Randomized Crossover Study in Adults Using Clear Aligners: Effects of Brushing, Chlorhexidine Mouthwash, and an Oxygen-Based Cleanser on Oral Microbial Ecology and Periodontal Indices

NCT ID: NCT07307716

Last Updated: 2025-12-29

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 21 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-12-31
• Study Completion Date: 2026-05-31

Brief Summary

This randomized crossover study will assess how three aligner-cleaning methods affect early supragingival oral microbial ecology and periodontal health in adults using clear aligners. Each participant will complete three (1-month) periods in a randomized sequence with (1-week) washouts between periods:

1. Mechanical toothbrushing with fluoride toothpaste (control),

2. Chlorhexidine (CHX) mouthwash, and

3. an oxygen-based cleanser (BlueM).

Primary ecological outcomes focus on early dysbiosis indicators Fusobacterium nucleatum and Prevotella intermedia measured on retrieved aligner inner-surface biofilm and on supragingival plaque at the gingival margin. Secondary outcomes include periodontal indices (plaque index, gingival index, bleeding on probing) at index teeth and the host inflammatory marker MMP-8 in matrix-paired extracts (plaque and aligner).

Study visits occur at baseline and at the end of each 1-month period. Supragingival plaque is collected from the upper and lower first molars and central incisors; used aligners are swabbed immediately after removal. Participants are instructed to wear aligners about 22 hours/day, change trays every 10 days, remove aligners for meals and oral hygiene, and drink only water while aligners are in.

Laboratory procedures include blinded culture enumeration under coded labels (performed by a single trained operator, FA), confocal laser scanning microscopy, and RNA isolation with species-specific qRT-PCR; microscopy is conducted unblinded after decoding. The study will determine whether chlorhexidine or an oxygen-based cleanser produces more favorable early ecological changes and periodontal outcomes than mechanical brushing alone in clear aligner therapy.

Conditions

Gingivitis; Dental Plaque

Keywords

Clear aligners; Chlorhexidine; BlueM; Oxygen-based cleanser; Mechanical toothbrushing; Supragingival plaque; Aligner biofilm; Fusobacterium nucleatum; Prevotella intermedia; MMP-8; Plaque index; Gingival index; Bleeding on probing; Randomized crossover

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: PREVENTION
• Blinding Strategy: SINGLE

Study Groups

Sequence ABC (Randomized)

Participant completes three 1-month periods in order (A to B to C), each separated by a 1-week washout. A = Mechanical toothbrushing with fluoride toothpaste (control); B = Chlorhexidine (CHX) mouthwash; C = Oxygen-based cleanser (BlueM). Trays are changed every 10 days; aligners are worn 22 h/day; water-only while aligners are in.

Group Type: EXPERIMENTAL

Mechanical toothbrushing (fluoride toothpaste)

Intervention Type: BEHAVIORAL

Control oral-hygiene period using mechanical toothbrushing with a fluoride-containing toothpaste, per standardized study instructions, for the assigned 1-month period. No chlorhexidine or oxygen-based cleanser is used during this period; aligners are removed for oral-hygiene procedures per protocol.

Chlorhexidine mouthwash (0.2%)

Intervention Type: DRUG

Chlorhexidine mouthwash used per standardized study instructions for the assigned 1-month period. No oxygen-based cleanser is used during this period; aligners are removed for mouthrinse use and oral-hygiene procedures per protocol. A 1-week washout without cleaning products separates periods.

Oxygen-based cleanser

Intervention Type: OTHER

Oxygen-based cleanser (BlueM) used per standardized study instructions for the assigned 1-month period. No chlorhexidine is used during this period; aligners are removed for product use and oral-hygiene procedures per protocol. A 1-week washout without cleaning products separates periods.

Sequence BCA (Randomized)

Participant completes three 1-month periods in order (B to C to A), each separated by a 1-week washout. A = Mechanical toothbrushing with fluoride toothpaste (control); B = CHX mouthwash; C = Oxygen-based cleanser (BlueM). Trays are changed every 10 days; aligners are worn 22 h/day; water-only while aligners are in.

Group Type: EXPERIMENTAL

Mechanical toothbrushing (fluoride toothpaste)

Intervention Type: BEHAVIORAL

Control oral-hygiene period using mechanical toothbrushing with a fluoride-containing toothpaste, per standardized study instructions, for the assigned 1-month period. No chlorhexidine or oxygen-based cleanser is used during this period; aligners are removed for oral-hygiene procedures per protocol.

Chlorhexidine mouthwash (0.2%)

Intervention Type: DRUG

Chlorhexidine mouthwash used per standardized study instructions for the assigned 1-month period. No oxygen-based cleanser is used during this period; aligners are removed for mouthrinse use and oral-hygiene procedures per protocol. A 1-week washout without cleaning products separates periods.

Oxygen-based cleanser

Intervention Type: OTHER

Oxygen-based cleanser (BlueM) used per standardized study instructions for the assigned 1-month period. No chlorhexidine is used during this period; aligners are removed for product use and oral-hygiene procedures per protocol. A 1-week washout without cleaning products separates periods.

Sequence CAB (Randomized)

Participant completes three 1-month periods in order (C to A to B), each separated by a 1-week washout. A = Mechanical toothbrushing with fluoride toothpaste (control); B = CHX mouthwash; C = Oxygen-based cleanser (BlueM). Trays are changed every 10 days; aligners are worn 22 h/day; water-only while aligners are in.

Group Type: EXPERIMENTAL

Mechanical toothbrushing (fluoride toothpaste)

Intervention Type: BEHAVIORAL

Control oral-hygiene period using mechanical toothbrushing with a fluoride-containing toothpaste, per standardized study instructions, for the assigned 1-month period. No chlorhexidine or oxygen-based cleanser is used during this period; aligners are removed for oral-hygiene procedures per protocol.

Chlorhexidine mouthwash (0.2%)

Intervention Type: DRUG

Chlorhexidine mouthwash used per standardized study instructions for the assigned 1-month period. No oxygen-based cleanser is used during this period; aligners are removed for mouthrinse use and oral-hygiene procedures per protocol. A 1-week washout without cleaning products separates periods.

Oxygen-based cleanser

Intervention Type: OTHER

Oxygen-based cleanser (BlueM) used per standardized study instructions for the assigned 1-month period. No chlorhexidine is used during this period; aligners are removed for product use and oral-hygiene procedures per protocol. A 1-week washout without cleaning products separates periods.

Interventions

Mechanical toothbrushing (fluoride toothpaste)

Control oral-hygiene period using mechanical toothbrushing with a fluoride-containing toothpaste, per standardized study instructions, for the assigned 1-month period. No chlorhexidine or oxygen-based cleanser is used during this period; aligners are removed for oral-hygiene procedures per protocol.

Intervention Type: BEHAVIORAL

Chlorhexidine mouthwash (0.2%)

Chlorhexidine mouthwash used per standardized study instructions for the assigned 1-month period. No oxygen-based cleanser is used during this period; aligners are removed for mouthrinse use and oral-hygiene procedures per protocol. A 1-week washout without cleaning products separates periods.

Intervention Type: DRUG

Oxygen-based cleanser

Oxygen-based cleanser (BlueM) used per standardized study instructions for the assigned 1-month period. No chlorhexidine is used during this period; aligners are removed for product use and oral-hygiene procedures per protocol. A 1-week washout without cleaning products separates periods.

Intervention Type: OTHER

Other Intervention Names

Colgate Total; CHX; BlueM

Eligibility Criteria

Inclusion Criteria

• Adults (≥18 years).
• Undergoing or scheduled for treatment with clear aligners (CA).
• Presence of upper and lower first molars and central incisors.
• Periodontal health at baseline (no sites with PD ≥ 4 mm; no clinical attachment loss at index teeth; BI/PI within normal limits).
• No periodontal therapy within the previous 6 months.
• Able and willing to comply with study instructions and follow-up visits; signed informed consent.
• Sufficient remaining CA treatment (clinician-estimated): ≥ 14 weeks to safely cover three 1 month protocol periods plus washouts.

Minimum planned aligners remaining: ≥ 11 aligners (assuming 10 days/aligner) or equivalent continuous CA duration per treating orthodontist.

Exclusion Criteria

• Patients requiring orthognathic surgery
• Uncontrolled systemic diseases (e.g., uncontrolled diabetes mellitus, autoimmune disease).
• Pregnancy or lactation.
• Use of systemic antibiotics and/or anti-inflammatory drugs within the last 3 months.
• Periodontal therapy within the last 6 months.
• Current tobacco use (smoking/smokeless) or vaping.
• Limited/express CA plans (e.g., ≤ 11 aligners or expected completion < 14 weeks).

Anticipated early completion of CA or major treatment changes (e.g., switch to fixed appliances) within the next ~4 months.

• Extensive caries, defective restorations, or prostheses affecting index teeth/sites.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Riyadh Elm University

OTHER

Sponsor Role: lead

Responsible Party

Faisal Ali Althobaiti

Resident, Orthodontics

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Dr. Faisal A Althobaiti, BDS

Role: PRINCIPAL_INVESTIGATOR

Riyadh Elm University

Dr. Nancy M Ajwa, MSc

Role: STUDY_DIRECTOR

Riyadh Elm University

Locations

Riyadh Elm University - Orthodontic Clinics

Riyadh, , Saudi Arabia

Countries

Saudi Arabia

Central Contacts

Faisal A Althobaiti, BDS

Role: CONTACT

Phone: +966594496974

Email: faisal.althobaiti2024@student.riyadh.edu.sa

Nancy M Ajwa, MSc

Role: CONTACT

Phone: +966554804564

Email: nancy.ajwa@riyadh.edu.sa

Facility Contacts

Faisal A Althoabiti, BDS

Role: primary

Nancy M Ajwa, MSc

Role: backup

References

Heller D, Helmerhorst EJ, Gower AC, Siqueira WL, Paster BJ, Oppenheim FG. Microbial Diversity in the Early In Vivo-Formed Dental Biofilm. Appl Environ Microbiol. 2016 Jan 8;82(6):1881-8. doi: 10.1128/AEM.03984-15.

Reference Type: BACKGROUND

PMID: 26746720 (View on PubMed)

Zhao R, Huang R, Long H, Li Y, Gao M, Lai W. The dynamics of the oral microbiome and oral health among patients receiving clear aligner orthodontic treatment. Oral Dis. 2020 Mar;26(2):473-483. doi: 10.1111/odi.13175. Epub 2020 Jan 8.

Reference Type: BACKGROUND

PMID: 31418980 (View on PubMed)

Miguel YD, Alcântara PR, Toyofuku ACMM, Shimizu RH. Periodontal monitoring in orthodontic treatment with orthodontic aligners: proof of concept. Rev Odontol UNESP. 2024;53:e20240016. doi:10.1590/1807-2577.01624

Reference Type: BACKGROUND

Other Identifiers

REU-ORTHO-ECOALIGN-XO-01

Identifier Type: -

Identifier Source: org_study_id