Transient nonkeratotic white lesions of the oral mucosa are often a result of chemical injuries caused by a variety of agents that are caustic when retained in the mouth for long periods of time, such as aspirin, silver nitrate, formocresol, sodium hypochlorite, paraformaldehyde, dental cavity varnishes, acidetching materials, and hydrogen peroxide.The white lesions are attributable to the formation of a superficial pseudomembrane composed of a necrotic surface tissue and an inflammatory exudate.
SPECIFIC CAUSATIVE AGENTS
SPECIFIC CAUSATIVE AGENTS
Aspirin Burn. Acetylsalicylic acid (aspirin) is a common source of burns of the oral cavity.Usually, the tissue is damaged when aspirin is held in the mucobuccal fold area for prolonged periods of time for the relief of common dental pain (Figure 5-4).
Silver Nitrate. Silver nitrate is commonly used by health care practitioners as a chemical cautery agent for the treatment of aphthous ulcers.It brings about almost instantaneous relief of symptoms by burning the nerve endings at the site of the ulcer. However, silver nitrate often destroys tissue around the immediate area of application and may result in delayed healing or (rarely) severe necrosis at the application site (Figure 5-5).Its use should be discouraged.
Hydrogen Peroxide. Hydrogen peroxide is often used as an intraoral rinse for the prevention of periodontal disease. At concentrations of ≥ 3%, hydrogen peroxide is associated with epithelial necrosis.Sodium Hypochlorite. Sodium hypochlorite, or dental bleach, is commonly used as a root canal irrigant and may cause serious ulcerations due to accidental contact with oral soft tissues.Dentifrices and Mouthwashes. Several cases of oral injuries and ulcerations due to the misuse of commercially available mouthwashes and dentifrices have been reported (Figure 56).An unusual sensitivity reaction with severe ulcerations and sloughing of the mucosa has been reported to have been caused by a cinnamon-flavored dentifrice (Figure 5-7). However, these lesions probably represent a sensitivity or allergic reaction to the cinnamon aldehyde in the toothpaste.
This reaction can appear to be very similar to the reactions caused by other chemical agents such as aspirin and hydrogen
This reaction can appear to be very similar to the reactions caused by other chemical agents such as aspirin and hydrogen
peroxide. Caustic burns of the lips, mouth, and tongue have been seen in patients who use mouthwashes containing alcohol and chlorhexidine.
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A case of an unusual chemical burn, confined to the masticatory mucosa and produced by abusive ingestion of fresh fruit and by the concomitant excessive use of mouthwash, has also been reported.
TYPICAL FEATURES
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The lesions are usually located on the mucobuccal fold area and gingiva. The injured area is irregular in shape, white, covered with a pseudomembrane, and very painful. The area of involvement may be extensive. When contact with the tissue is brief, a superficial white and wrinkled appearance without resultant necrosis is usually seen. Long-term contact (usually with aspirin, sodium hypochlorite, phenol, paraformaldehyde, etc) can cause severer damage and sloughing of the necrotic mucosa. The unattached nonkeratinized tissue is more commonly affected than the attached mucosa.
TREATMENT AND PROGNOSIS
The best treatment of chemical burns of the oral cavity is prevention. Children especially should be supervised while taking aspirin tablets, to prevent prolonged retention of the agent in the oral cavity.The proper use of a rubber dam during endodontic procedures reduces the risk of iatrogenic chemical burns. Most superficial burns heal within 1 or 2 weeks. A protective emollient agent such as a film of methyl cellulose may provide relief.However, deep-tissue burns and necrosis may require careful débridement of the surface, followed by antibiotic coverage. In case of ingestion of caustic chemicals or accidental exposure to severely corrosive agents, extensive scarring that may require surgery and/or prosthetic rehabilitation may occur.
33,42
A case of an unusual chemical burn, confined to the masticatory mucosa and produced by abusive ingestion of fresh fruit and by the concomitant excessive use of mouthwash, has also been reported.
TYPICAL FEATURES
42
The lesions are usually located on the mucobuccal fold area and gingiva. The injured area is irregular in shape, white, covered with a pseudomembrane, and very painful. The area of involvement may be extensive. When contact with the tissue is brief, a superficial white and wrinkled appearance without resultant necrosis is usually seen. Long-term contact (usually with aspirin, sodium hypochlorite, phenol, paraformaldehyde, etc) can cause severer damage and sloughing of the necrotic mucosa. The unattached nonkeratinized tissue is more commonly affected than the attached mucosa.
TREATMENT AND PROGNOSIS
The best treatment of chemical burns of the oral cavity is prevention. Children especially should be supervised while taking aspirin tablets, to prevent prolonged retention of the agent in the oral cavity.The proper use of a rubber dam during endodontic procedures reduces the risk of iatrogenic chemical burns. Most superficial burns heal within 1 or 2 weeks. A protective emollient agent such as a film of methyl cellulose may provide relief.However, deep-tissue burns and necrosis may require careful débridement of the surface, followed by antibiotic coverage. In case of ingestion of caustic chemicals or accidental exposure to severely corrosive agents, extensive scarring that may require surgery and/or prosthetic rehabilitation may occur.