How to choose a sterilization test?

How to choose a sterilization test

In implantology, mastering sterilization is a cornerstone of surgical safety. Beyond the sterilization cycle itself, verifying its effectiveness is essential. This involves using sterilization tests, which validate the performance of autoclaves and ensure compliance with protocols. But with so many types of tests available, how can you choose the right one?

Why use a sterilization test?

A sterilization test confirms that the sterilization cycle has reached the necessary parameters to eliminate all forms of microbial life, including bacterial spores. It does not replace the process—it validates it.

According to standard NF EN ISO 17665-1, there are several levels of control:

Physical tests: temperature, pressure, and duration data recorded by the autoclave

Chemical tests: class 1 to class 6 indicators

Biological tests: the most reliable, though the slowest

Types of sterilization tests

1. Chemical indicators

These change color when exposed to sterilization parameters (temperature, steam, time).

Class 1: Process indicators, placed on pouches. They confirm that the item has been exposed to a sterilization process but do not validate its effectiveness.

Class 2: Penetration tests like the Bowie-Dick test. Specific to steam autoclaves, they check for air removal and effective steam penetration. Should be performed daily before the first cycle.

Class 3 to 6: Integrating indicators of increasing sensitivity. Class 5 and 6 tests, known as "integrators", simulate the behavior of resistant microorganisms. They can be used inside trays or pouches for more accurate control.

2. Biological tests

These contain bacterial spores (often Geobacillus stearothermophilus). After sterilization, they are incubated to detect any bacterial growth.

Very reliable, but with a 24–48h incubation time, they are unsuitable for immediate release of instruments

Recommended for periodic performance checks of autoclaves (typically monthly)

How to choose the right test based on your practice

Need

Recommended test

Frequency

Verify each pouch

Class 1 chemical indicator

Every cycle

Validate steam penetration

Bowie-Dick (class 2)

Once daily

Precise internal control

Class 5 or 6 integrator

Every cycle (if required)

Microbiological verification

Biological test

Monthly or post-service

👉 In an implantology clinic, the ideal routine includes:

A daily Bowie-Dick test

Class 5 indicators in every load

A monthly (or weekly) biological test depending on activity volume

Regulatory references

HAS – Guide for managing infectious risk in dental clinics

CDC – Guidelines for disinfection and sterilization in healthcare facilities

NF EN ISO 11140 – Classification of chemical indicators

NF EN ISO 17665-1 – Requirements for steam sterilization

HYGITECH recommendations

Sur le sujet

Sterilisation paper blue