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Enrolling by Invitation

NCT Number: NCT07215598

Split-Mouth Comparison of Invisalign Attachments

This study evaluates how accurately the attachments used in Invisalign treatment (Align Technology Inc., San Jose, CA, USA) match their planned shapes and sizes in the ClinCheck software (ClinCheck®, Align Technology Inc., San Jose, CA, USA). Attachments are small tooth-colored bumps that help clear aligners grip the teeth and move them effectively.

The investigators are comparing two types of attachments: optimized and conventional, to determine which is bonded to the tooth more accurately and maintains its shape better over time. Participants beginning Invisalign treatment will have attachments placed as part of their normal care. Digital scans will be taken immediately after placement and during follow-up visits to assess attachment accuracy and wear.

The goal is to identify which attachment design provides greater precision and durability to improve the predictability and efficiency of Invisalign treatment planning.

Enrolling by Invitation

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Key information

Conditions

Wear, Restoration Clear Aligner Appliance Volume Assessment

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Maryland School of Dentistry

Baltimore, Maryland, 21201, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adults aged18 years or older.
  • Patients initiating Invisalign treatment with planned composite attachments.
  • Ability to provide written informed consent and agree to additional research intra-oral scans.
  • Good oral hygiene and absence of active periodontal disease at enrollment.

Exclusion criteria

  • Extensive dental restorations (composites, crowns, veneers) on study teeth that could interfere with attachment bonding.
  • Enamel defects or severe wear on study tooth surfaces affecting bonding accuracy.
  • Contraindications to digital intraoral scanning (e.g., severe gag reflex, metallic prostheses preventing accurate imaging).
  • Severe tooth malposition that would compromise accurate attachment placement.
  • Poor oral hygiene or active periodontal disease at enrollment and/or if the patient develops poor oral hygiene or active periodontal disease during treatment.

Treatment and study plan

Composite Aligner Attachment

Device

Composite aligner attachments are small, tooth-colored resin bumps bonded to specific teeth during Invisalign treatment to enhance aligner retention and force application. These attachments are digitally planned in ClinCheck software and fabricated using manufacturer-provided templates. In this study, two designs: optimized and conventional, will be compared for their accuracy and durability using 3D digital scans at multiple time points.

Primary outcomes

  1. Attachment Volume Accuracy

    Time frame: 1 month

    Quantitative comparison of planned versus bonded Invisalign attachment volumes measured using 3D (three dimensional) digital scans. Each bonded attachment will be segmented from intraoral STL (Standard Tessellation Language) files and superimposed onto the corresponding planned ClinCheck model. The absolute difference in attachment volume (in mm³) between planned and bonded models will be calculated to assess bonding accuracy for optimized and conventional designs.

  2. Attachment Active Surface Area Accuracy

    Time frame: 1 month

    Quantitative difference in attachment active surface area using intraoral 3D scans. STL models obtained at baseline (immediately after bonding) and at 1 month will be superimposed to calculate difference in active surface area (mm²). The mean difference between planned and bonded surface areas will be compared for optimized and conventional attachment designs to evaluate bonding precision.

  3. Positional Accuracy

    Time frame: 1 month

    Difference between planned and bonded attachment position, measured as centroid displacement (mm) after 3D registration of STL models at baseline and 1 month.

Secondary outcomes

  1. Volume Reduction Over Time

    Time frame: 6 months

    Quantitative change in attachment volume across follow-up using serial intraoral 3D scans. STL models acquired at baseline (immediately after bonding), 1, 3, and 6 months will be superimposed to calculate absolute loss in attachment volume (mm³) for optimized and conventional designs.

  2. Volume Loss (Percentage)

    Time frame: 6 months

    Relative change in attachment volume expressed as a percentage of the baseline volume. STL models from baseline, 1, 3, and 6 months will be analyzed to calculate mean percent reduction (%) in attachment volume for optimized and conventional designs.

  3. Active Surface Area Change Over Time

    Time frame: 6 months

    Longitudinal change in the active surface area of bonded attachments measured from serial intraoral 3D scans. Segmented STL models at baseline (immediately after bonding), 1, 3, and 6 months will be registered to compute absolute change in active surface area (mm²) for optimized and conventional designs.

  4. Active Surface Area Change (Percentage)

    Time frame: 6 months

    Relative change in attachment active surface area expressed as a percentage of the baseline value. STL models obtained at baseline and at 1, 3, and 6 months will be analyzed to calculate mean percent reduction (%) in active surface area for optimized and conventional attachments.

Sponsors and collaborators

Lead sponsor

University of Maryland, Baltimore

Other

Registry information

Official study title

Accuracy of Invisalign Attachments: A Split-Mouth Comparative Study of Optimized and Conventional Designs

Important dates

Study start
2025
Primary completion
2028
Study completion
2028
First posted
Oct 10, 2025
Registry last updated
Feb 10, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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