Dental Abscess (Including Acute Necrotising Gingivitis/Periodontitis)

Clinical definition:

A dental abscess refers to acute or chronic suppurative infection related to the teeth. Symptoms include severe pain, tooth sensitivity, inflammation, and swelling of the gums and face. Acute necrotizing gingivitis/periodontitis refers to acute very painful infection of the gingival margin. Clinical features include foul-smelling breath, necrosis and sloughing of gum margin, loss of gingiva and supporting bone around teeth. It may be associated with underlying illness (e.g. malnutrition, HIV) and may extend to the lips and cheeks without adequate treatment. Infections are usually caused by multiple oral bacteria including anaerobic organisms.


Child & Adolescent

Preferred antibiotic choice
Combination therapy with:

Amoxicillin (PO)


Metronidazole (PO)A

Amoxicillin- Powder for oral liquid: 125 mg (as trihydrate)/5 mL; 250 mg (as trihydrate)/5 mL; Solid oral dosage form: 250 mg; 500 mg (as trihydrate).40-45 mg/kg/dose 12 hourly, maximum dose: 1.5 g 12 hourly5 – 7 days
Metronidazole- Oral liquid: 200 mg (as benzoate)/5 mL. Tablet: 200 mg to 500 mg. Injection: 500 mg in 100-mL vial. 

7.5 mg/kg/dose 8 hourly, maximum dose 300 mg 8 hourly


Alternative antibiotic choice(s)
Clindamycin (PO)Capsule: 150 mg (as hydrochloride). Injection: 150 mg (as phosphate)/ mL; Oral liquid: 75 mg/5 mL (as palmitate).6 mg/kg/dose 6 hourly, maximum dose 450 mg 6 hourly5 days
In case of confirmed drug allergy or medical contraindication
Azithromycin (PO)Oral liquid: 200 mg/5 mL. Capsule: 250 mg; 500 mg (anhydrous).10 mg/kg once daily, maximum dose 500 mg3 – 5 days


Principles of Stewardship:

  • Referral to a dentist is recommended in all cases.
  • If the abscess is drained and the patient is improving, consider stopping antibiotics after 5 days of treatment.
  • For gingivitis alone without necrosis or abscess, do not treat with antibiotics.


  • If a patient cannot tolerate oral antibiotics or for severe disease, IV/IM antibiotics may be considered. Treat with:
    • Ampicillin (25 mg/kg/dose 6 hourly IV or IM, Maximum dose: 500 mg 6 hourly) PLUS metronidazole (7.5 mg/kg/dose 8 hourly IV, Maximum dose: 400 mg 8 hourly), or
  • Ceftriaxone (50 mg/kg/dose once daily IV or IM, Maximum dose: 1 g daily) PLUS metronidazole (7.5 mg/kg/dose 8 hourly IV, Maximum dose: 300 mg 8 hourly)