Inaccuracies and defects in frameworks for removable partial dentures.

We studied the accuracy of 167 removable partial denture frameworks made in five commercial dental laboratories according to detailed instructions given by dental students, under the supervision of experienced teachers. Fewer than one half of the frameworks proved to be perfect. Some of the faults were accepted in the clinic, but 42% had to be corrected: 26% in the clinic, and 16% in the laboratory. Laboratory problems could be blamed for two-thirds of the faults, and one-third seemed to be attributable to the clinic. The advantages of, for example, new impression materials seemed to disappear under other factors.