The objective of this study is to compare the resistance to shear forces of two pink composite materials (Gradia® gum shades) and (SR Nexco®) bonded to two different substrates: one being zirconia and the other a substrate metal complex represented by Cr-Co. Forty square samples were used for this study, twenty samples of Cr-Co and twenty samples of zirconia. Each of the 2 groups of samples was randomly subdivided into 2 subgroups (Group I and GC group), each consisting of 10 samples.Each sub-group received two types of gingival colored composite: Gradia® gum shades and SR Nexco®. A universal test machine (YL-01), with a load of 10kN, a speed of 1 mm / min and a flat insert, was used to apply shear forces to the substrate-composite resin interface.The shear forces at the breaking point were recorded in Newtons and then calculated in MPa. For SR Nexco®, mean shear strength was significantly higher whenthe base was metal (7,142 ± 2.54) compared to the Zirconia base (5.09 ± 1.44) (p = 0.022). For Gradia® gum shades, no significant difference between the twobases was observed (p = 0.348). Mean shear strength was higher with SR Nexco® compared to Gradia® gum shades for both groups of Cr-Co samples (p = 0.029)and zirconia (p = 0.047). Repair or manufacture of implant prostheses using composite resins, gingival colored, is a viable alternative. The prognosis is bestwhen the pink composite is applied to the metal.
Antar et al. (2024) studied this question.