Quick facts
- A clear aligner is a removable, tooth-coloured tray worn to move teeth through a planned series of stages; the staging is what makes it a sequential aligner.
- In the United States it files under 21 CFR 872.5470, Orthodontic plastic bracket, at Class II, product code NXC (Aligner, Sequential).
- In Canada it is an orthodontic appliance; Rule 3(a) of Schedule 1 places all denture materials and orthodontic appliances, and their accessories, at Class II.
- Rule 3 applies despite Rules 1 and 2, so the class does not change with the material of the tray or whether the appliance is fixed or removable.
- The aligner, its attachments and its retainers travel together as a system; the digital plan that stages the trays is described with the appliance it controls.
- Entries, classes and product codes below were checked against the eCFR, the Regulations and the openFDA classification database on 2026-10-13.
A clear aligner is a removable tray, moulded to a tooth-coloured plastic, that is worn over the teeth to move them a small amount before the next tray in a planned series is worn. The staging — the ordered set of trays that carries a case from its starting position to its finish — is what makes the appliance a sequential aligner rather than a single retainer. In the United States it sits in a named regulation number at Class II; in Canada it reaches the same class through the rule that places all orthodontic appliances there. This article sets out both routes and what the class means for the trays and accessories an orthodontic practice orders, with the dental bibs that cover the patient at the same chair.
What is a clear aligner?
It is a removable appliance made from a clear polymer sheet that has been formed over a model of the teeth. Each tray moves the teeth a fraction of the planned distance and is worn for a set period before the next tray is substituted. The full series, planned in advance and often modelled digitally, is the treatment. The trays are worn over the crowns and removed for eating and cleaning, so they are not fixed to the teeth and do not use brackets or wires.
That is what separates a sequential aligner from the other orthodontic appliances a practice already stocks. A bracket is bonded to a tooth; a band encircles one; an aligner is worn over the crown and is replaced as the movement is achieved. The three can be used in the same case, but they are described by different regulation entries and were classified on their own intended uses.
Is a clear aligner a Class II device in the United States?
Yes. 21 CFR 872.5470 is titled Orthodontic plastic bracket and the entry sits at Class II. The openFDA device classification API lists product code NXC (Aligner, Sequential) under that regulation number, alongside the plastic and ceramic bracket codes and an orthodontic-software code. A Class II device of this kind reaches the market through the premarket notification route with the controls the regulation sets.
The regulation has grown to cover the aligner and the software that plans the staging, which is why a practice that buys a digital treatment plan is buying part of a device family that also contains the trays. The class attaches to the intended orthodontic function, not to whether the appliance is a bracket or a tray.
| Item | Detail |
|---|---|
| US regulation | 21 CFR 872.5470 - Orthodontic plastic bracket |
| US class | Class II |
| Product codes | NXC (sequential aligner), plus the plastic and ceramic bracket codes and an orthodontic-software code |
| Route to market | Premarket notification before commercial distribution |
| Contact | Worn over the crowns; removed by the patient |
How does Canada classify a clear aligner?
Canada keeps no named entry for a clear aligner, but it does not need one, because Rule 3(a) of Schedule 1 of the Medical Devices Regulations is decisive: "Despite rules 1 and 2 — (a) all denture materials and orthodontic appliances, and their accessories, are classified as Class II." A clear aligner is an orthodontic appliance, and the staging trays, the attachments used with them and the retainers that follow are its accessories, so the whole set is Class II.
The words despite rules 1 and 2 are the part worth reading closely. Rule 2(1) would place a device that penetrates a body orifice at Class II in any case, and Rule 2(2) would place a device in the oral cavity as far as the pharynx at Class I. Rule 3(a) overrides both for orthodontic appliances, so an aligner's class does not turn on how far into the mouth it reaches or on the material of the tray. Rule 3(b), which places surgical and dental instruments at Class I, does not apply either: an aligner is an appliance, not an instrument.
| Item | Canada | United States |
|---|---|---|
| Named entry | None; classified by rule | 872.5470, Class II |
| Class | Class II (Rule 3(a)) | Class II |
| Governing text | Schedule 1, Rule 3(a) | 21 CFR 872.5470 |
| Route to market | Device licence (Class II) with ISO 13485 evidence | Premarket notification |
| Does the material matter? | No; Rule 3(a) covers all orthodontic appliances | Handled inside the Class II entry |
How is an aligner different from a bracket or a retainer?
The three are ordered and used together in a modern practice, but they are not the same article and they were classified on their own intended uses. A bracket is bonded to a tooth and holds a wire; a band encircles a tooth and carries an attachment; an aligner is worn over the crowns and is replaced in a planned series; a retainer holds the position after treatment. The class follows the intended use, so they sit in different entries.
| Appliance | How it is worn | Function | Class, Canada | Class, US |
|---|---|---|---|---|
| Clear aligner | Removable tray over the crowns | Sequential tooth movement | II (Rule 3(a)) | II (872.5470, NXC) |
| Bracket | Bonded to a tooth | Holds an archwire | II (Rule 3(a)) | I or II (872.5410 / 872.5470 by material) |
| Band | Fits around a tooth | Carries an attachment | II (Rule 3(a)) | II (872.5410 range) |
| Retainer | Removable appliance after treatment | Holds position | II (Rule 3(a)) | II |
The practical consequence is the same in both countries. A practice that stocks aligners alongside brackets and bands is buying three lines that share one class in Canada, because Rule 3(a) covers all orthodontic appliances and their accessories. For a purchase order the useful detail is therefore the tray count and the staging plan, not a separate class check for each line.
What should a practice check before ordering?
Three checks. First, confirm the exact regulation number and product code on the supplier's labelling, and treat the digital staging plan as part of the appliance it controls. Second, confirm the tray count and the case staging the clinician intends to run, because the consumable line is sized by the case rather than by the treatment plan's marketing name. Third, confirm the retainer and attachment line that follows the series, since those are the appliances' accessories under Rule 3(a) and travel with it.
An orthodontic practice also reorders the room consumables that sit at the same chair. Practice consumables for the whole room are listed under dental practices. Clinics that stock for a whole practice can order through the wholesale programme and request a bulk quote for a standing or annual order; the dental bibs sits in the same catalogue. Reselling? become a distributor.
How does the class affect a practice's routine?
The class sets the licence path to market; the practice's routine is its own. An aligner case is recorded with the start date, the planned staging, the trays issued and the reviews, so the progress of the case can be checked against the plan at any review. The trays are held as a case set so a mid-series replacement can be found, and the retainers are ordered at the point the series finishes.
Because the trays are worn over the crowns and removed by the patient, the routine also depends on the cleaning and storage instructions the maker states. None of that changes with the class; it is the ordinary routine an orthodontic practice keeps, and the record is what shows the case was run as the maker intended.
Sources
- openFDA device classification API
- Medical Devices Regulations, SOR/98-282, full text and Schedule 1
- Royal College of Dental Surgeons of Ontario, standards and guidelines
- Canadian Dental Association
- Public Health Ontario, infection prevention and control
- World Health Organization, oral health
- US FDA, medical device databases
- US FDA, overview of device regulation
- Health Canada, medical devices
- Health Canada, establishment licensing
- Standards Council of Canada
- CSA Group
- ISO 13485:2016, medical devices quality management
- ISO 14971:2019, application of risk management to medical devices
- CCOHS, OSH answers
- World Health Organization, oral health fact sheet
- Health Canada, medical device licence application guidance
Printable record sheet. An orthodontic practice keeps a printed case sheet for each aligner series, and a printable log is the copy the practice can hand to an auditor. Open the sterilization log sheet library — the downloadable pack holds a steam-cycle log, a reprocessing-room checklist and an equipment-maintenance sheet. No account and no sign-up; print as many copies as your log needs.
Log generator. Set the practice name, the clinician and the case list once and the generator lays out a dated case sheet for the month. Run the sterilization log generator to build a dated, facility-labelled cycle sheet you can print or file straight into your quality manual.
Ask a compliance specialist. Whether an aligner line follows a fixed or a removable route in Canada turns on Rule 3(a); a written answer keyed to your appliance and province settles it. Ask a compliance specialist — you get a written answer specific to your equipment and province, with the regulation or standard it is based on cited.
Related reading
- Orthodontic brackets in Canada vs the US
- Orthodontic bands in Canada vs the US
- Orthodontic supplies in Canada vs the US
CliniEco Medical supplies eye care, laboratory and dental consumables of the kind described in this article. MDEL #35334. This article is written for optometry, laboratory and dental procurement professionals and is not legal advice; the class of a device and the records a practice keeps belong to the manufacturer and to the requirements that apply to it.
Frequently Asked Questions
What class is a clear aligner in the United States?
Class II, under 21 CFR 872.5470, Orthodontic plastic bracket, with product code NXC for a sequential aligner.
What class is it in Canada?
Class II, through Rule 3(a) of Schedule 1 of the Medical Devices Regulations, which places all orthodontic appliances and their accessories at Class II.
Does the tray material change the class?
No. Rule 3(a) covers all orthodontic appliances and their accessories, so the class does not turn on the polymer used for the tray.
Does the digital treatment plan change the class?
A dedicated staging module that plans and drives the appliance is described with the appliance it controls, which is why the US regulation number also carries an orthodontic-software code.
What else is a clear aligner called?
It is also written as invisible aligner, clear tray aligner, sequential aligner, and removable orthodontic aligner.
Are retainers in the same class?
Yes. A retainer is an orthodontic appliance and, with any attachments, is an accessory under Rule 3(a), so it shares the class of the aligner line.
0 commentaire