In Vivo Evaluation of Diode Laser Use in Lingual Frenectomy: A Histological and Histomorphometric Study.

Background/Objectives: Morphological alterations of the lingual frenulum may impair sucking, speech articulation, and tongue mobility. In such cases, frenectomy is considered the most effective therapeutic approach. High-power lasers have been increasingly adopted due to their precision and reduced surgical trauma. This study aimed to compare the effects of frenectomy performed with a cold scalpel, electric scalpel, and diode laser in Wistar rats. Methods: Forty-five female rats, approximately six months old and weighing 250-300 g, were randomly allocated into three experimental groups (n = 15) according to the surgical technique used. Each group was further divided into three subgroups (n = 5) based on postoperative evaluation periods of 1, 3, and 7 days. After surgery, animals were euthanized at the predetermined time points, and tissue samples from the operated area were collected for histological analysis. Specimens were processed histologically, and sections were analyzed descriptively and semi-quantitatively for inflammatory response. Results: All surgical techniques produced similar inflammatory responses across the evaluated periods, with no statistically significant differences among groups. The inflammatory infiltrate was predominantly acute, characterized by the presence of neutrophils, lymphocytes, and macrophages, with scarce plasma cells and no multinucleated giant cells. Although the cold scalpel group showed greater variability in macrophage response over time, the electric scalpel and diode groups exhibited more consistent inflammatory patterns. Conclusions: All evaluated techniques were biologically equivalent with respect to the initial inflammatory response, with the electric scalpel and high-power laser showing slightly greater temporal stability.