FINISHING AND POLISHING RESIN DENTURE BASES
Figure 8 The flash around the borders of the denture is removed with an arbor band on a lathe.
Figure 9 An alternate but less satisfactory method is to use a stone in a dental handpiece. A smaller stone, either in a lathe or handpiece is used to remove the flash from the lingual portion of the mandibular denture. A large acrylic bur may be used; however, bur marks are more difficult to remove during polishing than marks left by abrasive instruments.
Figure 10 Excess resin around the teeth is removed with a sharp instrument. This step is not necessary if all wax was removed from the teeth before processing. The instrument shown here is a carbide bur which has been sharpened to a chisel edge and is held in an instrument holder.
Figure 11 The flash has been removed from the borders of the dentures. The posterior area of the palate has been thinned to its proper thickness and the dentures are now ready for polishing.
Some technicians stone the entire surface of the denture before polishing. This is necessary if the surface of the investment was porous and blebs are present over the surface of the denture. It is not necessary if the dentures have a smooth surface.
Figure 12 Polishing is a process of removing scratches with finer scratches. The first step in polishing is to use pumice and a revolving wheel. Pumice is used as a wet slurry which is placed on the denture. In this illustration a brush wheel is being used to polish the interproximal areas between the teeth.
The tissue surface of a denture is never polished. Polishing destroys the details necessary for good fit and retention. The polished surface extends just over the borders, but the borders are not reduced in height or width during polishing.
Figures 13 and 14