Influence of coronal preflaring using gates glidden and protaper instruments on the first apical file size determination - A comparative in vitro study

Abstract

The purpose of this study was to compare the first file that fits to the apex (FFFA) in each canal before and after early flaring to analyze if the size of file to fit to the apex would increase after flaring. Eighty mesial canals of lower first and second molars with complete apical formation and patent foramen were selected. The samples were randomly divided into two groups of 40 canals each. A file was fit to the apex in each canal and that size recorded. Coronal flaring was completed using Gates Glidden in group 1 and Pro Taper in group 2. After flaring a file was again fit to the apex in the same manner as before it is recorded. The mean diameter of first file fitting at apex before flaring (FFFAb) and first file fitting at apex after flaring (FFFAa) flaring was 12.30 (+ 4.31)×10-2 mm and 18.83 (+ 5.91)×10-2 mm respectively for group 1 and was 10.58 (+ 2.56)×10-2 mm and 18.25 (+ 5.94)×10-2 mm respectively for group 2. A paired t test of intragroup values indicated a significance difference (p<0.001) of file size before and after flaring. The increase in diameter was approximately two file sizes for both groups. From this observation it can be concluded that early coronal flaring increases the file size that snug at the apex and awareness of that difference gives the clinician a better sense of canal size. Early flaring of the canal provides better apical size information and with this awareness, a better decision can be made concerning the appropriate final diameter needed for complete apical shaping.