Improvement of strength parameters of a leucite-reinforced glass ceramic by dual-ion exchange.
An innovative dual ion-exchange process can improve the limited strength and the scatter-in-strength of technical glasses. The objective of this study was to prove whether such a two-stage ion-exchange process can also improve the limited strength and the problematic scatter-in-strength of dental ceramic materials. The first exchange was done in KNO3 on a leucite-reinforced glass-ceramic material, the second exchange in 70 mol% KNO3, 30 mol% Na NO3 at different treatment times and temperatures. The dual-exchange process approximately doubled the Weibull strength. Moreover, the Weibull modulus showed a four-fold increase, i.e., the coefficients of variation were reduced from 18.3 to 4.7%. We conclude that the dual-exchange process may help significantly to increase the clinical reliability of glass-ceramic dental restorations, because the strength and the scatter-in-strength will be substantially improved by this treatment.
Department of Dental Prosthetics, University of Technology, Aachen, Germany. h.fischer@rwth-aachen.de
H
H
Fischer
R
R
Marx
D000538:Aluminum Silicates / Q000737:chemistry*; D000704:Analysis of Variance; D019245:Compressive Strength; D003776:Dental Porcelain / Q000737:chemistry*; D006244:Hardness; D007474:Ion Exchange; D008422:Materials Testing; D018583:Pliability; D016019:Survival Analysis; D013718:Tensile Strength
D000538:Aluminum Silicates; C075815:IPS-Empress ceramic; D003776:Dental Porcelain