Analysis of forces developed during obturations. Comparison of three gutta-percha techniques

The aim of this study was to compare the forces developed during three obturation techniques: warm vertical compaction (WVC), lateral condensation (LC), and thermomechanical compaction (TMC). A force-analyzer device allowed us to record and analyze the forces exerted during the obturations. The different methods, which varied in instrumentation, duration, and compaction load, were studied from graphs representing the force application sequences. In addition, the graphs resulting from specific modifications in the LC technique (use of a single spreader) and deliberately induced failures with TMC (with a too-small condensor or with excessive load) were analyzed. The mean values for the vertical forces for WVC, LC, and TMC were, respectively, 2.5 +/- 0.4 kg, 1.1 +/- 0.3 kg, and 1.65 +/- 0.2 kg. The mean values for the lateral forces were, respectively, 0.85 +/- 0.2 kg, 0.35 +/- 0.1 kg, and 0.5 +/- 0.2 kg. The use of graphs provides a new approach to the analysis of obturation methods and may find its greatest application in the teaching of these techniques. It also has the potential to improve research into obturation technique.