Abstract
Gingival enlargement is also known as gingival hyperplasia or hypertrophy and it is an abnormal overgrowth of gingival tissues. This type of lesions can be produced by a large group of pathologic processes. The most common are the reactive hyperplasia which develops in response to a chronic tissue injury that stimulates an excessive tissue repair response. Often, dental prosthesis have been reported to cause this type of lesions due to a mechanical chronic irritation or by a reaction of the oral tissue to substances released into the oral environment by the materials used in manufacturing this type of prosthesis. One of these substances is the methylmethacrylate (PMMA), a widely used in dentistry. The first step in treatment of these lesions is the removal of the irritative factor which sometimes can lead to healing depending on the type of lesion. The challenge is to differentiate a lesion caused by a mechanical irritation from a lesion in which the cytotoxicity of PMMA may be the cause. Often, surgery is the only treatment option for the first situation. When we have an irritative reaction and a cytotoxicity reaction, we must treat them both. Keywords: methylmethacrylate, acrylic resin, TNF alfa, citotoxicity