Abstract

Periapical periodontitis (also termed apical periodontitis, AP, or periradicular periodontitis) is an acute or chronic inflammatory lesion around the apex of a tooth root which is usually caused by bacterial invasion of the pulp of the tooth. The term is derived from "peri-" meaning "around", "apical" referring to the apex of the root (the tip of the root), and "-itis" meaning a disease characterized by inflammation. Periapical periodontitis can be considered a sequela in the natural history of dental caries (tooth decay), irreversible pulpitis and pulpal necrosis, since it is the likely outcome of untreated dental caries, although not always. In some cases, periapical periodontitis can occur due to occlusal high spots post-restoration, endodontic root filling material extrusion or bacterial invasion and infection from a gingival communication (rather than a pulpal source). Periapical periodontitis may develop into a periapical abscess, where a collection of pus forms at the end of the root, the consequence of spread of infection from the tooth pulp (odontogenic infection), or into a periapical cyst, where an epithelial lined, fluid filled structure forms.

Radiographic features

The radiographic features of periapical inflammatory lesions vary depending on the time course of the lesion. Because very early lesions

may not show any radiographic changes, diagnosis of these lesions relies solely on the clinical symptoms . More chronic lesions may show lytic (radiolucent) or sclerotic (radiopaque) changes, or both.

Classification

The type of periapical periodontitis is usually classified according to whether it is an acute/symptomatic process or a chronic/asymptomatic process.

Classification | Acute periapical periodontitis

Acute periapical periodontitis, also termed acute apical periodontitis, acute periradicular periodontitis, or symptomatic periapical periodontitis.

Classification | Chronic periapical periodontitis

Chronic periapical periodontitis, also termed chronic apical periodontitis, chronic periradicular periodontitis, or assymptomatic periapical periodontitis

A periapical granuloma (also termed an apical granuloma or a radicular granuloma) is mass of chronically inflamed granulation tissue that forms at the apex of the root of a nonvital (dead) tooth. However, a periapical granuloma does not contain granulomatous inflammation, and therefore is not a true granuloma, but the term "periapical granuloma" is in common use.

Epidemiology

Periapical periodontitis of some form is a very common condition. The prevalence of periapical periodontitis is generally reported to vary according to age group, e.g. 33% in those aged 20–30, 40% in 30- to 40-year-olds, 48% in 40- to 50-year-olds, 57% in 50- to 60-year-olds and 62% in those over the age of 60. Most epidemiologic data has been generated in European countries, especially Scandinavia. Millions of root canal treatments are carried out in the United States each year, although the total number of root canal treatments is an imperfect indicator of the prevalence of periapical periodontitis, since not always is it performed due to the presence of periapacial periodontitis, and not all cases of asymptomatic periodontitis will be treated in this manner, either due to lack of patient attendance or watchful waiting.

Treatment Options

Treatment options include antibiotic therapy (not a permanent solution), endodontic (root canal) therapy, or extraction.