Successive spreader insertion forces induced by undergraduate students during canal obturation

Introduction: To investigate the forces induced by successive spreader insertions by undergraduate dental students. Materials and Methods: Thirty-eight artificial resin teeth (Real-T Endo, Acadental, Lenexa, KS, USA) were used. After canal preparation, the teeth were distributed equally into male and female students to perform canal obturation with the lateral compaction technique. A force gauge (M5-20 Advanced Digital Force Gauge; Mark-10 Corporation, NY, USA) was used for recording the spreader insertion force. Linear mixed model was used to assess the effects of both gender and repeated measures of spreader insertion on spreader penetration forces during canal obturation at a significance level of 5%. Results: The mean maximum forces measured were in the range of 1.13 ± 0.44-1.67 ± 0.64 kg. There was a significant difference between the five insertion times (P = 0.003), and the initial three insertion times were lower than the fourth and fifth times. Although female students apply more force, there was no significant difference when compared to that of male students (P = 0.136). Conclusion: The force gauge device can be used as educational tool to measure the force applied during canal obturation. Although the forces applied by female students were higher than the male students, they were all considered safe.