Clear Aligner Cleaning: Brushing, Chlorhexidine, and BlueM Effects on Oral Microbial Ecology and Periodontal Indices

Official title

Investigating the Impact of Cleaning Protocols on Oral Microbial Ecology and Early Dysbiosis Markers on Orthodontic Clear Aligner Patients: A Randomized Cross-over Clinical Study

Overview

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.

Interventions

• Behavioral 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.
• Drug 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.
• Other 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.

Primary outcome measures

• Fusobacterium nucleatum CFU in supragingival plaque at the gingival margin (index teeth) [Time frame: Baseline and end of each 1-month period (end of Period 1, Period 2, Period 3); 1-week washouts between periods.]
• Fusobacterium nucleatum CFU on retrieved aligner inner-surface biofilm [Time frame: Baseline and end of each 1-month period (end of Period 1, Period 2, Period 3); 1-week washouts between periods.]

Secondary outcome measures (6)

• Prevotella intermedia CFU on retrieved aligner inner-surface biofilm [Time frame: Baseline and end of each 1-month period (end of Period 1, Period 2, Period 3); 1-week washouts between periods.]
• Prevotella intermedia CFU in supragingival plaque at the gingival margin (index teeth) [Time frame: Baseline and end of each 1-month period (end of Period 1, Period 2, Period 3); 1-week washouts between periods.]
• MMP-8 concentration/activity in matrix-paired plaque and aligner extracts [Time frame: Baseline and end of each 1-month period (end of Period 1, Period 2, Period 3); 1-week washouts between periods.]
• Plaque Index (PI) at index teeth [Time frame: Baseline and end of each 1-month period (end of Period 1, Period 2, Period 3).]
• Gingival Index (GI) at index teeth [Time frame: Baseline and end of each 1-month period (end of Period 1, Period 2, Period 3).]
• Bleeding on Probing (BoP) at index teeth [Time frame: Baseline and end of each 1-month period (end of Period 1, Period 2, Period 3).]

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.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Crossover

Masking

Single blind

Primary purpose

Prevention

Study locations

Saudi Arabia · 1 center

• Riyadh Elm University - Orthodontic Clinics — Riyadh

Publications

• 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. PMID 26746720
• 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. PMID 31418980
• 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

Identifiers

NCT: NCT07307716 · REU-ORTHO-ECOALIGN-XO-01

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗