Labial White Spot Lesions and Proximal Caries Development in Orthodontic Patients Using Clear Aligners Versus Traditional Braces.

Incidence of White Spot Lesions and Proximal Caries During Orthodontic Treatment With Fixed Pre-adjusted Edgewise Appliances Versus Clear Aligners: A Pilot Randomized Clinical Trial

This randomized clinical trial evaluates the risk of developing early tooth decay in patients undergoing orthodontic treatment with either traditional fixed braces or clear aligners. Because orthodontic appliances can trap plaque and make tooth cleaning difficult, patients are at a higher risk for developing early decay, such as chalky "white spot lesions" on the visible surfaces of the teeth and hidden decay between the teeth (proximal caries).

In this six-month study, 24 participants are randomly assigned to receive either fixed braces or clear aligners. Researchers will monitor the participants' oral health prior to treatment, at 3 months, and at 6 months. To safely and accurately detect decay, the study uses standard visual examinations for the front of the teeth and a radiation-free optical scanner (Near-Infrared Imaging, or NIRI) to detect hidden cavities between the teeth.

The primary goal of this study is to compare how many new white spot lesions and hidden cavities between teeth develop in each group over the six-month observation period. Additionally, the study tracks how these early lesions behave over time, monitors changes in the patients' daily oral hygiene, and records how often patients in each group require professional dental cleaning procedures. Ultimately, this study aims to help patients and dental professionals make better-informed decisions regarding the specific cavity risks associated with each type of orthodontic appliance.

Study Overview

• Status: Completed
• Conditions: White Spot Lesions; Proximal Caries; Plaque Removal; Oral Hygiene in Orthodontic Patients
• Intervention / Treatment: Device: Fixed pre-adjusted edgewise orthodontic appliance; Device: Clear aligner therapy

Detailed Description

Background and Purpose While orthodontic treatments like traditional braces and clear aligners successfully straighten teeth, they introduce a significant challenge: they make it harder to keep teeth clean. Orthodontic appliances create new areas for dental plaque and bacteria to hide, which can rapidly lead to early tooth decay. This decay typically takes two forms: white spot lesions (WSLs), which are chalky, white marks that form on the visible front surfaces of the teeth, and proximal caries, which is hidden decay that develops in the tight spaces between adjacent teeth.

Historically, it was assumed that clear aligners were a "safer" alternative to braces regarding tooth decay because they can be removed for brushing and flossing. However, clear aligners cover the teeth for 22 hours a day, preventing natural saliva from washing away food and neutralizing acids. Because of this, the actual risk of developing both visible and hidden decay associated with the two treatments required rigorous investigation.

The primary purpose of this 6-month randomized clinical trial was to directly compare the risk, incidence, and behavior of early tooth decay in patients treated with conventional fixed braces versus those treated with clear aligners.

Study Design and Participants

This study was designed as a prospective, randomized clinical trial. A total of 24 eligible adult and adolescent participants who required orthodontic treatment were randomly assigned to one of two groups:

• Group 1: Fixed Appliances (traditional brackets and wires).
• Group 2: Clear Aligners (removable transparent trays). What Did the Researchers Measure?

To gain a complete picture of the patients' oral health, the research team tracked three major outcomes:

1. Visible Decay (White Spot Lesions) and Lesion Behavior: Researchers visually examined the front surfaces of the teeth to detect new white spot lesions. Uniquely, the study did not just count the lesions at the end of treatment; it tracked their dynamic behavior. By evaluating the teeth at 3 months and 6 months, researchers could see exactly when a lesion formed and whether it worsened, stabilized, or healed (remineralized) over time.
2. Hidden Decay (Proximal Caries) Using Advanced Optical Scanning: Detecting decay between the teeth usually requires X-rays, which expose patients to radiation and often miss the earliest stages of disease. To avoid unnecessary radiation and catch decay at its earliest optical phase, this study utilized Near-Infrared Imaging (NIRI). This cutting-edge, radiation-free scanner shines a safe, near-infrared light through the teeth (specifically focusing on the premolar teeth) to make hidden, early-stage decay glow brilliantly white on a digital screen.
3. Oral Hygiene Burden and Professional Cleaning Procedures: The study tracked how difficult it was for patients to maintain their oral hygiene. Instead of just asking patients how well they brushed, the researchers objectively measured the "hygiene burden" by recording how often patients in each group required Professional Mechanical Plaque Removal (PMPR)-or professional dental cleaning-during their routine orthodontic visits.

Study Timeline

• Baseline (Start of Treatment): Patients received a thorough clinical examination, an assessment of their past cavity history, and a baseline NIRI optical scan to ensure no hidden decay was present before the appliances were placed.
• 3-Month Check: A visual examination was conducted specifically to catch the rapid, early onset of visible white spot lesions as patients adapted to their new appliances.
• 6-Month Check: A full examination was conducted, including a visual check for white spot lesions and a second NIRI optical scan to detect any new hidden decay that formed between the teeth over the first six months of treatment.

Why This Study Matters This study provides highly valuable, real-world evidence for both patients and healthcare providers. By demonstrating that neither appliance is completely cavity-free, it helps orthodontists provide highly accurate, evidence-based informed consent to their patients. It reveals that while clear aligners may protect the front of the teeth better and require fewer professional cleaning procedures, they still carry a significant risk for hidden decay between the teeth. Ultimately, this study emphasizes that regardless of the appliance chosen, highly personalized, strict oral hygiene routines are mandatory to protect the teeth during orthodontic treatment.

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Arab Emirates
  • Sharjah city, United Arab Emirates
    • University of Sharjah

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Demographics: Patients aged 13-45 years, possessing fully erupted permanent dentition (excluding third molars).
• Malocclusion Severity: Skeletal class I according to an ANB angle of 2-4 degrees (Steiner, 1953), moderate lower malalignment of 4-9 mm based on Little's Irregularity Index, and a class I incisor relationship (British Standards Institute, 1983).
• Treatment Protocol: Comprehensive, dual-arch orthodontic treatment strictly on a non-extraction basis.
• Handover form from their referring dentist confirming absence of caries requiring restorations and that all indicated restorative therapies have been completed, in addition to no active periodontal disease or pathologic probing depths.
• No prior history of orthodontic treatment.
• No full coverage restorations (crowns/veneers) on anterior teeth or premolars.

Exclusion Criteria:

• Inability to maintain adequate oral hygiene prior to treatment initiation.
• Dental Anomalies and Missing Teeth: Congenitally missing teeth, presence of dental implants, or impacted teeth (excluding third molars).
• Structural Enamel Defects: Presence of developmental enamel defects that mimic or obscure demineralization, including enamel hypoplasia, fluorosis, or amelogenesis imperfecta.
• Fluoride Supplementation: Patients currently utilizing a prescribed, daily supplemental fluoride regimen beyond standard over-the-counter fluoridated toothpaste.
• Adjunctive Appliances: Treatment plans requiring the use of plaque-retentive adjunct intraoral appliances (e.g., expanders, distalizers).
• Contraindications to Therapy: Any existing biological contraindications to comprehensive orthodontic tooth movement (e.g., advanced root resorption).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Fixed labial braces group; Participants in this group will be treated with pre-adjusted fixed orthodontic appliances.	Device: Fixed pre-adjusted edgewise orthodontic appliance; Participants in this group will be treated with pre-adjusted fixed orthodontic appliances (Master Series®, American Orthodontics™, WI, USA). This system includes fixed brackets bonded on the labial surface of teeth and a sequence of progressively larger arch wires aimed at achieving alignment over time.; Other Names: Fixed orthodontic appliance; Fixed labial braces; Conventional braces; Edgewise appliance; Straight-wire Appliance; Fixed appliance; Fixed multibracket appliance; Fixed straight-wire technique; Pre-adjusted edgewise bracket system; Fixed braces; Pre-adjusted appliance; Fixed orthodontic braces
Active Comparator: Clear aligner group; Participants in this group will receive clear aligners customized based on a digital model of each patient's dentition.	Device: Clear aligner therapy; Participants in this group will receive clear aligners (Eon Aligner, Minneapolis, USA), designed and customized based on a digital model of each patient's dental structure. Aligners will be worn for at least 22 hours daily, and patients will change to a new aligner depending on treatment progress.; Other Names: Clear aligners; Clear aligner therapy (CAT); Eon aligner

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of White Spot Lesions	The development of new (incident) white spot lesions on the labial surfaces of teeth during orthodontic treatment. Lesions are detected and classified using the visual International Caries Detection and Assessment System (ICDAS).	Up to 6 months (assessed 1 week before treatment at baseline, then 3 months and 6 months into treatment)
Incidence of Proximal Caries	The development of new caries lesions on the interproximal surfaces of teeth (specifically premolars). Detection is performed non-invasively using Near-Infrared Imaging (NIRI) technology via an intraoral scanner.	Baseline (1 week before treatment) and 6 months into treatment.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Behavior of Early Incident and Pre-existing White Spot Lesions	The dynamic changes (progression, regression, or stability) of white spot lesions over time. This tracks both lesions that were present prior to treatment and early incident lesions that formed within the first 3 months, evaluated using changes in their ICDAS codes.	Assessed at 3 months and 6 months.
Change in Oral Hygiene Status	The changes in the participants' oral hygiene maintenance, evaluated clinically using a visual scale adapted from published literature.	Baseline and 6 months.
Frequency of Professional Mechanical Plaque Removal (PMPR)	The cumulative frequency of reactive professional mechanical plaque removal (PMPR) required by participants due to inadequate at-home plaque control. This data is extracted from the institutional electronic health records.	Up to 6 months.

Collaborators and Investigators

• Sponsor: University of Sharjah

Study record dates

Study Major Dates

• Study Start (Actual): January 8, 2024
• Primary Completion (Actual): November 27, 2025
• Study Completion (Actual): November 27, 2025

Study Registration Dates

• First Submitted: April 17, 2026
• First Submitted That Met QC Criteria: April 17, 2026
• First Posted (Actual): April 24, 2026

Study Record Updates

• Last Update Posted (Actual): April 30, 2026
• Last Update Submitted That Met QC Criteria: April 24, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Near-infrared imaging; White spot lesions; Fixed orthodontic appliances; Intraoral scanner; Proximal caries; Clear aligners; Caries risk assessment; Enamel demineralization; Professional mechanical plaque removal; Past caries experience
• Additional Relevant MeSH Terms: Dentistry; Orthodontic Appliances; Orthodontics; Orthodontic Appliances, Fixed
• Other Study ID Numbers: UoS-WSLPC-2024

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All IPD collected throughout the trial
• IPD Sharing Time Frame: IPD will be available once the trial is finalized up to 3 years post recruitment.
• IPD Sharing Access Criteria: Principal investigator and researchers will have access to all IPD collected throughout the trial once it has been depersonalized.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No