Effectiveness of four methods for preparing root canals: A scanning electron microscopic evaluation

Abstract

In this study, 140 curved root canals of extracted teeth were prepared by one of the four following methods: 1) hand preparation using K files and H files alternately; 2) automated preparation using a sonic air handpiece fitted with Rispisonic and Helisonic instruments or 3) fitted with Shapersonic instruments; or 4) mechanical preparation using Canal Finder instrumentation. The roots were ground saggitally and the specimens were evaluated by scanning electron microscopy. The shaping and cleaning effectiveness of the preparation methods were assessed in terms of surface condition of the canal walls at the level of their coronal, middle, and apical thirds. Each canal was evaluated according to a scale from 1 to 4. A statistical analysis was used to indicate any significant difference in surface condition among the four methods. The results obtained with the manual method were similar to those gained from the Canal Finder method, without any difference between the three parts of the canal. The surface condition of the canals prepared with both Sonic Air methods was better in the coronal and middle thirds than in the apical third where pulp residues were noticed.