A comparative study of temperature elevation on human teeth root surfaces during Nd:YAG laser irradiation in root canals

Abstract

The purpose of this study was to evaluate the temperatures on the root surfaces during Nd:YAG laser irradiation in root canals using pulse durations of 180 and 320 μs. Thirty extracted human teeth were used in this study. The teeth were enlarged up to ISO 40 (multi-rooted) or up to ISO 60 (single-rooted) by conventional technique using K-files. Then the teeth were placed into a water bath with a constant temperature of 37 °C and then irradiated with an Nd:YAG laser having an output power of 1.5 W, a frequency of 15 Hz, using an optic fiber of 200 μm diameter. The temperature on the root surface was measured by means of attaching thermocouples in three areas (coronal, mesial, and apical regions) of the root canals. The thermographic study showed that the average temperature elevation for both pulse durations on the root surfaces was less than 9 °C. There was no significant difference in the observed temperatures in coronal and mesial areas. Though a higher increase of temperature was observed in the apical region when the pulse length of the Nd:YAG laser was 320 μs. The results of the study showed that the temperature rises during Nd:YAG laser irradiation with parameters used in this study minimal to cause damage on bone and periodontal tissues. Moreover, it was suggested that in order to have lower temperature in the apical region, an Nd:YAG laser with a pulse length of 180 μs is preferred than one with a pulse length of 320 μs.

Temperature elevation during root canal treatment with a 445-nm diode laser—an in vitro study

“…In the present study, the temperature reached generally higher values in the apical thirds of the specimens, followed by those of the middle and cervical thirds. The results are in agreement with Strakas et al (2013), who stated that the difference between the mean values for pulse duration differences is higher for apical points followed by those of mesial and coronal points [35]. In contrast, Falkenstein et al (2014) found that the highest values for ΔTmax were in the middle of the root [30], due to the movement of the fiber tip which was guided parallel to the root surface in a constant horizontally swinging movement (∼ 2 mm).…”

Effect of Nd:YAG (1064-nm) and Diode Laser (980-nm) EDTA Agitation on Root Dentin Ultrastructure Properties

“…It was previously reported that Nd:YAG laser at 100 Hz/ 15 W caused an average temperature elevation of <9°C on the root surfaces and, according to the authors, this temperature change would cause minimal damage in bone and periodontal tissues (Strakas et al 2013). 29 As the present study used 15 Hz/1.5 W for Nd:YAG lasers, the temperature increase on the root surface woud have been minimal.…”

1064-nm Nd:YAG and 980-nm Diode Laser EDTA Agitation on the Retention of an Epoxy-Based Sealer to Root Dentin

“…It was previously reported that Nd:YAG laser at 100 Hz/15 W caused an average temperature elevation of less than 9 °C on the root surfaces and this temperature change would cause minimal damage in bone and periodontal tissues (20). As the present study used 15 Hz/1.5 W for Nd:YAG lasers, the temperature increase on the root surface would be minimal.…”