The Helix test is now the ARSPT: the updated daily steriliser test under AS 5369

The daily Helix test has been renamed and tightened under AS 5369. Which device, which sterilisers, how to run and record it, and what to do on a fail.
By Jesse Giannopoulos
5 min read

Ask most dental nurses what they run in the steriliser first thing in the morning and the answer is "the Helix". Under AS 5369:2023 that name has been retired. The daily test is now the air removal and steam penetration test, or ARSPT, and the standard is more specific than AS/NZS 4815 was about which device you use and when. Here is what changed and what to do about it.

What the test is for

A Class B steriliser (MELAG Vacuklav, DAC Professional and Premium, W&H Lisa and most other modern benchtop units) pulls a vacuum to remove air from the chamber before it lets steam in, then pulses steam and vacuum so steam can get inside hollow and wrapped items. If air removal is incomplete, pockets of air inside a handpiece or a pouch stop steam reaching the surface. That surface is not sterilised, even though the chamber sensors read 134 °C.

The daily ARSPT puts a known, hard-to-penetrate challenge in the chamber with a chemical indicator at the far end. A full colour change proves air removal and steam penetration were good enough that day. Cycle printouts cannot show this on their own, because the sensors sit in the chamber, not inside the load.

What changed

The name

Amendment 1 to AS 5369 renamed the "Bowie-Dick-type test" the air removal and steam penetration test. The ADA Guidelines 5th edition (amended) now lists "Helix test" as a term used before 2022 and "no longer current". Your policies, log sheets and training records should use the new name. Your supplier may still call the product a Helix test. The device is the same; the name is not.

The device must meet ISO 11140-6

For small steam sterilisers (chamber under 60 L, which is every dental benchtop unit) the test device must conform to ISO 11140-6:2022. That standard sets two reference challenges: a porous load (like the old textile Bowie-Dick pack) and a hollow load (the tube-and-capsule device dentists know). A box that says "Helix" but does not state ISO 11140-6 conformance does not meet the requirement. Check the packaging or the data sheet.

Hollow or porous device?

The standard and the ADA guideline (which has a flow chart on page 50) give a simple order:

  1. Follow your steriliser manual first. If it names the daily test device, use that.
  2. If the manual is silent or unclear, look at what you process. If hollow instruments often go through, handpieces, scaler handpieces and tips, suction tips, triplex tips, run a hollow-device ARSPT every day. In a dental practice that is almost everyone.
  3. If you only ever sterilise solid instruments, either a hollow or a porous device is fine.

Which sterilisers need it daily

Any steriliser running pre-vacuum (Class B) cycles, and S-type cycles used for hollow or wrapped loads. The only exception is a unit used solely for solid, unwrapped instruments on an N-type or qualifying S-type cycle. That rarely applies in dentistry.

PCDs in every load

Separate from the daily test, Table 8.2 of AS 5369 lists a process challenge device (a hollow PCD with a Type 2 indicator) in each load as recommended but optional for sterilisers without an air detector. Benchtop units do not have air detectors, so this stays a recommendation. If you already run a PCD in every hollow load, keep doing it. It is the only per-load proof of penetration you have.

How to run the daily ARSPT properly

  • Run it after the warm-up cycle if your steriliser has one, and before the first patient load, in an otherwise empty chamber unless the device instructions say otherwise.
  • Use the cycle the device and your steriliser manual specify. On MELAG and DAC units that is usually the dedicated test program, which runs the pulsing phase and a short hold at 134 °C.
  • Read the indicator against the reference on the pack. An even, complete colour change passes. Any pale, patchy or incomplete area fails.
  • Record it: date, steriliser, cycle number, device lot number, pass or fail, initials. Keep the strip with the day's records, or photograph it.
  • If it fails, do not process patient loads. Repeat the test once. If it fails again, take the steriliser out of service and call for repair. A failed ARSPT is usually a vacuum problem: a worn door seal, a vacuum pump or valve fault, or a blocked pressure-release path. Our MELAG and DAC error code guides list the codes that go with those faults.

What this test is not

The daily ARSPT does not replace the annual validation, and validation does not replace the daily test. Validation proves once a year, with independent loggers and biological indicators, that the process works for your loads. The daily test proves the machine is still doing today what it did on validation day. The ARSPT also does not replace the chemical indicator in each pouch, which tells whoever opens the pack that it went through a cycle.

Do I have to throw out my current test devices?

No. The ADA's advice is to keep testing as you have been and move to an ISO 11140-6 device when you next order. Just make sure the one you move to is the right type (hollow, for most dental practices) and update the name on your log sheet.

Frequently asked questions

Is the ARSPT the same as a Helix test?

A hollow-device ARSPT that meets ISO 11140-6 is what most people have been calling a Helix test. The name changed; the purpose did not. "Helix" is now a historical term in the ADA guidelines.

Is the ARSPT the same as a Bowie-Dick test?

A Bowie-Dick test is the porous-load version of the ARSPT, made for textile packs in large hospital sterilisers. For a dental benchtop unit processing handpieces, the hollow-device ARSPT is the right test.

How often must the ARSPT be run?

Every day, before the first patient load, on any steriliser running pre-vacuum cycles or processing hollow or wrapped items.

What does a failed ARSPT mean?

Air was not fully removed or steam did not fully penetrate the test device, so hollow instruments in a real load may not have been sterilised. Repeat once. If it fails again, stop using the steriliser and call a technician.

Does the vacuum (leak rate) test replace the ARSPT?

No. The vacuum test checks the chamber holds a vacuum. The ARSPT checks steam actually penetrates a hollow load. Run both at the frequency in your steriliser manual, which for most benchtop units is a weekly vacuum test and a daily ARSPT.

If your steriliser is failing its daily test, or you are not sure which device to use, call UDS on (02) 8313 0559. We service and validate MELAG, Dentsply Sirona and other benchtop sterilisers across Sydney, NSW and the ACT.

This article is general guidance from a service technician. It is not a substitute for the standard, the ADA guidelines or your steriliser's instructions.

About the author

Jesse Giannopoulos is a director of Universal Dental Solutions and a dental equipment technician with around ten years in the field. He holds a Certificate III in Electronics and Communications from the Royal Australian Navy and a restricted electrical licence, and spent years with Dentsply Sirona and Henry Schein before co-founding UDS with Ritesh Sharma. UDS is an authorised Dentsply Sirona service partner and MELAG dealer, servicing dental chairs, handpieces, compressors, suction and sterilisers for more than 250 practices across NSW and the ACT. Meet the team.

Still stuck?

Call Universal Dental Solutions on (02) 8313 0559 or book a service call online. Tell us what you have already checked and we will come prepared.