{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,14]],"date-time":"2026-07-14T05:04:08Z","timestamp":1784005448339,"version":"3.55.0"},"reference-count":45,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T00:00:00Z","timestamp":1783555200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100010393","name":"University of Maryland School of Dentistry","doi-asserted-by":"crossref","award":["1R01DE033442-01A1"],"award-info":[{"award-number":["1R01DE033442-01A1"]}],"id":[{"id":"10.13039\/100010393","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/100010393","name":"University of Maryland School of Dentistry","doi-asserted-by":"crossref","award":["R01 DE032692"],"award-info":[{"award-number":["R01 DE032692"]}],"id":[{"id":"10.13039\/100010393","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Background: Tooth root caries and periodontal tissue loss remain major challenges in elderly and periodontally compromised patients, while current restorative materials lack combined antibacterial and regenerative properties. Objective: The objective of this study was to develop a novel metformin-containing antibacterial composite for root cavity restorations to prevent recurrent caries and potentially promote periodontal tissue regeneration. Methods: Experimental composites contained 5% dimethylaminohexadecyl methacrylate (DMAHDM), varying metformin concentrations (2.5\u201315%), and glass fillers. Mechanical and antibacterial properties as well as cytocompatibility toward human periodontal ligament stem cells (hPDLSCs) were investigated. Results: The experimental composites achieved flexural strengths of 67.9 to 50.1 MPa (n = 6), significantly higher than (41.3 \u00b1 3.4 MPa) of commercial control Vitremer (p &lt; 0.05), while maintaining clinically acceptable elastic moduli of 3.7\u20133.1 GPa. Experimental composites achieved an 8-log reduction in Streptococcus mutans (S. mutans) biofilms and significantly reduced lactic acid production and metabolic activity compared to biofilms on commercial controls. The composite containing 15% metformin demonstrated acceptable cytocompatibility toward hPDLSCs under clinically relevant diluted conditions, matching commercial controls (p &gt; 0.1). Conclusions: These findings suggest that this novel composite possesses potent antibacterial activity, acceptable cytocompatibility, and adequate mechanical properties, making it promising for multifunctional root caries restorations.<\/jats:p>","DOI":"10.3390\/ma19142963","type":"journal-article","created":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T14:17:51Z","timestamp":1783606671000},"page":"2963","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Novel Metformin-Containing Antibacterial Composite for Root Caries Restorations"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3794-653X","authenticated-orcid":false,"given":"Ayman","family":"Altamimi","sequence":"first","affiliation":[{"name":"Dental Biomedical Sciences PhD Program, Graduate School, University of Maryland, Baltimore, MD 21201, USA"},{"name":"Department of Biomaterials and Regenerative Dental Medicine, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA"},{"name":"Department of Restorative Dental Sciences, College of Dentistry, University of Hail, Hail 55475, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3524-2515","authenticated-orcid":false,"given":"Ibrahim","family":"Ba-Armah","sequence":"additional","affiliation":[{"name":"Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Heba","family":"Alqarni","sequence":"additional","affiliation":[{"name":"Dental Biomedical Sciences PhD Program, Graduate School, University of Maryland, Baltimore, MD 21201, USA"},{"name":"Department of Biomaterials and Regenerative Dental Medicine, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA"},{"name":"Department of Pediatric Dentistry and Orthodontic Sciences, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7197-8239","authenticated-orcid":false,"given":"Nader","family":"Almutairi","sequence":"additional","affiliation":[{"name":"Dental Biomedical Sciences PhD Program, Graduate School, University of Maryland, Baltimore, MD 21201, USA"},{"name":"Department of Biomaterials and Regenerative Dental Medicine, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA"},{"name":"Department of Conservative Dental Sciences, College of Dentistry, Prince Sattam bin Abdulaziz University, Alkharj 11942, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9507-5416","authenticated-orcid":false,"given":"Yazeed","family":"Altamimi","sequence":"additional","affiliation":[{"name":"Dental Biomedical Sciences PhD Program, Graduate School, University of Maryland, Baltimore, MD 21201, USA"},{"name":"Department of Biomaterials and Regenerative Dental Medicine, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA"},{"name":"Department of Restorative Dental Sciences, College of Dentistry, University of Hail, Hail 55475, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohammad","family":"Alenizy","sequence":"additional","affiliation":[{"name":"Department of Restorative Dental Sciences, College of Dentistry, University of Hail, Hail 55475, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8046-9789","authenticated-orcid":false,"given":"Abraham","family":"Schneider","sequence":"additional","affiliation":[{"name":"College of Dentistry, Ohio State University, Columbus, OH 43210, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3383-8956","authenticated-orcid":false,"given":"Jirun","family":"Sun","sequence":"additional","affiliation":[{"name":"ADA Forsyth Institute, Cambridge, MA 02142, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7961-3787","authenticated-orcid":false,"given":"Michael D.","family":"Weir","sequence":"additional","affiliation":[{"name":"Department of Biomaterials and Regenerative Dental Medicine, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hockin H. K.","family":"Xu","sequence":"additional","affiliation":[{"name":"Department of Biomaterials and Regenerative Dental Medicine, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA"},{"name":"Center for Stem Cell Biology & Regenerative Medicine, School of Medicine, University of Maryland, Baltimore, MD 21201, USA"},{"name":"Marlene and Stewart Greenebaum Cancer Center, School of Medicine, University of Maryland, Baltimore, MD 21201, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/S0140-6736(07)60031-2","article-title":"Dental caries","volume":"369","author":"Selwitz","year":"2007","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"286","DOI":"10.1111\/j.1834-7819.2008.00064.x","article-title":"Dental caries: A dynamic disease process","volume":"53","author":"Featherstone","year":"2008","journal-title":"Aust. 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