Sterilisation concerns both freehand instruments and handpiece appliances and burrs. To ensure proper hygiene, a dentist must discard all dental hand instruments into a plastic container filled with an appropriate disinfectant. After soaking for the manufacturer-prescribed time, handheld instruments then undergo mechanical cleaning in a machine washer with special detergents; any dental materials stuck on the tools are taken off using ultrasonic devices or specialised solutions. Avoid manual cleaning; it is less effective and carries a high risk of injury. Then come the autoclaves, special sterilisers which expose the instruments to high heat for a specific amount of time. Sterilisers play a role in the cleaning of handpieces and burrs, too. Initially, handpieces require vigorous scrubbing with an appropriate detergent, while burrs are best freed from dental debris via ultrasound. Then both devices are ready for the autoclave.