Quantitative determination of cut efficiency during soft tissue surgery using diode lasers in the wavelength range between 400 and 1500 nm

Abstract

Within the scope of this ex vivo study, the cut efficiency was investigated with eight diode laser wavelengths in the range from 400 to 1500 nm. Incisions on porcine gingiva samples were generated in CW-mode at a power range of 0.5–4 W using a bare fiber (∅ = 320 μm) in contact and non-contact mode at a cut speed of 2 mm/s. Cut depths, cut widths, and thermal damages were recorded based on histological sections and were evaluated via measurement masks. Moreover, with respect to the controllability of a therapeutic measure, an efficiency factor was defined. At powers above 2 W, for 445 nm, the maximum cut depth was 820 μm and 344 μm for 810 nm, respectively. At all wavelength and power ranges, the cut width averaged 125 μm. At minimum output power (0.5 W), the spatial expansion of the thermal damage in the tissue surface layer corresponds in the blue/green wavelength range from the very beginning of the laser impact to the fiber core diameter. It could be shown that increases in the diode laser power output do not correlate to the same extent with the incision depth nor with thermal damage to tissue.

Evaluation of cutting efficiency and thermal damage during soft tissue surgery with 940 nm‐diode laser: An ex vivo study

“…However, in the current study, a poor positive correlation between cutting efficiency and output power of laser irradiation was revealed. Moreover, Hanke et al, 1 who investigated various wavelengths of laser radiations, found that the output power increase did not affect linearly and to the same extent the incision depth and thermal damage of gingival tissue, a fact that makes the therapeutic outcome more unpredictable and difficult to control. This was the reason for utilizing efficiency factor γ z , which involves those interactions of the parameters that can influence cutting behavior and thermal damage of the tissues.…”

“…The classification of the histological depictions of the different incisions followed the above categories as shown in Figure 5 1 . Only classes 1 and 2 were taken into account for the measurements.…”

“…Lasers are widely used in dentistry, mainly in the areas of periodontology, endodontics, and operative dentistry. [1][2][3] Dental lasers depending on their wavelength provide ablation properties and generate defined cutting lines and hemostasis via various interactions with the oral soft tissues such as photochemical, thermal, or ablative phenomena. 4 More specifically, semiconductor laser devices (diode lasers) with wavelengths from 445 to 980 nm are commonly used for coagulation or cutting of oral soft tissues.…”

“…Lasers are widely used in dentistry, mainly in the areas of periodontology, endodontics, and operative dentistry 1–3 . Dental lasers depending on their wavelength provide ablation properties and generate defined cutting lines and hemostasis via various interactions with the oral soft tissues such as photochemical, thermal, or ablative phenomena 4 .…”

The blue wavelengths in laser dentistry: a review of current literature

“…In this study 445 nm had the best cutting depth from all other wavelengths. Also the blue wavelengths (405 and 445 nm) alongside the green diode lasers (514 and 532 nm) had better thermal expansion profile, meaning that less output power is needed in order to achieve a good incision in gingival tissue in comparison to than near infrared diodes (810, 940, 980, 1064 nm) [3]. The increased cutting efficiency of 445-nm diode laser was also confirmed bt Braun et al, when compared to a 970-nm diode laser and high-frequency surgery.…”