This book is meant for students of dentistry to provide the suitable background in materials science that will enable them to properly comprehend dental materials as a dynamic science. It is the first in a series of three books, the other two covering direct restorative materials and indirect restorative materials, respectively. Simple language and an abundance of visual illustrations is provided in this book to serve as self-instructional material for students whose primary language is English, and at the same time as a lecture assisted book for students whose primary language is not English.