Indentation Hardness and Tribological Wear in Conditions of Sliding Friction of the Surface Layer of Composites Based on Methacrylate Resins with Ceramic Nanofiller

Biomaterials, that are the subject of this work, are the dental restorative materials classified as light cured polymer matrix ceramic composites or resin based composites. Dental composite materials are needed for repairment of human teeth. Fillings and other dental applications are exposed to biomechanical loading in the chewing process. Wear resistance and hardness are important functional properties. Currently, nanofiller composites play an important role among dental composites. The objective of this paper is to study and analyze friction, mechanical and wear properties of the surface of polymer matrix ceramic filed nanocomposites. Three material groups were used, one commercial composite Filek Z550 (3M ESPE, USA) and two experimental composites Ex-nano(G) and Ex-flow(G). Microindentation tests were conducted on the device Micro Combi Tester (Anton Paar GmbH, Germany). Rotating sliding ball-on-disc friction tests were performed against an alumina ball on 5 N load at 1 Hz in the bath of artificial saliva at 37C. The linear wear and friction coefficients were evaluated. In the light of the obtained results of contact and friction strength tests, it was found that the performance depends on the production technology of polymer-ceramic composites. Test results indicate that the share of filler nanoparticles in experimental composites is advantageous due to tribological wear.