J Korean Acad Prosthodont.  2001 Jun;39(3):282-296.

The effects of custom tray material on the accuracy of master cast reproduction

• Kim HK
• Chang IT
• Heo SJ
• Koak JY

Abstract

The accuracy of master cast reproduction by a polyvinylsiloxane impression material using two visible-light curing resin and autopolymerizing polymethyl methacrylate resin custom tray material was investigated. Custom trays were fabricated from a master cast that had three index points marked on both inner and outer vestibules and then poured in yellow stone. The distance between the reproduced index points were measured to be+/-0.001mm with a measuring microscope and the algebraic norms calculated for each tray material. No differences were found in the algebraic norms of inner and outer dimensions for upper tray impressions by ANOVA (p>0.05). However, T-test revealed that there were differences between upper and lower impressions and Turkey's has test revealed that in low tray impressions, the Palatray in inner, the Lightplast in outer dimensions respectively were different from other materials. The index points reproduced on the casts compared with the master cast, were closer together for upper tray impressions. All four tray materials produced acceptable casts, 1. Algebraic norms of inner and outer dimensions of the test casts for upper trays were not statistically different irrespective of materials (P>0.05). 2. T-test showed that there were differences between means with upper and lower trays especially in out dimension (P>0.05). 3. But, algebraic norms of inner and outer dimensions of the test casts for lower trays were statistically different between materials. 4. Palatray XL in inner, Lightpast-platten in outer dimensions respectively for lower trays were different from other materials, but, the nearest to the original model.

MeSH Terms

Polymethyl Methacrylate
Reproduction*
Polymethyl Methacrylate