Comparative study of diode lasers used for two time intervals for the treatment of teeth with vertical root fractures

Background/aim
Vertical root fracture treatment is considered a challenge in endodontics. And no single approach up till now gives satisfactory results. The present study aimed to compare the effect of a 970 nm diode laser in a continuous wave at different time intervals with a resin-based sealer or a resin-based sealer only on sealing of vertical root fractures of extracted teeth.
Materials and methods
Thirty upper single-rooted teeth were sectioned below the cement enamel junction. A groove of 5 mm length and 1 mm width was done at the root surface. Specimens were divided into three groups (10 each). Group 1 using sealer only, group 2 using a 970 nm diode laser irradiation at a power of 1.5 W at continuous mode for 60 s, and group 3 using a 970 nm diode laser irradiation at a power of 1.5 W and at continuous mode for 90 s. In groups group 2 and group 3, the root fracture line was filled with a sealer followed by diode laser irradiation and the gap size was examined by scanning electron microscopy. Temperature rise at the root surface was also measured using a temperature meter. Statistical analysis was carried out using one-way analysis of variance and the Tukey test (<0.05).
Results
The statistical analysis showed that using laser with a 1.5 W/90 s group 3 showed the statistically least fracture gap (1.22 μm) while group 1 showed a gap of 8.57 μm and group 2 a gap of 2.44 μm.
Conclusion
The present study concluded that the application of a 970 nm diode laser at 90 s decreased the gap between the sealer and the root surface at the fracture line in extracted teeth.