Digital vs Conventional VFR in Post-Orthodontic Retention

August 13, 2026 updated by: Syed Riaz Hashim, Ziauddin University

Comparison of Periodontal Health Parameters Using Conventional Versus Digital Vacuum Formed Retainer (VFR).

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.

Study Overview

Detailed Description

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.

Study Type

Interventional

Enrollment (Estimated)

52

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Dr Syed Riaz Hashim Principal Investigator
  • Phone Number: +92 3312763463
  • Email: syed.hashim@zu.edu.pk

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

No

Description

INCLUSION CRITERIA

  • Patients aged 15-30 years
  • Patients with good oral and general health
  • Patients in which both the arches were treated with fixed orthodontic treatment on a non-extraction basis completed within the last 1 month
  • Patients with minimum 24 permanent teeth present

EXCLUSION CRITERIA

  • Patients that are medically compromised due to a systemic disease
  • Patients having periodontal disease before debonding
  • Patients with severe and uncontrolled caries
  • Patients having cleft palate or any other severe facial deformity
  • Patients using drugs that have direct or indirect effect on the periodontal health such as phenytoin, cyclosporine etc.
  • Patients that have a habit of chronic smoking
  • Pregnant patients

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Group A - Digital VFR
Participants receive a vacuum-formed retainer thermoformed over a 3D-printed model generated from intraoral scanning, worn 22 hours/day for 6 months.
PETG, 1.5 mm, fabricated via intraoral scan and 3D-printed model
Active Comparator: Group B - Conventional VFR
Participants receive a vacuum-formed retainer thermoformed over a plaster model generated from alginate impressions, worn 22 hours/day for 6 months.
PETG, 1.5 mm, fabricated via alginate impression and plaster model

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Plaque Index
Time Frame: Baseline (T0), 1 month (T1), 3 months (T2), 6 months (T3).
(Silness and Loe method) 4-point scale (0-3) scored on four surfaces (facial, lingual, mesial, distal) of index teeth 16, 21, 31, 46
Baseline (T0), 1 month (T1), 3 months (T2), 6 months (T3).
Gingival Index
Time Frame: Baseline (T0), 1 month (T1), 3 months (T2), 6 months (T3).
(Loe and Silness method) 4-point scale (0-3) assessing inflammation and bleeding on four surfaces of index teeth 16, 21, 31, 46
Baseline (T0), 1 month (T1), 3 months (T2), 6 months (T3).
Periodontal Pocket Depth
Time Frame: Baseline (T0), 1 month (T1), 3 months (T2), 6 months (T3)
measured in mm with a UNC-15 probe at six sites per index tooth (mesiofacial, midfacial, distofacial, mesiolingual, midlingual, distolingual); deepest site recorded
Baseline (T0), 1 month (T1), 3 months (T2), 6 months (T3)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 1, 2026

Primary Completion (Estimated)

October 1, 2027

Study Completion (Estimated)

December 1, 2027

Study Registration Dates

First Submitted

August 7, 2026

First Submitted That Met QC Criteria

August 7, 2026

First Posted (Actual)

August 12, 2026

Study Record Updates

Last Update Posted (Actual)

August 14, 2026

Last Update Submitted That Met QC Criteria

August 13, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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