The Efficacy of Selected Sodium Hypochlorite Heating Methods for Increasing and Maintaining Its Intracanal Temperature—An Ex Vivo Study

Roberto De Santis,Michele Simeone,Vito Gallicchio,Gianrico Spagnuolo,Flavia Iaculli,Vincenzo Lodato,Carlo Rengo

doi:10.3390/app12020891

Abstract

Background: Enhancement of the temperature of sodium hypochlorite (NaOCl) solution would increase its cleaning potential and decontamination of the root canal system. Therefore, the aim of the present in vitro investigation was to compare the efficacy of different methods of NaOCl heating by evaluating the temperature profiles developed at different levels of the root canal system. Methods: Five thermocouples were applied at different levels of the root canal system of extracted human premolars. NaOCl solution was heated according to two methods: extraoral heating (50 °C, 60 °C, and 70 °C) using a magnetic hotplate heater and intracanal heating by F-06, XF-30/04, and ML-12 pluggers at 100 °C, 150 °C, and 180 °C. Results: The extraoral heating method was ineffective to produce a significant temperature increase at the root apex. Comparable results were obtained using the intracanal heating method through the ML-12 plugger that showed slightly better results only when set at 180 °C. On the other hand, negligible differences were observed in terms of temperature maintenance at several levels of the root between the F-06 and XF-30/04 pluggers, even though the time intervals were higher in case of XF-30/04. Conclusions: The intracanal heating method provided a better temperature persistence in the middle third of the root canal system. Conversely, extraoral heating was ineffective to produce a significant temperature increase at the apex of the root. Comparable results were obtained even using the ML-12 plugger.

Highlights

Endodontic success is strictly related to the removal of pulp tissue and to the disinfection of root canal system that may be colonized by microorganisms [1]
The rinsing agents may be used with different effective techniques to promote deep penetration into the entire anatomical aspect of the endodontic canal system, even those not reached by mechanical instrumentation [5]
A marked temperature drop, quantified by the difference between the temperature setting of the extraoral heating system and the peak temperature measured by the setting of the extraoral heating system and the peak temperature measured by the thermocouple (Tc) positioned at the cervical third level (Figure 2), was recorded as NaOCl solution was injected into the root canal

Summary

Introduction

Endodontic success is strictly related to the removal of pulp tissue and to the disinfection of root canal system that may be colonized by microorganisms [1]. Irrigation is reported to have an important antimicrobial/antibiofilm effect through the whole root canal, as well as the ability to remove the smear layer and/or debris produced by mechanical instrumentation [2,3]. The irrigation procedure in endodontics is clinically based on sodium hypochlorite (NaOCl), due to its antibacterial effects and ability to dissolve the organic tissue, coupled with ethylenediaminetetraacetic acid (EDTA), used to remove the smear layer. The rinsing agents may be used with different effective techniques to promote deep penetration into the entire anatomical aspect of the endodontic canal system, even those not reached by mechanical instrumentation [5]. The correct combination of endodontic irrigants and mechanical preparation techniques would contribute to provide an ideal cleaning [6]

Methods

Results

Discussion

Conclusion