AbstractRestoring both anterior and posterior teeth with resin-composite materials is now an established clinical procedure with almost universal acceptance. The clinical performance of these restorations in the patient's mouth is determined by a number of factors including the clinical techniques involved in their placement, the patient's oral habits, and the physical and mechanical properties of the restorative materials themselves. These materials are being increasingly used in load-bearing areas of the posterior dentition and are therefore inevitably subject to masticatory forces of varying magnitude. The success of different resin-composites in different applications is understood through their clinical performance and laboratory-based experimental evaluation.My research was divided into two parts; the first part was concerned with the examination of different types of contemporary restorative resin-composites and in the second part, I compared different methods of examination. In the first part, I investigated and compared different sets of varied types of resin-composites, such as flowable resin-composites, bulk-fill resin-composites and conventional resin-composites. Using different sets of these materials, I examined a number of properties that affect their clinical performance and durability.In the second part, I studied and compared the conventional (macroscopic) methods of investigation with nanoindentation method. Both methods were applied to examine and characterise different properties for some types of resin-composites.The flowable and the bulk-fill resin-composites exhibited satisfactory results comparable with conventional resin-composites. The properties investigated included strength properties, modulus of elasticity, hardness and viscoelastic time-dependent creep deformation. The results obtained by nanoindentation confirmed that this method of examination is a valuable experimental tool to investigate and characterise some mechanical properties of resin-composites.