Influence of relative positions of the heat carrier and lateral canal opening on gutta- percha obturation of lateral canals in a three-dimensional-printed model

Background/purpose: Effective filling of the lateral canals is of great significance in successful root canal treatment, but it is generally being challenging. This study aimed to evaluate the influence of relative positions of the heat carrier and lateral canal opening on guttapercha obturation of lateral canals in a three-dimensional (3D)-printed model.Materials and methods: Thermal conductivity and real-time temperature transmission of gutta-percha were investigated using laser flash and thermal infrared analyses. 3D-printed root canal models with lateral canals at 1, 3, and 5 mm from the apex were fabricated, and different relative positions of the heat carrier were tested. The obturation process was recorded on video, and the obturation depth of the lateral canals was observed using X-ray micro-computed tomography.Results: Gutta-percha showed low thermal conductivity of 1.07 W/(m$K), and heating increased the temperature of gutta-percha above 60 degrees C only within 1 mm beyond the heat carrier tip. For lateral canals at 1 and 3 mm from the apex, gutta-percha penetrated further with deeper penetration of the heat carrier (P < 0.05). For 5-mm lateral canals, the heat carrier was always at apical level and the gutta-percha obturation depth was more at 2 mm apically than at 3 or 4 mm (P < 0.05).

Automated summary

This study aimed to evaluate the influence of the relative positions of the heat carrier and lateral canal opening on gutta-percha obturation of lateral canals. The results showed that the relative positions of the heat carrier and lateral canal opening affect the obturation depth of gutta-percha.