Biomedical and Dental Sciences
Biomedical and Dental Sciences
This domain tests the basic science behind clinical decisions: oral microbiology, host response, bone metabolism, dental tissues, saliva, pharmacology, and systemic links.
Core rules
- Dental biofilm is a polymicrobial community; gingivitis is reversible inflammation, while periodontitis involves attachment loss and host-mediated tissue destruction.
- Calculus is mineralized biofilm; it is not the primary cause but provides a rough surface for biofilm.
- Bone remodeling depends on osteoblast and osteoclast balance; systemic risk factors (diabetes, smoking, osteoporosis) modify progression.
- Enamel demineralizes below pH approximately 5.5; fluoride promotes remineralization as fluorapatite.
- Saliva buffers acids, lubricates, and carries antimicrobial proteins; xerostomia raises caries and candidiasis risk.
- Drug classes matter: bisphosphonates (osteonecrosis risk), anticoagulants (bleeding), beta-blockers (xerostomia), and local anesthetics with epinephrine (cardiovascular caution).
Worked example
A patient with poorly controlled diabetes has 6-mm pockets and BOP. The biological link is bidirectional: hyperglycemia impairs neutrophil function and collagen synthesis, worsening periodontal destruction; periodontal inflammation increases insulin resistance. Reasoning: this supports medical referral, glycemic control counseling, and periodontal therapy rather than extraction alone.
Traps
- Equating gingivitis with periodontitis because both bleed.
- Blaming calculus rather than biofilm for inflammation.
- Forgetting that fluoride works topically, not only systemically.
- Ignoring xerostomia as a caries risk factor.
- Missing medication-related bleeding or osteonecrosis risk.