Accuracy and Periodontal Outcomes of Three Interproximal Enamel Reduction Techniques During Clear Aligner Therapy

NCT07377825 | Not Yet Recruiting

• 1 other identifier: REU-IPR-CAT-RCT-2026-001
• Study Type: interventional
• Target: 75
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized controlled clinical trial will compare three commonly used interproximal enamel reduction (IPR) techniques during clear aligner therapy in adult patients. IPR is a routine orthodontic procedure in which a small amount of enamel is removed between teeth to create space and help achieve the planned alignment. Seventy-five adults (18 years and older) indicated for receiving clear aligner treatment with IPR prescribed in their digital treatment plan will be enrolled at the orthodontic clinics of Riyadh Elm University (Riyadh, Saudi Arabia) and randomized in a 1:1:1 ratio to one of three IPR techniques: manual abrasive strips (manual arm), motor-driven oscillating strips (motor-driven arm), or abrasive discs (abrasive arm). IPR will be performed by the same trained operator according to the assigned technique. The primary outcome is IPR accuracy, defined as the difference between the amount of IPR planned digitally and the amount performed clinically, measured using intraoral scans taken before and immediately after IPR. Secondary outcomes are short-term periodontal outcomes, assessed on IPR teeth only using plaque and gingival bleeding indices at baseline and at a 6-week follow-up visit. The data analyst will be blinded to group allocation

Conditions

Dental Crowding,Interproximal Enamel Reduction; Malocclusion, Angle's Class; Periodontal Diseases

Keywords

Clear Aligner Therapy; Periodontal Disease; Interproximal Enamel Reduction

Outcome Measures

Primary Outcomes (1)

• Accuracy of interproximal enamel reduction (IPR) (planned vs performed, mm)

  Planned IPR (mm) will be extracted from the participant's initial digital treatment plan (ClinCheck) for the contacts scheduled for IPR at the study visit. Performed IPR (mm) will be quantified using intraoral scans obtained immediately before and immediately after IPR. STL files will be analyzed in OrthoCAD to measure the mesiodistal tooth widths of incisors, canines, and premolars receiving IPR. The amount of performed IPR will be calculated as the difference in the summed mesiodistal widths of the included teeth before vs after IPR (pre-IPR minus post-IPR). IPR accuracy will be calculated per participant as the discrepancy between planned and performed IPR (mm) and compared across the three groups.

  Baseline (pre-IPR intraoral scan) to immediately after IPR (post-IPR intraoral scan), same visit

Secondary Outcomes (2)

• Changes in plaque Index

  Baseline (pre-IPR) to 6 weeks after IPR.

• Changes in gingival bleeding index

  Baseline (pre-IPR) to 6 weeks after IPR.

Study Arms (3)

Manual arm

EXPERIMENTAL

Interproximal enamel reduction will be performed at the prescribed contacts using manual abrasive strips (6 mm separating abrasive strips, coarse; Ortho Organizers, Inc., Carlsbad, USA). (n = 25)

Procedure: Manual Arm

Motor-driven arm

EXPERIMENTAL

Interproximal enamel reduction will be performed at the prescribed contacts using motor-driven oscillating strips (OK Strips Kit with JAINTEK EVA handpiece operated at \< 15,000 rpm; JAINTEK Co., Ltd., Guri-si, Republic of Korea). (n = 25).

Procedure: Motor Driven Arm

Abrasive arm

EXPERIMENTAL

Interproximal enamel reduction will be performed at the prescribed contacts using abrasive discs (OK DIA DISC, double-sided, thickness 0.15 mm; JAINTEK Co., Ltd., Guri-si, Republic of Korea). (n = 25).

Procedure: Abrasive Arm

Interventions

Manual Arm PROCEDURE

Interproximal enamel reduction (IPR) will be performed at the contacts prescribed in the participant's digital treatment plan using manual abrasive strips (6 mm separating abrasive strips, coarse; Ortho Organizers, Inc., Carlsbad, USA). IPR will be performed by the same trained and calibrated operator, and interproximal clearance will be verified using metal interproximal gauges

Manual arm

Motor Driven Arm PROCEDURE

Interproximal enamel reduction will be performed at the prescribed contacts using motor-driven oscillating strips (OK Strips Kit with JAINTEK EVA handpiece operated at \< 15,000 rpm; JAINTEK Co., Ltd., Guri-si, Republic of Korea). IPR will be performed by the same trained and calibrated operator and interproximal clearance will be verified using metal interproximal gauges. (n = 25)

Motor-driven arm

Abrasive Arm PROCEDURE

Interproximal enamel reduction will be performed at the prescribed contacts using abrasive discs (OK DIA DISC, double-sided, thickness 0.15 mm; JAINTEK Co., Ltd., Guri-si, Republic of Korea). IPR will be performed by the same trained and calibrated operator and interproximal clearance will be verified using metal interproximal gauges. (n = 25)

Abrasive arm

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18 years or older with full permanent dentition.
• Undergoing clear aligner therapy (Invisalign) with a ClinCheck treatment plan that includes interproximal enamel reduction (IPR).
• Periodontally healthy at baseline (per clinic screening).

You may not qualify if:

• Orthodontic treatment plan including extractions.
• Proximal restorations or caries on any tooth surface targeted for IPR.
• Current smoking.
• Diabetes mellitus or other systemic diseases known to affect periodontal status.

Sponsors & Collaborators

• Riyadh Elm University: lead

Study Sites (1)

Riyadh Elm University

Riyadh, Riyadh Region, 12734, Saudi Arabia

Location

Related Publications (8)

• Shalchi M, Abdollahi N, Shafiei Haghshenas E, Khabbaz S, Olyaee P. Effect of Interdental Enamel Reduction on Clinical Attachment Loss, Bleeding on Probing, and Incidence of Caries in Treating Class I Malocclusion Cases: A Retrospective Cohort Study. Cureus. 2023 Feb 15;15(2):e35018. doi: 10.7759/cureus.35018. eCollection 2023 Feb.

  PMID: 36938231 BACKGROUND

• Gulec Ergun P, Arman Ozcirpici A, Atakan Kocabalkan A, Tuncer NI. Evaluation of the Consistency of Two Interproximal Reduction Methods in Clear Aligner Therapy: A Preliminary Study. Turk J Orthod. 2024 Mar 28;37(1):1-6. doi: 10.4274/TurkJOrthod.2023.2022.158.

  PMID: 38556946 BACKGROUND

• Gulec-Ergun P, Arman-Ozcirpici A, Atakan-Kocabalkan A, Tuncer NI. Comparison of the accuracy of three interproximal reduction methods used in clear aligner treatment. Clin Oral Investig. 2024 Jan 15;28(1):95. doi: 10.1007/s00784-024-05499-4.

  PMID: 38221544 BACKGROUND

• Kalemaj Z, Levrini L. Quantitative evaluation of implemented interproximal enamel reduction during aligner therapy. Angle Orthod. 2021 Jan 1;91(1):61-66. doi: 10.2319/040920-272.1.

  PMID: 33339043 BACKGROUND

• Fiori A, Minervini G, Nucci L, d'Apuzzo F, Perillo L, Grassia V. Predictability of crowding resolution in clear aligner treatment. Prog Orthod. 2022 Nov 28;23(1):43. doi: 10.1186/s40510-022-00438-z.

  PMID: 36437397 BACKGROUND

• Lagana G, Malara A, Lione R, Danesi C, Meuli S, Cozza P. Enamel interproximal reduction during treatment with clear aligners: digital planning versus OrthoCAD analysis. BMC Oral Health. 2021 Apr 19;21(1):199. doi: 10.1186/s12903-021-01487-2.

  PMID: 33874922 BACKGROUND

• Hariharan A, Arqub SA, Gandhi V, Da Cunha Godoy L, Kuo CL, Uribe F. Evaluation of interproximal reduction in individual teeth, and full arch assessment in clear aligner therapy: digital planning versus 3D model analysis after reduction. Prog Orthod. 2022 Mar 7;23(1):9. doi: 10.1186/s40510-022-00403-w.

  PMID: 35254555 BACKGROUND

• De Felice ME, Nucci L, Fiori A, Flores-Mir C, Perillo L, Grassia V. Accuracy of interproximal enamel reduction during clear aligner treatment. Prog Orthod. 2020 Jul 28;21(1):28. doi: 10.1186/s40510-020-00329-1.

  PMID: 32719906 BACKGROUND

MeSH Terms

Conditions

Crowding; Malocclusion; Periodontal Diseases

Condition Hierarchy (Ancestors)

Spatial Behavior; Behavior; Tooth Diseases; Stomatognathic Diseases; Mouth Diseases

Study Officials

• omar alkadhi

  Riyadh Elm University

  PRINCIPAL INVESTIGATOR

• Abdulwahab Ahmed Alamri

  Riyadh Elm University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

abdulwahab alamri

CONTACT

+966533363689; abdulwahab.alamri2024@student.riyadh.edu.sa

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor of Orthodontics

Model Details: Three-arm, parallel-group, superiority randomized controlled trial. Participants undergoing clear aligner therapy with IPR prescribed will be randomized 1:1:1 to manual arm, motor-driven arm, or abrasive arm. IPR accuracy will be assessed using intraoral scans before and immediately after IPR; periodontal indices will be assessed at baseline and 6-week follow-up

Study Record Dates

• First Submitted: January 22, 2026
• First Posted: January 30, 2026
• Study Start: March 1, 2026
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): November 1, 2026
• Last Updated: January 30, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

SA (1)