Inflammation of the oral mucosa can result in significant discomfort and disrupt eating habits, thereby diminishing quality of life. Nevertheless, limited self-care treatments are currently available. Oral liquid bandages provide protection by forming a thin film over injured tissues. This study aimed to evaluate the potential risk of acid erosion when a newly formulated oral liquid bandage (ORAPLA) unintentionally comes into contact with teeth and to determine the comparative risk of acid-related erosion at various time intervals corresponding to the upper limit of its continuous-use duration. ORAPLA was applied to enamel and dentin specimens prepared from 45 bovine mandibular anterior teeth, followed by an acid challenge in a simulated oral cavity containing artificial saliva. Each exposure cycle lasted 6 h. Enamel exhibited visible surface defects and a reduction in Vickers hardness after nine cycles, while surface roughness remained unchanged. Dentin samples showed greater parenchymal damage, elevated surface roughness, and a gradual decline in hardness as exposure time increased. No considerable acid corrosion was identified in enamel even after exposure equivalent to nine times the recommended usage limit, nor in dentin after six times that duration. Therefore, the overall acid erosion risk from accidental adherence to tooth surfaces appears minimal, and in a natural human oral environment with salivary buffering and remineralization, it is expected to be even less.
