The quality of post and cores made using a reduce-time casting technique

This study investigated the castability or casting completeness, surface roughness and dimensional accuracy of castings produced using a technique that requires as little as 24 minutes from the time of investment.

A total of 225 gold castings (45 per group) were fabricated using two standard and three accelerated casting protocols. For each casting protocol, 15 castings were made from a rectangular, diamond-shaped mesh Duralay pattern to be used for castability evaluation; 15 castings were made from a flat, square pattern for measurement of surface roughness, and 15 castings were made from a tapered Duralay dowel to evaluate dimensional accuracy. Castings made with Fast Fire 15 and Ceramigold investment with shortened burnout times were compared to those made using Beauty Cast and Fast Fire 15 investment following the manufacturer's recommendations. Castability was evaluated by counting the number of diamonds cast in a rectangular mesh. A profilometer was used to measure surface roughness. To check dimensional accuracy, the casting was replaced in the original mold and a traveling microscope was used to measure the size difference at 32x magnification.

There were no statistically significant differences in castability and dimensional accuracy throughout all groups (p > .05). There was a statistically significant difference in the surface roughness of casts formed by Ceramigold compared to the other groups (p < .001).

The short casting time using Fast Fire 15 can produce post and core castings that are of a quality acceptable for clinical use.