A comparative study of wound healing following incision with a scalpel, diode laser or Er,Cr:YSGG laser in guinea pig oral mucosa: A histological and immunohistochemical analysis

Abstract

Objective. This study compared wound healing following incisions with either a scalpel, a diode laser or an Er,Cr:YSGG laser in guinea pig oral mucosa. Material and methods. Three types of wound were made randomly with either a stainless-steel scalpel, a diode laser or an Er,Cr:YSGG laser in the buccal mucosa of 24 guinea pigs. Five guinea pigs were sacrificed on each of Days 1, 3, 5 and 7 post-surgery. Four guinea pigs were sacrificed on Day 14 post-surgery. Biopsy samples from each oral mucosa wound were examined using light microscopy and the expression of tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β1 was determined by immunohistochemical staining. The expression of TNF-α and TGF-β1 was evaluated by calculating the percentage of positively stained cells and immunostaining intensity was evaluated using a scale ranging from 0 to 3. Results. Infiltration of inflammatory cells decreased rapidly at Day 5 post-surgery in all three groups of animals. The highest level of TNF-α expression was found at Day 1 post-surgery for the diode laser wounds. The intensity of TNF-α immunostaining was highest at Day 3 post-surgery and lowest at Day 7 post-surgery for all three groups of animals. For the scalpel wounds, a lower level of TGF-β1 expression was seen until Day 3 post-surgery and a higher level from Day 7 post-surgery compared to laser wounds. The intensity of TGF-β1 immunostaining was highest at Day 1 post-surgery for the diode laser wounds. Conclusions. The diode laser is considered a good cutting device for oral mucosa; however, more tissue damage occurs than with the use of a scalpel or an Er,Cr:YSGG laser. Larger studies will be needed before fully endorsing the widespread use of the diode laser.