Background: High-quality root canal obturation plays a quite important role in the success of root canal treatment. Unsatisfied root canal obturation increases the possibility of the failure of root canal treatment. Warm vertical compaction has been widely used because of its advantages such as good plasticity, flow ability and homogeneity. However, the volume change (expansion and shrinkage) of gutta-percha adversely affects the filling efforts. Nowadays, warm vertical compaction technique includes obturation of the apical 1/3 part and the coronal 2/3 part of the root canal. The gutta-percha at the apical 1/3 part of the root canal was heated by inside-root canal-heating device while the coronal 2/3 part heated by a outside-root canal-heating device.To date in our hospital, the most commonly used gutta-percha in warm vertical compaction includes DENTSPLY MAILLEFER gutta-percha point(hereinafter referred to as A), GAPADENT gutta-percha point(hereinafter referred to as B), META gutta-percha point(hereinafter referred to as C). In this experiment, a self-designed volume dilatometric system was used, which can reflect the expansion and shrinkage of gutta-percha during the heating process. We compare the volume changes of the three kinds of gutta-percha points using the dilatometric system for clinical usage.
Objective: To compare the volume changes of the three kinds of gutta-percha points using a self-designed volume dilatometric system.
Methods: (1) Design the volume dilatometric system.
(2) Compare and investigate the volume changes of the three kinds of gutta-percha points using the dilatometric system.
Results: B exhibited the greatest expansion rate at the apical 1/3 part of canal. C exhibited the least shrinkage rate at the coronal 2/3 part of the root canal.
Conclusions: With the self-designed dilatometric system, we found that B showed the best thermomechanical properties for the apical 1/3 part of canal while C was the best for the coronal 2/3 part of the root canal.