Improving the wear performance of feldspathic veneering porcelain by ion-exchange strengthening. (November 2019)

• Record Type: Journal Article
• Authors: Meng, M.; Li, X.C.; Guo, J.W.; Zhou, M.; Niu, L.N.; Tay, F.R.; He, L.; Zhang, S.F.
• Is Part Of: Journal of dentistry. Volume 90(2019:Nov.)
• Publication Date: 2019-11
• Subjects: Feldspathic veneering porcelain -- Ion-exchange -- Wear performance; Dentistry -- Periodicals; Dentistry -- Periodicals; Dentisterie -- Périodiques; Electronic journals; 617.6005
• DOI: 10.1016/j.jdent.2019.103210
• Languages: English
• ISSNs: 0300-5712

Abstract

Abstract: Objectives: The present study examined the effects of Na + →K + ion-exchange on the wear performance of feldspathic veneering porcelain. Methods: Bar and disk specimens were prepared using IPS classic as the feldspathic veneering porcelain. After ion-exchange by immersion of the specimens in melted KNO3 at two temperatures for different time-periods, the bars were tested for flexural strength and Vickers surface hardness. The disks were paired with zirconia antagonists and tested with a pin-on-disk tribometer with 10 N for 70☓10 4 wear cycles in artificial saliva. Wear analysis of the porcelain and zirconia was performed using 3D profilometer and analysed with one-way analysis of variance and Tukey's post-hoc pairwise comparison procedures. Worn surfaces were examined with scanning electron microscopy. Results: The feldspathic veneering porcelain exhibited strong time-dependent wear behaviour, with typical running-in and steady wear stages. Ion-exchange treatments at 380 °C and 440 °C both enhanced the mechanical properties, decreased the wear rates of running-in wear and steady wear. The wear performance of porcelain treated by ion-exchange at lower temperature (380 °C) was improved significantly, especially reducing the wear rate of the running-in stage. Conclusion: A thicker ion-exchange layer with less stress relaxation may be obtained by ion-exchange at lower exchange temperature for a long processing time. Such a protocol improves the wear performance of the porcelain effectively. Clinical significance: Restorations with veneering porcelain may fail prematurely due to excessive wear. It important to improve the wear performance of the porcelain. Ion-exchange has the potential to strengthen dental veneering porcelain. Understanding the effect of ion-exchange on the wear performance of porcelain provides insight improving the wear performance of these restorations.