{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T14:03:29Z","timestamp":1785420209773,"version":"3.56.0"},"reference-count":41,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,19]],"date-time":"2026-07-19T00:00:00Z","timestamp":1784419200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100008920","name":"University of Saskatchewan","doi-asserted-by":"crossref","award":["#428059"],"award-info":[{"award-number":["#428059"]}],"id":[{"id":"10.13039\/100008920","id-type":"DOI","asserted-by":"crossref"}]},{"award":["#428059"],"award-info":[{"award-number":["#428059"]}],"id":[{"id":"https:\/\/ror.org\/010x8gc63","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Dentistry Journal"],"abstract":"<jats:p>Background\/Objectives: This exploratory study aimed to characterize the microbiological contamination of dental unit waterlines (DUWLs) and to conduct a preliminary evaluation of a 0.5% sodium hypochlorite shock treatment. Methods: Water samples from five dental units in a single teaching institution were collected from the air\/water syringe and high-speed handpiece lines at four time points: baseline, immediately after a shock treatment, and 7 and 14 days post-treatment. The water supply source was also analyzed. The intervention consisted of a 15-min exposure to 0.5% sodium hypochlorite. Bacterial and fungal contamination was assessed using validated semi-quantitative microbial samplers, and key bacterial isolates were identified. Results: Baseline assessments revealed substantial bacterial contamination in most units (\u2265301 CFU\/mL), despite minimal contamination in the water supply source (&lt;10 CFU\/mL). An immediate reduction in microbial counts was observed following the shock treatment for both bacteria and fungi counts; however, resilient species such as P. aeruginosa and the spore-forming B. cereus persisted, while K. pneumoniae was no longer detected. Bacterial levels increased again within 7 days in several units, while fungal contamination remained low at the follow-up. At 14 days, bacterial results were variable and inconsistent. In contrast, fungal contamination remained suppressed in most units throughout the follow-up period. Conclusions: The sodium hypochlorite shock treatment produced an immediate decrease in microbial load in DUWLs, but the findings suggest that its sustained effect on bacterial control may be limited. Given the small sample size and single-center design, these results should be interpreted cautiously. The study demonstrates the feasibility of implementing a structured DUWL monitoring and maintenance program using a simple, low-cost sodium hypochlorite protocol, providing a practical model for improving water quality and patient safety in dental clinics.<\/jats:p>","DOI":"10.3390\/dj14070451","type":"journal-article","created":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T06:09:09Z","timestamp":1784527749000},"page":"451","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Implementation and Preliminary Evaluation of a Low-Cost Sodium Hypochlorite Shock Disinfection Protocol for Dental Unit Waterlines"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-0773-2915","authenticated-orcid":false,"given":"Let\u00edcia","family":"Silveira Carneiro","sequence":"first","affiliation":[{"name":"School of Dentistry, University of S\u00e3o Paulo, Ribeir\u00e3o Preto 14040-904, SP, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria Ang\u00e9lica","family":"Borba Vieira Ferreira","sequence":"additional","affiliation":[{"name":"School of Pharmaceutical Sciences, Federal University of Alfenas, Alfenas 37130-001, MG, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2879-4055","authenticated-orcid":false,"given":"L\u00edsia Aparecida","family":"Costa Gon\u00e7alves","sequence":"additional","affiliation":[{"name":"School of Dentistry, Federal University of Alfenas, Alfenas 37130-001, MG, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1596-9709","authenticated-orcid":false,"given":"Fabio Antonio","family":"Colombo","sequence":"additional","affiliation":[{"name":"School of Pharmaceutical Sciences, Federal University of Alfenas, Alfenas 37130-001, MG, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amanda","family":"Latercia Tranches Dias","sequence":"additional","affiliation":[{"name":"Institute of Biomedical Sciences, Federal University of Alfenas, Alfenas 37130-001, MG, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1133-6242","authenticated-orcid":false,"given":"Marina","family":"Lara de Carli","sequence":"additional","affiliation":[{"name":"School of Dentistry, Federal University of Alfenas, Alfenas 37130-001, MG, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4894-8605","authenticated-orcid":false,"given":"Michelle Foigel","family":"Siqueira","sequence":"additional","affiliation":[{"name":"College of Dentistry, University of Saskatchewan, Saskatoon, SK S7N 5E4, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"80","DOI":"10.4103\/ijdr.ijdr_463_22","article-title":"Microbial Contamination of Dental Unit Waterlines among Dental Clinics of India- An In vitro Study","volume":"35","author":"Kengadaran","year":"2024","journal-title":"Indian J. 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