Dental Abscess

Dental abscess is an acute localized collection of pus associated with a tooth or its supporting structures resulting from polymicrobial bacterial infection. The infection commonly originates from untreated dental caries, pulpal necrosis, periodontal disease, or trauma.

Accumulation of purulent material leads to increased tissue pressure, severe pain, tissue destruction, and potential spread into adjacent fascial spaces. Untreated dental abscess may progress to serious life-threatening odontogenic infections.

Pathophysiology

Dental abscess develops following bacterial invasion of dental or periodontal tissues.

Mechanism of disease development

• Dental caries or trauma exposes dental pulp

• Bacterial invasion causes pulpitis

• Pulp necrosis occurs due to vascular compromise

• Infection spreads beyond the root apex

• Suppuration develops within periapical tissues

• Pus accumulates causing pressure and severe pain

• Infection spreads through bone and soft tissues

• Sinus tract or fascial space infection may develop

Common causative microorganisms

• Streptococcus viridans group

• Staphylococcus aureus

• Prevotella species

• Fusobacterium species

• Peptostreptococcus species

• Mixed anaerobic oral flora

Classification

Periapical Abscess

• Originates from infected dental pulp

• Associated with non-vital tooth

Periodontal Abscess

• Arises from periodontal pocket infection

• Associated with gum disease

Pericoronal Abscess

• Occurs around partially erupted tooth

Risk Factors

• Untreated dental caries

• Poor oral hygiene

• Periodontal disease

• Tooth trauma

• Failed dental restoration

• Immunosuppression

• Diabetes mellitus

• Malnutrition

• Tobacco use

• Delayed dental treatment

Signs and Symptoms

Local features

• Severe throbbing tooth pain

• Gingival swelling

• Facial swelling

• Tooth tenderness to percussion

• Pus discharge around affected tooth

• Bad taste in mouth

• Tooth mobility

• Trismus (limited mouth opening)

Systemic features

• Fever

• Chills

• Malaise

• Fatigue

• Tender regional lymphadenopathy

Diagnostic Criteria

Diagnosis is primarily clinical and includes:

• Fever with systemic discomfort

• Localized throbbing dental pain

• Swelling of gingiva or facial tissues

• Presence of pus discharge

• Tender offending tooth

• Trismus

• Enlarged tender regional lymph nodes

• Aspiration yielding pus confirms abscess

Investigations

Laboratory investigations

• Pus for Gram stain

• Culture and sensitivity (non-responding cases)

• Full blood count when systemic infection suspected

• Blood glucose testing in recurrent infections

Radiological investigations

• Periapical X-ray

• Orthopantomogram (OPG)

Indications include:

• Deep infection suspicion

• Recurrent abscess

• Treatment planning

• Suspected bone involvement

Management

Management requires elimination of infection source plus antimicrobial therapy.

Non-Pharmacological Management

• Incision and drainage of abscess

• Daily irrigation and dressing

• Irrigation using:

  • Hydrogen peroxide 3%

  • Followed by Normal saline 0.9%

• Removal of infection source:

  • Tooth extraction, or

  • Endodontic treatment

• Adequate hydration

• Nutritional support

• Pain relief measures

• Monitoring for spread of infection

Supportive therapy may include:

• IV Normal saline 0.9%

• IV Ringer’s Lactate for dehydrated patients

Pharmacological Management

(According to Tanzania Standard Treatment Guidelines, 2022)

Non-severe infection

• Amoxicillin 500 mg orally every 8 hours for 5 days

PLUS

• Metronidazole 400 mg orally every 8 hours for 5 days

Severe infection

• Amoxicillin–clavulanic acid 625 mg orally every 8 hours for 5 days

PLUS

• Metronidazole 400 mg orally every 8 hours for 5 days

Penicillin allergy

• Erythromycin 500 mg orally every 8 hours for 5 days

Parenteral therapy

(When patient cannot swallow or infection is life-threatening)

• Ampicillin 500 mg IV or IM every 6 hours

OR

• Ceftriaxone 1 g IV once daily

PLUS

• Metronidazole 500 mg IV every 8 hours

Switch to oral antibiotics after clinical improvement.

Important Clinical Note

Incision and drainage is mandatory in established abscess.

Antibiotic therapy alone without definitive drainage or removal of the infection source leads to treatment failure and increased risk of severe odontogenic infection.

Early referral for definitive dental care is essential.

Criteria for Referral to Dental / Maxillofacial Surgeon

• Rapidly progressive swelling

• Difficulty breathing

• Difficulty swallowing

• Fascial space involvement

• Temperature greater than 39°C

• Severe trismus (mouth opening less than 10 mm)

• Toxic or septic appearance

• Immunocompromised patient

• Suspected deep neck infection

Complications

• Facial cellulitis

• Ludwig’s angina

• Osteomyelitis of the jaw

• Deep neck space infection

• Cavernous sinus thrombosis

• Airway obstruction

• Sepsis

• Mediastinitis

Prevention

• Early treatment of dental caries

• Regular dental check-ups

• Proper oral hygiene practices

• Prompt management of tooth pain

• Adequate control of systemic diseases

• Avoid self-medication

• Early dental consultation

Patient Education

• Complete prescribed antibiotics

• Maintain oral hygiene

• Avoid chewing on affected side

• Attend follow-up visits

• Seek urgent care if swelling increases

• Report fever or difficulty swallowing immediately

Prognosis

Prognosis is excellent when early drainage and appropriate antimicrobial therapy are provided. Delayed treatment significantly increases the risk of life-threatening odontogenic and deep fascial infections.