The chemical and biologic properties of dental materials are discussed with each group of materials presented in the chapters that follow this chapter focuses on the physical and mechanical properties ii physical properties a density the amount or mass of a material in a given volume is the density of the material a common unit of density is g cm 3. Physical properties of dental materials cooperative research by the national bureau of standards and the weinstein research laboratories wilmer souder aeur washington d c washington d c aeur physicist national bureau of standards 1 wh souder cg peters bureau of standards technologic paper no 157 dent cosmos 1920 an . What are physical properties physical properties are based on the laws of mechanics acoustics optics thermodynamics elasticity magnetism radiation atomic structure or nuclear phenomena examples color creep viscosity etc 4 abrasion and abrasion resistance abrasion is the process of scraping or wearing phillips science of dental materials 11th edition hardness property of being difficult to indent cut or scratch phillips science of dental materials 11th