Accidental intraoral injection of formalin during extraction: case report

Transparent, clear solutions such as hydrogen peroxide, alcohol, sodium hypochlorite, formaldehyde, and local anaesthetics are widely used in dentistry, so the tissues are liable to accidental injury. Formalin, a 37%-40% solution of formaldehyde, is extensively used in 10% solution as a tissue preservative, but it has toxic effects on systems such as the gastrointestinal tract, respiratory tract, skin, and mucosa. However, we know of few reports of cases of inadvertent injection of alcohol and formalin directly into the human body. In this case report we describe the early and delayed clinical effects of accidental intraoral injection of formalin, the subsequent symptoms and management, and some prudent points that should be learnt to avoid such incidents in the future.