Accessibility / Report Error

Effect of endodontic chelating solutions on the bond strength of endodontic sealers

Abstract

The purpose of this in vitro study was to evaluate the effect of various chelating solutions on the radicular push-out bond strength of calcium silicate-based and resin-based root canal sealers. Root canals of freshly-extracted single-rooted teeth (n = 80) were instrumented by using rotary instruments. The specimens were randomly divided into 4 groups according to the chelating solutions being tested: (1) 17% ethylenediaminetetraacetic acid (EDTA); (2) 9% etidronic acid; (3) 1% peracetic acid (PAA); and (4) distilled water (control). In each group, the roots were further assigned into 2 subgroups according to the sealer used: (1) an epoxy resin-based sealer (AH Plus) and (2) a calcium silicate-based sealer (iRoot SP). Four 1 mm-thick sections were obtained from the coronal aspect of each root (n = 40 slices/group). Push-out bond strength test was performed at a crosshead speed of 1 mm/min., and the bond strength data were analyzed statistically with two-way analysis of variance (ANOVA) with Bonferroni’s post hoc test (p < 0.05). Failure modes were assessed quantitatively under a stereomicroscope. Irrespective of the irrigation regimens, iRoot SP exhibited significantly higher push-out bond strength values than AH Plus (p < 0.05). For both the sealers, the use of chelating solutions increased the bond strength, but to levels that were not significantly greater than their respective controls (p > 0.05). iRoot SP showed higher resistance to dislocation than AH Plus. Final irrigation with 17% EDTA, 9% Etidronic acid, and 1% PAA did not improve the bond strength of AH Plus and iRoot SP to radicular dentin.

Root Canal Obturation; Root Canal Irrigants; Dentin


Introduction

Three-dimensional obturation of the root canal is one of the key factors for success in endodontic therapy.1Epley SR, Fleischman J, Hartwell G, Cicalese C. Completeness of root canal obturations: Epiphany techniques versus gutta-percha techniques. J Endod. 2006 Jun;32(6):541-4. Today, most root canal filling methods continue to utilize different formulations of gutta-percha in conjunction with a minimum amount of sealer. This standard approach aims to provide a gap-free interface between root canal filling and dentin, which is essential for both establishing a fluid-tight seal,2Shipper G, Ørstavik D, Teixeira FB, Trope M. An evaluation of microbial leakage in roots filled with a thermoplastic synthetic polymer-based root canal filling material (Resilon). J Endod. 2004 May;30(5):342-7. and providing resistance for dislocation of the root filling during tooth flexure and operative procedures.3Huffman BP, Mai S, Pinna L, Weller RN, Primus CM, Gutmann JL, et al. Dislocation resistance of ProRoot Endo Sealer, a calcium silicate-based root canal sealer, from radicular dentine. Int Endod J. 2009 Jan;42(1):34-46. To date, numerous materials have been developed to improve the sealing ability and stability of the root canal filling.

Among a wide spectrum of commercially available root canal sealers, a hydrophilic calcium silicate-based endodontic sealer, iRoot SP has gained popularity in recent years. iRoot SP exhibits excellent physical properties, antimicrobial activity, biocompatibility, and adhesion to root dentin under different moisture conditions.4Zhang W, Li Z, Peng B. Ex vivo cytotoxicity of a new calcium silicate-based canal filling material. Int Endod J. 2010 Sep;43(9):769-74. , 5Nagas E, Uyanik MO, Eymirli A, Cehreli ZC, Vallittu PK, Lassila LV, et al. Dentin moisture conditions affect the adhesion of root canal sealers. J Endod. 2012 Feb;38(2):240-4. , 6Nagas E, Cehreli Z, Uyanik MO, Durmaz V. Bond strength of a calcium silicate-based sealer tested in bulk or with different main core materials. Braz Oral Res. 2014 Jan-Feb;28(1):1-7. The composition of iRoot SP is similar to white mineral trioxide aggregate,4Zhang W, Li Z, Peng B. Ex vivo cytotoxicity of a new calcium silicate-based canal filling material. Int Endod J. 2010 Sep;43(9):769-74. which adheres to dentin through physicochemical reaction.7Sarkar NK, Caicedo R, Ritwik P, Moiseyeva R, Kawashima I. Physicochemical basis of the biologic properties of mineral trioxide aggregate. J Endod. 2005 Feb;31(2):97-100.

Over the years, several methods have been tested to improve adhesion of root canal sealers to radicular dentin. Removal of the smear layer is one of these techniques,8Violich DR, Chandler NP. The smear layer in endodontics - a review. Int Endod J. 2010 Jan;43(1):2-15. and numerous irrigation solutions/regimens have been recommended for that purpose.9Zehnder M. Root canal irrigants. J Endod. 2006 May;32(5):389-98. Chelating solutions are able to remove the smear layer, and expose a large number of dentinal tubules,1010 Torabinejad M, Handysides R, Khademi AA, Bakland LK. Clinical implications of the smear layer in endodontics: a review. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2002 Dec;94(6):658-66. which in turn may promote adhesion due to an increased contact area that would ensure a better adaptation between the sealer and root canal dentin.1111 Sayin TC, Serper A, Cehreli ZC, Kalayci S. Calcium loss from root canal dentin following EDTA, EGTA, EDTAC, and tetracycline-HCl treatment with or without subsequent NaOCl irrigation. J Endod. 2007 May;33(5):581-4. However, chelating solutions are also capable of extracting major inorganic elements (e.g., calcium ions) from surface dentin, and partial demineralization may interfere with the bonding effectiveness of canal sealers that chemically adhere to root dentin.1111 Sayin TC, Serper A, Cehreli ZC, Kalayci S. Calcium loss from root canal dentin following EDTA, EGTA, EDTAC, and tetracycline-HCl treatment with or without subsequent NaOCl irrigation. J Endod. 2007 May;33(5):581-4. , 1212 Hennequin M, Pajot J, Avignant D. Effects of different pH values of citric acid solutions on the calcium and phosphorus contents of human root dentin. J Endod. 1994 Nov;20(11):551-4. , 1313 Schwartz RS. Adhesive dentistry and endodontics. Part 2: bonding in the root canal system-the promise and the problems: a review. J Endod. 2006 Dec;32(12):1125-34. To date, little information exists on the effect of chelating solutions on the radicular push-out bond strength of calcium silicate-based and resin-based root canal sealers.

In the light of these observations, the aim of this in vitro study was to evaluate the effect of 17% ethylenediaminetetraacetic acid (EDTA), 9% etidronic acid, and 1% peracetic acid (PAA) chelating solutions on the bond strength of iRoot SP and a resin-based root canal sealer (AH Plus) to radicular dentin. The null hypothesis tested was that various chelating solutions would affect the bond strength of root canal sealers.

Methodology

Specimen Preparation

Eighty periodontally involved, freshly extracted single-rooted human teeth with straight roots, fully formed apices, free of previous root fillings, and root cracks were used. The crowns of all teeth were removed using a water-cooled, slow-speed diamond precision saw (IsoMet 1000; Buehler, Lake Bluff, USA), so as to adjust the length of the roots to a standardized length of 16 mm. The root canals were prepared using ProTaper rotary instruments (Dentsply-Maillefer, Ballaigues, Switzerland) up to master apical rotary size F3 (#30), in conjunction with 2 mL of 5.25% sodium hypochlorite (NaOCl) irrigation between each file and a final rinse with 5 mL distilled water. The specimens were randomly divided into four groups (n = 20 each) according to the final irrigation solutions applied: 1.5 mL of 17% EDTA (Pulpdent Corporation, Watertown, MA) (pH = 7); 2.5 mL of 9% etidronic acid (Zschimmer & Schwarz Mohsdorf GmbH & Co. KG, Burgstädt, Germany) (pH < 2); 3.5 mL of 1% peracetic acid (Sigma-Aldrich, Steinheim, Germany); and distilled water (control). In each group, the specimens were further randomly divided into two groups (n = 10 each) according to root canal sealer used: (a) AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany), and (b). iRoot SP (Innovative BioCeramix Inc., Vancouver, Canada). All materials were applied by one calibrated operator in strict adherence to the manufacturers’ recommendations. Following root filling procedures, canal openings were sealed with Cavit™-G (3M ESPE, GmbH, Seefeld, Germany). The specimens were stored at 37°C and 100% humidity for 1 week to allow complete setting of the test materials.

Push-out bond strength test

Four 1 mm-thick horizontal sections were obtained from each specimen (n = 40 slices/group) consecutively from coronal-to-apical direction using a water-cooled precision saw (Isomet). Root sections demonstrating oval root canal form (i.e., nonistrumented areas) were discarded and replaced with a new specimen prepared in accordance with the experimental protocol. Thereafter, the filling material was loaded with a stainless steel cylindrical plunger, which provided the most extended coverage over the filling material without contacting the surrounding dentin (Figure 1). Due to the convergence of the root canal sections, the push-out force was applied from apical-to- coronal. Loading was performed on a universal testing machine, (Lloyd Instruments Ltd., Fareham, United Kingdom) at a cross-head speed of 1 mm/min until bond failure occurred. The force was recorded by using Nexygen data-analysis software (Lloyd Instruments Ltd., Fareham, United Kingdom), and the debonding values were used to calculate push-out strength in megapascals (MPa), according to the following formula: Push-out bond strength (MPa) = Maximum load (Newton)/ Adhesion area of root canal filling (mm2).

Figure 1
Schematic representation of the push-out test. (F) direction of force; (P) cylindrical plunger; (D) root dentin cylinder (1 mm thick); (RCF) root canal filling (sealer and core material).

The failure modes of each specimen on both surfaces were evaluated under a stereomicroscope (Olympus Optical Co. Ltd., Tokyo, Japan) at 40X magnification and classified into one of the following categories: I: Adhesive (failure at the sealer-dentin interface or sealer-core interface), II: Cohesive (failure within sealer or dentin), and III: Mixed (failure in both the sealer and dentin).1414 Skidmore LJ, Berzins DW, Bahcall JK. An in vitro comparison of the intraradicular dentin bond strength of Resilon and gutta-percha. J Endod. 2006 Oct;32(10):963-6.

Statistical evaluation

Push-out bond strength data were analyzed statistically in Statistical Package for Social Sciences V.11.5 software (SPSS, IBM, New York, USA) for Windows 2007 (Microsoft, New Mexico, USA) by two-way analysis of variance (ANOVA) with Bonferroni’s post hoc test with the significance level of p < 0.05.

Results

The push-out bond strength values (MPa) are presented in Table 1 as mean ± standard deviation.

Table 1
Push-out bond strength values (MPa, mean ± standard deviation) of the experimental groups.

In all experimental groups, iRoot SP yielded significantly higher push-out bond strength values than AH Plus (p < 0.05). Although the tested chelating solutions improved the bond strength of both canal sealers, the increase was not significantly greater than their respective control values (p = 0.296). Likewise, the use of different chelating solutions had no significant effect on the debonding values in both the sealer groups (p = 0.937).

The failure modes of the test groups are listed in Table 2. The majority of specimens had adhesive failures along the sealer-dentin interface. Figure 2 depicts a representative image of adhesive failure (iRoot SP), which was the most frequent in the present study.

Table 2
The failure modes (A: Adhesive, C: Cohesive, M: Mixed) distribution (%).

Figure 2
Representative image of adhesive failure.

Discussion

The bond strength of root canal sealers to radicular dentin helps maintain the integrity of the sealer-dentin interface without being disrupted in long term.2Shipper G, Ørstavik D, Teixeira FB, Trope M. An evaluation of microbial leakage in roots filled with a thermoplastic synthetic polymer-based root canal filling material (Resilon). J Endod. 2004 May;30(5):342-7. , 1515 Ureyen Kaya B, Keçeci AD, Orhan H, Belli S. Micropush-out strengths of gutta-percha versus thermoplastic synthetic polymer-based systems-an ex vivo study. Int Endod J. 2008 Mar;41(3):211-8. The push-out test is an efficient and reliable technique to assess bond strength of root canal filling materials to root dentin.1616 Goracci C, Tavares AU, Fabianelli A, Monticelli F, Raffaelli O, Cardoso PC, et al. The adhesion between fiber posts and root canal walls: comparison between microtensile and push-out bond strength measurements. Eur J Oral Sci. 2004 Aug;112(4):353-61. Results obtained within the experimental conditions of the present study indicate that iRoot SP yields higher dentin bond strength than AH Plus, regardless of the irrigation regimens employed. This finding may be explained in part by the calcium silicate composition of iRoot SP, which helps minimize shrinkage during the setting process.1717 Zhang W, Li Z, Peng B. Assessment of a new root canal sealer’s apical sealing ability. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009 Jun;107(6):e79-82. The extremely small particle size and the level of viscosity that enhances the flow of iRoot SP into dentinal tubules may have further enhanced its bonding effectiveness to root canal dentin, resulting in increased resistance to dislocation.1818 Shokouhinejad N, Gorjestani H, Nasseh AA, Hoseini A, Mohammadi M, Shamshiri AR. Push-out bond strength of gutta-percha with a new bioceramic sealer in the presence or absence of smear layer. Aust Endod J. 2013 Dec;39(3):102-6.

In all groups, the predominant fracture mode was adhesive failure along the sealer-filling material interface. This observation of adhesive failures in the majority of the specimens may indicate inadequate level of chemical adhesion between sealers (iRoot SP and AH Plus) and the core material.

Several authors have recommended the sequential use of organic and inorganic solvents as endodontic irrigants, since no single solution has yet proved to be capable of removing the smear layer alone.8Violich DR, Chandler NP. The smear layer in endodontics - a review. Int Endod J. 2010 Jan;43(1):2-15. A combination of NaOCl and EDTA solutions is recommended for the efficient removal of the smear layer from the surface of the root canal wall.1919 Calt S, Serper A. Time-dependent effects of EDTA on dentin structures. J Endod. 2002 Jan;28(1):17-9. However, this combined irrigation regimen can lead to erosion of the dentin surface.2020 Ozdemir HO, Buzoglu HD, Calt S, Cehreli ZC, Varol E, Temel A. Chemical and ultramorphologic effects of ethylenediaminetetraacetic acid and sodium hypochlorite in young and old root canal dentin. J Endod. 2012 Feb;38(2):204-8. Further, exposure of root dentin to EDTA for extended periods may decrease the modulus of elasticity and the flexure strength of dentin.2121 Yasuda G, Inage H, Kawamoto R, Shimamura Y, Takubo C, Tamura Y, et al. Changes in elastic modulus of adhesive and adhesive-infiltrated dentin during storage in water. J Oral Sci. 2008 Dec;50(4):481-6. Such decrease may adversely affect the physical and mechanical properties of dentin, and eventually increase the risk for root fracture.2222 Uzunoglu E, Aktemur S, Uyanik MO, Durmaz V, Nagas E. Effect of ethylenediaminetetraacetic acid on root fracture with respect to concentration at different time exposures. J Endod. 2012 Aug;38(8):1110-3. Hence, the use of alternative chelating solutions with less or no detrimental effect on root dentin would be most desirable.2323 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 Apr;42(4):335-43. Among several decalcifying agents available, PAA appears to be a potential alternative to EDTA to dissolve the smear layer and disinfect the root canal system.2323 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 Apr;42(4):335-43. , 2424 Guerreiro-Tanomaru JM, Morgental RD, Faria-Junior NB, Berbert FL, Tanomaru-Filho M. Antibacterial effectiveness of peracetic acid and conventional endodontic irrigants. Braz Dent J. 2011;22(4):285-7. A previous study has shown that 1% PAA had similar effect against Enterococcus faecalis compared with NaOCl and chlorhexidine.2424 Guerreiro-Tanomaru JM, Morgental RD, Faria-Junior NB, Berbert FL, Tanomaru-Filho M. Antibacterial effectiveness of peracetic acid and conventional endodontic irrigants. Braz Dent J. 2011;22(4):285-7. PAA solution contains and liberates acetic acid, which is a weak chelating agent, but can reduce the smear layer as effective as EDTA.2323 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 Apr;42(4):335-43. The results of this study necessitates rejection of the null hypothesis, because the debonding values obtained after PAA treatment were statistically similar to those of EDTA-treated specimens.

Etidronic acid [also known as Etidronate or 1-hydroxyethylidene-1,1-bisphosphonate (HEBP)] is a non-toxic bisphosphonate, whose use as a soft chelating irrigation agent exerts minimal detrimental effect on root dentin while removing the smear.2525 De-Deus G, Zehnder M, Reis C, Fidel S, Fidel RA, Galan Júnior J, et al. Longitudinal co-site optical microscopy study on the chelating ability of etidronate and EDTA using a comparative single-tooth model. J Endod. 2008 Jan;34(1):71-5. , 2626 Tartari T, Duarte Junior AP, Silva Júnior JO, Klautau EB, Silva E Souza Junior MH, Silva E Souza Junior PA. Etidronate from medicine to endodontics: effects of different irrigation regimes on root dentin roughness. J Appl Oral Sci. 2013 Sep-Oct;21(5):409-15. Here, in both iRoot SP and AH Plus groups, final irrigation with 9% etidronic acid resulted in slightly higher bond strength values than those achieved with 17% EDTA and 1% PAA irrigation. Despite some differences in the irrigation protocols, this finding is in agreement with a recent study,2727 Neelakantan P, Varughese AA, Sharma S, Subbarao CV, Zehnder M, De-Deus G. Continuous chelation irrigation improves the adhesion of epoxy resin-based root canal sealer to root dentine. Int Endod J. 2012 Dec;45(12):1097-102. which showed an improvement in the bond strength of AH Plus when a chelating irrigation protocol involving a mixture of 18% etidronic acid and 5% NaOCl was used in the instrumentation phase. The authors suggested that the use of 17% EDTA as a final rinse could better facilitate exposure of the collagen network and render the dentin substrate more conducive to bonding of AH Plus sealer, which can adhere to the organic phase of radicular dentin.2727 Neelakantan P, Varughese AA, Sharma S, Subbarao CV, Zehnder M, De-Deus G. Continuous chelation irrigation improves the adhesion of epoxy resin-based root canal sealer to root dentine. Int Endod J. 2012 Dec;45(12):1097-102. In the present study, EDTA was deliberately omitted from the experimental protocol to distinguish the effect of etidronic acid as a final irrigant. Further, a lower concentration of etidronic acid (9%) was utilized, since the demineralization kinetics promoted by both 9% and 18% etidronic acid have been shown to be similar.2525 De-Deus G, Zehnder M, Reis C, Fidel S, Fidel RA, Galan Júnior J, et al. Longitudinal co-site optical microscopy study on the chelating ability of etidronate and EDTA using a comparative single-tooth model. J Endod. 2008 Jan;34(1):71-5.

Compared with the present results obtained using chelating solutions, significantly lower bond strength values were achieved in the NaOCl-treated (control) specimens. This finding strongly suggests that the presence of smear layer has a negative impact on the adhesion of iRoot SP and AH Plus. Thus, for the tested sealers, the micromorphological pattern of the root canal surface achieved by removal of the smear layer maybe more relevant than the mineral content to explain the bonding effectiveness to dentin, though the latter definitely requires further confirmation.2828 Hara AT, Queiroz CS, Giannini M, Cury JA, Serra MC. Influence of the mineral content and morphological pattern of artificial root caries lesion on composite resin bond strength. Eur J Oral Sci. 2004 Feb;112(1):67-72. The increase in surface roughness could be clinically beneficial, because retention is provided by the micromechanical interactions of the canal sealer with dentin tubules.2929 Ballal NV, Mala K, Bhat KS. Evaluation of the effect of maleic acid and ethylenediaminetetraacetic acid on the microhardness and surface roughness of human root canal dentin. J Endod. 2010 Aug;36(8):1385-8. , 3030 Hu X, Ling J, Gao Y. Effects of irrigation solutions on dentin wettability and roughness. J Endod. 2010 Jun;36(6):1064-7.

Conclusion

Within the experimental conditions of this in vitro study, it can be concluded that the tested chelating solutions do not improve the bond strength of AH Plus and iRoot SP to the radicular dentin. From the clinical point of view, these results may indicate selection of a chelating solution that is capable of removing the smear with minimal adverse effect on dentin would be advantageous. Based on the present bond strength data, PAA appears to be a suitable alternative to EDTA, provided that its efficacy is further demonstrated with respect to several other properties including antibacterial effect, biocompatibility, alteration of the chemical composition of root canal dentin, and finally, its interaction with other endodontic sealers.

References

  • 1
    Epley SR, Fleischman J, Hartwell G, Cicalese C. Completeness of root canal obturations: Epiphany techniques versus gutta-percha techniques. J Endod. 2006 Jun;32(6):541-4.
  • 2
    Shipper G, Ørstavik D, Teixeira FB, Trope M. An evaluation of microbial leakage in roots filled with a thermoplastic synthetic polymer-based root canal filling material (Resilon). J Endod. 2004 May;30(5):342-7.
  • 3
    Huffman BP, Mai S, Pinna L, Weller RN, Primus CM, Gutmann JL, et al. Dislocation resistance of ProRoot Endo Sealer, a calcium silicate-based root canal sealer, from radicular dentine. Int Endod J. 2009 Jan;42(1):34-46.
  • 4
    Zhang W, Li Z, Peng B. Ex vivo cytotoxicity of a new calcium silicate-based canal filling material. Int Endod J. 2010 Sep;43(9):769-74.
  • 5
    Nagas E, Uyanik MO, Eymirli A, Cehreli ZC, Vallittu PK, Lassila LV, et al. Dentin moisture conditions affect the adhesion of root canal sealers. J Endod. 2012 Feb;38(2):240-4.
  • 6
    Nagas E, Cehreli Z, Uyanik MO, Durmaz V. Bond strength of a calcium silicate-based sealer tested in bulk or with different main core materials. Braz Oral Res. 2014 Jan-Feb;28(1):1-7.
  • 7
    Sarkar NK, Caicedo R, Ritwik P, Moiseyeva R, Kawashima I. Physicochemical basis of the biologic properties of mineral trioxide aggregate. J Endod. 2005 Feb;31(2):97-100.
  • 8
    Violich DR, Chandler NP. The smear layer in endodontics - a review. Int Endod J. 2010 Jan;43(1):2-15.
  • 9
    Zehnder M. Root canal irrigants. J Endod. 2006 May;32(5):389-98.
  • 10
    Torabinejad M, Handysides R, Khademi AA, Bakland LK. Clinical implications of the smear layer in endodontics: a review. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2002 Dec;94(6):658-66.
  • 11
    Sayin TC, Serper A, Cehreli ZC, Kalayci S. Calcium loss from root canal dentin following EDTA, EGTA, EDTAC, and tetracycline-HCl treatment with or without subsequent NaOCl irrigation. J Endod. 2007 May;33(5):581-4.
  • 12
    Hennequin M, Pajot J, Avignant D. Effects of different pH values of citric acid solutions on the calcium and phosphorus contents of human root dentin. J Endod. 1994 Nov;20(11):551-4.
  • 13
    Schwartz RS. Adhesive dentistry and endodontics. Part 2: bonding in the root canal system-the promise and the problems: a review. J Endod. 2006 Dec;32(12):1125-34.
  • 14
    Skidmore LJ, Berzins DW, Bahcall JK. An in vitro comparison of the intraradicular dentin bond strength of Resilon and gutta-percha. J Endod. 2006 Oct;32(10):963-6.
  • 15
    Ureyen Kaya B, Keçeci AD, Orhan H, Belli S. Micropush-out strengths of gutta-percha versus thermoplastic synthetic polymer-based systems-an ex vivo study. Int Endod J. 2008 Mar;41(3):211-8.
  • 16
    Goracci C, Tavares AU, Fabianelli A, Monticelli F, Raffaelli O, Cardoso PC, et al. The adhesion between fiber posts and root canal walls: comparison between microtensile and push-out bond strength measurements. Eur J Oral Sci. 2004 Aug;112(4):353-61.
  • 17
    Zhang W, Li Z, Peng B. Assessment of a new root canal sealer’s apical sealing ability. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009 Jun;107(6):e79-82.
  • 18
    Shokouhinejad N, Gorjestani H, Nasseh AA, Hoseini A, Mohammadi M, Shamshiri AR. Push-out bond strength of gutta-percha with a new bioceramic sealer in the presence or absence of smear layer. Aust Endod J. 2013 Dec;39(3):102-6.
  • 19
    Calt S, Serper A. Time-dependent effects of EDTA on dentin structures. J Endod. 2002 Jan;28(1):17-9.
  • 20
    Ozdemir HO, Buzoglu HD, Calt S, Cehreli ZC, Varol E, Temel A. Chemical and ultramorphologic effects of ethylenediaminetetraacetic acid and sodium hypochlorite in young and old root canal dentin. J Endod. 2012 Feb;38(2):204-8.
  • 21
    Yasuda G, Inage H, Kawamoto R, Shimamura Y, Takubo C, Tamura Y, et al. Changes in elastic modulus of adhesive and adhesive-infiltrated dentin during storage in water. J Oral Sci. 2008 Dec;50(4):481-6.
  • 22
    Uzunoglu E, Aktemur S, Uyanik MO, Durmaz V, Nagas E. Effect of ethylenediaminetetraacetic acid on root fracture with respect to concentration at different time exposures. J Endod. 2012 Aug;38(8):1110-3.
  • 23
    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 Apr;42(4):335-43.
  • 24
    Guerreiro-Tanomaru JM, Morgental RD, Faria-Junior NB, Berbert FL, Tanomaru-Filho M. Antibacterial effectiveness of peracetic acid and conventional endodontic irrigants. Braz Dent J. 2011;22(4):285-7.
  • 25
    De-Deus G, Zehnder M, Reis C, Fidel S, Fidel RA, Galan Júnior J, et al. Longitudinal co-site optical microscopy study on the chelating ability of etidronate and EDTA using a comparative single-tooth model. J Endod. 2008 Jan;34(1):71-5.
  • 26
    Tartari T, Duarte Junior AP, Silva Júnior JO, Klautau EB, Silva E Souza Junior MH, Silva E Souza Junior PA. Etidronate from medicine to endodontics: effects of different irrigation regimes on root dentin roughness. J Appl Oral Sci. 2013 Sep-Oct;21(5):409-15.
  • 27
    Neelakantan P, Varughese AA, Sharma S, Subbarao CV, Zehnder M, De-Deus G. Continuous chelation irrigation improves the adhesion of epoxy resin-based root canal sealer to root dentine. Int Endod J. 2012 Dec;45(12):1097-102.
  • 28
    Hara AT, Queiroz CS, Giannini M, Cury JA, Serra MC. Influence of the mineral content and morphological pattern of artificial root caries lesion on composite resin bond strength. Eur J Oral Sci. 2004 Feb;112(1):67-72.
  • 29
    Ballal NV, Mala K, Bhat KS. Evaluation of the effect of maleic acid and ethylenediaminetetraacetic acid on the microhardness and surface roughness of human root canal dentin. J Endod. 2010 Aug;36(8):1385-8.
  • 30
    Hu X, Ling J, Gao Y. Effects of irrigation solutions on dentin wettability and roughness. J Endod. 2010 Jun;36(6):1064-7.

Publication Dates

  • Publication in this collection
    2015

History

  • Received
    23 Sept 2014
  • Accepted
    13 Jan 2015
  • Received
    09 Apr 2015
Sociedade Brasileira de Pesquisa Odontológica - SBPqO Av. Prof. Lineu Prestes, 2227, 05508-000 São Paulo SP - Brazil, Tel. (55 11) 3044-2393/(55 11) 9-7557-1244 - São Paulo - SP - Brazil
E-mail: office.bor@ingroup.srv.br