Bond strength between veneer porcelains and CAD/CAM ceramic to CP titanium and evaluation of fracture load and effect of aging on low fusing porcelain fired over CP TI and CAD / CAM materials cemented onto CP TI

Abstract

OBJECTIVES: The aim of this study was to evaluate the bond strength of three different veneering porcelains fired over CP Titanium and a CAD/CAM ceramic cemented to CP Titanium. METHODS: Sixty-four bars of CP Titanium grade II (25±1x 3±0.5x 0.5±0.05 mm) were divided randomly into four groups: Group 1: Titankeramik (Vita Zahnfabrik), Group 2: Triceram (Dentaurum), Group 3: Initial Ti (GC), and Group 4: MKII blocks (Vita). Each veneer porcelain (groups 1-3) was applied with dimensions limited to 8x3x1mm and fired on CP Ti bars following the manufacturer’s instructions and ISO 9693 recommendations. Group 4, Vita Mark II blocks were sectioned into sixteen bars (8x3x1mm) and cemented with Multilink Implant cement (Ivoclar) on CP Ti bars. Fifteen specimens from each group were tested for bond strength by Schwickerath crack initiation test (ISO 9693) using an Instron machine; the mode of failure and bond interface was evaluated by SEM / EDS. RESULTSs: The data were analyzed statistically using ANOVA and Tukey ≤ 0.05. Group 4 is significantly higher than the other groups. Group 1 is significantly higher than group 3, but similar to group 2. SEM/EDS analysis reveals that the modes of failure for groups 1 - 4 are a mixture of adhesive, mixed, and cohesive failures. CONCLUSION: Cementing a milled ceramic to CP Ti produces bond strength significantly greater than conventional veneering porcelains.