Acetal milling plastic
Formerly advertised in dental technology as "Dental-D" for injection moulding, polyoxymethylene homopolymer (called POM or acetal) is characterised by its high biocompatibility and fracture resistance, as well as its versatility, because you can make many things from it, from splints to crowns to clasp dentures. However, acetal had a serious disadvantage in injection moulding: the thermal expansion during liquefaction to the injection temperature was very high. This made work difficult even on special expansion models and only experienced technicians were able to produce larger parts with a good fit.
MediPlus now has Acetal available as a blank for the milling technique, so that the problem of thermal expansion can be completely avoided and one can concentrate almost exclusively on the advantages of this amazing material! For the processing of Acetal or POM the milling software usually offers its own parameter sets, because this material is also extremely popular in mechanical engineering. It may be better to use single-edged milling machines, because temperatures above 150°C should be avoided, especially when milling thin-walled constructions. However, the good fracture resistance allows milling of overlay rails, which cover teeth thin-walled and absorb their shape at layer thicknesses of 1.5 mm. This also allows switching gaps to be closed without having to fear excessive rail breakage.
POM is inherently chemically stable and does not bond with other plastics, including PMMA. If necessary, special conditioners such as Visio-Link® (Bredent) are used for this purpose. Acetal can be thermoplastically post-processed and can be polished to a high gloss.
MediPlus now has Acetal available as a blank for the milling technique, so that the problem of thermal expansion can be completely avoided and one can concentrate almost exclusively on the advantages of this amazing material! For the processing of Acetal or POM the milling software usually offers its own parameter sets, because this material is also extremely popular in mechanical engineering. It may be better to use single-edged milling machines, because temperatures above 150°C should be avoided, especially when milling thin-walled constructions. However, the good fracture resistance allows milling of overlay rails, which cover teeth thin-walled and absorb their shape at layer thicknesses of 1.5 mm. This also allows switching gaps to be closed without having to fear excessive rail breakage.
POM is inherently chemically stable and does not bond with other plastics, including PMMA. If necessary, special conditioners such as Visio-Link® (Bredent) are used for this purpose. Acetal can be thermoplastically post-processed and can be polished to a high gloss.