Histologic evaluation of the width of soft tissue necrosis adjacent to carbon dioxide laser incisions. This study evaluated the width of tissue necrosis lateral to carbon dioxide laser incisions on human intraoral excisional biopsy specimens. Measurements were made on specimens including epithelium, muscle, dense and loose connective tissue, and salivary gland. Results showed a mean width of tissue necrosis of 86 microns in epithelium, 85 microns in muscle, 51 microns in loose connective tissue, 96 microns in dense connective tissue, and 41 microns in salivary gland. The range of thermal necrosis in different tissue types is probably based on the water content within each type. A cellular partially homogenized zone of reversible thermal damage up to 500 microns in width was visible adjacent to the zone of thermal necrosis. The relatively narrow width of tissue necrosis with this technique may account for the claimed superior properties of laser-induced wounds compared with those created by electrosurgery. 