Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Gum (Periodontal) Disease ?
    ### Response:
    In some studies, researchers have observed that people with periodontal disease (when compared to people without periodontal disease) were more likely to develop heart disease or have difficulty controlling their blood sugar. But so far, it has not been determined whether periodontal disease is the cause of these conditions.
    