OR21 - Impact of Repeated Activation on Heat Output of Electric Pluggers

Abstract: Introduction: Electric pluggers that output repeatable and reliable heat are required to thermoplasticize gutta percha for endodontic obturation. The purpose of this study was to evaluate the accuracy and reliability of heat output by Buchanan electronic pluggers after repeated activation cycles. Methods: The Elements Obturation Unit (Kerr Endodontics) was operated in “Downpack” mode according to the manufacturer’s recommendations: a temperature of 200°C with automatic heat cutoff after four seconds of activation. Fifteen Buchanan Heat Pluggers (Kerr Endodontics) were tested, 5 of each of the following sizes: Extra-Fine (XF: 30/.04), Fine (F: 55/.06), and Fine-Medium (FM: 55/.08). Pluggers were allowed to cool for 5-10 seconds between activations, and were activated 25 times per day for 80 days. There were a total of 2,000 activations per plugger. A thermocouple secured in a custom-made jig, and an electronic datalogger (Omega Engineering Inc.) were used to record a single peak temperature for each plugger at the final activation of each day. Results: There was no significant change in heat generation across 2,000 activations for any of the plugger sizes. Size 0.04(XF) pluggers output heat at a significantly lower temperature compared to the 0.06(F) and 0.08(FM) pluggers. Three of the five XF pluggers ceased functioning before 2,000 activations (238, 313 and 421 activations, respectively). Conclusions: Buchanan Heat Pluggers in sizes 0.06 and 0.08 can reliably output heat at a level appropriate to thermoplasticize gutta percha for up to 2,000 activations. Size 0.04 pluggers may be prone to lower temperature output than larger plugger sizes.