The biaxial flexural strength and reliability of four dental ceramics--Part II.
OBJECTIVE
The biaxial flexural strength and reliability of four dental ceramics including: Empress glass ceramic (EM), Cerinate porcelain (CE), Corum porcelain (CO) and Alpha porcelain (AL) were compared.


METHODS
Twenty disc specimens per material were prepared overglazed and tested. The piston on three ball test was used to test the specimens in a universal testing machine at a crosshead speed of 0.15 mm/min. Weibull analysis provided m-values and the 1 and 5% probabilities of failure.


RESULTS
Mean strengths (MPa +/- SD) were: EM, 133.5 +/- 21.5; CE, 109.1 +/- 11.3; CO, 119.8 +/- 19.2; and AL, 68.2 +/- 9.9. There was no statistical difference between EM or CO and CO and CE strengths (P > 0.05). Weibull m-values included: EM, 6.60; CE, 10.20; CO, 5.27; and AL, 6.93. Cerinate had the highest m-value (P < 0.01) and good dependability.


CONCLUSIONS
Empress was not stronger or more reliable than many of the frit materials.
Cattell
M J
MJ
Royal London School of Medicine and Dentistry, UK.
Clarke
R L
RL
Lynch
E J
EJ
D000538:Aluminum Silicates / Q000737:chemistry; D000704:Analysis of Variance; D002516:Ceramics / Q000737:chemistry*; D003442:Crowns; D003776:Dental Porcelain / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D003801:Dental Veneers; D007284:Inlays; D008422:Materials Testing; D018583:Pliability; D011336:Probability; D015203:Reproducibility of Results; D013314:Stress, Mechanical
D000538:Aluminum Silicates; C085095:Cerinate; C075815:IPS-Empress ceramic; D003776:Dental Porcelain