摘要： Objective The aim of this study was to evaluate, ex vivo, the histological effects of 445-nm diode laser (Eltech K-Laser srl, Treviso, Italy), during an oral soft tissue biopsy. Materials and methods Thirty samples from pig cadaver tongues were obtained, through five laser settings, in continuous and pulsed wave (CW and PW). Samples were divided into six groups of five pieces each. A control specimen was taken by a scalpel. All samples were examined with an optical microscope by a blinded pathologist. Thermal effects on epithelium and connective tissues were measured with LAS 4.8 software. Finally, a statistical evaluation was made using GraphPadPrism 7.0 software. Results All specimens, except one, showed a damage lower than 1 mm. Readability was always optimal; there was a different thermal effect between epithelial and connective tissue and in CW and PW samples, confirmed by statistical analysis too. Conclusions A 445-nm diode laser creates a minimum thermal effect, that has no implications in the histological evaluation of benign lesions. In suspicious lesions, a safety margin of 1 mm, compared with a scalpel, is preferable. Clinical relevance A 445-nm diode laser has excellent surgical properties and can manage many arduous clinical cases, such as vascularized lesions. In the excision of suspected lesions, it is necessary to compare, case by case, clinical advantages to possible histological implications.