This study evaluated and compared the diametral tensile strength (DTS) of phosphate-bonded investment (PBI) material (ringless) used in removable cast partial denture fabrication.
The PBI material, Wirovest used in this study was subjected to four different drying methods. A total of 80 specimens were prepared in a cylindrical form; 20 specimens were air dried for 2 h, 20 specimens were dried in a conventional oven at 230°C for 1 h, 20 specimens were dried in microwave oven at 600 W for 10 min, and remaining 20 specimens were dried first in microwave oven and then in conventional oven. The dried specimens were tested at 2-h interval for diametral compression at a crosshead speed of 0.5 cm/min.
The microwave drying technique and drying by combination method resulted in greater DTS, respectively.