Heat Transfer to the External Root Surface During Use of Wireless Heated Pluggers: An In Vitro Study
Joon Koh DMD1, Albert F. McMullen DDS, FACD2*
1Postgraduate Endodontic Resident, Louisiana State University Health Sciences Center (LSUHSC), USA.
2Department Head and Postgraduate Director, Endodontics, Louisiana State University Health Sciences Center (LSUHSC), USA.
*Corresponding Author: Albert F. McMullen DDS, FACD, Department Head and Postgraduate Director, Endodontics, Louisiana State University Health Sciences Center (LSUHSC), USA.
https://doi.org/10.58624/SVOADE.2026.07.021
Received: May 11, 2026
Published: June 03, 2026
Citation: Koh J, McMullen AF III. Heat Transfer to the External Root Surface During Use of Wireless Heated Pluggers: An In Vitro Study. SVOA Dentistry 2026, 7:3, 159-166. doi: 10.58624/SVOADE.2026.07.021
Abstract
Introduction: Heat generated during thermoplastic obturation may be transferred to surrounding periodontal tissues. The purpose of this study was to evaluate the thermal behavior of wireless heated plugger systems and to determine the time required to produce a 10 °C increase in external root surface temperature, as well as the influence of dentin thickness on heat transfer.
Methods: Five wireless heated plugger systems were evaluated for plugger tip temperature profiles during 25 seconds of continuous activation. Forty extracted human teeth were instrumented to ProTaper Ultimate F3 and obturated using a warm vertical compaction technique. External root surface temperature was measured 5 mm from the apex using a thermocouple, and the time required to reach a 10 °C increase was recorded for four systems. Each specimen was tested with all systems in randomized order. Dentin thickness was measured using cone-beam computed tomography. Data were analyzed using analysis of variance with Tukey post hoc testing and linear regression (P < .05).
Results: Plugger tip temperature profiles varied among systems, with Azdent and Gutta Smart demonstrating substantial temperature overshoot exceeding 500 °C, whereas B&L Alpha II and ZARC maintained more stable temperatures near the preset value. The time required to produce a 10 °C increase differed among systems (P < .05), with Gutta Smart demonstrating the shortest mean activation time (5.2 seconds) and Azdent the longest (11.4 seconds). A significant positive association was observed between dentin thickness and time to temperature increase for all systems (R² = 0.34–0.53, P < .001).
Conclusions: Wireless heated plugger systems exhibit distinct thermal behaviors; however, plugger tip temperature does not directly predict heat transfer to the external root surface. Dentin thickness is a primary determinant of heat transfer, and careful control of activation time is recommended, particularly in teeth with reduced dentin thickness.
Keywords: Warm Vertical Condensation, Heated Pluggers, Endodontics
