Effect of Novel Chelating Agents on the Dislodgement Resistance of Biodentine: An Ex-Vivo Study

ABSTRACT

Objective:  To investigate the effect of 0.26mol/L Clodronate Disodium Tetrahydrate, 9% Etidronic acid (HEDP), and 17% Ethylenediaminetetraacetic acid (EDTA) on the dislodgement resistance of Biodentine.

Material and Methods:  80 human single-rooted premolar teeth were selected. For bond strength analysis, samples were treated (n=15) according to the irrigation protocol employed: EDTA Group - 2.5% sodium hypochlorite (NaOCl) + 17% EDTA; HEDP Group - 9% Etidronic acid + 2.5% NaOCl; Clodronate Group- 0.26mol/L Clodronate + 2.5% NaOCl; and Control Group- 2.5% NaOCl + Distilled Water. Root canals were condensed with Biodentine, and 1.5 mm thick dentine discs were produced, and push-out bond strength was analysed. For FTIR analysis, dentine samples (n=5) were prepared (1cm × 1cm). Pre and post-irrigation scans were performed to compare compositional changes in the Amide III, Phosphate, and Carbonate infrared bands. One-way analysis of variance with post-hoc Tukey’s test was employed to analyze the results.

Results:  The highest bond strength value was obtained with 0.26mol/L Clodronate, followed by 9% HEDP and 17% EDTA (p<0.001). Amide III: Phosphate levels decreased with EDTA and HEDP, whereas the opposite was observed with Carbonate: Phosphate. No difference was observed with 0.26 mol/L Clodronate. Fractographic analysis revealed 20% adhesive failure, 48% mixed failure, and 32% adhesive failure, respectively.

Conclusion:  0.26 mol/L Clodronate produced the most favourable outcome in terms of bond strength of Biodentine.

Keywords:
Clodronic Acid; Etidronic Acid; Endodontics; Smear Layer.

Introduction

Chemo-mechanical preparation forms an integral part of performing a root canal treatment successfully, as it renders the root canals free from bacterial biofilms and debris [¹]. While it reduces the microbial load, the instrumentation of the canals leads to the formation of a layer of inorganic and organic residue, known as the smear layer [²]. The smear layer decreases the ability of the root canal irrigating solutions and intracanal medicaments to diffuse into the dentinal tubules and isthmuses [³]. Additionally, the microorganisms left behind become entrapped within the smear layer, contributing to endodontic treatment failures [⁴]. Hence, the elimination of this smear layer is of prime importance. The endodontic irrigants employed to remove the smear layer include a combination of sodium hypochlorite (NaOCl) and a chelating agent. Owing to their decalcifying action, the chelating agents tend to alter the calcium-phosphorus ratio. This, in turn, can alter the microhardness, adhesion and sealing ability of the dental materials to root canal dentin [⁵].

The conventionally employed irrigation regimen using 2.5% NaOCl and 17% Ethylenediaminetetraacetic acid (EDTA), leads to intertubular tunneling defects [⁶], resulting in erosion of the interradicular dentin [⁷]. Further research led to the origin of the concept of continuous chelation [⁸]. This technique advocates combining a weak chelating agent with NaOCl as a single root canal irrigation solution. 9% Etidronic acid (HEDP), being biocompatible with 2.5% NaOCl, is one such chelator that has proven beneficial in continuous chelation. This combination prevented the formation of a smear layer without aggressively demineralizing the dentine substrate [⁹]. It also improved the adhesion of the dental materials to root canal dentine, better than sequential irrigation with 2.5% NaOCl followed by 17% EDTA [¹⁰]. Although the (NaOCl/HEDP) combination exhibits favourable results, the compounds formed by combining these two agents are chemically unstable [¹¹], leading to the loss of free available chlorine (FAC) present in NaOCl over time [¹²]. This may compromise the clinical performance (antibacterial and tissue dissolution) and the storage period of the NaOCl/HEDP combination.

Clodronate is a novel chelating agent that, at alkaline pH, can be used in continuous chelation. It maintains the FAC for over 18 hours at room temperature and for 3 months at 2-4 degrees [¹³]. 0.26 mol/L Clodronate with 2.5% NaOCl has resulted in better organic tissue dissolution while maintaining favourable amounts of FAC [¹⁴]. However, continuous chelation employing HEDP or Clodronate has the potential to decrease the pH of the hypochlorite solution, leading to the breakdown of NaOCl into Chlorine gas, thereby impairing the clinical effectiveness of NaOCl [¹⁵]. Therefore, the irrigation protocol employed should ensure a strong bond between the dental materials and the root canal dentin. A calcium silicate-based material that has gained popularity in recent times is Biodentine (Septodont, Saint-Maur-des-Fossés, France), due to its resemblance and added benefits over MTA, like short setting time [¹⁶], better handling characteristics [¹⁷], and lower discoloration potential [¹⁸]. It forms microtags into dentinal tubules, rendering a good sealing ability [¹⁹]. A previous study [²⁰] has demonstrated the beneficial effect of irrigating the root canal with 9% HEDP on the push-out bond strength (POBS) of Biodentine. However, the effect of 0.26 mol/L Clodronate on the POBS of Biodentine has not yet been evaluated. Hence, the present study aims to evaluate the effect of 17% EDTA, 9% HEDP and 0.26 mol/L Clodronate when used with NaOCl on the dislodgement resistance of Biodentine. The null hypothesis was that 0.26 mol/L Clodronate, 9% HEDP and 17% EDTA would have similar effects on the dislodgment resistance of Biodentine.

Material and Methods

Ethical Clearance

Human-extracted teeth were used and the ethical clearance of which was obtained from the Institutional Review Board (582/2022) on 27/03/2023. The study was conducted in accordance with the Declaration of Helsinki.

Sample Size Estimation

G* Power Software (Heinrich Heine University, Dusseldorf, Germany) was used for the sample size estimation. With a 95% confidence level, 90% power, standard deviation of 0.67 and mean difference of 0.83, the sample size of a minimum of 15 in each group was determined [²¹]. For FTIR analysis, five samples were used per group.

Sample Selection

A total of 80 non-carious premolars with single roots that were extracted for orthodontic reasons were selected for the study. A root curvature for all the teeth was ensured to be less than 30^o [²²]. The presence of one canal, a closed apex, absence of intra-radicular resorption, calcifications, or fillings was verified using a radiograph and surgical microscope. Debridement of the samples was performed using an ultrasonic scaler. The samples were later stored at 4 °C in saline with 0.2% sodium azide aqueous solution (Millipore Sigma, St. Louis, MO, USA) until further use.

Irrigant Preparation

The irrigation solution preparation was done as follows:

• A commercially available 17% EDTA solution (Meta Biomed, Chungcheongbuk-do, Republic of Korea) was used, after adjusting its pH to 11.1 with sodium hydroxide.

• A 60% aqueous solution of HEDP (Sigma-Aldrich, Merck KGaA, Darmstadt, Germany) was diluted to 9% using distilled water, and the pH was adjusted to 11.6 using deionized water and sodium hydroxide, respectively. This was mixed with equal quantities of 2.5% NaOCl (Septodont, Saint-Maur-des-Fossés, France) to obtain a final pH of 12.6.

• Disodium Clodronate (Sigma-Aldrich, Merck KGaA, Darmstadt, Germany), 99% pure, was prepared to 0.26 mol/L using deionized water. The pH was adjusted to 10.7 using sodium hydroxide. Before its use, the solution was mixed with equal quantities of 2.5% NaOCl to obtain a final pH of 12.6.

pH was monitored throughout the experiment, and the measurements were taken for all groups using a digital Seven Excellence S400 pH meter (Mettler-Toledo Ltd., Leicester, UK).

Specimen Preparation

Decoronation of the samples was performed using a diamond disc (Horico, Berlin, Germany) to standardize the root lengths. Working length determination was performed by inserting a size 10 K file (Dentsply Sirona, North Carolina, USA) into the root canal until just visible at the apical foramen. This was followed by subtracting 1 mm from the previously recorded length. Before the irrigation protocol, sticky wax was used to cover the apices of the teeth to simulate a closed-end system, which would promote an effective reverse flow of the irrigant. The samples were then randomly divided into four groups (n=15) using a sequence generator (www.random.org), depending upon the type of irrigating regimen. Additionally, the operators were blinded to the group assessments to minimize any bias in the experiment. Root canals were enlarged sequentially by employing Peeso reamers sizes #1 - #4 (Mani Inc., Tokyo, Japan).

Irrigation Techniques

• EDTA Group: 2.5% NaOCl (5 mL for 1 min) after each instrument change, followed by 17% EDTA (5 mL for 1 min) as a final rinse.

• HEDP Group: 2.5% NaOCl + 9% HEDP were mixed in equal quantities and were used as a single irrigant in the continuous chelation technique. This mixture (5 mL for 1 min) was used after each instrument change, followed by 2.5% NaOCl/9% HEDP (5 mL for 1 min) as a final rinse.

• Clodronate Group: 2.5% NaOCl + 0.26 mol/L Clodronate was mixed in equal quantities and was used as a single irrigant in the continuous chelation technique. This mixture (5 mL for 1 min) was used after each instrument change, followed by 2.5% NaOCl/ 0.26 mol/L Clodronate (5 mL for 1 min) as a final rinse.

• Control Group: 2.5% NaOCl (5 mL for 1 min) after each instrument change, followed by distilled water (5 mL for 1 min) as a final rinse.

Following the aforementioned protocol, each root canal of each sample was additionally irrigated with distilled water (5 mL) for 1 min to eliminate any precipitate that may have formed. Irrigation of the samples was performed using a 30-gauge side-vented needle (Vista Dental Inc., Racine, WI, USA) that was kept 1mm short of the working length. Sterile paper points were then used to dry the specimens. Biodentine was mixed according to the manufacturer’s instructions and incrementally placed into the root canals of respective groups using an MTA carrier and was further condensed with hand pluggers. All the samples were radiographed to confirm dense obturation free from voids. To ensure a complete set of cement, the samples were stored for 24 hours at 37ºC.

Push-Out Bond Strength analysis

After submerging each sample in cold-cure acrylic (Dentsply Sirona Inc., Mumbai, India), the obturated root samples were sectioned horizontally from the middle third using a hard tissue microtome (Leica Biosystems GmbH, Nussloch, Germany) under continuous water cooling. A dentine disc measuring 1.5 ± 0.1 mm in thickness was obtained from each root sample, which was verified using a digital calliper. The POBS testing was done with the universal testing machine (Instron, Norwood, MA, USA). A stainless-steel plunger of 0.6 mm with a crosshead speed of one mm per minute was used to deliver the force in the apical-coronal direction. The plunger was positioned so that it came into contact only with the Biodentine. The maximum force (F) applied at the time of bond failure was noted in Newtons. The POBS was derived in Mega Pascals as follows:

POBS (MPa) = Force (N)/Adhesion surface area (mm²);

Adhesion surface area (mm²) = 2×π×r×h, wherein π is the constant 3.14, “r” is the radius of the prepared root canal and “h” is the thickness of the root disc.

Fractographic Analysis

Stereomicroscopic analysis was performed using an Olympus SZX61 microscope (Evident, Tokyo, Japan) at 40X magnification to evaluate the bond failures of samples from all four groups. They were categorized into three groups based on the modes of bond failure: 1. Adhesive failure: At the interface of root canal walls and Biodentine; 2. Cohesive failure: In between the bulk of Biodentine, and 3. Mixed failure: A mix of both adhesive and cohesive failures.

Fourier Transform Infrared Spectrophotometer (FTIR) Analysis

A total of 20 dentine slices measuring 1cm ×1cm were obtained from the root canals of five extracted human single-rooted teeth. The root canal dentine surface of each sample was serially wet-polished using 800-1200 grit abrasives with a single-disc tabletop polisher (Bainpot VT, Guadalajara, Mexico). This procedure rendered a smooth surface, which could favour the absorbance of infrared radiation. This was followed by immersion of the specimens in distilled water under an ultrasonic bath (1 minute) to remove residual material after polishing. The specimens were blotted dry using absorbent paper points (Dentsply Sirona) to mimic the clinical environment and reproduce the tissue characteristics, thereby avoiding excessive dehydration. The samples were then equally divided into groups of four (n=5), such as those used in POBS analysis. Pre-treatment compositional analysis of Amide III, Phosphate and Carbonate infrared bands was determined using an FTIR spectrophotometer of a diamond ATR set-up (JASCO, Deutschland GmbH, Pfungstadt, Germany). Then the specimens were treated with irrigating agents, such as POBS analysis. Specimens were placed into test tubes containing 10 mL of the experimental irrigating agents and agitated for 30 minutes under ultrasonic conditions. After the stipulated time, the remnants of irrigating solutions were removed by immersing the samples in distilled water (10 mL) for 10 mins, followed by drying using absorbent points (Dentsply Sirona). Post-treatment infrared spectrum areas of the respective bands were determined using baseline tracing. Spectra were obtained between 400 and 4000/cm at 4/cm resolution by using 64 scans per measurement. The alterations in the inorganic and organic components of the dentin were used to calculate the amide III/phosphate and carbonate/phosphate ratios, respectively.

Statistical Analysis

The data were statistically analyzed using SPSS Statistics Version 25.0 software (IBM Corp, Armonk, NY). The normality of the data was evaluated using the Kolmogorov-Smirnov test. POBS was analysed using one-way ANOVA with the post hoc Tukey honest significant difference (HSD) test. p<0.05 was considered to be statistically significant (95% confidence).

Results

Push-Out Bond Strength Analysis

The various irrigating solutions used in comparing the dislodgement resistance of Biodentine resulted in significant differences among them (p<0.001). The highest POBS of 15.78 ± 1.2 MPa was observed with the Clodronate Group, followed by 9.12 ± 0.8 MPa and 6.56 ± 0.6 MPa for the HEDP Group and EDTA Group, respectively. The lowest POBS of 4.38 ± 0.5 MPa was seen in the Control Group.

Fractographic Analysis

In the EDTA Group, 40% of the bond failures were mixed (6), 33.3% were adhesive (5), and 26.6% were cohesive (4). In the HEDP Group, 53.3% was mixed (8), 40% cohesive (6) and 6.6% adhesive (1) type. In the Clodronate Group, 46.6% cohesive (7), 40% was mixed (6), and 13.3% adhesive (2) type. In the Control Group, 60% was mixed (9), 26.6% adhesive (4), and 13.33% cohesive (2) type. Overall, adhesive failure was observed in 12 out of 60 samples (20%), mixed failure in 29 out of 60 samples (48%), and cohesive type of failure in 19 out of 60 samples (32%). The representative images of the failure modes are shown in Figure 1.

Figure 1
Stereomicroscopic images of bond failures of the samples treated with experimental irrigating agents.

FTIR Analysis

Amide III: Phosphate Ratio:

Post-irrigation, the amide III: phosphate ratio increased in the EDTA Group and HEDP Group, respectively, while it decreased significantly in the Control Group. No statistical difference was noted between the Clodronate Group (Table 1).

Table 1
FTIR analysis of various irrigation groups measuring amide/phosphate and carbonate/phosphate ratios before (pre) and after (post) treatment.

Irrigant	Amide/Phosphate (PRE)	Amide/Phosphate (POST)	Carbonate/ Phosphate (PRE)	Carbonate/Phosphate (POST)
	Mean (SD)	Mean (SD)	Mean (SD)	Mean (SD)
EDTA Group	8.7 ± 2.1A	119.8 ± 8.1B	17.6 ± 1.9a	-29.9 ± 8.2b
HEDP Group	7.7 ± 1.2A	35.52 ± 11.1B	20.1± 4.8a	15.2 ± 4.8b
Clodronate Group	5.9 ± 2.1A	4.4 ± 1.3A	15.0 ± 2.1a	21.1 ± 5.1a
Control Group	4.7 ± 0.9A	0.2 ± 0.8B	13.5 ± 3.6a	13.8 ± 6.4a

Carbonate: Phosphate Ratio:

Carbonate/ Phosphate ratio decreased significantly in the EDTA Group and the HEDP Group, while insignificant changes were seen in the Clodronate Group (Table 1)

Figure 2 represents the preand post-infrared absorption spectra of dentine treated with various chelating agents.

Figure 2
Superimposed infrared spectra of dentin subjected to preand post-irrigation with 17% EDTA, 9% HEDP, 0.26mol/L Clodronate, and distilled water.

Discussion

The current study was performed to evaluate the effect of root conditioning with 0.26 mol/L Clodronate, 9% HEDP, and 17% EDTA on the dislodgment resistance of Biodentine. Results revealed that 0.26mol/L Clodronate exhibited the highest POBS, followed by 9% HEDP and 17% EDTA, respectively. Thus, the null hypothesis proposed was rejected.

The superior performance of 0.26mol/L Clodronate, with respect to the dislodgment resistance of Biodentine, can be correlated with the FTIR analysis performed in this study. FTIR analysis demonstrated that 0.26mol/L Clodronate did not significantly reduce the Carbonate: Phosphate ratio of dentin, as opposed to 9% HEDP and 17% EDTA, where significant reduction was noted. This may be due to greater maintenance of the FAC by Clodronate/NaOCl mixture when compared to the combination of NaOCl with EDTA or HEDP [¹⁴]. The Clodronate/NaOCl mixture, having its longer duration of action in continuous chelation, would have been more effective in the removal of the organic component of the smear layer. This, alongside its alkaline nature, would have caused a minimal effect on the setting reaction of Biodentine, leading to its higher bond strength to root dentine.

EDTA is commonly used as a final irrigating solution in endodontics to eliminate the smear layer. Root canal dentin conditioned with EDTA results in high bond strengths of resin-based cement [²³]. However, recent studies have highlighted its adverse effects on calcium silicate-based preparations [²³]. The current study also demonstrated that irrigation with 17% EDTA resulted in lower bond strength values of Biodentine, which is in accordance with previous studies [²⁰]. This could be attributed to its chelating action and formation of calcium complexes from the calcium released by Biodentine, resulting in the dissolution of the binding phase, and thus compromising the adhesion and the formation of the mineral infiltration zone [²⁴]. EDTA also forms more stable complexes with calcium, thus sequestering more calcium than HEDP [²⁵], which could have resulted in a significant reduction of the Carbonate: Phosphate ratio as seen in the FTIR analysis.

The control group containing plain 2.5% NaOCl showed the lowest bond strength. This could be attributed to its inability to remove the inorganic component of the smear layer, thus compromising the bond strength of Biodentine. Moreover, NaOCl is known to interfere with the adhesion of calcium silicate cements [²⁶], which may have been countered in the other groups due to the inclusion of chelating agents. The results for the POBS of the NaOCl group are in accordance with the FTIR analysis, which showed the highest reduction in the Amide: Phosphate ratio compared to other groups. This could be due to the greater dissolution of the collagen from the dentinal substrate owing to the longer exposure time of NaOCl to the bonding substrate.

Fractographic analysis was performed to test the type of bond failures after the POBS analysis. The majority of failures in the 17% EDTA and control groups were adhesive, compared to the Clodronate and HEDP groups, which showed cohesive failures. More adhesive failures occurred at the tooth-cement interface in the EDTA and control groups owing to their weaker bonds with Biodentine. In the Clodronate and HEDP groups, failures occurred within the cement due to its high POBS values. The measurement of shear stress in the present study was done using POBS evaluation, which is known to closely replicate the clinical conditions [²⁷]. Its reliability in measuring the marginal adaptability of the material to the surrounding dentin has been well-documented and studied in various studies [²⁸,²⁹]. The thickness of the dentine discs was kept to a minimum (1.5mm) to avoid overestimating the POBS values.

NaOCl was used at a 2.5% concentration throughout the experiment due to its lesser cytotoxic effect and good tissue dissolution ability [³⁰]. The action of chelating agents, namely 9% HEDP and 17% EDTA is pH-dependent [³¹]. Therefore, stringent measures were taken to maintain the ideal pH of the irrigating solutions before the initiation of the procedures. Temperature conditions are known to affect the pH of the irrigant solution [³²] and play a crucial role in FTIR analysis, by influencing their molecular behaviour, evaporation and instrumental sensitivity. Hence, a standard temperature condition of 23ºC was maintained throughout the experiment, using a digital thermometer to avoid any alteration in the values.

Endodontic irrigants affect the chemical structure of dentine, namely the inorganic and organic components, which are measured through the Carbonate: Phosphate and Amide III: Phosphate ratios, respectively [³³]. Numerous studies have evaluated these structural changes using FTIR (Fourier Transform Infrared Radiation) analysis [³⁴,³⁵]. Hence, in the present study, FTIR analysis was employed to evaluate the effect of different chelating agents on the structural changes of the dentin matrix.

For the present study, a pilot study was conducted, requiring a minimum of 30 minutes of exposure time to the irrigation solutions to distinctly evaluate the dentinal changes in the amide III: phosphate ratios using FTIR [³⁵]. However, for assessing the POBS of Biodentine, the root canals were conditioned for less time to mimic the clinical scenario. Hence, the results of POBS and FTIR cannot be completely correlated, as FTIR demands more specimen preparation and prolonged exposure times, whereas dislodgement resistance testing can be conducted in a simulated clinical setup in extracted teeth.

While ex-vivo studies are valuable for initial exploration, it has certain limitations. The measurement values obtained in this study may vary in clinical scenarios with the alteration in temperature, irrigation techniques, nature of the dentine, and moisture present in the root canal. Hence, further clinical studies are warranted to assess the outcomes of POBS of Biodentine using a combination of NaOCl and Clodronate as an endodontic irrigant.

Conclusion

Within the limitations of the study, 0.26 mol/L disodium Clodronate exhibited the highest dislodgement resistance of Biodentine to root canal dentin when compared to 17% EDTA and 9% HEDP.

• Financial Support
  None.

Data Availability

The data used to support the findings of this study can be made available upon request to the corresponding author.

References

• ^[1] Bystrom A, Sundqvist G. Bacteriologic evaluation of the efficacy of mechanical root canal instrumentation in endodontic therapy. Scand J Dent Res 1981; 89(4):321-328. https://doi/10.1111/j.1600-0722.1981.tb01689.x
  » https://doi/10.1111/j.1600-0722.1981.tb01689.x
• ^[2] Clark-Holke D, Drake D, Walton R, Rivera E, Guthmiller JM. Bacterial penetration through canals of endodontically treated teeth in the presence or absence of the smear layer. J Dent 2003; 31(4):275-281. https://doi.org/10.1016/S0300-5712(03)00032-0
  » https://doi.org/10.1016/S0300-5712(03)00032-0
• ^[3] Wang Z, Shen Y, Haapasalo M. Effect of smear layer against disinfection protocols on Enterococcus faecalis-infected dentin. J Endod 2013; 39(11):1395-1400. https://doi.org/10.1012/j.joen.2013.05.007
  » https://doi.org/10.1012/j.joen.2013.05.007
• ^[4] Drake DR, Wiemann AH, Rivera EM, Walton RE. Bacterial retention in canal walls in vitro: Effect of smear layer. J Endod 1994; 20(2):78-82. https://doi.org/10.1016/S0099-2399(06)81186-6
  » https://doi.org/10.1016/S0099-2399(06)81186-6
• ^[5] Rajakumaran A, Ramesh H, Ashok R, Balaji L, Ganesh A. Smear layer removal and microhardness alteration potential of a naturally occurring antioxidant - An in vitro study. Cureus 2019; 11(7):241. https://doi.org/10.7759/cureus.5241
  » https://doi.org/10.7759/cureus.5241
• ^[6] Lottanti S, Gautschi H, Sener B, Zehnder M. Effects of ethylenediaminetetraacetic, etidronic and peracetic acid irrigation on human root dentine and the smear layer. Int Endod J 2009; 42(4):335-343. https://doi.org/10.1111/j.1365-2591.2008.01514.x
  » https://doi.org/10.1111/j.1365-2591.2008.01514.x
• ^[7] Nogueira BM, da Costa Pereira TI, Pedrinha VF, Rodrigues PA. Effects of different irrigation solutions and protocols on mineral content and ultrastructure of root canal dentine. Iran Endod J 2018; 13(2):209. https://doi.org/10.22037/iej.v13i2.19287
  » https://doi.org/10.22037/iej.v13i2.19287
• ^[8] Zehnder M, Schmidlin P, Sener B, Waltimo T. Chelation in root canal therapy reconsidered. J Endod 2005; 31(11):817-820. https://doi.org/10.1097/01.don.000158233.59316.fe
  » https://doi.org/10.1097/01.don.000158233.59316.fe
• ^[9] Tartari T, Bachmann L, Zancan RF, Vivan RR, Duarte MAH, Bramante CM. Analysis of the effects of several decalcifying agents alone and in combination with sodium hypochlorite on the chemical composition of dentine. Int Endod J 2018; 51(1):42-54. https://doi.org/10.1111.iej.12764
  » https://doi.org/10.1111.iej.12764
• ^[10] De-Deus G, Namen F, Galan Jr J, Zehnder M. Soft chelating irrigation protocol optimizes bonding quality of Resilon/Epiphany root fillings. J Endod 2008; 34(6):703-705. https://doi.org/10.1016/j.joen.2008.02.024
  » https://doi.org/10.1016/j.joen.2008.02.024
• ^[11] Biel P, Mohn D, Attin T, Zehnder M. Interactions between the tetrasodium salts of EDTA and 1-hydroxyethane 1, 1-diphosphonic acid with sodium hypochlorite irrigants. J Endod 2017; 43(4):657-661. https://doi.org/10.1016/j.joen.2016.12.006
  » https://doi.org/10.1016/j.joen.2016.12.006
• ^[12] Zollinger A, Mohn D, Zeltner M, Zehnder M. Short-term storage stability of NaOCl solutions when combined with Dual Rinse HEDP. Int Endod J 2018; 51(6):691-696. https://doi.org/10.1111/iej.12875
  » https://doi.org/10.1111/iej.12875
• ^[13] Wright PP, Cooper C, Kahler B, Walsh LJ. From an assessment of multiple chelators, clodronate has potential for use in continuous chelation. Int Endod J 2020; 53(1):122-134. https://doi.org/10.1111/iej.13213
  » https://doi.org/10.1111/iej.13213
• ^[14] Wright PP, Scott S, Kahler B, Walsh LJ. Organic tissue dissolution in clodronate and etidronate mixtures with sodium hypochlorite. J Endod 2020; 46(2):289-294. https://doi.org/10.1016/j.joen.2019.10.020
  » https://doi.org/10.1016/j.joen.2019.10.020
• ^[15] Wright PP, Kahler B, Walsh LJ. Alkaline sodium hypochlorite irrigant and its chemical interactions. Materials 2017; 10(10):1147. https://doi.org/10.3390/ma10101147
  » https://doi.org/10.3390/ma10101147
• ^[16] Torabinejad M, Hong CU, McDonald F, Ford TRP. Physical and chemical properties of a new root-end filling material. J Endod 1995; 21(7):349-353. https://doi.org/10.1016/S0099-2399(06)80967-2
  » https://doi.org/10.1016/S0099-2399(06)80967-2
• ^[17] Mooney GC, North S. The current opinions and use of MTA for apical barrier formation of non-vital immature permanent incisors by consultants in paediatric dentistry in the UK. Dent Traumatol 2008; 24(1):65-69. https://doi.org/10.1111/j.1600-9657.2006.00495.x
  » https://doi.org/10.1111/j.1600-9657.2006.00495.x
• ^[18] Accorinte ML, Loguercio AD, Reis A, Carneiro E, Grande RH, Murata SS, et al. Response of human dental pulp capped with MTA and calcium hydroxide powder. Oper Dent 2008; 33(5):488-495. https://doi.org/10.2341/07-143
  » https://doi.org/10.2341/07-143
• ^[19] Arora D. Bioactive dentin replacement. IOSR J Dent Med Sci 2013; 12:51-57. https://doi.org/10.9790/0853-1245157
  » https://doi.org/10.9790/0853-1245157
• ^[20] Paulson L, Ballal NV, Bhagat A. Effect of root dentin conditioning on the pushout bond strength of Biodentine. J Endod 2018; 44(7):1186-1190. https://doi.org/10.1016/j.joen.2018.04.009
  » https://doi.org/10.1016/j.joen.2018.04.009
• ^[21] Stelzer R, Schaller HG, Gernhardlt CR. Push-out bond strength of RealSeal SE and AH Plus after using different irrigation solutions. J Endod 2014; 40(10):1654-1657. https://doi.org/10.1016/j.joen.2014.05.001
  » https://doi.org/10.1016/j.joen.2014.05.001
• ^[22] S.W.Schneider, A comparison of canal preparations in straight and curved root canals, Oral Surg Oral Med Oral Pathol 1971; 32(2):271-275. https://doi.org/10.1016/0030-4220(71)90230-1
  » https://doi.org/10.1016/0030-4220(71)90230-1
• ^[23] Dureja A, Purayil TP, Ballal VN, George SD. Effect of different chelating agents on the wettability of CeraSeal and AH Plus sealers to intraradicular dentin: An in vitro study. Saudi Endod J 2023 13(3):248-253. https://doi.org/10.4103/sej.sej_17_23
  » https://doi.org/10.4103/sej.sej_17_23
• ^[24] Lee YL, Lin FH, Wang WH, Ritchie HH, Lan WH, Lin CP. Effects of EDTA on the hydration mechanism of mineral trioxide aggregate. J Dent Res 2007; 86(6):534-538. https://doi.org/10.1177/154405910708600609
  » https://doi.org/10.1177/154405910708600609
• ^[25] Stanga M. Chemistry of Aqueous Solutions. In: Cleaning and Disinfection in the Food Industry. Weinheim, Germany: Wiley; 2010. https://doi.org/10.1002/9783527629459.ch1
  » https://doi.org/10.1002/9783527629459.ch1
• ^[26] Camilleri J. Color stability of white mineral trioxide aggregate in contact with hypochlorite solution. J Endod 2014; 40(3):436-440. https://doi.org/10.1016/j.joen.2013.09.040
  » https://doi.org/10.1016/j.joen.2013.09.040
• ^[27] Pane E, Palamara J, Messer H. Critical evaluation of the push out test for root canal filling materials. J Endod 2013; 39(5):669-673. https://doi.org/10.1016/j.joen.2012.12.032
  » https://doi.org/10.1016/j.joen.2012.12.032
• ^[28] Prasanthi P, Garlapati R, Nagesh B, Sujana V, Kiran Naik KM, Yamini B. Effect of 17% ethylenediaminetetraacetic acid and 0.2% chitosan on pushout bond strength of biodentine and ProRoot mineral trioxide aggregate. An in vitro study. J Conserv Dent 2019; 22(4):387-390. https://doi.org/10.4103/JCD.JCD_56_19
  » https://doi.org/10.4103/JCD.JCD_56_19
• ^[29] İpek İ, Ünal M, Güner A, Candan M. Push-out bond strength of Biodentine, MTA repair HP, and a new pre-mixed NeoPutty bioactive cement: Scanning electron microscopy energy dispersive X-ray spectroscopy analysis. J Aust Ceram Soc 2022; 58:171-179. https://doi.org/10.1007/s41779-021-00663-5
  » https://doi.org/10.1007/s41779-021-00663-5
• ^[30] Marion JJ, Manhães FC, Bajo H, Mageste Duque TM. Efficiency of different concentrations of sodium hypochlorite during endodontic treatment. Literature review. Dental Press Endod 2012; 2(4):32-37.
• ^[31] Deari S, Mohn D, Zehnder M. Dentine decalcification and smear layer removal by different ethylenediaminetetraacetic acid and 1-hydroxyethane-1,1-diphosphonic acid species. Int Endod J 2019; 52(2):237-243. https://doi.org/10.1111/iej.12987
  » https://doi.org/10.1111/iej.12987
• ^[32] Tartari T, Borges MMB, de Araújo LBB, Vivan RR, Bonjardim LR, Duarte MAH. Effects of heat in the properties of NaOCl alone and mixed with etidronate and alkaline tetrasodium EDTA. Int Endod J 2021; 54(4):616-627. https://doi.org/10.1111/iej.13450
  » https://doi.org/10.1111/iej.13450
• ^[33] Doğan H, Qalt S. Effects of chelating agents and sodium hypochlorite on mineral content of root dentin. J Endod 2001; 27(9):578-580. https://doi.org/10.1097/00004770-200109000-00006
  » https://doi.org/10.1097/00004770-200109000-00006
• ^[34] Padmakumar I, Hinduja D, Mujeeb A, Kachenahalli NR, Kumar SA, Mirza MB, et al. Evaluation of effects of various irrigating solutions on chemical structure of root canal dentin using FTIR, SEM, and EDS: An in vitro study. J Funct Biomater 2022; 13(4):197. https://doi.org/10.3390/jfb13040197
  » https://doi.org/10.3390/jfb13040197
• ^[35] Ballal NV, Roy A, Zehnder M. Effect of sodium hypochlorite concentration in continuous chelation on dislodgement resistance of an epoxy resin and hydraulic calcium silicate sealer. Polym J 2021; 13(20):3482. https://doi.org/10.3390/polym13203482
  » https://doi.org/10.3390/polym13203482

Edited by

• Academic Editor:
  Wilton Wilney Nascimento Padilha

Publication Dates

• Publication in this collection
  08 Dec 2025
• Date of issue
  2026

History

• Received
  24 Apr 2024
• Reviewed
  21 Dec 2024
• Accepted
  18 Mar 2025