Digital vs Conventional VFR in Post-Orthodontic Retention

Overview

This study is comparing two ways of making a retainer, the clear, removable kind worn after braces to see whether the way it's made affects gum health. One type is made using a digital scan of the teeth, and the other is made the traditional way, using a plaster mold. The study will look at how each type affects plaque buildup, gum swelling, and the depth of the space between the tooth and gum over a six-month period. About 52 people who have just finished braces on both their upper and lower teeth will take part. Participants will be assigned to one of two groups: one group will receive a digitally made retainer, and the other will receive a traditionally made retainer. Retainer Fitting Before the study begins, each participant's retainer is custom-made for their teeth, either from a digital scan or a plaster mold, depending on which group they're in. Participants will wear their retainer for 22 hours a day, taking it out only to eat and brush their teeth. Daily Care Throughout the study, participants will follow the same tooth-brushing and gum-care routine, so that any differences seen between the two groups can be linked to the retainer itself rather than to differences in oral hygiene. Participants will be asked to avoid using mouthwash while wearing the retainer. Check-Up Visits Participants will attend four check-ups over six months: Before the retainer is placed (baseline) One month after placement Three months after placement Six months after placement At each visit, a dentist will check the teeth and gums for plaque buildup, gum swelling or bleeding, and pocket depth (the space between the tooth and gum) using a small measuring tool called a probe. Follow-Up The final check-up at six months marks the end of the study for each participant. Participants can leave the study at any time if they choose.

Orthodontic retention is essential to prevent relapse following active orthodontic treatment, and vacuum-formed retainers (VFRs) are widely used due to their aesthetics and ease of fabrication. Conventional VFRs are fabricated over a plaster model derived from alginate impressions, while digital VFRs are fabricated over a 3D-printed model generated from an intraoral scan. This randomized clinical trial compares periodontal health outcomes; Plaque Index, Gingival Index, and Periodontal Pocket Depth, between the two fabrication methods. Fifty-two participants (26 per arm) aged 15-30 years who have completed non-extraction fixed orthodontic treatment on both arches within the last month will be enrolled via non-probability consecutive sampling. Group A will receive digitally fabricated VFRs; Group B will receive conventionally fabricated VFRs, both made of 1.5 mm PETG material. Participants will wear retainers 22 hours daily and follow standardized oral hygiene instructions. Periodontal parameters will be assessed on index teeth 16, 21, 31, and 46 at baseline (T0) and at 1, 3, and 6 months (T1-T3) post-placement. Gingival Index will follow the Loe and Silness method; Plaque Index will follow the Silness and Loe method; pocket depth will be measured with a UNC-15 probe at six sites per tooth. Data will be analyzed in SPSS v27 using independent-sample t-tests/Mann-Whitney U tests for between-group comparisons and paired t-tests for within-group change from baseline, with stratification for age and gender as effect modifiers.