NDEB AFK cheat sheet

Enamel is about 96% inorganic by weight, mainly hydroxyapatite, contains no collagen, and is formed by ameloblasts; mature enamel does not regenerate.

Dentin is about 70% inorganic and 20% organic, mainly type I collagen; dentinal tubules contain odontoblast processes, and fluid movement causes hydrodynamic sensitivity.

Dental pulp is low-compliance loose connective tissue with odontoblasts, vessels, and nociceptors; inflammation raises interstitial pressure and causes pain.

Periodontal ligament width is about 0.15–0.38 mm; Sharpey fibers attach cementum to alveolar bone and transmit occlusal force.

Resting membrane potential is about -70 mV; threshold near -55 mV opens voltage-gated sodium channels, and repolarization occurs by potassium efflux.

RANKL binds RANK on osteoclast precursors to promote osteoclastogenesis; osteoprotegerin is a soluble decoy receptor, and PTH increases RANKL indirectly via osteoblasts.

Warfarin inhibits vitamin K epoxide reductase, reducing functional factors II, VII, IX, X and proteins C and S; its effect is monitored by INR.

Whole saliva flow is about 0.3–0.5 mL/min at rest and 1.5–2.0 mL/min when stimulated; bicarbonate and pH rise with flow, increasing buffering.

Trigeminal V3 provides motor innervation to muscles of mastication and sensory innervation to mandibular teeth; V2 is sensory to maxillary teeth and gingiva.

Endodontic working length is usually 0.5–1.0 mm short of the radiographic apex at the apical constriction to limit overinstrumentation and debris extrusion.

Crown ferrule should be at least 1.5–2 mm of circumferential sound tooth structure; post space should preserve at least 4–5 mm of apical gutta-percha seal.

Periodontitis staging uses clinical attachment loss and radiographic bone loss: stage I is under 15%, stage II is 15–33%, and stages III–IV exceed 33% with complexity factors.

ICDAS scores range from 0 to 6: 0 is sound, 1–2 are early enamel changes, 3–4 involve dentin, and 5–6 show cavitation; higher scores indicate deeper caries.

Primary mandibular central incisors erupt at 6–10 months, primary dentition is complete by about 2.5–3 years, and permanent first molars erupt at about 6 years.

Inferior alveolar nerve block targets the pterygomandibular space near the mandibular foramen and anesthetizes the inferior alveolar and lingual nerves; buccal tissue often needs a separate injection.

Antibiotic prophylaxis before invasive dental procedures is indicated for prosthetic heart valves, previous infective endocarditis, and certain congenital heart diseases, not mitral valve prolapse.

An oral ulcer or lesion persisting longer than two weeks, especially if indurated, painless, fixed, or bleeding, warrants urgent referral or biopsy to exclude malignancy.

Osseointegration is direct bone-to-implant contact without intervening fibrous tissue; stable primary stability and titanium surface roughness favor successful integration.

Sensitivity = true positives / (true positives + false negatives); a highly sensitive test is useful for ruling out disease when negative.

Specificity = true negatives / (true negatives + false positives); a highly specific test is useful for ruling in disease when positive.

Positive predictive value = true positives / all positive results, and negative predictive value = true negatives / all negative results; both depend on disease prevalence.

Incidence counts new cases per population at risk per unit time; prevalence counts all existing cases at a point and rises with longer disease duration.

Relative risk = incidence in exposed / incidence in unexposed in cohort studies; odds ratio = odds of exposure in cases / odds in controls in case-control studies.

Absolute risk reduction = control event rate minus treatment event rate; number needed to treat = 1 / absolute risk reduction.

Transtheoretical model stages are precontemplation, contemplation, preparation, action, and maintenance; relapse can move a person to an earlier stage.

Community water fluoridation is typically about 0.7 mg/L and reduces caries by roughly 25%; excessive fluoride intake during enamel development can cause fluorosis.

Valid informed consent requires capacity, disclosure of material risks and alternatives, comprehension, and voluntary authorization; confidentiality is a related ethical duty.