{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T21:15:28Z","timestamp":1790284528274,"version":"4.1.0"},"reference-count":29,"publisher":"Oxford University Press (OUP)","issue":"4","license":[{"start":{"date-parts":[[2018,10,12]],"date-time":"2018-10-12T00:00:00Z","timestamp":1539302400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/journals\/pages\/open_access\/funder_policies\/chorus\/standard_publication_model"}],"funder":[{"name":"University of Malaya Clinical Postgraduate Research","award":["PPPC\/C1-2015\/DGD\/12"],"award-info":[{"award-number":["PPPC\/C1-2015\/DGD\/12"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2019,8,8]]},"abstract":"<jats:title>Summary<\/jats:title>\n               <jats:sec>\n                  <jats:title>Objectives<\/jats:title>\n                  <jats:p>The aim of this study was to compare vacuum-formed thermoplastic retainers (VFRs) constructed on stone models (VFR-CV) and those constructed on three-dimensional (3D) printed models (VFR-3D) based on patients\u2019 perspective and post-treatment stability.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Study design<\/jats:title>\n                  <jats:p>The research was designed as a crossover, randomized control trial.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Materials and methods<\/jats:title>\n                  <jats:p>Subjects comprised patients receiving fixed appliances at a teaching institution and indicated for VFRs. Post-treatment stone models were scanned with a structured-light scanner. A fused deposition modelling machine was used to construct acrylonitrile-butadiene-styrene (ABS)-based replicas from the 3D scanned images. VFRs were fabricated on the original stone and printed models. Analysis comprised independent t-tests and repeated measures analysis of variance.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Randomization<\/jats:title>\n                  <jats:p>Subjects were allocated to two groups using Latin squares methods and simple randomization. A week after debond, subjects received either VFR-CV first (group A) or VFR-3D first (group B) for 3 months, then the interventions were crossed over for another 3 months.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Blinding<\/jats:title>\n                  <jats:p>In this single-blinded study, subjects were assigned a blinding code for data entry; data were analysed by a third party.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Outcome measures<\/jats:title>\n                  <jats:p>The primary outcome measured was oral health-related quality of life (OHRQoL) based on Oral Health Impact Profile-14 (OHIP-14). Secondary outcome was post-treatment stability measured using Little\u2019s Irregularity Index (LII).<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>A total of 30 subjects (15 in each group) were recruited but 3 dropped out. Analysis included 13 subjects from group A and 14 subjects from group B. Group A showed an increase in LII (P &lt; 0.05) after wearing VFR-CV and VFR-3D, whereas group B had no significant increase in LII after wearing both VFRs. Both groups reported significant improvement in OHRQoL after the first intervention but no significant differences after the second intervention. LII changes and OHIP-14 scores at T2 and T3 between groups, and overall between the retainers were not significantly different. No harm was reported during the study.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusion<\/jats:title>\n                  <jats:p>VFRs made on ABS-based 3D printed models showed no differences in terms of patients\u2019 OHRQoL and stability compared with conventionally made retainers.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Registration<\/jats:title>\n                  <jats:p>NCT02866617 (ClinicalTrials.gov).<\/jats:p>\n               <\/jats:sec>","DOI":"10.1093\/ejo\/cjy063","type":"journal-article","created":{"date-parts":[[2018,9,2]],"date-time":"2018-09-02T15:34:19Z","timestamp":1535902459000},"page":"370-380","source":"Crossref","is-referenced-by-count":18,"title":["Comparing retainers constructed on conventional stone models and on 3D printed models: a randomized crossover clinical study"],"prefix":"10.1093","volume":"41","author":[{"given":"Norhidayah","family":"Mohd Tahir","sequence":"first","affiliation":[{"name":"Department of Paediatric Dentistry and Orthodontics, University of Malaya, Kuala Lumpur, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1627-3671","authenticated-orcid":false,"given":"Wan Nurazreena","family":"Wan Hassan","sequence":"additional","affiliation":[{"name":"Department of Paediatric Dentistry and Orthodontics, University of Malaya, Kuala Lumpur, Malaysia"},{"name":"Clinical Craniofacial Dentistry Research Group, University of Malaya, Kuala Lumpur, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roslan","family":"Saub","sequence":"additional","affiliation":[{"name":"Department of Community Oral Health and Clinical Prevention, Faculty of Dentistry, University of Malaya, Kuala Lumpur, 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