Dental Product

Dentures continue to be an important and major market for plastics. Use is made of acrylics (PMMAs) that includes full dentures, partial dentures, teeth, denture reliners, fillings and miscellaneous uses. PMMAs provide strength, exceptional optical properties, low water absorption and solubility, and excellent dimensional stability. In the past plastics used included nitrocellulose, phenol-formaldehyde, and vinyls as denture base materials. Results, however, were not satisfactory because these plastics did not have the proper requisites of dental plastics. Since then, PMMAs have kept their lead as the most useful dental plastics, although many new plastics have appeared and others are being tested.

Todate plastics are not very useful as filling materials with only about 2wt% of all fillings using plastics. The low mechanical properties of

Examples of surgical implants (Courtesy of Plastics FALLO)

Examples of surgical implants (Courtesy of Plastics FALLO)

plastics in comparison with metals limit their application where stresses are great. It is interesting to note development efforts has taken place in the use of whiskers for reinforcing dental plastic, metal, and ceramic fillings. Some preliminary test results on the addiuon of randomly distributed chopped, short whiskers to a coating plasdc have reversed the previous proportional loss of strength with powder additions. Although this is far from theoretical, it is already quite significant in that it allows the addition of pigment for coloring purposes and a restoration of the loss of strength with whisker additions.

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