The effect of titanium, zirconia, modified peek framework and thermal aging on shear bond strength of three different gingiva-colored composites

The aim of the study is to evaluate the effect of different framework materials currently used in fixed restorations and thermal aging on the shear bond strength of gingiva colored composite materials used to provide pink aesthetics. 90 samples (10x10x2 mm) were prepared from titanium, zirconia and modified PEEK material. After surface polishing, titanium, zirconia was sandblasted with 3 bar, modified PEEK 1.5 bar pressure with 110 µm Al2O3 powders. Samples were divided into three and a separate pink composite system (Gradia Gum, Anaxgum, Nexco) was applied to each of them together with the company's recommended primer and pink opaque. Half of the samples(n=15) were stored in 37oC water for 24 hours and the and the other half was thermally aged with 10000 cycles at 5-55oC. Shear bond strength test was applied to all samples with a cross head speed of 1mm/min in a universal testing device. Failure types were evaluated with a stereomicroscope, and one sample from each group was analyzed with the FIB-SEM device. A 3-way ANOVA test was used for the statistical evaluation of the results, and pairwise comparisons were made since the interaction between the groups was significant. Nexco as the gingiva-colored composite, modified PEEK as the framework material generally showed lower shear bond strength. The variation of the gingiva-colored composite and framework material used has an effect on the shear bond strength. Thermal aging process adversely affected the bond strength in all groups.