Periapical abscess

Periapical abscess is an acute or chronic localized collection of pus located at the apex of a tooth root resulting from bacterial infection of the dental pulp. The condition commonly develops as a complication of untreated dental caries, pulpitis, trauma, or periodontal disease.

The infection spreads from the necrotic pulp through the root canal into the periapical supporting bone, leading to inflammatory destruction and suppuration.

Periapical abscess may present as:

• Acute diffuse infection

• Chronic abscess with sinus tract (fistula)

• Localized circumscribed abscess

If untreated, infection may extend into surrounding fascial spaces causing serious odontogenic infections.

Pathophysiology

Periapical abscess develops through the following stages:

• Dental caries or trauma causes pulp inflammation (pulpitis)

• Progressive pulp necrosis occurs due to bacterial invasion

• Microorganisms spread through root canal system

• Infection exits through apical foramen

• Inflammatory response develops in periapical bone

• Bone resorption and pus formation occur

• Pressure accumulation produces severe pain

• Abscess may drain intraorally or extraorally forming sinus tract

Common causative microorganisms

• Streptococcus species

• Peptostreptococcus species

• Prevotella species

• Fusobacterium species

• Anaerobic mixed oral flora

Risk Factors

• Untreated dental caries

• Dental trauma

• Cracked or fractured tooth

• Failed dental restoration

• Poor oral hygiene

• Periodontal disease

• Immunosuppression

• Diabetes mellitus

• Delayed dental treatment

Signs and Symptoms

• Severe persistent throbbing toothache

• Sensitivity to hot and cold stimuli

• Pain radiating to jaw, ear, or neck

• Pain during chewing or biting

• Tooth tenderness on pressure

• Facial or cheek swelling

• Gingival swelling around affected tooth

• Fever

• Enlarged tender lymph nodes

• Foul taste or odor in mouth

• Sudden discharge of pus with temporary pain relief

• Difficulty swallowing or breathing in severe infection

Diagnostic Criteria

Diagnosis is mainly clinical and includes:

• Complaint of localized tooth pain

• Pain aggravated by hot or cold foods

• Pain on occlusion

• Tenderness on vertical percussion

• Localized gingival swelling

• Possible tooth mobility

• Presence of sinus tract in chronic cases

Investigations

Radiological Investigation

• Periapical dental X-ray (mandatory)

Findings may include:

• Periapical radiolucency

• Loss of lamina dura

• Bone resorption

• Periapical granuloma or cyst formation

Advanced Imaging

• CT scan indicated when:

  • Infection spread is suspected

  • Fascial space involvement exists

  • Deep neck infection suspected

Management

Management focuses on:

• Drainage of infection

• Elimination of infection source

• Pain relief

• Prevention of spread

Non-Pharmacological Management

Establish drainage (definitive treatment)

For posterior teeth:

• Extraction of offending tooth under local anesthesiaOR

• Root canal treatment where tooth preservation is possible

For anterior teeth:

• Root canal treatment preferred

• Extraction performed only when tooth is non-restorable

Local anesthesia:

• Lignocaine 2% with adrenaline 1:80,000 used to facilitate drainage

Additional measures:

• Incision and drainage where fluctuant swelling exists

• Removal of necrotic pulp tissue

• Irrigation of infected area

• Maintenance of oral hygiene

Pharmacological Management

(According to Tanzania Standard Treatment Guidelines – 2022)

Analgesics

• Paracetamol 1 g orally every 6–8 hours for 3 days

OR

• Ibuprofen 400 mg orally every 8 hours

Antibiotic Therapy

Antibiotics are indicated when:

• Systemic symptoms are present

• Facial swelling exists

• Spread of infection suspected

• Chronic infection with bone involvement

First-line therapy:

• Amoxicillin 500 mg orally every 8 hours for 7 days

PLUS

• Metronidazole 400 mg orally every 8 hours for 7 days

Penicillin Allergy

• Erythromycin 500 mg orally every 8 hours for 7 days

PLUS

• Metronidazole 400 mg orally every 8 hours for 7 days

Complications

Untreated periapical abscess may lead to:

• Dental cellulitis

• Facial space infection

• Ludwig’s angina

• Osteomyelitis of the jaw

• Sinus tract formation

• Deep neck space infection

• Sepsis

• Airway compromise

Prevention

• Early treatment of dental caries

• Regular dental examination

• Proper oral hygiene practices

• Timely restoration of damaged teeth

• Prompt management of dental trauma

• Completion of dental treatment plans

Patient Education

• Seek dental care early for tooth pain

• Maintain regular tooth brushing and flossing

• Complete prescribed medications

• Avoid self-medication

• Attend follow-up visits

• Report recurrence of swelling or fever immediately

Prognosis

Prognosis is excellent when drainage and definitive dental treatment are performed early. Delay in treatment increases risk of severe odontogenic and systemic infection.