In-vitro i̇nvestigation of the bond strength between different i̇ndirect resin composite materials and different types of bonding systems

In this study, it was aimed to apply different indirect resin composite materials on teeth and direct composite materials using different types of bonding systems and to compare the results obtained by applying the shear strength test in vitro. In the study, 64 empty autopolymerizing acrylic samples were prepared. 32 pieces non-carious and non-restorative intact human molar teeth and 32 pieces disc shaped Z250 (3M ESPE, St. Paul, MN, USA) composite samples. Two subgroups were formed by applying RelyX U200 (3M ESPE GmbH Dental Products, Neuss, Germany) self adhesive resin cement and RelyX Ultimate (3M ESPE GmbH Dental Products, Neuss, Germany) total etch adhesive resin cement on these materials with the recommendations of the manufacturers. Scotchbond Universal Etch (3M ESPE GmbH Dental Products, Neuss, Germany) and Single Bond Universal (3M ESPE GmbH Dental Products, Neuss, Germany) were applied to RelyX Ultimate applied group. Cylindrical rod shaped samples obtained form Gradia (GC Corporation Tokyo, Japan), Ceramage Body (ShofuInc, Kyoto) , Japan), Tescera ATL (Bisco Dental Products Richmond, USA) and Lava Ultimate(3M ESPE, Seefeld, Germany) were cemented and experimental groups were formed (n=12). Shear force resistance was measured by performing 230 experiments. Fractured surfaces were examined by stereomicroscope and fracture types were determined. Sample surfaces were examined by SEM scanning electron microscope. While evaluating the findings obtained in the study, SPSS IBM 24.0 Software program was used for statistical analysis. The data were evaluated with Shapiro Wilk's test, Mann-Whitney U test and Chi-Square test with a significance level of p<0.05. There is a statistically significant difference in the tensile strength of indirect restorative materials cemented on the tooth with different adhesive systems (p<0.05). The highest shear bond strength on the tooth is in the Ceramage group bonded with RelyX Ultimate adhesive, and the lowest shear bond strength is found in the Ceramagegroup bonded with RelyX U200 adhesive. There is a statistically significant difference in the tensile strength of indirect restorative materials cemented with different adhesive systems on the Z250 composite block (p<0.01). The highest shear bond strength on the composite is in Tescera ATL group cemented with RelyX Ultimate, and the lowest shear bond strength is found in Lava Ultimate group cemented with RelyX U200. As a result of this study, it is found that composite restorations broken in the mouth or deep dentin caries on posterior teeth can be restored with indirect restorations and the adhesive cement type is of great importance for the durability of the restoration.