{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,9]],"date-time":"2026-03-09T17:27:02Z","timestamp":1773077222682,"version":"3.50.1"},"reference-count":27,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,3,7]],"date-time":"2026-03-07T00:00:00Z","timestamp":1772841600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Dentistry Journal"],"abstract":"<jats:p>Background: The effective elimination of root canal microbiota is essential for the treatment of apical periodontitis. The smear layer formed during instrumentation limits the penetration of irrigants into dentinal tubules, making chelation a critical component of irrigation protocols. While ethylenediaminetetraacetic acid (EDTA) is commonly used for smear layer removal, etidronate has been proposed as an alternative due to its chemical compatibility with sodium hypochlorite. The aim of this study was to compare the effectiveness of different irrigation protocols in eliminating microorganisms from the root canal system in patients with chronic apical periodontitis. Methods: Thirty patients aged 18\u201344 years diagnosed with chronic apical periodontitis (ICD-10 code K04.5) were included. Three irrigation protocols were evaluated: (1) 3% sodium hypochlorite followed by 17% EDTA; (2) 3% sodium hypochlorite followed by a 9% aqueous solution of etidronate; and (3) a 9% solution of etidronate dissolved in 3% sodium hypochlorite (continuous chelation). Microbiological samples were collected before and after root canal instrumentation and irrigation. Microbial analysis was performed using gas chromatography\u2013mass spectrometry. Results: All protocols resulted in a reduction in microbial load. However, protocols using 3% sodium hypochlorite with 17% EDTA and continuous chelation with etidronate in sodium hypochlorite demonstrated a greater number of statistically significant reductions. Sequential irrigation with aqueous etidronate showed the lowest antimicrobial effectiveness. Conclusions: Continuous chelation with etidronate in 3% sodium hypochlorite showed promising antimicrobial performance and may represent a clinically feasible alternative irrigation strategy.<\/jats:p>","DOI":"10.3390\/dj14030151","type":"journal-article","created":{"date-parts":[[2026,3,9]],"date-time":"2026-03-09T08:58:45Z","timestamp":1773046725000},"page":"151","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Impact of Smear Layer Removal Using Etidronate- and EDTA-Based Irrigation Protocols on Root Canal Microbiota: An In Vivo Study"],"prefix":"10.3390","volume":"14","author":[{"given":"Svetlana","family":"Razumova","sequence":"first","affiliation":[{"name":"Department of Propaedeutics of Dental Diseases, Medical Institute, Patrice Lumumba Peoples\u2019 Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, Moscow 117198, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anzhela","family":"Brago","sequence":"additional","affiliation":[{"name":"Department of Propaedeutics of Dental Diseases, Medical Institute, Patrice Lumumba Peoples\u2019 Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, Moscow 117198, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0187-7483","authenticated-orcid":false,"given":"Anzhelika","family":"Kryuchkova","sequence":"additional","affiliation":[{"name":"Department of Propaedeutics of Dental Diseases, Medical Institute, Patrice Lumumba Peoples\u2019 Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, Moscow 117198, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zilolakhon","family":"Khakimova","sequence":"additional","affiliation":[{"name":"Department of Propaedeutics Dentistry, Andijan State Medical Institute, Yu.Otabekov 1, Andijan City 170119, Uzbekistan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nazira","family":"Khabibova","sequence":"additional","affiliation":[{"name":"Department of Conservative Dentistry, Bukhara State Medical Institute Named After Abu Ali ibn Sino, Bukhara 200126, Uzbekistan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexander","family":"Volkov","sequence":"additional","affiliation":[{"name":"Department of Therapeutic Dentistry, E.V. Borovsky Institute of Dentistry, FSAEI HE I.M. Sechenov First MSMU of MOH of Russia, Sechenovskiy University, 8\/2 Trubetskaya St., Moscow 119991, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0911-3063","authenticated-orcid":false,"given":"Haydar","family":"Barakat","sequence":"additional","affiliation":[{"name":"Department of Propaedeutics of Dental Diseases, Medical Institute, Patrice Lumumba Peoples\u2019 Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, Moscow 117198, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Natalya","family":"Dikopova","sequence":"additional","affiliation":[{"name":"Department of Therapeutic Dentistry, E.V. Borovsky Institute of Dentistry, FSAEI HE I.M. Sechenov First MSMU of MOH of Russia, Sechenovskiy University, 8\/2 Trubetskaya St., Moscow 119991, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1526","DOI":"10.1111\/iej.14125","article-title":"The immune landscape in apical periodontitis: From mechanism to therapy","volume":"57","author":"Wen","year":"2024","journal-title":"Int. Endod. J."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"395","DOI":"10.1111\/iej.13782","article-title":"Effectiveness of root canal instrumentation for the treatment of apical periodontitis: A systematic review and meta-analysis","volume":"56","author":"Arias","year":"2023","journal-title":"Int. Endod. 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