Percentage Taper Variations in Endodontic Files- A Review

Endodontic files were initially standardized with a linear variant percentage of 2% taper. These file system shows a drastic difference in percentage taper which can impair the formation of a smooth confluent root canal preparation. A constant percentage file sizing system was later introduced in 1991; it makes more logical sense in the percentage taper of files. However the actual volume of dentin removed between files is inconsistent. At this increase in size, the difference in dentin removal between each file varies from approximately 16% between the first two sizes and approximately 45% between the last two sizes The next system of file introduced is constant volume removal (CVR) type. In this file system the diameter increases uniformly from D1 to D2.The volume of file is the frustum (formed between D1 and D2), each subsequent file in the set has volume greater than its previous file in a predetermined manner