable insights into endodontics.

All groups in the study showed some extruded debris during endodontic retreatment, with the Reciproc group having more extrusion than others. The canal obturation technique significantly influences the amount of extrusion, highlighting its importance in clinical decisions to avoid postoperative complications. Successful retreatment requires understanding factors affecting debris extrusion, with caution advised when using the Reciproc system. Further research is needed to improve strategies and techniques for better patient comfort and treatment outcomes in endodontics.

Author contributions

Uzun I: Project development, Data Collection, Manuscript writing

Çağlar B.M: Data analysis, Data Collection

Funding: This study was supported by the Samsun Ondokuz Mayis University Research Fund (Project No: PYO.DIS.1904.20.007).

Ethical approval: The Clinical Research Ethics Committee of Ondokuz Mayıs University approved the study protocol (2020/341).

Conflict of interest: Authors deny any conflict of interest.

Patel S, Arias A, Whitworth J, et al. (2020) Outcome of endodontic treatment - the elephant in the room. Int Endod J.53(3):291-7.
Mente J, Hage N, Pfefferle T, et al. (2009) Mineral trioxide aggregate apical plugs in teeth with open apical foramina: a retrospective analysis of treatment outcome. Journal of Endodontics. 35(10):1354-8.
Ricucci D, Siqueira Jr JF, Loghin S, et al. (2014) Repair of extensive apical root resorption associated with apical periodontitis: radiographic and histologic observations after 25 years. Journal of Endodontics. 40(8):1268-74.
Delzangles B. (1998) Apical periodontitis and resorption of the root canal wall. Dental Traumatology. 4(6):273-7.
Rodríguez G, Patel S, Durán-Sindreu F, et al. (2017) Influence of cone-beam computed tomography on endodontic retreatment strategies among general dental practitioners and endodontists. Journal of Endodontics. 43(9):1433-7.
Pirani C, Pelliccioni GA, Marchionni S, et al. (2009) Effectiveness of three different retreatment techniques in canals filled with compacted gutta-percha or Thermafil: a scanning electron microscope study. Journal of Endodontics. 35(10):1433-40.
Rödig T, Reicherts P, Konietschke F, et al. (2014) Efficacy of reciprocating and rotary N i T i instruments for retreatment of curved root canals assessed by micro‐CT. International endodontic journal. 47(10):942-8.
Huang X, Ling J, Wei X, et al. (2007) Quantitative evaluation of debris extruded apically by using ProTaper Universal Tulsa rotary system in endodontic retreatment. J Endod. 33(9):1102-5.
Siqueira JF, Jr.(2003) Microbial causes of endodontic flare-ups. Int Endod J. 36(7):453-63.
Arslan H, Doğanay E, Alsancak M, et al. ( 2016) Comparison of apically extruded debris after root canal instrumentation using Reciproc(®) instruments with various kinematics. Int Endod J. 49(3):307-10.
Koçak S, Koçak MM, Sağlam BC, et al. (2013) Apical extrusion of debris using self-adjusting file, reciprocating single-file, and 2 rotary instrumentation systems. J Endod.39(10):1278-80.
Schneider SW. (1971) Compare canal preparations in straight and curved root canals. Oral surgery, Oral medicine, Oral pathology. 32(2):271-5.
Ren H, Chen J, Deng F, et al. (2013) Comparison of cone-beam computed tomography and periapical radiography for detecting simulated apical root resorption. The Angle Orthodontist. 83(2):189-95.
Cohen S, Hargreaves KM. Cohen's pathways of the pulp: Mosby Elsevier; 2011.
Hülsmann M, Schäfer E. (2009) Apical patency: fact and fiction-a myth or a must? A contribution to the discussion. Endo.3(4):285-307.
Tanalp J, Güngör T. (2014) Apical extrusion of debris: a literature review of an inherent occurrence during root canal treatment. Int Endod J.47(3):211-21.
Årtun J, Van't Hullenaar R, Doppel D, Kuijpers-Jagtman AM. (2009) Identification of orthodontic patients at risk of severe apical root resorption. American Journal of Orthodontics and Dentofacial Orthopedics. 135(4):448-55.
Cwyk F, SAINT PIERRE F, Tronstad L, editors. (1984) Endodontic implications of orthodontic tooth movement. Journal of Dental Research; amer assoc dental research 1619 duke st, alexandria, VA 22314.
Da Silveira PF, Vizzotto MB, Montagner F, et al. (2014) Development of a new in vitro methodology to simulate internal root resorption. Journal of Endodontics. 40(2):211-6.
Topcuoglu HS, Demirbuga S, Topcuoglu G. (2020) Evaluation of apically extruded debris during removing canal filling material using three different Ni-Ti systems and hand files in teeth with simulated apical root resorption. Int Endod J. 53(3):403-9.
Altundasar E, Nagas E, Uyanik O, et al. (2011) Debris and irrigant extrusion potential of 2 rotary systems and irrigation needles. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology. 112(4):e31-e5.
Bürklein S, Schäfer E. (2012) Apically extruded debris with reciprocating single-file and full-sequence rotary instrumentation systems. J Endod. 38(6):850-2.
Myers GL, Montgomery S. (1991) A comparison of weights of debris extruded apically by conventional filing and Canal Master techniques. Journal of Endodontics. 17(6):275-9.
Hassanloo A, Watson P, Finer Y, et al. (2007) Retreatment efficacy of the Epiphany soft resin obturation system. International Endodontic Journal. 40(8):633-43.
Silva EJNL, Sá L, Belladonna FG, Neves AA, et al.(2014) Reciprocating versus rotary systems for root filling removal: assessment of the apically extruded material. Journal of Endodontics. 40(12):2077-80.
Dincer AN, Er O, Canakci BC. (2015) Evaluation of apically extruded debris during root canal retreatment with several NiTi systems. Int Endod J. 48(12):1194-8.
Canakci BC, Ustun Y, Er O, Genc Sen O. (2016) Evaluation of Apically Extruded Debris from Curved Root Canal Filling Removal Using 5 Nickel-Titanium Systems. J Endod. 42(7):1101-4.
Topçuoğlu HS, Ulusan Ö, Topçuoğlu G, et al. (2018) Apically extruded debris during the removal of canal filling material from root canals using three techniques. J Investig Clin Dent. 9(3):e12337.
Akbulut MB, Akman M, Terlemez A, Magat G, et al. ( 2016) Efficacy of Twisted File Adaptive, Reciproc and ProTaper Universal Retreatment instruments for root-canal-filling removal: A cone-beam computed tomography study. Dental Materials Journal. 35(1):126-31.
Özyürek T, Demiryürek EÖ. (2016) Efficacy of different nickel-titanium instruments in removing gutta-percha during root canal retreatment. Journal of endodontics.42(4):646-9.

No competing interests reported.

Download PDF

Version 1

posted

You are reading this latest preprint version

Evaluation of Apically Extruded Debris during Root Canal Filling Material Removal in Teeth with External Apical Root Resorption: A Comparison of Different Obturation Techniques

Status:

Version 1

Abstract

Aim

Material and Method:

Results

Conclusion

Clinical Relevance:

INTRODUCTION

MATERIALS AND METHODS

Reciproc group:

PTUR group: ProTaper Universal Retreatment (PTUR)

VDW.RotateR group: VDW.Rotate Retreatment (VDW.RotateR)

RESULTS

DISCUSSION

CONCLUSION

Declarations

References

Additional Declarations

Status:

Version 1