Composite resins are types of synthetic resins which are used in dentistry as restorative material or adhesives. Synthetic resins evolved as restorative materials since they were insoluble, aesthetic, and insensitive to dehydration and were inexpensive. This book presents topical research in the study of resin composites, including water immersion and impact damage effects on resin composites; fabrication and evaluation of bioactive dental composites; nanostructured organosilicate composites; the electromagnetic properties of a composite made of metal particles dispersed in resin and posterior composite resin restoration.