A method for forming an integrated or repaired dental framework involves portions of dental framework formed of a polymeric material such as polyetheretherketone (PEEK) repeating units are provided with a male member 5 on a joint surface 3 of one portion 1 and a female member 6 on a joint surfaces 4 of a second portion 2, with the male and female members arranged to mate together to hold the portions together at the joint surfaces and then welded together by ultrasonic welding. Injection moulding of dental prosthetic items by injecting a flowable thermoplastic composition into a mould under pressure from a pre-moulding chamber is also disclosed.
