Taper .02 or .04 in endodontic obturation (filling)

With the incorporation of mechanical systems to the endodontic practice, an increase in tapering of the instruments and gutta-percha cones used in shaping and obturation of root canals was also introduced.  The goal of this paper was to evaluate if  increase of such taper allows to increase gutta-percha mass to an apical level, whenever canals are filled by lateral condensation technique.  Thirty single root teeth with apical curvature were used whose canals were instrumented by means of ProFile System (Denstply-Maillefer, Ballaigues, Switzerland) up to #35 caluber.  To perform such filling they were divided into 2 groups (A-B) and master cones of .02 and .04 taper gutta-percha respectively, also in both of them accessory cones of a lower size than the spreader used which was in all cases of sharp tip stainless steel material. An AH26 was employed as sealant agent. Each tooth was grinded the apical 2mm of the root and after a thorough polish a photograph of the resulting surface was taken (level 1). This procedure was repeated for a second and third time (level II-III) after performing both grindings of ± 1mm in the radicular rennant.  On the digitalized photograph imaging, percentages that gutta-percha occupied in each of the canal levels were determined.  Statistical analysis showed that differences were not significant p > 0.05) when each group was compared and also in apico-coronal direction all the 3 levels tested, but there was a significant difference when comparison of such levels was made between both groups (Levels I: p > 0.0001,  II: p < 0.001 and                  III: p < 0.01). We conclude that taper increase was not improved of filling quality, since in those canals instrumented by means of ProFile System (taper .04) and filled master cones .02, gutta-percha mass was found to be significantly greater than that otained with cones .04 taper in all the 3 levels studied.
Key words: filling canals  –  gutta-percha cones
Project sponsored by Science and Technology Secretariat, National University of Córdoba.