This book entitled "Biofilm in Endodontics". The ultrastructure of Endodontic Biofilm should be precisely studied, so as to better understand its physiology, ecology, pathogenicity and how the Biofilm microbes respond to root canal disinfectants. Unravelling the specific composition of endodontic biofilm will require the integration of sophisticated microscopic and molecular microbiological approaches. This knowledge is of utmost important for a detailed understanding of endodontic biofilms, but also in helping to develop better treatment strategies for its eradication in order to achieve complete disinfection of the root canal system and success of endodontic therapy. This textbook enlightens about Endodontic Biofilm; Its Composition, Types, Ultrastructure, Formation and Elimination. Sincere attempt was made to include numerous figures and tables for better understanding of the subject.