Tobacco
Smoking and chewing tobacco tend to increase the risk of nerve damage. Tobacco contains nicotine, which is a substance that reduces the flow of saliva. Generally, long-term smoking has adverse effects on the oral health of individuals. A study [2] proves that long term smoking would reduce SFR significantly and increase dental and oral disorders connected to dry mouth.
According to the Center for Disease Control and Prevention [3], smoking causes heart diseases, lung disease, cancer, diabetes, and chronic obstructive pulmonary disease. Moreover, it increases the risk of tuberculosis, some eye infections, and the immune system’s problems, which include rheumatoid arthritis.