Endocrine Disrupting Monomer Release in Clear Aligner Systems and Fixed Orthodontic Treatment: a Randomized Controlled Clinical Study

Ahmet Yağcı

Status: Active, not recruiting

Conditions: Endocrine Disruptors

Treatments: Device: Fixed Orthodontic Appliance Treatment; Device: Clear aligner treatment

Study type: Interventional

Funder types: Other

Identifiers

NCT06685029

TDH-2024-13280

Details and patient eligibility

About

The aim of this study is to evaluate the release of endocrine disrupting monomers from clear aligners as a result of exposure to intraoral factors by measuring their concentration in saliva and to evaluate their reliability of use in terms of general health by comparing them with the fixed orthodontic treatment group. It is also aimed to compare the groups in terms of total treatment duration, treatment effectiveness and white spot lesion formation.

Full description

The aim of our study is to evaluate the saliva concentration of endocrine-disrupting monomers released from attachments used and clear aligners produced directly by the orthodontist in the clinic and indirectly produced by companies. Accordingly comparing them with the fixed orthodontic treatment group and assessing clear aligner's safety for general health. It is also aimed to compare the groups in terms of treatment time spent, treatment effectiveness and white spot lesion formation. Endocrine-disrupting chemicals are substances that interfere with the synthesis, metabolism, or effects of hormones, causing deviation from normal reproduction and homeostatic control in organisms. Bisphenol A (BPA), a monomer, is also included in the chemicals listed as endocrine disruptors by the World Health Organization. Different studies have suggested that Bisphenol A may cause adverse health effects by acting as an endocrine disruptor. While previous research has been conducted on BPA release or monomer leakage related to orthodontic materials, there is limited evidence regarding the safety aspects of thermoplastic aligners or retainers. The concentrations of endocrine-disrupting monomers in the saliva of patients undergoing treatment with directly produced aligners by orthodontists and indirectly produced aligners by companies will be examined in comparison to patients undergoing fixed orthodontic treatment. Patients will not receive any treatment other than routine orthodontic care.

Enrollment: 52 patients

Sex: All

Ages: 15 to 24 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Absence of primary teeth in the oral cavity, with permanent teeth fully erupted,
• Presence of a non-extraction orthodontic treatment plan,
• Age range of 15 to 24 years,
• Presence of mild to moderate dental crowding (0-6 mm of crowding),
• Classification as skeletal Class I (ANB: 2±2°),
• Absence of any craniofacial anomalies,
• Normal vertical growth pattern (Sn-GoGn: 32±6°),
• No congenital tooth agenesis (excluding third molars),
• Absence of atypical tooth morphology,
• No extracted permanent teeth,
• Absence of dental caries,
• Good level of oral hygiene,
• Healthy periodontal tissues.

Exclusion criteria

• Presence of any systemic disease,
• History of previous fixed orthodontic treatment,
• History of allergy to any dental material,
• Use of medications containing estrogen analogs,
• Patients with a history of xerostomia and a salivary flow rate of less than 0.1 ml per minute,
• Patients with more than five composite restorations.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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52 participants in 4 patient groups

Dİrect In-House Aligner Group

Experimental group

Description:

Patients in this group are treated with clear aligners produced directly by the clinician. The physical model production step is eliminated with direct production technique.Intraoral scan images were obtained from these patients with the 3Shape TRIOS (3Shape, Copenhagen, Denmark) scanning device. Then, the 3D scan images were transferred to the Maestro 3D Dental Studio (New Age, Pisa, Italy) computer software. Using these scan images, the teeth were gradually moved according to the planned final treatment result. The number of transparent plates required is calculated by the program according to the total amount of planned tooth movement. Then, Tera Harz TC-85DAC (Graphy, Seoul, Korea) resin and Asiga MAX UV (Asiga, Sydney, Australia) 3D printer were used for the direct production of the plates designed in the program. The aligners produced were then delivered to the patients.

Treatment:

Device: Clear aligner treatment

Invisalign Group

Experimental group

Description:

Intraoral scan images were obtained with the 3Shape TRIOS (3Shape, Copenhagen, Denmark) scanning device from patients who would receive Invisalign (Align Technology, Santa Clara, CA) clear aligners. These 3D intraoral scan images, together with the intraoral and extraoral photographs, radiographic records, and clinical examination findings obtained from the patients, were uploaded to the cloud software 'ClinCheck' for Invisalign . Necessary instructions were written regarding the patients' treatment plans. Afterwards, patient specific 3D treatment simulations sent to the clinician by the companies were reviewed and the necessary revisions were made. The final accepted treatment plan was approved and the aligners were produced by the relevant companies and sent to our clinic.The clear aligners produced are delivered to the patients and treatment started.

Treatment:

Device: Clear aligner treatment

ClearCorrect Group

Experimental group

Description:

Intraoral scan images were obtained with the 3Shape TRIOS (3Shape, Copenhagen, Denmark) scanning device from patients who would receive Invisalign (Align Technology, Santa Clara, CA) and ClearCorrect (ClearCorrect®, Round Rock, TX, USA) clear aligners. These 3D intraoral scan images, together with the intraoral and extraoral photographs, radiographic records, and clinical examination findings obtained from the patients, were uploaded to the cloud software 'ClinCheck' for Invisalign . Necessary instructions were written regarding the patients' treatment plans. Afterwards, patient specific 3D treatment simulations sent to the clinician by the companies were reviewed and the necessary revisions were made. The final accepted treatment plan was approved and the aligners were produced by the relevant companies and sent to our clinic.The clear aligners produced are delivered to the patients and treatment started.

Treatment:

Device: Clear aligner treatment

Fixed Orthodontic Treatment Group

Experimental group

Description:

In the fixed orthodontic treatment group, all tooth surfaces to which brackets would be bonded were etched with 37% phosphoric acid (dline Phosphoric Acid Etching Gel UAB, Medicinos linij Karaliauciaus str. 29 LT-78348 Siauliai Lithuania) for 30 seconds, then bond (3M Unitek Transbond XT, Minnesota, U.S.A.) was applied and light was applied to all teeth separately for 5 seconds with a light device (Valo Cordless curing light Ultradent Products, Inc. 505 W. Ultradent Drive (10200 South) South Jordan, UT 84095) \[165, 166\]. Afterwards, composite (3M Unitek Transbond XT, Minnesota, U.S.A.) was applied to the base of the metal brackets (AO Mini Master Roth 018, Altenhofstrasse 80, 66386 St. Ingbert, Germany) and after it was placed on the tooth surface and the composite residues around the bracket were cleaned, light was applied for 5 seconds for each bracket. Then, arch wires were applied and the fixed orthodontic treatment of the patients was started.

Treatment:

Device: Fixed Orthodontic Appliance Treatment