L20 Dentoalveolar abscess Flashcards
Where is streptococcus salivarius found?
In the saliva and on the tongue
What bacteria are found subginigvally?
Strictly anaerobic bacteria
- S. sanguinis
- Lactobacillus species
- Actinomyces species
- Fusobacterium species
- Treponema species
- Veillonella species
- Capnocytophaga
- Prevotella
- A.a
- P.gingivalis
What type of bacteria cause periapical abscesses?
Subgingival bacteria
Strict anaerobes
Gram negative
How does dental caries progress to a dentoalveolar abscess?
- Necrotic tooth can either progress to dentoalveolar abscess straight away or a periapical granuloma which can last weeks, years etc before becoming an abscess
- Chronic inflammatory processes at the root apex cause bone resorption
What is Ludwig’s angina?
Where a dental infection spreads into the pharyngeal tissue planes (neck), obstructs the airway and can lead to death.
What is cavernous sinus thrombosis?
Where infection from the maxilla spreads backwards into the sinus.
What are alternative names for dentoalveolar abscesses?
- Periapical abscess
- Acute periapical periodontitis
What dictates the spread of infection?
- Anatomical structures e.g. muscle attachments
- Infection perforates alveolar bone below attachment of buccinator = extra oral swelling
- Infection perforates bone above the attachement of buccinator = intra oral swelling
What are the clinical and radiological features of a dentoalveolar abscess?
- Constant throbbing pain
- Often localised to a single tooth
- TTP
- Negative to sensibility testing
- Intraoral and/or extraoral swelling
- Radiograph will show a periapical radiolucency
How should a microbiological sample be taken?
Needle aspiration to reduce contamination from saliva and protect the strict anaerobes present.
- Will see a mixed bacterial species
- The gram negative bacteria are those causing the abscess
- Strict anaerobes
- PMNs present
Name the facultative and strib anaerobes found in dental abscesses.
What are the 2 forms of antimicrobial suscpetibility testing?
- Incubated agar plate with a disc of antimicrobial, check for zone of inhibtion
- E-Test: incubated agar plate with a strip of antimicrobial of varying concentrations, can get a value of the MIC - minimum inhibitory concentration for that specific bacterial species
What species is most commonly resistant to penicillin, why is this?
Prevotella species
Produce beta lactamase
How can drainage be established?
- Incision of soft tissues (drain placed for continued drainage)
- Extraction of tooth
- Pulp extirpation
When should you consider antibiotics for a dentoalveolar abscess?
- Infection is spreading
- Drainage not achieved
- Patient is systemically unwell
- Patient is immunocompromised
What are the 3 first line abx?
- Amoxicillin 500mg capsules TDS for 5 days (double dose for severe infection)
- Phenoxymethylpenicillin 500mg (250mg tablet x2) QDS for 5 days (double dose for severe infection)
- Metronidazole 400mg tablets TDS for 5 days (interacts with alcohol and warfarin)
What is the mechanism of penicillin action?
Binds to transpeptidase active site on cell wall of bacteria. Causes cell wall to break down = bacterial lysis.
What are the 3 second line abx?
- Clindamycin 150mg QDS for 5 days (risk of abx associated colitis) capsules
- Co-amoxiclav 250/125mg TDS for 5 days (risk of cholestatic jaundice) clavulanic acid inhibits beta lactamase, tablets
- Clarithromycin 250mg BD for 7 days (not for statins, warfarin, preg, breast feeding, caution with hepatic or renal impairment or prolonged QT interval) tablets
What prescribing considerations should be made?
- Previous hypersensitivity reactions
- Drug interactions
- Pregnancy or breastfeeding
- Medical conditions e.g. hepatic or renal impairment
What is a chronic discharing sinus?
Untreated abscess = chronic infection tract extraorally
Describe pericoronitis.
- Operculum overlying partially erupted tooth
- Ecological niche for anaerobic bacteria to proliferate under the operculum
- Irrigation
- Abx if there is swelling or systemic involvement
- Metronidazole
- May require XLA of ipsilateral maxillary third molar, on occlusion the upper third molar may cause trauma to the operculum so can be removed
Describe suppurative sialadentitis.
- Acute bacterial infection of a salivary gland
- Usually the parotid or submandibular gland
- Painful swelling and purulent discharge
- Amoxicillin if pt systemically unwell
How is peri-implantitis managed?
A destructive inflammatory proves affecting the soft and hard tissues surrounding a dental implant.
Microbiology is similar to that of periodontal disease.
Treatment = debridement, not abx
