Marginal Biofilm Distribution and Periodontal Response to Supragingival and Juxtagingival Aligner Designs

Summary

* This prospective, longitudinal, within-person (split-mouth) clinical study evaluates the influence of two clear aligner trimming-line designs on marginal soft-tissue biofilm distribution and periodontal tissue response over a six-month period.
* Two trimming-line designs are compared. The supragingival design has a straight, horizontal edge that extends approximately 2 mm onto the marginal gingiva, resting in direct contact with the gingival surface but not entering the gingival sulcus. The juxtagingival design follows the scalloped contour of the gingival margin and terminates at the free gingival margin, without covering the gingiva and without entering the sulcus.
* Each participant receives both designs simultaneously, one per dental arch, and therefore serves as their own control. The assignment of each design to an arch is determined by the treating clinician according to the orthodontic treatment indications and is not randomized.
* The primary outcome is the percentage of sites with bleeding on probing per arch at six months. Secondary outcomes are bleeding on probing at three months, mean probing depth, maximum probing depth, and the Turesky-Quigley-Hein plaque index, with three exploratory photographic soft-tissue variables describing marginal gingival plaque presence, vestibular interdental papilla plaque presence, and the marginal demarcation pattern. Clinical and photographic assessments are performed at baseline (before aligner delivery), at three months, and at six months.
* All aligners are fabricated from a tri-layer clear aligner material (CA Pro, SCHEU-DENTAL GmbH, Iserlohn, Germany) by a single orthodontic laboratory.

Conditions

• Periodontal Diseases
• Dental Plaque
• Gingivitis

Interventions

DEVICE

Supragingival aligner trimming-line

Clear aligner trimmed with a supragingival straight-cut margin extending approximately 2 mm onto the marginal gingiva, in direct contact with the gingiva but not entering the sulcus. Fabricated from CA Pro tri-layer thermoplastic material (SCHEU-DENTAL GmbH, Iserlohn, Germany; CE-marked) by Orto Performance Orthodontic Laboratory, Cluj-Napoca, Romania. The intervention under study is the trimming-line design, not the aligner material; material and thickness are identical to the comparator.

DEVICE

Juxtagingival festooned aligner trimming-line

Clear aligner trimmed with a juxtagingival festooned margin following the scalloped gingival contour, terminating at the free gingival margin without covering the gingiva or entering the sulcus. Fabricated from CA Pro tri-layer thermoplastic material (SCHEU-DENTAL GmbH, Iserlohn, Germany; CE-marked) by Orto Performance Orthodontic Laboratory, Cluj-Napoca, Romania. The intervention under study is the trimming-line design, not the aligner material; material and thickness are identical to the comparator.

Sponsors & Collaborators

• Orto Performance Orthodontic Laboratory, Cluj-Napoca, Romania (aligner fabrication)

  collaborator UNKNOWN

• George Emil Palade University of Medicine, Pharmacy, Sciences and Technology of Targu Mures

  lead OTHER

Principal Investigators

• LUMINITA LAZAR, PhD, Professor · George Emil Palade University of Medicine, Pharmacy, Sciences, and Technology of Targu Mures, 38 Gheorghe Marinescu Street, 540139 Targu Mures, Romania

Study Design

Allocation

NON_RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2025-03-01

Primary Completion

2026-07-15

Completion

2026-07-15

Countries

• Romania

Study Locations