Biological response to directly 3D-printed orthodontic retainers

Evaluation of Biological Reaction of Direct Three Dimensional Printed Retainers

NA · Al-Azhar University · NCT07098325

We will test whether 0.5 mm versus 1.0 mm thick directly 3D-printed retainers change bacterial growth and color in people who have just finished fixed braces.

Quick facts

PhaseNA
Study typeInterventional
Enrollment26 (estimated)
SexAll
SponsorAl-Azhar University (other)
Locations1 site (Asyut)
Trial IDNCT07098325 on ClinicalTrials.gov

What this trial studies

This interventional study will fit patients who completed fixed orthodontic treatment with directly 3D-printed clear retainers manufactured at two thicknesses (0.5 mm and 1.0 mm). Participants with good oral hygiene and no habits like smoking will be followed over time to measure bacterial colonization and color stability of the retainers. Primary outcomes are quantitative bacterial growth and objective color change; a secondary outcome is determining the optimal thickness for biological performance in clear aligner fabrication. Patients taking medications that affect saliva, with periodontitis, intrinsic tooth discoloration, or who cannot follow instructions will be excluded.

Who should consider this trial

Good fit: Ideal candidates are people who have finished fixed orthodontic therapy, have good oral hygiene, do not smoke, and can follow written instructions.

Not a fit: Patients on medications that affect saliva, those with periodontitis or intrinsic tooth discoloration, or uncooperative individuals may not receive benefit from this study.

Why it matters

Potential benefit: If successful, this could identify a retainer thickness that reduces bacterial buildup and staining, improving hygiene and retainer longevity.

How similar studies have performed: Directly 3D-printed retainers are a recent innovation and studies specifically comparing thickness for bacterial growth and color are limited, so this approach is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* -Finished fixed orthodontic therapy and seeking for retention as a part of their original treatment plan.
* Good oral hygiene.
* No habits (e.g., smoking)

Exclusion Criteria:

* Medication affecting saliva.

  * intrinsic tooth discoloration.
  * Uncooperative patients.
  * Patient with periodontitis.
  * Learning difficulties and inability to read written instructions.

Where this trial is running

Asyut

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Orthodontic Retainers, Different thicknesses, Direct three dimensional printed retainers, Bacterial growth, Color change

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.