Solubility of root canal sealers with different organic solvents Emre Bodrumlu, PhD, DDS,a Ozgur Er, PhD, DDS,b and Guven Kayaoglu, PhD, DDS,c Samsun, Kayseri, and Ankara, Turkey ONDOKUZ MAYIS UNIVERSITY, ERCIYES UNIVERSITY, AND GAZI UNIVERSITY Objective. The aim of this study was to assess the solubility of the new root canal sealer Epiphany and to compare it with 2 conventional sealers against 2 organic solvents commonly used in retreatment. Study design. Standardized cylindric glass molds 5 mm wide and 2 mm high were filled with freshly mixed root canal sealers AH Plus, Ketac-Endo, and Epiphany. Samples were stored at 37°C for 2 weeks. Each sample was immersed in chloroform or eucalyptus oil for 2 min, 5 min, and 10 min. The mean percentage loss of weight was determined for each material in each solvent and for each immersion period. Results. There were no significant differences at 2 and 5 min (P ⬎ .05) for all tested sealers in all immersed solvents. AH Plus and Epiphany sealers showed significantly higher solubilities (P ⬍ .05) in chloroform than in eucalyptus oil. Epiphany was the most soluble root canal sealer in both the solvents. Ketac-Endo was the least soluble sealer in both chloroform and eucalyptus oil at all exposure times (P ⬍ .05). Conclusion. The root canal sealers Epiphany and AH Plus dissolved to some extent and more than Ketac-Endo, using either eucalyptus oil or chloroform as the solvent. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;106: e67-e69) The retreatment procedure comprises re-entry into the root canal system and removal of the existing root filling throughout the canal length, to allow disinfection of the root canal system. Removal of root canal filling material is a requirement for retreatment. Several techniques for removing the root canal filling materials, including the use of solvents, heat, hand files, rotary files, and ultrasonic instruments, used either alone or in combination.1 However, root canal sealers are more difficult to remove from the root canal system.1 Many studies have suggested chloroform as the most effective solvent for most filling materials.2,3 It has been shown to have an excellent capacity for dissolution compared with other solvents, such as eucalyptol, xylol, or halothane.2-4 However, Barbosa et al.5 states that chloroform can damage the periapical tissues when extruded. According to several authors, eucalyptol is a suitable alternative to chloroform as a dissolving solvent.4,6 Several studies have assessed the dissolving efficacy of organic solvents on various root canal sealers.2,6-8 a Assistant Professor, Operative Dentistry and Endodontics ment, Faculty of Dentistry, Ondokuz Mayis University. b Assistant Professor, Operative Dentistry and Endodontics ment, Faculty of Dentistry, Erciyes University. c Research Assistant, Operative Dentistry and Endodontics ment, Faculty of Dentistry, Gazi University. Received for publication Mar 1, 2008; returned for revision 2008; accepted for publication May 2, 2008. 1079-2104/$ - see front matter © 2008 Mosby, Inc. All rights reserved. doi:10.1016/j.tripleo.2008.05.007 DepartDepartDepartApr 30, Although there are several studies about the solubility of AH Plus2,3 and Ketac-Endo2,3,9,10 root canal sealers, there is no knowledge about the solubility properties of the Epiphany root canal sealer with common organic solvents. The aim of the present study was to assess the solubility of the Epiphany root canal sealer and compare it with 2 conventional sealers against 2 organic solvents commonly used in root canal retreatment. MATERIALS AND METHODS Three different root canal sealers were tested in this study: AH Plus (Dentsply, Konstanz, Germany), KetacEndo (3M Espe, Seefeld, Germany), and Epiphany (Pentron Clinical Technologies, Wallingford, CA). These root canal sealers were mixed according to the manufacturers’ instructions. Freshly mixed sealers (n ⫽ 81 for each sealer) were placed in standard cylindirical glass molds with 5 mm diameter and 2 mm height. A glass microscope slide was then pressed onto the upper surface to make the surface flat. The samples were stored in a chamber with 75% relative humidity at 37°C for 2 weeks to allow the materials to set completely. The excess material was trimmed level with the surface of the mold with a sharp scalpel, and the samples were taken out of the molds. The samples were then weighed in grams 3 times with a digital scale (XB 220A; Precisa, Dietikon, Switzerland). The mean values were calculated. Samples were then divided into 3 equal groups of 27 samples each for immersion in eucalyptus oil (Eucalyptoli Aethorolum; Kemig, Zagreb, Croatia), chloroe67 e68 OOOOE September 2008 Bodrumlu, Er, and Kayaoglu Table I. Mean percentage ⫾ SD of weight loss for each sealer in chloroform and eucalyptus oil Eucalyptus oil Chloroform Sealer 2 min 5 min 10 min 2 min 5 min 10 min Epiphany AH Plus Ketac-Endo 5.51 ⫾ 0.54 4.82 ⫾ 0.51 0.36 ⫾ 0.40 6.17 ⫾ 0.48 5.29 ⫾ 0.57 0.68 ⫾ 0.44 7.54 ⫾ 0.46 6.47 ⫾ 0.53 1.56 ⫾ 0.42 6.66 ⫾ 0.61 5.96 ⫾ 0.56 0.67 ⫾ 0.36 7.27 ⫾ 0.54 6.45 ⫾ 0.57 1.36 ⫾ 0.42 8.67 ⫾ 0.62 7.62 ⫾ 0.54 2.15 ⫾ 0.34 form (Merck, Darmstadt, Germany), or distilled water as control. Each group was divided further into 3 equal subgroups (n ⫽ 9) for 2, 5, and 10 min of immersion. Each sample was immersed in 10-mL aliquots of fresh solvent in glass Petri caps at room temperature. Both surfaces of the samples were accessible to the solvent. After the designated immersion period, specimens were removed with tweezers and allowed to dry for 24 h at 37°C. The specimens were then weighed again 3 times and mean values calculated. The mean percentage loss of weight was determined for each material in each solvent and for each immersion period. Mann-Whitney U, Kruskall-Wallis, and Wilcoxon signed rank tests were used to determine whether there were significant differences among the groups. RESULTS Dissolution means and standard deviations as percentage for sealers immersed in different solvents are presented in Table I. As anticipated, the root canal filling could not be removed with distilled water in control groups, which significantly differs from the results of other solvents. In the chloroform solvent group, there was no significant difference between 2- and 5-min values of dissolution (P ⬎ .05) for all root canal sealers. However, Epiphany and AH Plus showed significantly higher solubilities at 10 min in the chloroform solvent than Ketac-Endo (P ⬍ .05). Epiphany showed significantly higher solubilities than AH Plus at 10 min in the chloroform group (P ⬍ .05). In the eucalyptus oil solvent group, there was no significant difference between 2- and 5-min values of dissolution (P ⬎ .05) for all root canal sealers. In this group also, Epiphany and AH Plus showed significantly higher solubilities than Ketac-Endo at 10 min in the eucalyptus oil solvent (P ⬍ .05). Epiphany showed significantly higher solubilities than AH Plus at 10 min in the eucalyptus oil group (P ⬍ .05). Epiphany was the most soluble sealer in both solvents. Ketac-Endo was the least soluble sealer in both chloroform and eucalyptus oil for all exposure times (P ⬍ .05). Epiphany and AH Plus sealers showed significantly higher solubilities in chloroform (P ⬍ .05) than in eucalyptus oil for all observation periods than KetacEndo (P ⬍ .05). DISCUSSION Nonsurgical endodontic retreatment of previously obturated root canals is the initial treatment of choice for the management of endodontic failures.11 Removing as much sealer and gutta-percha as possible from inadequately prepared and obturated root canal systems is critical to uncover remnants of necrotic tissue or bacteria that may be responsible for periapical inflammation and failure. However, the root canal sealers can not be completely removed.12 Therefore, organic solvents have been used and proposed to decrease the resistance of filling materials in the root canal space. Nowadays, commonly used solvents have a good capacity for removing the root canal filling materials. Solvents such as chloroform, eucalyptol, xylene, and orange oil12 have been advocated (P ⬍ .05) for their capacity to dissolve the root-canal fillings. Although there are few reports in the literature regarding the solubility of endodontic sealers immersed in organic solvents, there exist no specific standards for the measurement of endodontic solvents on root canal sealer solubility. However, in the present study, the method that was generally preferred was also used in most of the earlier literature.3,13 Controlled and careful use of chloroform in dental practice has exhibited that it can be valuable for success removal of root canal filling materials. The Food and Drug Administration does not have the jurisdiction to prohibit the use of chloroform by dentists and does not have proof that it is carcinogenic to humans.14 In contrast, Chutich et al.15 demonstrated that it does not have a toxic risk for patients when a minimal quantity of solvent is used. Eucalyptus oil is an alternative to chloroform for clinical use as a solvent to remove the root canal filling materials.4,6,16 However, Oyama et al.17 stated that the efficacy of chloroform was similar to that of the eucalpyptus oil. Therefore, the dissolution profiles of several root canal sealers in eucalyptus oil and in chloroform were investigated in the present study. According to the results of some studies,2,3,6 chloro- OOOOE Volume 106, Number 3 form was a far more effective solvent than eucalyptus oil for root canal sealers such as AH 26, AH Plus, and Ketac-Endo than eucalyptus oil in 2, 5, and 10 min.2 The findings of the present study are in agreement with those studies comparing the relative efficacy of eucalyptus oil and chloroform for dissolving epoxy resin– based AH Plus. Additionally, Hansen6 found that the efficacy of chloroform was better than that of the eucalpyptus oil when dissolving AH 26. The differences might be the result of the different resinous sealer groups. The results of the present study indicate that all of the tested root canal sealers were soluble to some degree. However, Whitworth and Boursin3 also stated that AH Plus was also found to be highly soluble in volatile solvents and reported that AH Plus dissolved more than Ketac-Endo in chloroform solvent after 10 min. Additionally, some studies showed that the solvents were insufficient for dissolving Ketac-Endo root canal sealer,3,9,10 as was found in the present study. In a study by Versiani et al.,18 the metallic solubilities of AH Plus and Epiphany sealers were tested in distilled deionized water by atomic absorption method, and it was found that the metal ion solubility of Epiphany was higher than that of AH Plus.18 However, the main finding of the present study was that Epiphany dissolves more than the other sealers when exposed to chemical solvents. Particularly, chloroform was more effective in dissolving Epiphany as well as the other sealers. This study exhibited that Epiphany was the most soluble sealer in both solvents. This may be explained by the fact that the filler content of the material may also affect its water sorption characteristics, and it was reported that Epiphany contains calcium hydroxide fillers that absorb water.19,20 In conclusion, the sealers Epiphany and AH Plus dissolved to some extent, and more so than KetacEndo, using either eucalyptus oil or chloroform as the solvent. However, Epiphany root canal sealer is highly soluble in the solvents eucalyptus oil and chloroform. Therefore, this factor should be considered by clinicians as they make decisions on material selections. Further investigation should be conducted to find a more universally effective solvent for use in root canal retreatment. REFERENCES 1. Ruddle CJ. Nonsurgical endodontic retreatment. J Calif Dent Assoc 2004;32:474-84. 2. Schafer E, Zandbiglari T. A comparison of the effectiveness of Bodrumlu, Er, and Kayaoglu e69 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. chloroform and eucalyptus oil in dissolving root canal sealers. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002; 93:611-6. Whitworth JM, Boursin EM. Dissolution of root canal sealer cements in volatile solvents. Int Endod J 2000;33:19-24. Hunter KR, Doblecki W, Pelleu GB. Halothane and eucalyptol as alternatives to chloroform for softening gutta-percha. J Endod 1991;17:310-2. Barbosa SV, Burkard DH, Spangberg LS. Cytotoxic effects of gutta-percha solvents. J Endod 1994;20:6-8. Hansen MG. Relative efficiency of solvents used in endodontics. J Endod 1998;24:38-40. Erdemir A, Adanir N, Belli S. In vitro evaluation of the dissolving effect of solvents on root canal sealers. J Oral Sci 2003; 45:123-6. Wilcox LR. Endodontic retreatment with halothane versus chloroform solvent. J Endod 1995;21:305-7. Friedman S, Moshonov J, Trope M. Efficacy of removing glass ionomer cement, zinc oxide eugenol, and epoxy resin sealers from retreated root canals. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1992;73:609-12. Ray H, Seltzer S. A new glass ionomer root canal sealer. J Endod 1991;17:598-603. Moiseiwitsch JR, Trope M. Nonsurgical root canal therapy treatment with apparent indications for root-end surgery. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998;86:335-40. Sundqvist G, Figdor D. Endodontic treatment of apical periodontitis. In: Ostavik D, Pitt, Ford TR, editors. Essential endodontology. 5th ed. Oxford: Blackwell; 2003. p. 242. Martos J, Gastal MT, Sommer L, Lund RG, Del Pino FA, Osinaga PW. Dissolving efficacy of organic solvents on root canal sealers. Clin Oral Invest 2006;10:50-4. McDonald MN, Vire DE. Chloroform in the endodontic operatory. J Endod 1992;18:301-3. Chutich MJ, Kaminki EJ, Miller DA, Lautenschlager EP. Risk assessment of the toxicity of solvents of gutta-percha used in endodontic retreatment. J Endod 1998;24:213-6. Uemura M, Hata G, Toda T, Weine FS. Effectiveness of eucalyptol and d-limonene as gutta-percha solvents. J Endod 1997;23:739-41. Oyama KO, Siqueira EL, Santos M. In vitro study of effect of solvent on root canal retreatment. Braz Dent J 2002;13:208211. Versiani MA, Carvalho-Junior JR, Padilha MI, Lacey S, Pascon EA, Sousa-Neto MD. A comparative study of physicochemical properties of AH Plus and Epiphany root canal sealants. Int Endod J 2006;39:464-71. Soderholm KJ, Zigan M, Ragan M, Fischlschweiger W, Bergman M. Hydrolytic degradation of dental composites. J Dent Res 1984;63:1248-54. Oysaed H, Ruyter I.E. Water sorption and filler characteristics of composites for use in posterior teeth. J Dent Res 1986;65:1315-8. Reprint requests: Emre Bodrumlu, PhD, DDS Operative Dentistry and Endodontics Department Ondokuz Mayis University Faculty of Dentistry 55139 Kurupelit-Samsun Turkey bodrumlu@omu.edu.tr