AtlasDentalPeriapical Abscess

Dental Diseases

Periapical Abscess

aka Dental Abscess · Dentoalveolar Abscess · Apical Abscess

Localised collection of pus at the root apex resulting from pulp necrosis and bacterial infection.

Acute
Pain, swelling, systemic signs
Chronic
Sinus tract, minimal symptoms
Treatment
Drainage + RCT/extraction

Red Flags

  • ·Trismus
  • ·Dysphagia
  • ·Dyspnoea
  • ·Floor of mouth elevation
  • ·Fever >38.5°C

§ overviewOverview

Acute or chronic suppurative process at the periapex secondary to non-vital pulp.

§ icdICD Classification

K04.7

§ etiologyEtiology

  • 01Sequela of untreated caries/pulpitis
  • 02Trauma
  • 03Failed RCT

§ epidemiologyEpidemiology

Common; major cause of dental emergency visits.

§ pathogenesisPathogenesis

Pulp necrosis → bacterial proliferation → PMN accumulation → pus formation → bone resorption → intra/extra-oral sinus if untreated.

§ clinicalClinical Features

  • 01Acute: severe throbbing pain, tooth elevation ('high tooth'), swelling, fever
  • 02Chronic: sinus tract (parulis), mild discomfort or asymptomatic

§ signsSigns & Symptoms

  • 01Tender to percussion
  • 02Mobility
  • 03Regional lymphadenopathy
  • 04Fluctuant swelling

§ differentialDifferential Diagnosis

  • 01Periodontal abscess
  • 02Pericoronitis
  • 03Osteomyelitis
  • 04Lateral periodontal cyst

§ radiographicRadiographic Features

  • 01Widened PDL space (acute)
  • 02Periapical radiolucency (chronic)

§ investigationsInvestigations

  • 01Vitality tests (negative)
  • 02PA radiograph
  • 03Aspiration if fluctuant

§ treatmentTreatment

  • 01Establish drainage: access opening or I&D
  • 02RCT or extraction
  • 03Antibiotics if spreading infection / systemic signs

§ medicalMedical Management

  • 01Amoxicillin 500 mg TDS × 5 days
  • 02Metronidazole add-on for anaerobes
  • 03Analgesics

§ complicationsComplications

  • 01Cellulitis
  • 02Fascial space spread
  • 03Ludwig's angina
  • 04Cavernous sinus thrombosis
  • 05Sepsis

§ prognosisPrognosis

Excellent with drainage and definitive treatment.

§ examKey Examination Points

  • 01Drainage is paramount; antibiotics without drainage fail
  • 02Chronic abscess = radiolucency + sinus tract
  • 03Extraction if non-restorable

§ revisionQuick Revision Summary

  • 01Incision and drainage principle
  • 02Parulis = chronic sinus tract
  • 03Antibiotics adjunctive, not primary

§ vivaBDS Viva Questions

  • 01How do you differentiate periapical from periodontal abscess?
  • 02What is the significance of a sinus tract?
  • 03When are antibiotics indicated?

§ mcqsMCQs — Assessment (3)

Question 1

Most important initial treatment for periapical abscess:

Question 2

A 'gum boil' (parulis) indicates:

Question 3

Radiograph of acute periapical abscess may show:

References

  1. Neville BW. Oral & Maxillofacial Pathology, 4e
  2. Topazian RG. Oral and Maxillofacial Infections, 4e

Draft — pending faculty review. Educational use only; verify against current guidelines and primary sources before clinical application.