The burning sensation experienced when using smokeless tobacco, often called “dip,” is a direct and expected physiological reaction, not merely a subjective feeling. This reaction occurs because the product is chemically formulated to be abrasive and highly irritating to the delicate tissues lining the mouth. The goal of this chemical manipulation is to maximize the absorption of nicotine into the bloodstream. Understanding the specific mechanisms behind this immediate irritation and the subsequent physical damage it causes is important for comprehending the long-term oral health consequences of using smokeless tobacco.
The Immediate Chemical Causes of the Burn
The immediate burning sensation is largely a consequence of the high alkalinity of smokeless tobacco products. Nicotine is most efficiently absorbed through the oral mucosal lining when it is in its “free-base,” or un-ionized, form, which is achieved in an alkaline environment. To ensure this rapid and potent nicotine delivery, manufacturers add alkalinizing agents like sodium carbonate, sodium bicarbonate, or calcium hydroxide (slaked lime) to the tobacco mixture.
The addition of these chemicals raises the product’s pH significantly, often ranging from 7.0 up to 8.4 or higher, making the product substantially less acidic than the natural oral environment. This high pH is caustic and chemically irritates the soft tissues of the mouth, causing the characteristic burning or stinging sensation upon contact. Furthermore, many products contain flavorings, such as wintergreen or mint, which are known to have their own irritating properties that contribute to the overall feeling of a burn.
Physical Damage to Gum Tissue
The chemical irritation from the product’s high alkalinity initiates an acute physical response in the oral mucosa. The caustic environment damages the protective layer of the gum tissue, leading to an inflammatory reaction known as stomatitis. This reaction is a localized attempt by the body to neutralize the irritant and repair the damaged cells.
The area where the dip is habitually placed, typically the lower lip or cheek, becomes visibly red, swollen, and tender shortly after exposure. The constant presence of the tobacco quid also introduces abrasive particles that cause mechanical trauma, further contributing to mucosal abrasion and micro-lesions. This combined chemical and mechanical assault can lead to the formation of small ulcers or lesions at the site of contact, indicating cellular injury and, in severe cases, localized tissue death.
Chronic Consequences of Tissue Damage
Repeated and chronic exposure to the chemical and physical trauma of smokeless tobacco leads to long-term, irreversible changes in the oral cavity. One of the most common and visible long-term effects is gingival recession, especially at the site where the tobacco quid is held. The constant irritation and inflammation cause the gum tissue to pull away from the tooth root, exposing the sensitive root surface.
Leukoplakia and Cancer Risk
Chronic irritation also frequently results in the development of a precancerous lesion known as leukoplakia. Leukoplakia presents as a white patch or plaque on the oral mucosa that cannot be wiped away. This is a direct consequence of the body attempting to protect itself by thickening the outer layer of tissue. While not all leukoplakia lesions become cancerous, they are considered potentially malignant disorders, and the risk of transformation to oral squamous cell carcinoma is significantly elevated in smokeless tobacco users. The location of oral cancer is often specific to the exact area where the product was habitually placed.