INVESTIGATION OF BOND STRENGTH BETWEEN REINFORCED GLASS CERAMICS AND ADHESIVE SYSTEMS WITH DIFFERENT SHELF LIFE

Aim: To investigate the bonding capability of resin cement with different shelf-lives and also, to examine the microshear bond strength between various reinforced-glass ceramics and composite resin cement.
Materials and methods: Three different glass ceramic blocks were used in this study; Leucite-reinforced glass ceramic (LRC), lithium silicate glass ceramic reinforced with zirconia (ZLC) and lithium-disilicate glass ceramic (LDC). The blocks were cut with a saw with the thickness of 1 mm. and placed in acrylic molds. The composite rods prepared in 1mm. diameter and they were bonded to ceramic surfaces with resin cement (Multilink N, Ivoclar AG) with three different shelf lives (Group 1: Not-past shelf-life, group 2: shelf-life past 6 months, group 3: Shelf-life past 12 months). Microshear bond strength test was applied to the samples.
Results: According to the statistical analysis, a significant difference was found between leucite-reinforced glass ceramic (LRC) and lithium-disilicate glass ceramic (LDC) in the group 3 (p=0.047). In all three ceramic samples, significant difference was found between group 1 and group 2 (p=0.007). There was no statistically difference between LDC, LRC, ZLC samples in the group 1.
Conclusion: Resin cement with shelf-life past 12 months decreased the bond strength, while resin cement with shelf-life past 6 months did not affect the bond strength.