Endodontic Dry Heat Sterilizers in Canada vs the US: Which Class Applies?

Quick facts

• A glass bead sterilizer heats small glass beads by electricity and sterilises endodontic and other dental instruments by dry heat.
• United States: 21 CFR 872.6730 classifies an endodontic dry heat sterilizer as Class III, and requires a premarket approval application or a notice of completion of a product development protocol to be filed on or before April 21, 1997 for a device in commercial distribution before May 28, 1976.
• Class III is unusual in the dental code. The same section also carries a glass bead sterilizer, and a general dry heat sterilizer sits in a different section, 21 CFR 880.6870, in Class II.
• Canada: the classification rule is short. Rule 13(b) of Schedule 1 to the Medical Devices Regulations, SOR/98-282 classifies a medical device intended for disinfecting or sterilizing a medical device as Class II.
• So the same chairside unit is a Class III premarket approval device in the United States and a Class II licensed device in Canada.
• The class gap is the headline, but the practical question for a practice is smaller and more immediate: whether the unit is still part of the reprocessing workflow at all.

A glass bead sterilizer is a small, unglamorous item that sits at the end of the endodontic tray. It also happens to be one of the very few dental devices the United States placed in Class III, which is the class that normally means a premarket approval application. The reason is historical rather than technical, and the difference between the two countries on this device is the widest in the category. This article sets out the two routes, the neighbouring entries, and what a practice should be able to show for the unit and its monitoring.

What does an endodontic dry heat sterilizer do?

The section describes it precisely: a device intended to sterilise endodontic and other dental instruments by the application of dry heat, with the heat supplied through glass beads that have been heated by electricity.

Three properties decide whether it can carry a reprocessing workflow:

• Temperature and exposure time. Dry heat moves more slowly than steam, and the contact between the beads and the instrument is what carries the heat.
• Load geometry. Instruments have to be inserted so that the bead contact covers the surfaces that need sterilising, which is why the technique is not interchangeable with a chamber cycle.
• Verification. Where the unit is used on critical items, the monitoring that surrounds it is what an inspection asks about.

The unit is a sterilizer, and in both countries a sterilizer is classified as the class of the thing that does the sterilising rather than as an accessory to the instrument it sterilises.

How is the unit classified in each country?

The two answers are four classes apart in appearance and one sentence apart in practice.

Item	Canada	United States
Endodontic dry heat sterilizer	Rule 13(b), Class II	21 CFR 872.6730, Class III
Premarket position	Licence class derived by rule	Premarket approval application or completed product development protocol
Glass bead sterilizer	Rule 13(b), Class II	Filed under 21 CFR 872.6730, Class III
General dry heat sterilizer	Rule 13(b), Class II	21 CFR 880.6870, Class II
Steam sterilizer	Rule 13(b), Class II	21 CFR 880.6880, Class II
Tabletop steam sterilizer used in a clinic	Rule 13(b), Class II	21 CFR 880.6880, Class II
Wording that decides the case	Intended for disinfecting or sterilizing a medical device	The identification in the section, which names endodontic and dry heat

The Canadian text is one line: a medical device that is intended to be used for disinfecting or sterilizing a medical device is classified as Class II. That rule does not distinguish between a bench autoclave, a glass bead unit and a chemical sterilant processor. All three are devices that sterilise another device, so all three are Class II.

The American text is longer because the United States classified these devices individually during the transitional period after the 1976 amendments. Section 872.6730 states Class III in a single word and then sets the filing date: a premarket approval application or a notice of completion of a product development protocol was required to be filed on or before April 21, 1997 for any endodontic dry heat sterilizer that was in commercial distribution before May 28, 1976, or that had been found substantially equivalent to such a device before that date. A device not covered by that transitional provision has to have an approved application or a declared completed protocol in effect before it is placed on the market.

Why is the class so different from the neighbouring devices?

Because the American class was set device by device, and the class of a sterilizer in the United States turns on what the device says it sterilises.

• A general dry heat sterilizer is described in 21 CFR 880.6870 and is Class II.
• A steam sterilizer is described in 21 CFR 880.6880 and is Class II.
• An endodontic dry heat sterilizer is described in 872.6730 in the dental part and is Class III.

The pattern that emerges is that the dental part of the code contains some pre-amendment devices that were never reclassified. The endodontic dry heat sterilizer is one of them, and the filing date in the section is the evidence of that origin.

Canada does not carry that history into the rules. Rule 13(b) is a single functional test, applied to whatever the device sterilises, and the answer is Class II in every case. For a practice operating on both sides of the border, the practical difference is not in how the unit is used but in what has to exist before the unit can be placed on the market at all.

Because the class is only half the story, it is worth setting the record requirements beside it:

Record	What it shows	Where it belongs
Maker's cycle instruction	Temperature, exposure time and loading method	With the equipment file
Process indicator	That the cycle ran	On or in each pack
Biological indicator	The lethality of the process	With the cycle log
Incubation record	Incubator temperature and read time	With the cycle log
Equipment list entry	Whether the unit is in the reprocessing workflow	Equipment file
Licence or clearance position	Class and premarket status of the unit	With the purchase record

What should a practice be able to show for a sterilizer of this type?

Six items, and the first is the one that decides whether the rest are needed.

• The decision on where it sits in the reprocessing workflow. A sterilizer that is not in the workflow still appears on the equipment list, and the list should say so.
• The maker's cycle instruction. Temperature, exposure time and the loading method are stated by the maker.
• The monitoring that surrounds the cycle. A process indicator tells the operator that the cycle ran; a biological indicator is what speaks to the lethality of the process, and the monitoring type has to match the cycle.
• The incubator and read time. Where a biological indicator is used, the incubator and its temperature belong with the record.
• The log. Cycle date, load, result, and the action taken where a result is not acceptable.
• The licence or the clearance record. In Canada, the class and the licence position; in the United States, the premarket position of the unit.

Which consumables does a reprocessing room use?

A reprocessing room restocks indicators, tape, pouches, records and gloves in the same cycle as its instruments. For practices buying at case level, the wholesale ordering page sets out account and case terms, and the B2B wholesale collection lists the lines held for institutional buyers. The autoclave tape and indicator tape set covers cycle identification, the 24-hour biological indicator incubator covers the read step, and practices that want to see the monitoring lines together can start with the biological indicator 5-pack trial and the sterilization monitoring collection.

Sources

1. 21 CFR 872.6730, endodontic dry heat sterilizer
2. 21 CFR 880.6870, dry heat sterilizer
3. 21 CFR 880.6880, steam sterilizer
4. 21 CFR 880.6860, chemical sterilizer
5. 21 CFR 880.9, limitations of exemptions
6. Medical Devices Regulations, SOR/98-282, full text and Schedule 1
7. Health Canada, medical devices
8. openFDA device classification API
9. FDA device classification database
10. Royal College of Dental Surgeons of Ontario, standards and guidelines
11. Canadian Dental Association
12. Canadian Dental Hygienists Association
13. Public Health Ontario, infectious diseases
14. Public Health Ontario, laboratory test information index
15. CLSI standards
16. Canadian Centre for Occupational Health and Safety, OSH answers
17. World Health Organization, oral health
18. US OSHA bloodborne pathogens standard, 1910.1030
19. ISO 10993-1:2018, biological evaluation of medical devices
20. ISO 11609:2017, dentistry, dentifrices

Related reading

• Instrument Reprocessing Categories in Canada vs the US: Critical, Semi-Critical and Non-Critical
• Spore Testing for Dental Clinics: Daily BI Monitoring in Ontario
• Chemical Indicator Strips vs Autoclave Tape: Which Belongs in the Sterilization Log
• Instrument Reprocessing Workflow: Clean, Disinfect, Sterilize Explained

CliniEco Medical supplies eye care, laboratory and clinic consumables of the kind described in this article. MDEL #35334. This article is written for clinic, procurement and infection-control professionals and is not clinical guidance; sterilizer selection, cycle validation and monitoring frequency belong to the practice's infection-control lead and the provincial requirements that apply to it.

Frequently Asked Questions

What class is an endodontic dry heat sterilizer in the United States?

Class III. 21 CFR 872.6730 classifies an endodontic dry heat sterilizer as Class III and requires a premarket approval application or a notice of completion of a product development protocol to be filed on or before April 21, 1997 for a device that was in commercial distribution before May 28, 1976, or that had been found substantially equivalent to such a device before that date.

Is Class III the same as a premarket approval device?

It is the class that requires premarket approval or a completed product development protocol. For an endodontic dry heat sterilizer, the section sets the transitional filing date and then states that any other such sterilizer has to have an approved application or a declared completed protocol in effect before being placed on the market.

What class is the same sterilizer in Canada?

Class II. Rule 13(b) of Schedule 1 to the Medical Devices Regulations classifies a medical device intended for disinfecting or sterilizing a medical device as Class II, and the rule does not distinguish between dry heat, steam and chemical sterilizers.

Is a general dry heat sterilizer also Class III in the United States?

No. A general dry heat sterilizer is described in 21 CFR 880.6870 and is Class II, and a steam sterilizer is described in 21 CFR 880.6880 and is also Class II. The Class III result in the dental part of the code applies to the endodontic dry heat sterilizer and to the glass bead sterilizer filed under the same section.

Why is this device Class III when other dental devices are Class I?

Because the American class was set device by device, and the dental part of the code contains pre-amendment devices that were never reclassified. The filing date written into the section is the trace of that origin rather than a statement about how the device behaves.

What should a practice keep for a sterilizer of this type?

The maker's cycle instruction, the monitoring that matches the cycle, the incubator and read record where a biological indicator is used, and the cycle log with the action taken where a result is not acceptable. Where the unit is not part of the reprocessing workflow, the equipment list should say so rather than leaving the entry unexplained.