IADR Abstract Archives
In Vitro Evaluation of Gingival Ablation with Various Laser Systems
Objectives: The aim of this study is to histologically and morphologically investigate the thermal effects of gingival ablation with various lasers.
Methods: Er:YAG [1W, pulsed wave (PW)], Er,Cr:YSGG [1W, PW], CO2 [1W, continuous wave (CW)], Diode [1W, CW], and Nd:YAG [1W, PW] lasers; and an electroscalpel and a scalpel as controls; were employed for gingival ablation in resected porcine gingival sheets. After ablations, the wounds were observed using stereomicroscopy and scanning electron microscopy (SEM), and the histological sections were analyzed by light microscopy. Temperature changes during ablation were measured by using an infrared thermal imaging camera.
Results: Stereomicroscopically, carbonization was negligible (after Er:YAG), slight (after Er,Cr:YSGG), moderate (after Nd:YAG and electroscalpel), and severe (after CO2 and Diode). Under SEM observation, the Er:YAG, Er,Cr:YSGG, scalpel, and electroscalpel resulted in relatively smooth wound surfaces, whereas the CO2, Diode, and Nd:YAG resulted in relatively “melted” and “resolidified” wound surface appearances. In the histological analysis, the epithelial wound edges were smooth for Er:YAG, while epithelial collapse was observed with Er,Cr:YSGG, CO2, Diode, and Nd:YAG. At 1W of power level, employed in the present study, Diode and Nd:YAG lasers did not deeply ablate connective tissue, as compared to the other lasers. Thermal coagulation was minimal (approximately 25-30µm in thickness) following Er:YAG laser ablation, as compared to the other groups: Er,Cr:YSGG (55-70µm), electroscalpel (70-80µm), Diode and Nd:YAG lasers (140-155µm), and CO2 (180µm). The highest temperature elevation (over 500°C) was observed during irradiation with CO2, followed by lower temperature elevations observed with Diode and Nd:YAG (approximately 260°C), Er:YAG (160°C), electroscalpel (135°C), and Er,Cr:YSGG (85°C).
Conclusions: Er:YAG laser showed effective, and more refined, gingival ablation with minimal thermal effects on the surrounding tissues.
Methods: Er:YAG [1W, pulsed wave (PW)], Er,Cr:YSGG [1W, PW], CO2 [1W, continuous wave (CW)], Diode [1W, CW], and Nd:YAG [1W, PW] lasers; and an electroscalpel and a scalpel as controls; were employed for gingival ablation in resected porcine gingival sheets. After ablations, the wounds were observed using stereomicroscopy and scanning electron microscopy (SEM), and the histological sections were analyzed by light microscopy. Temperature changes during ablation were measured by using an infrared thermal imaging camera.
Results: Stereomicroscopically, carbonization was negligible (after Er:YAG), slight (after Er,Cr:YSGG), moderate (after Nd:YAG and electroscalpel), and severe (after CO2 and Diode). Under SEM observation, the Er:YAG, Er,Cr:YSGG, scalpel, and electroscalpel resulted in relatively smooth wound surfaces, whereas the CO2, Diode, and Nd:YAG resulted in relatively “melted” and “resolidified” wound surface appearances. In the histological analysis, the epithelial wound edges were smooth for Er:YAG, while epithelial collapse was observed with Er,Cr:YSGG, CO2, Diode, and Nd:YAG. At 1W of power level, employed in the present study, Diode and Nd:YAG lasers did not deeply ablate connective tissue, as compared to the other lasers. Thermal coagulation was minimal (approximately 25-30µm in thickness) following Er:YAG laser ablation, as compared to the other groups: Er,Cr:YSGG (55-70µm), electroscalpel (70-80µm), Diode and Nd:YAG lasers (140-155µm), and CO2 (180µm). The highest temperature elevation (over 500°C) was observed during irradiation with CO2, followed by lower temperature elevations observed with Diode and Nd:YAG (approximately 260°C), Er:YAG (160°C), electroscalpel (135°C), and Er,Cr:YSGG (85°C).
Conclusions: Er:YAG laser showed effective, and more refined, gingival ablation with minimal thermal effects on the surrounding tissues.