Expert consensus on irrigation and intracanal medication in root canal therapy

Abstract

Chemical cleaning and disinfection are crucial steps for eliminating infection in root canal treatment. However, irrigant selection or irrigation procedures are far from clear. The vapor lock effect in the apical region has yet to be solved, impeding irrigation efficacy and resulting in residual infections and compromised treatment outcomes. Additionally, ambiguous clinical indications for root canal medication and non-standardized dressing protocols must be clarified. Inappropriate intracanal medication may present side effects and jeopardize the therapeutic outcomes. Indeed, clinicians have been aware of these concerns for years. Based on the current evidence of studies, this article reviews the properties of various irrigants and intracanal medicaments and elucidates their effectiveness and interactions. The evolution of different kinetic irrigation methods, their effects, limitations, the paradigm shift, current indications, and effective operational procedures regarding intracanal medication are also discussed. This expert consensus aims to establish the clinical operation guidelines for root canal irrigation and a position statement on intracanal medication, thus facilitating a better understanding of infection control, standardizing clinical practice, and ultimately improving the success of endodontic therapy.

References

1. Yue L.& Wang, X. Y. Cariology and endodontics (3rd edition). (Peking University Medical Press, 2022).
2. Hülsmann, M., Peters, O. A.& Dummer, P. M. H. Mechanical preparation of root canals: shaping goals, techniques and means.Endod. Top. 10, 30-76 (2005).
3. Arias A.& Peters, O. A. Present status and future directions: canal shaping.Int. Endod. J. 55(Suppl 3), 637-655 (2022).
4. Young, G. R., Parashos, P.& Messer, H. H. The principles of techniques for cleaning root canals.Aust. Dent. J. 52, S52-S63 (2007).
5. Sundqvist G. R.Taxonomy, ecology, and pathogenicity of the root canal flora.Oral. Surg. Oral. Med. Oral. Pathol. 78, 522-530 (1994).
6. Nair P. N.R., Henry, S., Cano, V. & Vera, J. Microbial status of apical root canal system of human mandibular first molars with primary apical periodontitis after “one-visit” endodontic treatment.Oral. Surg. Oral. Med. Oral. Pathol. Oral. Radiol. Endod. 99, 231-252 (2005).
7 7.Guo, H. J., Yue, L. & Gao, Y. [Status of bacterial colonization in infected root canal].Beijing Da Xue Xue Bao Yi Xue Ban 43, 26-28 (2011).
8. Safavi, K. E., Spngberg, L. S.W. & Langeland, K. Root canal dentinal tubule disinfection.J. Endod. 16, 207-210 (1990).
9. Haapasalo M.& Ørstavik, D. In vitro infection and of dentinal tubules.J. Dent. Res. 66, 1375-1379 (1987).
10. Pereira, R. S.et al.Microbial analysis of root canal and periradicular lesion associated to teeth with endodontic failure.Anaerobe 48, 12-18 (2017).
11. Kawashima N., Wadachi R., Suda H., Yeng T.& Parashos, P. Root canal medicaments.Int. Dent. J. 59, 5-11 (2009).
12 12.Liang, Y. H. & Yue, L. [Root canal treatment: key steps in root canal irrigation and medicaments].Zhonghua Kou Qiang Yi Xue Za Zhi 54, 788-792 (2019).
13. McGill, S., Gulabivala, K., Mordan, N. & Ng, Y. L. The efficacy of dynamic irrigation using a commercially available system (RinsEndo®) determined by removal of a collagen ‘bio‐molecular film’from an ex vivo model.Int. Endod. J. 41, 602-608 (2008).
14. Estrela, C.et al.Mechanism of action of sodium hypochlorite.Braz. Dent. J. 13, 113-117 (2002).
15. Ruksakiet, K.et al.Antimicrobial efficacy of chlorhexidine and sodium hypochlorite in root canal disinfection: a systematic review and meta-analysis of randomized controlled trials.J. Endod. 46, 1032-1041 (2020).
16. Mohammadi, Z., Jafarzadeh, H.& Shalavi, S. Antimicrobial efficacy of chlorhexidine as a root canal irrigant: a literature review.J. Oral. Sci. 56, 99-103 (2014).
17. Souza, M. A.et al.Comparative evaluation of the retaining of QMix and chlorhexidine formulations on human dentin: a chemical analysis.Clin. Oral. Investig. 21, 873-878 (2017).
18. Huo Zhiyuan, Y. L. & Zou, X. Research progress on root canal sonic irrigation.Int. J. Stomatol. 50, 91-99 (2023).
19 19.Wang, D., Gao, X. & Shen, S. [Comparison of antimicrobial efficacy of four endodontic irrigants using an in vitro model infected by Enterococcus faecalis].Zhonghua Kou Qiang Yi Xue Za Zhi 42, 223-224 (2007).
20. Grawehr M., Sener B., Waltimo T.& Zehnder, M. Interactions of ethylenediamine tetraacetic acid with sodium hypochlorite in aqueous solutions.Int. Endod. J. 36, 411-417 (2003).
21. Rossi-Fedele, G., Doğramacı, E. J., Guastalli, A. R., Steier, L. & de Figueiredo, J. A. P. Antagonistic interactions between sodium hypochlorite, chlorhexidine EDTA, and citric acid.J. Endod. 38, 426-431 (2012).
22. Cintra L. T.A. et al. The use of NaOCl in combination with CHX produces cytotoxic product.Clin. Oral. Investig. 18, 935-940 (2014).
23. Rasimick B. J., Nekich M., Hladek M. M., Musikant B. L.& Deutsch, A. S. Interaction between chlorhexidine digluconate and EDTA.J. Endod. 34, 1521-1523 (2008).
24. Basrani B.Endodontic Irrigation. Chemical Disinfection of the Root Canal System (Springer International Publishing AG, 2015).
25. Boutsioukis C.& Arias-Moliz, M. T. Present status and future directions—irrigants and irrigation methods.Int. Endod. J. 55(Suppl 3), 588-612 (2022).
26. Boutsioukis, C.et al.Evaluation of irrigant flow in the root canal using different needle types by an unsteady computational fluid dynamics model.J. Endod. 36, 875-879 (2010).
27. European Society of Endodontology. Quality guidelines for endodontic treatment: consensus report of the European Society of Endodontology.Int. Endod. J. 39, 921-930 (2006).
28. Boutsioukis, C.et al.The effect of needle-insertion depth on the irrigant flow in the root canal: evaluation using an unsteady computational fluid dynamics model.J. Endod. 36, 1664-1668 (2010).
29. Boutsioukis, C.et al.The effect of apical preparation size on irrigant flow in root canals evaluated using an unsteady Computational Fluid Dynamics model.Int. Endod. J. 43, 874-881 (2010).
30. Blanken J.,De Moor, R. J. G., Meire, M. & Verdaasdonk, R. Laser induced explosive vapor and cavitation resulting in effective irrigation of the root canal. Part 1: a visualization study.Lasers. Surg. Med. 41, 514-519 (2009).
31. Vaz-Garcia, E. S. et al. Mechanical properties of anatomic finishing files: XP-Endo Finisher and XP-Clean.Braz. Dent. J. 29, 208-213 (2018).
32. Bao P., Shen Y., Lin J.& Haapasalo, M. In vitro efficacy of XP-Endo Finisher with 2 different protocols on biofilm removal from apical root canals.J. Endod. 43, 321-325 (2017).
33. Elnaghy, A. M., Mandorah, A.& Elsaka, S. E. Effectiveness of XP-endo Finisher, EndoActivator, and File agitation on debris and smear layer removal in curved root canals: a comparative study.Odontology 105, 178-183 (2017).
34. Neelakantan P., Khan K., Li K. Y., Shetty H.& Xi, W. Effectiveness of supplementary irrigant agitation with the Finisher GF Brush on the debridement of oval root canals instrumented with the Gentlefile or nickel-titanium rotary instruments.Int. Endod. J. 51, 800-807 (2018).
35. Moreinos D., Dakar A., Stone N. J.& Moshonov, J. Evaluation of time to fracture and vertical forces applied by a novel gentlefile system for root canal preparation in simulated root canals.J. Endod. 42, 505-508 (2016).
36. Asnaashari M., Kooshki N., Salehi M. M., Azari-Marhabi, S. & Amin Moghadassi, H. Comparison of antibacterial effects of photodynamic therapy and an irrigation activation system on root canals infected with enterococcus faecalis: an in vitro study.J. Lasers. Med. Sci. 11, 243-248 (2020).
37. Hizarci U., Koçak S., Sağlam B. C.& Koçak, M. M. Effect of different irrigation activation techniques on the amount of apical debris extrusion.Tanta. Dent. J. 16, 29-32 (2019).
38. Hanafy, M. S., Kamel, W. H.& Nour El Din, M. M. Effect of XP-Endo finisher on post-instrumentation pain after using different NiTi rotary systems.Al-Azhar. Dent. J. Girls 7, 157-164 (2020).
39. Mj R.The use of ultrasonics in root canal therapy and root resection.J. Dent. Med. 12, 12-18 (1957).
40. Plotino G., Pameijer C. H., Grande N. M.& Somma, F. Ultrasonics in endodontics: a review of the literature.J. Endod. 33, 81-95 (2007).
41. Van der Sluis, L. W. M., Versluis, M., Wu, M. K. & Wesselink, P. R. Passive ultrasonic irrigation of the root canal: a review of the literature.Int. Endod. J. 40, 415-426 (2007).
42. Stock C. J.Current status of the use of ultrasound in endodontics.Int. Dent. J. 41, 175-182 (1991).
43. Weller, R. N., Brady, J. M.& Bernier, W. E. Efficacy of ultrasonic cleaning.J. Endod. 6, 740-743 (1980).
44. Gu, L.et al.Review of contemporary irrigant agitation techniques and devices.J. Endod. 35, 791-804 (2009).
45. Middha M., Sangwan P., Tewari S.& Duhan, J. Effect of continuous ultrasonic irrigation on postoperative pain in mandibular molars with nonvital pulps: a randomized clinical trial.Int. Endod. J. 50, 522-530 (2017).
46. Malki, M.et al.Irrigant flow beyond the insertion depth of an ultrasonically oscillating file in straight and curved root canals: visualization and cleaning efficacy.J. Endod. 38, 657-661 (2012).
47. Tronstad L., Barnett F., Schwartzben L.& Frasca, P. Effectiveness and safety of a sonic vibratory endodontic instrument.Endod. Dent. Traumatol. 1, 69-76 (1985).
48. Zeng, C.et al.Antibacterial efficacy of an endodontic sonic-powered irrigation system: an in vitro study.J. Dent. 75, 105-112 (2018).
49. Walmsley, A. D., Lumley, P. J.& Laird, W. R. E. The oscillatory pattern of sonically powered endodontic files.Int. Endod. J. 22, 125-132 (1989).
50. Jiang L., Verhaagen B., Versluis M.& van der Sluis, L. W. M. Evaluation of a sonic device designed to activate irrigant in the root canal.J. Endod. 36, 143-146 (2010).
51. Li Q., Zhang Q., Zou X.& Yue, L. Evaluation of four final irrigation protocols for cleaning root canal walls.Int. J. Oral. Sci. 12, 29(2020).
52. Urban K., Donnermeyer D., Schäfer E.& Bürklein, S. Canal cleanliness using different irrigation activation systems: a SEM evaluation.Clin. Oral. Investig. 21, 2681-2687 (2017).
53. Liu C., Li Q., Yue L.& Zou, X. Evaluation of sonic, ultrasonic, and laser irrigation activation systems to eliminate bacteria from the dentinal tubules of the root canal system.J. Appl. Oral. Sci. 30, e20220199(2022).
54. Desai P.& Himel, V. Comparative safety of various intracanal irrigation systems.J. Endod. 35, 545-549 (2009).
55. Parente, J. M.et al.Root canal debridement using manual dynamic agitation or the EndoVac for final irrigation in a closed system and an open system.Int. Endod. J. 43, 1001-1012 (2010).
56. Schoeffel G. J.The EndoVac method of endodontic irrigation, part 2-efficacy. Dent. Today 27, 82, 84, 86-87 (2008).
57. Haapasalo, M.et al.Apical pressure created during irrigation with the GentleWave™ system compared to conventional syringe irrigation.Clin. Oral. Investig. 20, 1525-1534 (2016).
58. Haapasalo, M.et al.Tissue dissolution by a novel multisonic ultracleaning system and sodium hypochlorite.J. Endod. 40, 1178-1181 (2014).
59. Choi H. W., Park S. Y., Kang M. K.& Shon, W. J. Comparative analysis of biofilm removal efficacy by multisonic ultracleaning system and passive ultrasonic activation.Materials 12, 3492(2019).
60. DiVito, E., Peters, O. A. & Olivi, G. Effectiveness of the erbium: YAG laser and new design radial and stripped tips in removing the smear layer after root canal instrumentation.Lasers Med. Sci. 27, 273-280 (2012).
61. Akcay M., Arslan H., Durmus N., Mese M.& Capar, I. D. Dentinal tubule penetration of AH Plus, iRoot SP, MTA fillapex, and guttaflow bioseal root canal sealers after different final irrigation procedures: a confocal microscopic study.Lasers. Surg. Med. 48, 70-76 (2016).
62. Peters O. A., Bardsley S., Fong J., Pandher G.& DiVito, E. Disinfection of root canals with photon-initiated photoacoustic streaming.J. Endod. 37, 1008-1012 (2011).
63. Yost, R. A.et al.Evaluation of 4 different irrigating systems for apical extrusion of sodium hypochlorite.J. Endod. 41, 1530-1534 (2015).
64. Ahmad I. A.Rubber dam usage for endodontic treatment: a review.Int. Endod. J. 42, 963-972 (2009).
65 65.Society of Cariology and Endodontology, C. S. A. [Guidelines for root canal treatment].Zhonghua Kou Qiang Yi Xue Za Zhi 49, 272-274 (2014).
66. Akhlaghi N. M., Dadresanfar B., Darmiani S.& Moshari, A. Effect of master apical file size and taper on irrigation and cleaning of the apical third of curved canals.J. Dent. 11, 188-195 (2014).
67. Khademi, A., Yazdizadeh, M.& Feizianfard, M. Determination of the minimum instrumentation size for penetration of irrigants to the apical third of root canal systems.J. Endod. 32, 417-420 (2006).
68. Jones, R. Endodontics. Colleagues for Excellence. Root Canal Irrigants and Disinfectants. (American Association of Endodontists, 2011).
69. Hussein H.& Kishen, A. Local immunomodulatory effects of intracanal medications in apical periodontitis.J. Endod. 48, 430-456 (2022).
70. Fouad A. F., Diogenes A. R., Torabinejad M.& Hargreaves, K. M. Microbiome changes during regenerative endodontic treatment using different methods of disinfection.J. Endod. 48, 1273-1284 (2022).
71. Grossman, L. I. Rationale of endodontic treatment. Dent. Clin. North. Am. 483-490 (1967).
72. Schilder H.Cleaning and shaping the root canal.Dent. Clin. North. Am. 18, 269-296 (1974).
73. Chang Y. C., Tai K. W., Chou L. S.& Chou, M. Y. Effects of camphorated parachlorophenol on human periodontal ligament cells in vitro.J. Endod. 25, 779-781 (1999).
74. Haapasalo M., Qian W., Portenier I.& Waltimo, T. Effects of dentin on the antimicrobial properties of endodontic medicaments.J. Endod. 33, 917-925 (2007).
75. Ordinola-Zapata, R., Noblett, W. C., Perez-Ron, A., Ye, Z. & Vera, J. Present status and future directions of intracanal medicaments.Int. Endod. J. 55(Suppl 3), 613-636 (2022).
76. Duncan, H. F.et al.Treatment of pulpal and apical disease: The European Society of Endodontology (ESE) S3-level clinical practice guideline.Int. Endod. J. 56(Suppl 3), 238-295 (2023).
77. Society of Cariology and Endodontology, C. S. A. Guidelines for root canal therapy.Chin. J. Dent. Res. 18, 213-216 (2015).
78. AAE Clinical Practice Committee. Guide to Clinical Endodontics (6th ed.), <https://www.aae.org/specialty/download/guide-to-clinical-endodontics> (2019).
79. Penesis, V. A.et al.Outcome of one-visit and two-visit endodontic treatment of necrotic teeth with apical periodontitis: a randomized controlled trial with one-year evaluation.J. Endod. 34, 251-257 (2008).
80. Karaoğlan F.,Miçooğulları Kurt, S. & Çalışkan, M. K. Outcome of single- versus two-visit root canal retreatment in teeth with periapical lesions: a randomized clinical trial.Int. Endod. J. 55, 833-843 (2022).
81. Patil A. A., Joshi S. B., Bhagwat, S. V. & Patil, S. A. Incidence of postoperative pain after single visit and two visit root canal therapy: a randomized controlled trial. J. Clin. Diagn. Res. 10, ZC09-ZC12 (2016).
82. Figini L., Lodi G., Gorni F.& Gagliani, M. Single versus multiple visits for endodontic treatment of permanent teeth: a Cochrane systematic review.J. Endod. 34, 1041-1047 (2008).
83. Tanomaru Filho, M., Leonardo, M. R. & da Silva, L. A. B. Effect of irrigating solution and calcium hydroxide root canal dressing on the repair of apical and periapical tissues of teeth with periapical lesion.J. Endod. 28, 295-299 (2002).
84. Tepel J.,Darwisch el Sawaf, M. & Hoppe, W. Reaction of inflamed periapical tissue to intracanal medicaments and root canal sealers.Endod. Dent. Traumatol. 10, 233-238 (1994).
85. Schwendicke F.& Göstemeyer, G. Single-visit or multiple-visit root canal treatment: systematic review, meta-analysis and trial sequential analysis.BMJ Open 7, e013115(2017).
86. Siqueira J. F.& Lopes, H. P. Mechanisms of antimicrobial activity of calcium hydroxide: a critical review.Int. Endod. J. 32, 361-369 (1999).
87. Mohammadi Z.& Dummer, P. M. H. Properties and applications of calcium hydroxide in endodontics and dental traumatology.Int. Endod. J. 44, 697-730 (2011).
88. Sjögren U., Figdor D., Spångberg L.& Sundqvist, G. The antimicrobial effect of calcium hydroxide as a short-term intracanal dressing.Int. Endod. J. 24, 119-125 (1991).
89. Zancan, R. F.et al.Antimicrobial activity and physicochemical properties of calcium hydroxide pastes used as intracanal medication.J. Endod. 42, 1822-1828 (2016).
90. Lin, J.et al.Comparison of mineral trioxide aggregate and calcium hydroxide for apexification of immature permanent teeth: a systematic review and meta-analysis.J. Formos. Med. Assoc. 115, 523-530 (2016).
91. Alfadda S., Alquria T., Karaismailoglu E., Aksel H.& Azim, A. A. Antibacterial effect and bioactivity of innovative and currently used intracanal medicaments in regenerative endodontics.J. Endod. 47, 1294-1300 (2021).
92. Lu J., Liu H., Lu Z., Kahler B.& Lin, L. M. Regenerative endodontic procedures for traumatized immature permanent teeth with severe external root resorption and root perforation.J. Endod. 46, 1610-1615 (2020).
93. Waltimo T. M., Orstavik D., Sirén E. K.& Haapasalo, M. P. In vitro susceptibility of Candida albicans to four disinfectants and their combinations.Int. Endod. J. 32, 421-429 (1999).
94. van der Waal, S. V., Connert, T., Crielaard, W. & de Soet, J. J. In mixed biofilms Enterococcus faecalis benefits from a calcium hydroxide challenge and culturing.Int. Endod. J. 49, 865-873 (2016).
95. Haapasalo H. K., Sirén E. K., Waltimo T. M., Ørstavik D.& Haapasalo, M. P. Inactivation of local root canal medicaments by dentine: an in vitro study.Int. Endod. J. 33, 126-131 (2000).
96. Pereira, T. C.et al.Intratubular decontamination ability and physicochemical properties of calcium hydroxide pastes.Clin. Oral. Investig. 23, 1253-1262 (2019).
97. de Sousa, B. C., Gomes, Fd. A., Ferreira, C. M. & de Albuquerque, D. S. Filling lateral canals: influence of calcium hydroxide paste as a root canal dressing.Indian J. Dent. Res. 24, 528-532 (2013).
98. Ricucci, D., Candeiro, G. T.M., Bugea, C. & Siqueira, J. F. Complex apical intraradicular infection and extraradicular mineralized biofilms as the cause of wet canals and treatment failure: report of 2 cases.J. Endod. 42, 509-515 (2016).
99. Hawkins J. J., Torabinejad M., Li Y.& Retamozo, B. Effect of three calcium hydroxide formulations on fracture resistance of dentin over time.Dent. Traumatol. 31, 380-384 (2015).
100. Whitbeck, E. R., Quinn, G. D.& Quinn, J. B. Effect of calcium hydroxide on the fracture resistance of dentin.J. Res. Natl. Inst. Stand. Technol. 116, 743-749 (2011).
101. Uslu, O., Dikmen, G.& Orhan, E. O. Intrinsic physicochemical interactions of calcium hydroxide-based medications.Microsc. Res. Tech. 84, 432-440 (2021).
102. Alaçam, T., Görgül, G.& Omürlü, H. Evaluation of diagnostic radiopaque contrast materials used with calcium hydroxide.J. Endod. 16, 365-368 (1990).
103. Lima, K. C., Fava, L. R.& Siqueira, J. F. Susceptibilities of Enterococcus faecalis biofilms to some antimicrobial medications.J. Endod. 27, 616-619 (2001).
104. Komorowski R., Grad H., Wu X. Y.& Friedman, S. Antimicrobial substantivity of chlorhexidine-treated bovine root dentin.J. Endod. 26, 315-317 (2000).
105. Martinho F. C., Gomes C. C., Nascimento G. G., Gomes A. P.M. & Leite, F. R. M. Clinical comparison of the effectiveness of 7- and 14-day intracanal medications in root canal disinfection and inflammatory cytokines.Clin. Oral. Investig. 22, 523-530 (2018).
106. Sirén, E. K., Haapasalo, M. P.P., Waltimo, T. M. T. & Ørstavik, D. In vitro antibacterial effect of calcium hydroxide combined with chlorhexidine or iodine potassium iodide on Enterococcus faecalis.Eur. J. Oral. Sci. 112, 326-331 (2004).
107. Ferreira, N. S.et al.Microbiological profile resistant to different intracanal medications in primary endodontic infections.J. Endod. 41, 824-830 (2015).
108. Manzur A., González A. M., Pozos A., Silva-Herzog, D. & Friedman, S. Bacterial quantification in teeth with apical periodontitis related to instrumentation and different intracanal medications: a randomized clinical trial.J. Endod. 33, 114-118 (2007).
109. Ordinola-Zapata, R. et al. Antimicrobial activity of triantibiotic paste, 2% chlorhexidine gel, and calcium hydroxide on an intraoral-infected dentin biofilm model.J. Endod. 39, 115-118 (2013).
110. Wei, X.et al.Expert consensus on regenerative endodontic procedures.Int. J. Oral Sci. 14, 55(2022).
111. Stacey S. K.& McEleney, M. Topical corticosteroids: choice and application.Am. Fam. Physician. 103, 337-343 (2021).
112. Kirwan J.Principles of glucocorticoid therapy.Ann. Rheum. Dis. 62, 495(2003).
113. Chance K., Lin L., Shovlin F. E.& Skribner, J. Clinical trial of intracanal corticosteroid in root canal therapy.J. Endod. 13, 466-468 (1987).
114. Chu F. C.S., Leung, W. K., Tsang, P. C. S., Chow, T. W. & Samaranayake, L. P. Identification of cultivable microorganisms from root canals with apical periodontitis following two-visit endodontic treatment with antibiotics/steroid or calcium hydroxide dressings.J. Endod. 32, 17-23 (2006).
115. Bryson E. C., Levin L., Banchs F., Abbott P. V.& Trope, M. Effect of immediate intracanal placement of Ledermix Paste(R) on healing of replanted dog teeth after extended dry times.Dent. Traumatol. 18, 316-321 (2002).
116. Pierce, A. N., Heithersay, G.& Lindskog, S. Evidence for direct inhibition of dentinoclasts by a corticosteroid/antibiotic endodontic paste.Endod. Dent. Traumatol. 4, 44-45 (1988).
117. Isaksson, M. Corticosteroids.Dermatol. Ther. 17, 314-320 (2004).
118. Kim, S. T., Abbott, P. V.& McGinley, P. The effects of Ledermix paste on discolouration of immature teeth.Int. Endod. J. 33, 233-237 (2000).
119. Buchman A. L.Side effects of corticosteroid therapy.J. Clin. Gastroenterol. 33, 289-294 (2001).
120 120.Society of Cariology and Endodontology, C. S. A. [Guidelines for the use of microscopes in endodontics].Zhonghua Kou Qiang Yi Xue Za Zhi 51, 465-467 (2016).
121. Pasricha, S. K., Makkar, S. & Gupta, P. Pressure alteration techniques in endodontics- a review of literature. J. Clin. Diagn. Res. 9, ZE01-ZE06 (2015).
122. Goel S.& Tewari, S. Smear layer removal with passive ultrasonic irrigation and the NaviTip FX: a scanning electron microscopic study.Oral. Surg. Oral. Med. Oral. Pathol. Oral. Radiol. Endod. 108, 465-470 (2009).
123. Sousa B. C.D. et al. Persistent extra-radicular bacterial biofilm in endodontically treated human teeth: scanning electron microscopy analysis after apical surgery.Microsc. Res. Tech. 80, 662-667 (2017).
124. El-Kishawi, M. & Khalaf, K. An update on root canal preparation techniques and how to avoid procedural errors in endodontics.Open Dent. J. 15, 318-324 (2021).
125. Mozayeni M. A., Haeri A., Dianat O.& Jafari, A. R. Antimicrobial effects of four intracanal medicaments on enterococcus faecalis: an in vitro study.Iran Endod. J. 9, 195-198 (2014).
126. Shamma B. M., Kurdi S. A., Rajab A.& Arrag, E. A. Evaluation of antibacterial effects of different intracanal medicaments on Enterococcus faecalis in primary teeth: an in vitro study.Clin. Exp. Dent. Res. 9, 341-348 (2023).
127. Ahmad M. Z., Sadaf D., Merdad K. A., Almohaimeed A.& Onakpoya, I. J. Calcium hydroxide as an intracanal medication for postoperative pain during primary root canal therapy: a systematic review and meta-analysis with trial sequential analysis of randomised controlled trials.J. Evid. Based. Dent. Pract. 22, 101680(2022).
128. Orucoglu H.& Cobankara, F. K. Effect of unintentionally extruded calcium hydroxide paste including barium sulfate as a radiopaquing agent in treatment of teeth with periapical lesions: report of a case.J. Endod. 34, 888-891 (2008).
129. Adams D. O.The granulomatous inflammatory response. A review.Am. J. Pathol. 84, 164-192 (1976).
130. Sabokbar A., Fujikawa Y., Murray D. W.& Athanasou, N. A. Radio-opaque agents in bone cement increase bone resorption.J. Bone. Joint. Surg. 79, 129-134 (1997).
131. De Moor, R. J. G. & De Witte, A. M. J. C. Periapical lesions accidentally filled with calcium hydroxide.Int. Endod. J. 35, 946-958 (2002).