RESIN BASED MATERIALS (PDF)

INTRODUCTION
Esthetic dentistry can be defined as the art and science of dentistry, applied to create or enhance beauty of an individual within functional and physiological limits.
Where as cosmetic dentistry is application of the principles of esthetics and certain illusionary principles, performed to signify or enhance beauty of an individual to suit the role he has to play in his day to day life or otherwise. Appearance is closely linked to social acceptance and professional success. No longer are people satisfied with just looking good, it must be coupled with a complete feeling of total well-being. Newer technologies are being harnessed for this purpose and advanced research is being undertaken. Thus, focus of dentistry in the present times is not only on prevention and treatment of disease but also on meeting the demands for better esthetics. Newer dental materials developed for esthetic enhancement are now chosen for their excellent mechanical as well as esthetic qualities. Esthetic dentistry is emerging as one of the most progressive and challenging branches of this field. Thus dentistry has evolved from a curative to a creative science in a very short span.
The modern history of esthetic restorative materials was started with silicate cement, introduced by Fletcher in 1878, the principle anterior restorative material of those days. But, silicate cements were discouraged later on because of their poor strength, irritation to pulp tissue and brittleness. Even the nature of its setting and structure were but imperfectly understood. Self curing acrylic resin was introduced to the dental profession in the mid- 1950s. Initially used for the construction of denture bases, acrylic resin has also been used for many other purposes, including denture teeth, temporary restorations, intraoral splints and veneering agents for crowns and bridges. Since their introduction, acrylic based materials have continued to play a major role in restorative and prosthetic dentistry. But they too showed poor physical properties like high polymerization, shrinkage and coefficient of thermal expansion, irritation to pulp and dimensional instability.
In attempt to improve their properties, and the potential for greater application of resins came about with the introduction of the bisphenol A and glycidyl methacrylate, or BIS-GMA, system by R Bowen in the early 1960s .