Asian Journal of Biomedical and Pharmaceutical Sciences

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Short Communication - Asian Journal of Biomedical and Pharmaceutical Sciences (2023) Volume 13, Issue 99

Evaluate the effect of irrigants agents used in curved canals during instrumentation using different imaging technology

Dr Yesh Sharma1*, Dr Diya Sharma2, Dr Akshat Waran1, Dr Kailash Asawa2, Dr Mridula Tak2, Dr Sai Kancharlawar2, Dr Ankita Rawal2

1Department of Conservative Dentistry and Endodontics, Pacific Dental College and Hospital, Rajasthan, India.

2Department of Public Health Dentistry, Pacific Dental College and Hospital, Rajasthan, India

*Corresponding Author:
Dr Yesh Sharma
Department of Conservative Dentistry and Endodontics
Pacific Dental College and Hospital
Udaipur, Rajasthan, India

Received: 24-Feb-2023, Manuscript No. AAJBPS-23-91559; Editor assigned: 27-Feb-2022, PreQC No. AAJBPS-23-91554(PQ); Reviewed: 13-Mar-2023, QC No. AAJBPS-23-91554; Revised: 17-Mar-2023, Manuscript No. AAJBPS-23-91554(R); Published: 24-Mar-2023, DOI:10.35841/2249-622X.99.174

Citation: Sharma Y. Evaluate The Effect Of Irrigants Agents Used In Curved Canals During Instrumentation Using Different Imaging Technology. Asian J Biomed Pharmaceut Sci. 2023;13(99):174


EDTA, Chelating agents, Root canal preparation, Transportation, Micro-computed tomography.


One of the most important aspects of endodontic treatment is preparing the root canal [1]. Proper cleaning and shaping provides access for irrigants to reach the entire canal length and provides space for medicaments and obturation materials. Over-instrumentation may lead to changes in canal anatomy which make it difficult to adequately obdurate the canal. In teeth where the canal anatomy is altered during retreatment, healing is significantly decreased compared to when canal anatomy is respected [2, 3]. Teeth with complex root canal systems have a greater risk of procedural errors. Nearly all root canals are curved [4, 5]. Flexible endodontic files will straighten inside the root canal during instrumentation [6]. Instrumentation of curved canals over prepares the outer wall of the curve near the apex and the inner wall of the curve near the crown [7]. The reduced thickness of dentin in one direction results in stress distribution changes which may increase the risk of vertical root fracture [8].

During root canal instrumentation, chelating agents may be used. Many instrument manufacturers recommend using chelating agents as lubricants to decrease rotary instrument separation. Ethylenediaminetetraacetic acid (EDTA) was introduced for endodontic use by Nygaard-Ostby in 1957 to aid in narrow and calcified canal preparation. EDTA has a strong demineralizing effect. It softens dentin, enlarges dentinal tubules and denatures collagen fibers [9].

A canal rinse with 17% EDTA followed by 5.25% NaOCl effectively removes the smear layer. RC- Prep™ (Premier Dental, Philadelphia, PA, USA) is a common paste-type chelating agent combining 15% EDTA, 10% urea peroxide and glycol in an aqueous base [10, 11]. According to Bramante and Betti, instrumentation with NiTi hand files using EDTA caused greater deviation of the root canal from its original path in the apical third of curved canals [12].

The purpose of this study was to compare the effects of chelating agents used to prepare moderately curved root canals of extracted maxillary first and second molars [13, 14]. Using micro-CT and imaging software, 3-dimensional models of root canals before and after preparation were constructed. Measurements were made before and after root canal instrumentation, to record changes in canal volume and length, and transportation.

Materials and Methods

Preparation of Canals thirty six mandibular premolars were selected from a collection of extracted teeth. The palatal roots were resected and discarded. Standard access cavities were prepared. An ISO 10 k- file was inserted into the canal until it was flush with the apical terminus. Preoperative radiographs were taken and the curvatures of the canals were determined using the method described by Schneider [15].

Canals with fully formed apices and curvature of 10 to 30 degrees were included. Using a digital caliper with 0.01mm resolution (Digimatic Caliper, Mitutoyo America Corp, USA) the length of the canals was measured. The length of the specimens was standardized to 20mm by reducing the coronal tooth structure and the working length was set to 19mm.

The specimens were randomly divided into three groups. The canal of each specimen was instrumented using a crown down technique with 0.06 taper Profile® (DENTSPLY Tulsa Dental, Tulsa, OK) nickel titanium rotary files to a master apical file size 30. Canals assigned to group 1 were irrigated with 2 mL 1.0% sodium chloride between each file.

Canals assigned to group 2 were irrigated with 2 mL 1.0% sodium chloride between each file and the canals were flooded with 17% EDTA (Pulpdent Corp., Watertown, MA) prior to the use of each file. Canals assigned to group 3 were irrigated with 2 mL 1.0% sodium chloride between each file and RCPrep ™ (Premier Dental, Philadelphia, PA) filled the pulp chamber prior to the use of each file. The curvature of the canal, the volume of the chelating agent used and the time that it took to instrument the canals were recorded.

The exact steps used to construct the pre-instrumentation models were recorded and used to construct the postinstrumentation models. The models were aligned using the external contours of the coronal tooth structure. Using 3Matic™ software (Materialise, Leuven, Belgium), the crown, pulp chamber, apical extent of the canal beyond working length, accessory canals and fins were removed from the models. This leaves only the portion of the main canal that was prepared by the rotary files to be evaluated for the change in volume and transportation. The volumes for the pre- and post-instrumentation models were calculated. The center of gravity was calculated at cross-sectional slices beginning at working length and moving coronally at 1mm increments. Canal transportation was calculated by measuring the distance between the centers of gravity of the pre- and post-instrumentation models at each cross section.


The curvature of the canals ranged from 22.1 to 30.09 degree with the mean curvature of 27, 26.4 and 27.1 degrees for the group 1, group 2, and group 3 respectfully. The volume of 17% EDTA used ranged from 0.20 mL to 0.35 mL and the volume of RC Prep ™ used ranged from 0.25 mL to 0.45mL. The change in working length ranged from 0.01mm to 0.39mm. When the effect of the type of irrigant or chelating agent on the change in working length was evaluated a minute decrease was detected.

Overall, the canals in which RC Prep™ was used during instrumentation showed the least change in working length (0.091±0.40),whereas those canals in which only saline was used showed the largest 8 change in working length (0.19±0.20). Using a one-way ANOVA, on the basis of the p-value (0.452) there was no significant difference in these 3 groups. The change in volume ranged from 0.219 mm to 3.95 mm.

Mean changes in volume. Canals that were instrumented with 17% EDTA as the chelating agent showed the largest change in volume (2.222 ± 0.886), whereas those instrumented with RCPrep™ showed the smallest change in volume (1.260 ± 0.578). The effect of the type of irrigant or chelating agent on the change in volume was evaluated using a one-way ANOVA. On the basis of the p-value (0.079) there is no significant difference between the three groups.

Transportation was measured at 1 mm increments from working length to the coronal orifice. Transportation could not be measured in 3 samples due to unusual canal anatomy. All 3 samples belonged to the saline group. A two-way analysis was performed to determine if the effect of the type of irrigant or chelating agent used on the average transportation was the same at all levels of the canal. The p-value was 0.741, which suggests that the effects of one factor were not different at the different levels of the other factor.

A one-way ANOVA was then conducted for each variable. The transportation between the levels of the canal was found to be significantly difference (p-value < 0.0005). A post-hoc analysis was conducted using the Tukey multiple comparison method. The difference was found between the apical and coronal levels and between the middle and coronal levels.


Procedural errors have been shown to affect the outcome of endodontic treatment. Currently there is no evidence that shows that transportation has a direct effect on clinical outcomes [7]. Canal transportation could lead to inadequately cleaned canals resulting in persistent apical pathosis, perforations or thinning of the canal walls leading to vertical fractures. This may lead to a need for surgical root canal treatment. Apical transportation >0.3mm was shown to negatively affect the apical seal in canals obturated by lateral compaction of guttapercha [14], which could also affect clinical outcomes. The anatomy of the canals preoperatively appeared to effect the change in volume and transportation. Retrospectively, the constrictions of the canals were compared after a large difference in the change in volume was observed. The canals that were more constricted preoperatively had a larger change in volume and greater transportation. Mean canal transportation ranged from 2.6μm to 17.8μm. Transportation was greatest in the coronal portion of the canal. This corresponds to the area of the rotary files that have the greatest mass and least flexibility. This may indicate that the physical properties of the file may be responsible for transportation versus the irrigant or chelating agent used. The purpose of this study was to evaluate the effects of using EDTA during root canal preparation. To do this we chose to evaluate both RC-Prep™ and 17% EDTA, which is the highest concentration of EDTA commercially available. The use of 17% EDTA during instrumentation is not a standard protocol that we currently use as studies have shown that prolonged exposure can negatively affect the remaining tooth structure [11, 12]. In this study we are using a much smaller volume of EDTA than was used. The volume used may not be significant as Crumpton et al. found that there was no difference in the smear layer removal with varied volumes of EDTA.


Under the conditions of this interim analysis, the irrigant or chelating agent used did not significantly affect the change in working length, change in volume and transportation. The change in volume approached statistical significance.

In the author’s opinion this is due to the uneven distribution of canals with constricted anatomy. With a larger sample size the p-value would most likely increase and further prove that the use of a chelating agent during instrumentation does not significantly affect the size and shape of the instrumented canal.


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