[Effect of different time intervals on the fracture strength of die stone materials].
OBJECTIVE
To evaluate the fracture resistance of three types die stone materials at different time intervals.


METHODS
Maxillary master casts were made of ploymerized methyl methacrylate resins. Three types die stone materials were used. A total of 144 casts were prepared, separated and tested on the self-made testing machine at 0.5, 1.6 and 16 hours to measure the resistance to fracture.


RESULTS
The data were analyzed with ANOVA at alpha = 0.05 and n = 12. Results showed that the cast fracture strength was affected by cast material and setting time obviously.


CONCLUSIONS
It is recommended that the cast setting time should be 6-16 hours.
Zhang
Z
Z
Department of Prosthodontics, Beijing Hospital for Stomatology, Capital University of Medical Sciences, Beijing 100050, China.
Li
Q
Q
Luo
C
C
D001696:Biomechanical Phenomena; D003764:Dental Materials; D003779:Denture Design; D013997:Time Factors
D003764:Dental Materials