Testing <scp>LLM</scp> Diagnostics in Endodontics: The Impact of Linguistic Variation on Unseen Cases

GPT-5 Plus outperformed Gemini 2.5 Flash on benchmark dataset; however, it was sensitive to linguistic variations. Perturbation negatively influenced the performance of GPT-5 Plus, emphasising the need to further investigate the linguistic phenomenon that may have affected the model's degradation. Additionally, the descriptive qualitative analysis demonstrated relatively higher performance for Gemini 2.5 Flash compared to GPT-5 Plus on the original dataset and across linguistic variations. However, owing to the descriptive nature of findings and limited sample size, the results should be interpreted with caution.