Care and Reprocessing of Surgical and Dental Instruments
Stainless steel surgical and dental instruments last a long time – provided they are handled correctly. Most damage such as stains, rust or stiff joints does not occur during use but during reprocessing. This guide gives an overview of the steps of instrument reprocessing, typical faults and practical tips for instrument care. It does not replace the manufacturer's reprocessing instructions or the requirements that apply to your facility.
Key facts at a glance
- Remove soiling right after use and prevent it from drying on.
- Automated cleaning and disinfection in a washer-disinfector is easier to standardise than manual cleaning.
- After cleaning, check every instrument for cleanliness, damage and function.
- Lubricate joints, ratchets and threads with a sterilisable instrument oil.
- Steam sterilisation at 134 °C is the usual method for stainless steel instruments.
- Chlorides, for example from saline solution or blood residues, are a common cause of pitting corrosion.
- The manufacturer's reprocessing instructions always take precedence.
Basics and sources
In Germany, the reprocessing of medical devices follows the joint recommendation of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) at the Robert Koch Institute (RKI) and the Federal Institute for Drugs and Medical Devices (BfArM). Among other things, it describes the risk classification of medical devices and the requirements for validated processes. Practical advice on preserving instrument value is provided by the so-called “Red Brochure” of the Instrument Reprocessing Working Group (AKI). This guide summarises general principles. The reprocessing instructions of the respective manufacturer take precedence; the operator is responsible for correct reprocessing in their facility. Outside Germany, the national requirements apply.
The steps of instrument reprocessing
1. Preparation right after use
Remove gross soiling such as blood, tissue residues, cement or filling material as early as possible. Dried-on residues are hard to remove later and can promote corrosion. Keep the time until reprocessing as short as possible. Do not place instruments in physiological saline solution.
2. Cleaning and disinfection
Automated reprocessing in a washer-disinfector is considered the method of choice because it is reproducible and can be validated. Correct loading is important: place scissors, clamps and needle holders open, do not stack instruments, and avoid spray shadows. Trays and instrument cassettes help keep instruments organised and well rinsed.
In manual reprocessing, instruments are fully immersed in a suitable cleaning and disinfecting solution. Follow the concentration and contact time specified by the product's manufacturer. Use soft plastic brushes for cleaning, never metal brushes or abrasives. An ultrasonic bath can support cleaning of joints and serrations. Then rinse thoroughly – demineralised water is recommended for the final rinse to avoid stains – and dry completely.
3. Visual inspection and function check
After cleaning, every instrument is inspected, ideally with a magnifier for fine working ends:
- Have all residues been removed, including from serrations, teeth and joints?
- Are there cracks, bends, broken tips or corrosion?
- Do forceps and clamps close exactly, do ratchets engage securely, do scissors cut cleanly?
Damaged or corroded instruments are taken out of use so they do not affect other instruments.
4. Lubricating the joints
Instruments with joints, ratchets or threads are lubricated after cleaning – ideally before the final function check. Apply a drop of sterilisable, steam-permeable instrument oil to the joint and ratchet and work the instrument several times. Wipe off excess oil. Silicone-based oils are unsuitable. Lubrication prevents friction corrosion and keeps instruments moving smoothly.
5. Packaging
For sterilisation, instruments are packed in a suitable sterile barrier system, for example transparent sterilisation pouches, sterilisation containers or wrapped cassettes. Pack clamps and needle holders open or at most on the first ratchet step so there is no constant stress on the joint. Protect sharp working ends.
6. Steam sterilisation
Stainless steel instruments are usually sterilised in a steam steriliser with fractionated pre-vacuum at 134 °C. Programme, holding time and load depend on the validated process and the steriliser manufacturer's specifications. After the programme, let the instruments dry completely before storing them.
Common faults and their causes
| Appearance | Possible cause | Remedy |
|---|---|---|
| Whitish or grey stains | Lime or other minerals from the rinse water | Final rinse with demineralised water |
| Iridescent discolouration | Residues of cleaning agents, water quality | Check dosage, rinse thoroughly |
| Extraneous rust (flash rust) | Rust transferred from damaged instruments or pipes | Remove corroded instruments, find the cause |
| Pitting (small holes with a rust ring) | Chlorides, e.g. from saline, blood or water | Prevent drying on, no contact with saline |
| Friction corrosion at the joint | Lack of lubrication, metal abrasion | Lubricate joints regularly |
| Cracks at the joint (stress corrosion cracking) | Sterilisation in closed position, constant stress | Reprocess open or on the first ratchet step |
Stains are usually cosmetic and can often be removed. Corrosion, on the other hand, permanently damages the material and can spread to other instruments.
Practical tips for instrument care
- Fully reprocess new instruments before their first use.
- Treat instruments made of different materials separately, as specified by the manufacturer.
- Always clean scissors, clamps and needle holders open.
- Do not drop fine tips of forceps and scissors onto hard surfaces.
- Check instruments with tungsten carbide inserts regularly for chipped inserts.
- For organised storage, use instrument trays and mesh cassettes from our dental sets & storage category.
How surgical and dressing forceps differ is explained in our guide surgical forceps. For periodontal instruments, see Gracey curettes.
FAQ
Why do stainless steel instruments rust?
Stainless steel is corrosion-resistant but not immune. Common causes are chlorides, extraneous rust from other instruments and lack of lubrication of the joints.
At what temperature are instruments sterilised?
Steam sterilisation at 134 °C is common for stainless steel instruments. The validated process and the manufacturer's instructions are decisive.
Which oil is suitable for surgical instruments?
A sterilisable, steam-permeable instrument oil, usually paraffin-based. Silicone oils are not suitable.
Can stains on instruments be removed?
Lime stains and discolouration can often be removed with suitable basic cleaners. Rust and pitting, however, are a reason to inspect the instrument and take it out of use if necessary.
Where can I find binding reprocessing requirements?
In Germany, in the KRINKO/BfArM recommendation on the reprocessing of medical devices, in the AKI Red Brochure and in the manufacturer's reprocessing instructions.