{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T15:58:35Z","timestamp":1780588715290,"version":"3.54.1"},"reference-count":46,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Life"],"abstract":"<jats:p>Background: This study evaluates the increase in gingival thickness following the administration of injectable atelocollagen. Materials and Methods: A retrospective analysis was conducted using the medical records of 60 patients with a thin gingival phenotype at baseline, treated between 2017 and 2025. All patients received a standardised protocol for soft tissue thickness modification using atelocollagen injections. Based on the continuation of maintenance therapy, patients were divided into Group A (n = 30), consisting of patients who received booster doses at six-month intervals following completion of the full treatment protocol, and Group B (n = 30), consisting of patients who did not continue maintenance therapy. The observation period for all patients was five years. Gingival thickness was assessed by periodontal probe transparency using a standard WHO probe (WHO 621) and the Hu-Friedy Colorvue Biotype Probe. Longitudinal changes were analysed using linear mixed-effects models (LMMs) for continuous outcomes and generalised linear mixed-effects models (GLMMs) with a binomial distribution and logit link for binary outcomes, accounting for repeated measurements at the patient level. Results: Significant effects of Group and Time, as well as their interaction, were observed for the proportion of sites with a thick gingiva (Group effect: F (1,93.14) = 57.94, p &lt; 0.001; Group \u00d7 Time interaction: p &lt; 0.001). GLMM analysis confirmed a significant Group \u00d7 Time interaction (\u03c72 = 23.11, p &lt; 0.001), indicating sustained gingival thickness improvement in Group A and a gradual decrease in effectiveness in Group B. Conclusions: Injectable atelocollagen represents a reliable, effective, and user-friendly method for long-term modification of gingival thickness, particularly when supported by maintenance therapy.<\/jats:p>","DOI":"10.3390\/life16010065","type":"journal-article","created":{"date-parts":[[2026,1,2]],"date-time":"2026-01-02T12:23:44Z","timestamp":1767356624000},"page":"65","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Gingival Thickness Improvement After Atelocollagen Injection\u2014Retrospective Study"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7988-1282","authenticated-orcid":false,"given":"Sylwia","family":"Klewin-Steinb\u00f6ck","sequence":"first","affiliation":[{"name":"Department of Periodontology and Oral Mucosa Diseases, Poznan University of Medical Science, 70 Bukowska St., 60-812 Poznan, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4803-7406","authenticated-orcid":false,"given":"Anna","family":"Duda-Sobczak","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine and Diabetology, Poznan University of Medical Science, 2 Mickiewicza St., 60-830 Poznan, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2029-2277","authenticated-orcid":false,"given":"Marzena Liliana","family":"Wyganowska","sequence":"additional","affiliation":[{"name":"Department of Periodontology and Oral Mucosa Diseases, Poznan University of Medical Science, 70 Bukowska St., 60-812 Poznan, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1016\/S0011-8532(22)02947-0","article-title":"A re-evaluation of osseous surgery","volume":"13","author":"Ochsenbein","year":"1969","journal-title":"Dent. 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