Ceramometal Bond Strength Analysis using New and Recast Nonprecious Alloys with Three Different Ceramics

Objectives: This study is undertaken to evaluate the dependence of bond strength of 100% fresh nonprecious alloy and the combination of 50% recast (used) alloy and 50% fresh alloy with three different veneering ceramic material. Materials and methods: To evaluate the shear bond strength between new and recast alloy nonprecious Ni-Cr alloy (System KN®, Adentatec, Germany) was used with three different commercially available ceramics. A total of 60 samples were prepared and divided in two groups depending on the new or recast alloy. The 30 specimens of new alloy (group A) and 30 specimens of recast alloy (group B) were fabricated. Each group was again divided into three subgroups of 10 specimens for ceramic veneering Vita VMK-95 [V], IPS Classic [I] and Noritake [N] as veneering ceramic materials. Thus, six subgroups were formed as groups AV, AI, AN, BV, BI and BN. Groups AV and BV were veneered with Vita Ceramics, Groups AI and BI were veneered with IPS Classic (Ivoclar) and Groups AN and BN were veneered with Noritake. Then, shear bond strength between new and recast alloy was analyzed for each type of ceramics using MTS machine. Results: The bond strength between new [group A] and recast alloy [group B] using three different veneering ceramics were evaluated. It was found that the new or the fresh alloy had highest shear bond strength than the recast alloy. Statistically, it was found that there was significant difference in bond strength between the new and recast alloys, when same type of ceramics was compared. When comparing ceramics, the Noritake group had highest bond strength, while other groups, that is, Vita and Ivoclar had comparatively low bond strength. Conclusion: From this study, conclusion can be drawn that the use of 50% recast alloy shows reduction in bond strength values. Therefore, the use of recast alloy should not exceed more than 50%, as it would compromise the properties of alloy and the efficacy of bond strength between ceramic and alloy.