Wear, RestorationNCT07215598

Split-Mouth Comparison of Invisalign Attachments

A study testing Composite Aligner Attachment in people with Wear, Restoration and Volume Assessment, run by University of Maryland, Baltimore at 1 site in United States.

Enrolling by invitation

Enrolling by invitation. The study team selects and invites participants, usually from an existing group of patients.

Sites and contacts

Official record

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Trial summary

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). Read more about this study

Who is it for?: Ages 18 years and older
Conditions the study is for: Wear, Restoration, Volume Assessment, Clear Aligner Appliance
What is being tested?: Composite Aligner Attachment
Type of treatment: Medical device
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 30 participants
Where: 1 siteUnited States
Study dates: 20 Nov 2025to Jul 2028
Phase: Interventional
Are there results?: Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 years and older
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

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.

Who cannot join

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.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

United States1 site

University of Maryland School of Dentistry
Baltimore, Maryland, 21201

Other trials in United States

About this study

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

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.

Conditions: Wear, Restoration, Volume Assessment, Clear Aligner Appliance
Being tested: Composite Aligner Attachment
Keywords: volume assessment, invisalign, clear aligner, digital orthodontics, attachment wear

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Composite Aligner AttachmentDevice
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.

Study groups in NCT07215598
Study group	Role	What they receive
Optimized	Active comparator	Optimized attachments are small, tooth-colored composite bumps placed on teeth during Invisalign treatment to help aligners deliver controlled forces for tooth movement. These attachments are digitally designed in the ClinCheck software to optimize force direction and retention. In this arm, optimized attachments will be bonded according to the manufacturer's standard template and curing protocols. Their bonded geometry and wear over time will be compared to those of conventional attachments placed on the contralateral teeth. Receives: Device: Composite Aligner Attachment
Conventional	Active comparator	Conventional attachments are tooth-colored composite bumps placed on teeth during Invisalign treatment to improve aligner retention and control tooth movement. These attachments are designed with standard rectangular or ellipsoid shapes, following established clinical templates. In this arm, conventional attachments will be bonded using manufacturer-recommended materials and curing protocols. Their placement accuracy and wear characteristics will be compared to those of optimized attachments placed on the contralateral teeth within the same participant. Receives: Device: Composite Aligner Attachment

What is being measured

The primary outcome is the main question the study is designed to answer.

Attachment Volume Accuracy
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.
Measured: 1 month
Attachment Active Surface Area Accuracy
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.
Measured: 1 month
Positional Accuracy
Difference between planned and bonded attachment position, measured as centroid displacement (mm) after 3D registration of STL models at baseline and 1 month.
Measured: 1 month

Secondary outcomes (4)

Volume Reduction Over Time
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.
Measured: 6 months
Volume Loss (Percentage)
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.
Measured: 6 months
Active Surface Area Change Over Time
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.
Measured: 6 months
Active Surface Area Change (Percentage)
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.
Measured: 6 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

20 Nov 2025Jul 2028

First posted10 Oct 2025
Study start20 Nov 2025
Primary completionJul 2028 (estimated)
Study completionJul 2028 (estimated)

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Publications (4)Papers the sponsor has linked to this study.
Other trials for Wear, RestorationStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase N/A
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Crossover
Model description: This is a prospective, randomized split-mouth (crossover) study evaluating two types of Invisalign attachments: optimized and conventional. Each participant receives both attachment types on contralateral teeth, allowing within-subject comparison of placement accuracy and wear under identical clinical conditions.
Masking: None (open label)
Enrolment: 30 participants (estimated)

IDs, dates and publications

ClinicalTrials.gov ID: NCT07215598
Sponsor's protocol ID: HP-00115664
Status last verified: Jan 2026
First submitted: 7 Oct 2025
Last updated: 10 Feb 2026
Results posted: No
Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: Yes
Individual data sharing: Yes: De-identified individual participant data (IPD), including attachment type, attachment volume, surface deviation, and changes in attachment shape and wear over time, will be shared upon reasonable request. Supporting materials such as the data dictionary, study protocol, statistical analysis plan, informed consent form, and computational methods for volumetric evaluation in MeshMixer will also be made available to qualified researchers for further analysis.

Publications

Muthuswamy Pandian S, Subramanian AK, Vaiid N. Comparison of efficacy and accuracy of tooth movements in optimized and conventional attachments of clear aligners - A systematic review and meta-analysis. J Oral Biol Craniofac Res. 2025 Sep-Oct;15(5):1123-1133. doi: 10.1016/j.jobcr.2025.07.019. Epub 2025 Jul 29.
PubMed 40778386
Li Q, Yang K. Surface wear of attachments in patients during clear aligner therapy: a prospective clinical study. Prog Orthod. 2024 Feb 19;25(1):7. doi: 10.1186/s40510-023-00506-y.
PubMed 38369617
Fausto da Veiga Jardim A, Curado de Freitas J, Estrela C. Surface wear and adhesive failure of resin attachments used in clear aligner orthodontic treatment. J Orofac Orthop. 2024 May;85(Suppl 1):52-62. doi: 10.1007/s00056-023-00471-5. Epub 2023 Jun 14.
PubMed 37314488
Bellocchio AM, Portelli M, Ciraolo L, Ciancio E, Militi A, Peditto M, Barbera S, Nucera R. Evaluation of the Clinical Variables Affecting Attachment Reproduction Accuracy during Clear Aligner Therapy. Materials (Basel). 2023 Oct 23;16(20):6811. doi: 10.3390/ma16206811.
PubMed 37895792

Study at a glance

From the registry record, last updated by the sponsor on 10 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Accuracy of Invisalign Attachments: A Split-Mouth Comparative Study of Optimized and Conventional Designs
ClinicalTrials.gov ID: NCT07215598
Acronym / sponsor ID: HP-00115664
Conditions: Wear, Restoration, Volume Assessment, Clear Aligner Appliance
Keywords: volume assessment, invisalign, clear aligner, digital orthodontics, attachment wear
Study type: Interventional
Recruitment status: Enrolling by invitation
Enrolment: 30 participants (estimated)
Lead sponsor: University of Maryland, BaltimoreUniversity, hospital or other
Study start: 20 Nov 2025 (actual)
Primary completion: Jul 2028 (estimated)
Study completion: Jul 2028 (estimated)
First posted: 10 Oct 2025 (actual)
Results: Not posted in the source record

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

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

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Crossover
Masking: None (open label)
Number of arms: 2
Model description: This is a prospective, randomized split-mouth (crossover) study evaluating two types of Invisalign attachments: optimized and conventional. Each participant receives both attachment types on contralateral teeth, allowing within-subject comparison of placement accuracy and wear under identical clinical conditions.

Arm	Type	Receives
Optimized	Active comparator	Device: Composite Aligner AttachmentOptimized attachments are small, tooth-colored composite bumps placed on teeth during Invisalign treatment to help aligners deliver controlled forces for tooth movement. These attachments are digitally designed in the ClinCheck software to optimize force direction and retention. In this arm, optimized attachments will be bonded according to the manufacturer's standard template and curing protocols. Their bonded geometry and wear over time will be compared to those of conventional attachments placed on the contralateral teeth.
Conventional	Active comparator	Device: Composite Aligner AttachmentConventional attachments are tooth-colored composite bumps placed on teeth during Invisalign treatment to improve aligner retention and control tooth movement. These attachments are designed with standard rectangular or ellipsoid shapes, following established clinical templates. In this arm, conventional attachments will be bonded using manufacturer-recommended materials and curing protocols. Their placement accuracy and wear characteristics will be compared to those of optimized attachments placed on the contralateral teeth within the same participant.

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (4 listed)

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.

Key exclusion criteria (5 listed)

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.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
Composite Aligner AttachmentComposite 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.	Device	Conventional, Optimized

Primary outcome

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.
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.
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.

4 secondary outcomes

Volume Reduction Over Time
Time frame: 6 months
Volume Loss (Percentage)
Time frame: 6 months
Active Surface Area Change Over Time
Time frame: 6 months
Active Surface Area Change (Percentage)
Time frame: 6 months

Results and safety

This study is still under way. Results are not available in the source record yet.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 10 Feb 2026.
Background: PubMed 40778386Muthuswamy Pandian S, Subramanian AK, Vaiid N. Comparison of efficacy and accuracy of tooth movements in optimized and conventional attachments of clear aligners - A systematic review and meta-analysis. J Oral Biol Craniofac Res. 2025 Sep-Oct;15(5):1123-1133. doi: 10.1016/j.jobcr.2025.07.019. Epub 2025 Jul 29.
Background: PubMed 38369617Li Q, Yang K. Surface wear of attachments in patients during clear aligner therapy: a prospective clinical study. Prog Orthod. 2024 Feb 19;25(1):7. doi: 10.1186/s40510-023-00506-y.
Background: PubMed 37314488Fausto da Veiga Jardim A, Curado de Freitas J, Estrela C. Surface wear and adhesive failure of resin attachments used in clear aligner orthodontic treatment. J Orofac Orthop. 2024 May;85(Suppl 1):52-62. doi: 10.1007/s00056-023-00471-5. Epub 2023 Jun 14.
Background: PubMed 37895792Bellocchio AM, Portelli M, Ciraolo L, Ciancio E, Militi A, Peditto M, Barbera S, Nucera R. Evaluation of the Clinical Variables Affecting Attachment Reproduction Accuracy during Clear Aligner Therapy. Materials (Basel). 2023 Oct 23;16(20):6811. doi: 10.3390/ma16206811.
Invisalign Attachments explanationLink provided by the sponsor.
Individual participant dataSharing planned: Yes. De-identified individual participant data (IPD), including attachment type, attachment volume, surface deviation, and changes in attachment shape and wear over time, will be shared upon reasonable request. Supporting materials such as the data dictionary, study protocol, statistical analysis plan, informed consent form, and computational methods for volumetric evaluation in MeshMixer will also be made available to qualified researchers for further analysis.

Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.

The record lists no contact. Use the official record to reach the sponsor.

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A study testing Composite Aligner Attachment in people with Wear, Restoration and Volume Assessment, run by University of Maryland, Baltimore at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: enrolling by invitation, as of the sponsor's last update on 10 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Attachment Volume Accuracy (time frame: 1 month). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07215598, which also lists 4 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Feb 2026; AzTrials last refreshed its copy on 26 Oct 2026.