The KNMT guideline on infection prevention in dental practices defines the reprocessing chain as a one-way workflow from contaminated to sterile. Each step must be completed in order, without backtracking. NEN-EN-ISO 15883 covers washer-disinfectors, NEN-EN 13060 covers small steam sterilizers and NEN-EN-ISO 17665-1 covers the sterilization process itself. Here is the complete chain for a Dutch dental practice.
The reprocessing chain is the fundamental concept of sterilization in dental practices: instruments always progress from contaminated to clean, then from clean to sterile, without ever going back. This unidirectional flow prevents the recontamination of instruments already processed. In a Dutch dental practice, the Wkkgz (Care quality, complaints and disputes act) Articles 2 and 3, the KNMT guideline on infection prevention in dental practices and the IGJ Supervision Framework for Infection Prevention in Dental Care (2018) require premises to be organized to support this principle -- separate zones for contaminated instruments, cleaning, packaging, and sterile storage.
Immediately after use, instruments are immersed in a decontamination bath (enzymatic or detergent-disinfectant solution). This step reduces the initial microbial load and protects staff during subsequent handling. Soaking time varies depending on the product used (typically 15 to 30 minutes). Rotary instruments (turbines, contra-angle handpieces) follow manufacturer instructions -- some require lubrication before cleaning.
Cleaning removes organic residue (blood, saliva, debris) that would prevent effective sterilization. In Dutch dental practices, the washer-disinfector per NEN-EN-ISO 15883 is the standard -- automated, reproducible, and recommended for practices with high instrument volume. The ultrasonic bath (cavitation cleaning, effective for hollow and articulated instruments) is an additional option. Manual brush cleaning remains acceptable but is less reproducible and carries a higher risk of sharps injuries.
After cleaning, instruments are rinsed with clean water (ideally purified or demineralized water to avoid limescale deposits) then thoroughly dried. Drying is an often-overlooked but essential step: wet instruments in a pouch compromise the sterility of the packaging. Drying can be done with medical-grade compressed air or a single-use lint-free cloth.
Each instrument is visually inspected (residual contamination, functional condition, corrosion) before packaging. Instruments are placed in sterilization pouches (heat-resistant paper/plastic) appropriate to their size. Pouches are sealed by heat sealing. The sterilization date and cycle number must appear on each pouch -- this marks the beginning of traceability.
Pouches are placed in the autoclave following loading guidelines (do not overload, do not stack pouches). In Dutch dental practice, the class B autoclave per NEN-EN 13060 is the standard -- the only class capable of sterilizing hollow instruments and wrapped loads. The standard cycle is 134 degrees C for 18 minutes (prion cycle). Before the first load of the day, a Bowie-Dick or helix test validates proper autoclave function.
At the end of the cycle, the autoclave generates a report containing the recorded parameters (temperature, pressure, duration). This report is the cornerstone of traceability -- it proves that sterilization conditions were achieved.
Dental turbines, contra-angle handpieces, and ultrasonic scaler tips are hollow instruments -- steam must penetrate internal channels to ensure sterilization. This is why a class B autoclave (with pre-vacuum cycle) is essential: class N autoclaves do not reliably sterilize hollow instruments. The KNMT guideline on infection prevention and the Spaulding classification designate these as "critical" instruments -- instruments with elevated reprocessing requirements.
Turbines require particular attention: lubrication per manufacturer's instructions before cleaning, use of the helix test (not Bowie-Dick) to validate steam penetration into channels, and individual packaging in appropriately sized pouches. A failed helix test means hollow instruments in the load are not sterilized -- even if the autoclave report shows "cycle passed." For details on autoclave testing, see the biological controls guide.
After successful sterilization, the load is formally released by the responsible person designated under the KNMT guideline. Sterilized pouches are stored in a clean, dry space, away from dust and direct light. The use-by date depends on the packaging type and storage conditions -- in practice, from 1 to 6 months depending on the packaging. A pouch whose integrity is compromised (torn, opened, wet) must be repackaged and resterilized.
For details on calculating the use-by date, see our dedicated guide.
Traceability is the step most practices neglect -- and the one IGJ inspectors check first during a practice visit. Each autoclave cycle must be documented: date, time, program, result, operator, loaded instruments. The link between the patient, the instruments used, and the sterilization cycle must be established and verifiable. For patient-record-linked sterilizations the 20-year WGBO retention applies (BW Article 7:454, in force since 1 January 2020) -- the longest retention period for sterilization documentation in any European market where SecuSteri operates.
This is precisely what SecuSteri does: the autoclave report is imported automatically, the operator selects the instruments in the load, signs with their PIN code, and the traceability record is generated. QR labels link each pouch to its cycle.
Skipping pre-cleaning (dried residue is much harder to remove during cleaning). Packaging instruments that are still wet. Overloading the autoclave (prevents steam from reaching all surfaces). Breaking the reprocessing chain (placing clean instruments on a contaminated surface). Not documenting cycles (a missing or incomplete register is the leading cause of findings during IGJ practice visits). Performing release without a qualified responsible person.
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