The single cone obturation technique with a modified warm filler.

Objectives: The aim of this study was to develop a new method of obturation by warm sealer in conjunction to single cone gutta-percha and evaluate the suitability of this technique to obturate complex root canal systems.

Methodology: Three root canal sealers namely, AH Plus, BioRoot RCS, GuttaFlow and a prototype sealer composed of tricalcium silicate and 30% zirconium oxide mixed with water and water-soluble polymer were investigated. The sealers were tested for flow, film thickness, setting time and radiopacity following ISO 6876 (2012) recommendations at room temperature and following heat application at 100°C to change the sealer properties. All the test sealers were characterized by scanning electron microscopy and energy dispersive spectroscopy. The volume of voids when used with a single cone obturation technique both unmodified and modified by heat was evaluated using microcomputed tomography.

Results: Although the prototype sealer was designed to be similar to the BioRoot, its physical properties were found to be different. All sealers tested were affected by the heat and exhibited a change in the physical properties mainly the setting time, flow, film thickness and void volume.

Conclusions: The application of heat affected the sealer properties and void volume. The single cone obturation technique may not be suitable for complex canal anatomy and furthermore, AH Plus should not be subjected to high temperatures as its properties deteriorate and void volume increases.