Bond Strength of BelleGlassTM to C&B Metal and Zirconia Substrates

Objective: Bonding indirect resins to C&B substrates may extend the clinical lifetime of these restorations, as with PFMs.  In this study, three-month, six-month and one-yr. bonding data of Belleglass^TM to C&B alloys (precious-nonprecious) and Zirconia are reported.  Methods: 24 hr and one-month data were reported in a previous study (IADR Abst.# 1860 March 2006).  The bonding mechanism  makes use of the stability of the ceramo-metal bond.  Porcelain opaquers with matched coefficient of thermal expansion were fired onto the substrates according  to manufacturer's instructions and the surface was etched with HF acid at optimized etching times.  Eight samples of each material were tested after three-months, six-months and one-yr. storage in 37ºC water with themocycling 5,000 X between 5-55ºC.  The means and standard deviation (s.d.) were calculated and anova analysis (p<0.05) was used to determine any significant differences between the means.   Results:  The bond data are presented in the attached table along with previous data (superscripts indicate differences between the means).  After one-yr. storage in 37º water with thermocycling, there were significant losses in strength in some materials, but bond values remained high.  Conclusion:  The bond strength data indicate that a stable long-term bond between indirect resins and C&B substrates may be possible using the ceramo-metal bond (study funded by Kerr Corp.)