{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T05:19:15Z","timestamp":1787635155099,"version":"build-2736575974"},"reference-count":24,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2026,8,22]],"date-time":"2026-08-22T00:00:00Z","timestamp":1787356800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Cooperative Research Project of the Research Center for Biomedical Engineering"},{"id":[{"id":"https:\/\/ror.org\/04fz8r448","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001700","name":"Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100001700","id-type":"DOI","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/048rj2z13","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Zirconia orthodontic brackets exhibit favorable mechanical and esthetic properties; however, their chemically inert surfaces can limit adhesion to resin cements. This study evaluated the effect of multi-gas atmospheric plasma irradiation on the shear bond strength (SBS) of zirconia brackets. Zirconia brackets were treated with nitrogen (N2), argon (Ar), or air plasma for 3 and 10 s and compared with untreated controls and conventional alumina-sandblasted specimens. Surface wettability was assessed by contact angle measurements, and surface chemical changes were analyzed using Fourier transform infrared (FT-IR) spectroscopy. After 10 s of plasma treatment, the water-contact angle decreased from 64.3\u00b0 \u00b1 8.4\u00b0 in the untreated group to 17.9\u00b0 \u00b1 6.4\u00b0, 18.8\u00b0 \u00b1 2.7\u00b0, and 16.8\u00b0 \u00b1 5.3\u00b0 with Ar, N2, and air, respectively. For SBS testing, zirconia brackets were bonded to bovine enamel, stored in distilled water at 37 \u00b0C for 24 h, and subsequently tested (n = 12\u201315 per group). The mean SBS was 20.99 \u00b1 2.87 MPa for the untreated group, 25.50 \u00b1 2.40 MPa for the sandblasted group, and 23.63 \u00b1 3.33, 23.99 \u00b1 3.26, and 23.98 \u00b1 3.58 MPa after 10-s Ar, N2, and air plasma treatment, respectively. FT-IR revealed no new absorption peaks. Within the limitations of this study, multi-gas atmospheric plasma treatment markedly reduced the apparent water-contact angle measured on flat zirconia specimens, whereas its effect on SBS relative to the untreated group was not statistically significant.<\/jats:p>","DOI":"10.3390\/ma19173564","type":"journal-article","created":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T10:07:53Z","timestamp":1787566073000},"page":"3564","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Surface Activation of Zirconia Orthodontic Brackets by Multi-Gas Atmospheric Plasma: Effects on Shear Bond Strength"],"prefix":"10.3390","volume":"19","author":[{"given":"Ryota","family":"Okubo","sequence":"first","affiliation":[{"name":"Division of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Tohoku University, Sendai 980-8575, Miyagi, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5131-6043","authenticated-orcid":false,"given":"Peng","family":"Chen","sequence":"additional","affiliation":[{"name":"Division of Interdisciplinary Co-Creation (ICC-Division), Liaison Center for Innovative Dentistry, Graduate School of Dentistry, Tohoku University, Sendai 980-8575, Miyagi, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Taiki","family":"Osawa","sequence":"additional","affiliation":[{"name":"Laboratory for Future Interdisciplinary Research of Science and Technology (FIRST), Institute of Integrated Research (IIR), Institute of Science Tokyo, Yokohama 226-8501, Kanagawa, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8949-294X","authenticated-orcid":false,"given":"Akitoshi","family":"Okino","sequence":"additional","affiliation":[{"name":"Laboratory for Future Interdisciplinary Research of Science and Technology (FIRST), Institute of Integrated Research (IIR), Institute of Science Tokyo, Yokohama 226-8501, Kanagawa, Japan"},{"name":"Institute of Biomedical Engineering (BME), Institute of Science Tokyo, Yokohama 226-8501, Kanagawa, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hiroyasu","family":"Kanetaka","sequence":"additional","affiliation":[{"name":"Division of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Tohoku University, Sendai 980-8575, Miyagi, Japan"},{"name":"Division of Interdisciplinary Co-Creation (ICC-Division), Liaison Center for Innovative Dentistry, Graduate School of Dentistry, Tohoku University, Sendai 980-8575, Miyagi, Japan"},{"name":"Laboratory for Future Interdisciplinary Research of Science and Technology (FIRST), Institute of Integrated Research (IIR), Institute of Science Tokyo, Yokohama 226-8501, Kanagawa, Japan"},{"name":"Division of Advanced Dental Science and Technology, Graduate School of Biomedical Engineering, Tohoku University, Sendai 980-8579, Miyagi, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"689","DOI":"10.3390\/ceramics7020045","article-title":"Effect of acid surface treatments on the shear bond strength of metal bracket to zirconia ceramics","volume":"7","author":"Wongrachit","year":"2024","journal-title":"Ceramics"},{"key":"ref_2","first-page":"7","article-title":"Adhesion to zirconia used for dental restorations: A systematic review and meta-analysis","volume":"17","author":"Bernasconi","year":"2015","journal-title":"J. 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Geometrical product specifications (GPS)\u2014Surface texture: Areal\u2014Part 2: Terms, definitions and sur-face texture parameters (Standard No. ISO 25178)."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/17\/3564\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T04:33:38Z","timestamp":1787632418000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/17\/3564"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,22]]},"references-count":24,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["ma19173564"],"URL":"https:\/\/doi.org\/10.3390\/ma19173564","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,22]]}}}