Quick facts
- A denture reline material is the resin or soft liner that restores the fit of a denture against the ridge when the tissue beneath it has changed.
- United States: an over-the-counter denture reliner is reached at 21 CFR 872.3560, placed in Class II; the openFDA classification API lists it under product code EBP.
- Canada: denture materials and their accessories are classified as Class II by Rule 3(a) of Schedule 1 to the Medical Devices Regulations, SOR/98-282, which names denture materials alongside orthodontic appliances.
- The two countries land on the same class: Class II in the United States and Class II in Canada, by different machinery.
- A reline changes the fit of a device already in the mouth, so the material is filed against the denture rather than as a standalone article.
- The entry and rule text below were checked against the current CFR text and the Regulations on 2026-10-08.
A denture reline material is the resin that a denture is lined with when the ridge under it has resorbed and the fit has gone. It is applied chairside in the hard reline, or supplied for home use in the over-the-counter reliner, and either way it sits between the denture base and the tissue for months at a time. It is a denture material in both countries, and that is the fact that fixes its class. This article sets out what the material does, how each country files it, and what a practice should be able to point at when a reline is placed and when a home reliner is dispensed.
What does a denture reline material do?
The material fills the space between the denture base and the ridge that has changed, so that the denture sits on tissue rather than rocking on it. A hard reline is processed in the laboratory or in the mouth and sets rigid, and a soft reline stays resilient so that it cushions the ridge. The thickness of the layer, the material's set and its bond to the base decide how long the fit lasts.
Because the material changes the fit of a device the patient already wears, it is a denture material rather than a standalone product. That is the fact the rules act on, and it is why a reline and a denture cleanser do not share a class even though both are bought with the denture in mind.
How does the United States file a reline material?
In the United States the over-the-counter reliner is reached by a named entry. 21 CFR 872.3560 covers an over-the-counter denture reliner, and the section places it in Class II. The openFDA classification API lists it under product code EBP at Class II. A Class II device of this kind reaches the market under general and special controls.
The hard reline resin used chairside sits beside it in the same material family, and it follows the maker's instructions for the denture base it is bonded to. A practice comparing a home reliner with a chairside reline is comparing a device the patient applies with one the clinician applies, not one device and its part.
Why does Canada reach Class II by rule?
Canada classifies the material through the special rule for dental materials in Schedule 1. Rule 3(a) puts all denture materials and orthodontic appliances and their accessories in Class II, whether they are applied in the mouth or in the laboratory. A reline material is a denture material, so it falls to that rule and reaches Class II.
The rule sits beside the one for instruments. Rule 3(b) puts all surgical or dental instruments in Class I, which is why a reline material and an instrument used to place it do not share a class even though both are in the same tray. Rule 3(c) puts all latex condoms in Class II, which shows the same rule grouping a material with a pacifier-shaped article by what it does rather than by what it is made of.
| Item | Canada | United States |
|---|---|---|
| Class | Class II, by Rule 3(a) | Class II |
| Named entry | No entry names the reline; it is a denture material | 21 CFR 872.3560 |
| Basis of the class | The rule that fits a denture material | The named entry the reliner is filed under |
| Product code | Not applicable | EBP |
| An instrument for comparison | Class I under Rule 3(b) | Its own instrument entry |
| Premarket route | Device licence under section 32 for a Class II device | General and special controls |
| Quality system | CAN/CSA-ISO 13485 certificate behind the licence | Quality system regulation |
The two countries agree on the class and disagree on how they reach it: the United States names the reliner and Canada reaches it through the rule for a denture material. A practice that keeps the maker's instructions with the material has the document the class implies.
Which standards sit behind the material?
The class says how the material is regulated; the standards say how it has to behave. ISO 13485:2016 is the quality management basis behind the licence, and ISO 14971:2019 is the risk management basis behind the design file. A practice that asks for those two documents is asking for the evidence behind the fit the material claims.
| Element | What it covers | Why it matters at the chair |
|---|---|---|
| Set | Whether the material sets hard or stays soft | A soft liner cushions; a hard liner carries the load |
| Layer thickness | How thick the reline is | A layer too thick changes the vertical dimension |
| Bond | How the material holds to the base | A poor bond is a reline that lifts at the edge |
| Cure | How the material is set | The cure decides the monomer the tissue is exposed to |
| Monomer | Residual monomer in the set material | Residual monomer is the common tissue complaint |
| Records | The material lot and the case | The link between a reline and the denture it was placed on |
A reline that cannot show its lot and a denture that cannot be traced to the material it was lined with are the two gaps that meet on the same bench.
How is a reline assessed before it is placed?
A reline is assessed against the denture it is placed on rather than on its own. The fit of the base, the health of the tissue and the space that has opened up are what the material is chosen to fill, and the maker's instructions decide which material suits which case. A reline placed without that assessment fills the wrong space and lifts at the edge.
The material side is the other half. The set, the layer thickness and the cure are the three fields that decide how the material behaves against the tissue, and the lot is the field that ties the reline to the batch it came from. Keeping the assessment and the material record together is what makes the reline traceable as well as fitted.
What else sits beside the reline?
A denture practice stocks the service as a set. A denture cleaning tablet and bath is the daily care step that keeps the tissue side clean, and a universal dental adhesive is the item a patient may use between visits. Clinics that monitor their own reprocessing pair the sterilization monitoring collection with the 24-hour biological indicator 50-pack. Multi-site groups ordering at case level use the wholesale ordering page, and the B2B wholesale collection lists the lines held for institutional buyers. Reselling? become a distributor.
Sources
- 21 CFR 872.3560, OTC denture reliner
- openFDA device classification API
- Medical Devices Regulations, SOR/98-282, full text and Schedule 1
- US FDA, medical devices
- Health Canada, medical devices
- Standards Council of Canada
- CSA Group
- ISO 13485:2016, medical devices quality management
- ISO 14971:2019, risk management of medical devices
- Royal College of Dental Surgeons of Ontario, standards and guidelines
- Canadian Dental Association
- Public Health Ontario, infection prevention and control
- CCOHS, OSH answers
- World Health Organization, oral health
A denture service is audited on the record that follows the material. The printable reline and denture log is a blank sheet with columns for the patient, the denture, the material, the lot, the date and the operator, so a reline can be reconciled with the denture it was placed on.
The reline log generator on the same page sizes the sheet to the number of relines a practice runs, so a single-chair office and a multi-site group print the form at the volumes they need.
Every practice and every material differs. Ask a compliance specialist and you will get a written answer specific to your equipment and province, with the regulation or standard it is based on cited.
Related reading
- Dental cements in Canada vs the US: which class
- Temporary dental filling materials in Canada vs the US: which rules
- Dental crown materials in Canada vs the US: which material and class
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 procurement professionals and is not legal advice; the class of a device and the records kept by a practice belong to the manufacturer and to the requirements that apply to it.
Frequently Asked Questions
What class is a denture reline material in Canada?
Denture materials and their accessories are classified as Class II by Rule 3(a) of Schedule 1, so a reline material reaches Class II whether it is applied in the mouth or in the laboratory.
What class is an over-the-counter reliner in the United States?
It is a named entry at 21 CFR 872.3560 in Class II, and the openFDA classification API lists it under product code EBP.
Do the two countries agree on the class?
Yes. The reline material is Class II in the United States and Class II in Canada, reached by a named entry on one side and by the denture-material rule on the other.
Why is a reline material a higher class than an instrument?
Rule 3(a) puts denture materials and orthodontic appliances in Class II, while Rule 3(b) puts instruments in Class I, so the material and the instrument used to place it do not share a class.
What is the difference between a hard and a soft reline?
A hard reline sets rigid and carries the load of the denture, while a soft reline stays resilient and cushions the ridge. The maker's instructions govern which one is used and how it is cured.
Why does residual monomer matter?
It is the substance a patient is most likely to notice in a freshly placed reline, so the cure schedule the maker specifies is the step that decides how the set material behaves against the tissue.
What should a practice record for a reline?
The material, the lot, the denture and the date, kept together as a traceability record. That is the link between a reline and the denture it was placed on.
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