Dental Abscess

Updated: Jan 22, 2019
  • Author: Jane M Gould, MD, FAAP; Chief Editor: Jeff Burgess, DDS, MSD  more...
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Practice Essentials

A dentoalveolar abscess is an acute lesion characterized by localization of pus in the structures that surround the teeth. Most patients are treated easily with analgesia, antibiotics, drainage, and/or referral to a dentist or oral-maxillofacial surgeon. However, the physician should be aware of potential complications of simple dentoalveolar abscess.



The term dentoalveolar abscess comprises 3 distinct processes, as follows:

  • A periapical abscess that originates in the dental pulp and is usually secondary to dental caries is the most common dental abscess in children. Dental caries erode the protective layers of the tooth (ie, enamel, dentin) and allow bacteria to invade the pulp, producing a pulpitis. Pulpitis can progress to necrosis, with bacterial invasion of the alveolar bone, causing an abscess.

  • A periodontal abscess involves the supporting structures of the teeth (periodontal ligaments, alveolar bone). [1] This is the most common dental abscess in adults, but may occur in children with impaction of a foreign body in the gingiva.

  • Pericoronitis describes the infection of the gum flap (operculum) that overlies a partially erupted tooth.

Developmental and acquired conditions are associated with dental abscesses in childhood. Developmental conditions include abnormal morphology of the crown (eg, dens invaginatus, dens evaginatus) and abnormal structure of the dentine (eg, dentine dysplasia, dentinogenesis imperfecta, osteogenesis imperfecta, familial hypophosphatemia). Acquired conditions include pre-eruptive intracoronal resorption and mandibular infected buccal cyst. [2]

Odontogenic infections are polymicrobial, with an average of 4-6 different causative bacteria. The dominant isolates are strictly anaerobic gram-negative rods and gram-positive cocci, in addition to facultative and microaerophilic streptococci. Anaerobic bacteria outnumber aerobes 2-3:1. [3] In general, strictly anaerobic gram-negative rods are more pathogenic than facultative or strictly anaerobic gram-positive cocci.

Generally, a nonpathologic resident bacterium gains entry when the host's defenses are breached, rather than when a nontypical microorganism is introduced. The predominant species associated with dental abscess include Bacteroides, Fusobacterium, Actinomyces, Peptococcus,Peptostreptococcus, and Porphyromonas as well as Prevotella oralis, Prevotella melaninogenica, and Streptococcus viridans. Beta-lactamase producing organisms occur in approximately one third of dental abscesses. [4]

The use of molecular techniques such as 16S rRNA gene sequencing and polymerase chain reaction (PCR) have identified difficult-to-culture organisms and expanded knowledge of the microflora associated with dental abscess. Examples include Treponema, Atopobium, Bulleidia extructa, and Mogibacterium species, as well as Cryptobacterium curtum. [5] A recent Brazilian study using 16S rRNA PCR and sequencing performed on cultivable bacteria from acute apical abscesses revealed the most common identified bacteria were Prevotella sp, Pseudoramibacter alactolyticus, Parvimonas micra, Dialister invisus, Filifactor alocis and Peptostreptococcus stomatis. Recently, a study using 16S rRNA sequencing in 15 patients with primary endodontic infections with and without a sinus tract to the oral cavity revealed Propionibacterium acnes as the most prevalent isolate recovered from lesions with an intraoral communication. Additionally, the authors found no difference in the number of species identified from lesions with or without intraoral communication. [6]




Mortality is rare and is usually due to airway compromise. Morbidity relates to pain, probable tooth loss, and dehydration. See Complications.


No race predilection is observed.


No sex predilection is noted.


Dental abscess is rare in infants because abscesses do not form until teeth erupt. In children, periapical abscess is the most common type of dental abscess. This is because of the combination of poor hygiene, thinner enamel, and the primary dentition having more abundant blood supply, which allows for an increased inflammatory response. In adults, periodontal abscess is more common than periapical abscess.