Dentistry
Dentistry questions cover caries and periodontal disease, oral potentially malignant disorders, dental trauma and the few situations where antibiotic prophylaxis is still justified.
Caries and periodontitis
- Caries is driven by Streptococcus mutans fermenting sugars; management is risk-based, from fluoride and sealants to restoration.
- Periodontitis is a plaque-induced inflammatory destruction of the periodontium; key organisms include Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Smoking and poorly controlled diabetes are the major modifiable risks.
Oral pathology
- Oral potentially malignant disorders: leukoplakia, erythroplakia and proliferative verrucous leukoplakia. Erythroplakia has the highest malignant transformation rate.
- Oral squamous cell carcinoma most often affects the lateral border of the tongue and floor of the mouth.
Dental trauma
- Avulsed permanent tooth: handle by the crown, rinse with saline or milk, replant within 30 minutes, splint for about two weeks and refer. Transport the tooth in milk or saline. Do not replant a primary tooth.
Prophylaxis
- Infective endocarditis prophylaxis is now limited to high-risk patients (prosthetic valve, previous endocarditis, certain congenital heart disease, cardiac transplant valvulopathy) undergoing invasive dental procedures.
Worked example
A 10-year-old falls and a permanent central incisor is avulsed and stored dry for 40 minutes. Replant it immediately after gentle rinsing, splint and refer for pulp evaluation, because extraoral dry time above 30 minutes markedly worsens periodontal healing.
Traps
Scrubbing the root, replanting a primary tooth, and prescribing antibiotics for every extraction are common wrong answers.