Dear Narelle Parfitt.
Usually screw implants are take parts in Vendor trays for operation on the bones. These types of implants are produce from materials that have resistant to fluids in human body. All of the screws that we sterilizing on our department are not have surface coating that can be damage in ultrasonic bath with alkaline detergent. Screw implants are having simple shape and you can use ultrasonic bath to clean it. However cleaning process – it is not just cleaning, it is disinfection process too – that you should use WD machine after ultrasonic bath to follow ISO 15883.
Hope its help.
Petr Demidov, Moscow, Russia, drpedro@mail.ru