Lesion clinically appearing as a red-coloured (erosion, ulcer, bulla), occurring after contact with a external (e.g. pencil, screwdriver) or internal traumatic agent (e.g. food, an unsuitable filling or fractured teeth/residual root). Once the agent has been identified, its elimination is advisable and the application of a hyaluronic gel with amino acids. If the lesion does not disappear within 15 days, a biopsy and histo-cytopathological examination are required.