NBDE Part II flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Working length definition

Distance from a coronal reference point to where canal preparation should stop, typically 0.5 to 1.0 mm short of the radiographic apex.

Sodium hypochlorite function

Irrigant that dissolves necrotic and vital organic tissue and kills microorganisms; used at 0.5% to 5.25% and never mixed with chlorhexidine because a precipitate forms.

Master apical file size

Final apical instrument, determined by enlarging the first file that binds at working length by at least three sizes, or by sizing three files larger than the initial apical file.

Amalgam cavosurface angle

Amalgam requires a 90-degree cavosurface margin without a bevel, because beveled enamel leaves thin unsupported amalgam that fractures under occlusal load.

Hybrid layer

Resin-infiltrated demineralized dentin formed after acid etching and adhesive application; its quality determines dentin bond strength and resistance to microleakage.

Polymerization shrinkage stress

Contraction of composite during curing, greatest at bonded interfaces; reduced by placing increments no thicker than about 2 mm and by soft-start curing.

Maximum lidocaine dose

For a healthy adult, 7 mg/kg or about 500 mg total; a 2% cartridge contains 36 mg, so roughly 13 cartridges, with lower limits for children.

Inferior alveolar block target

The lingula, approached with the needle 6 to 10 mm above the mandibular occlusal plane, posterior to the coronoid notch, depositing about 1.5 mL of solution.

Dry socket

Fibrinolytic alveolar osteitis occurring 3 to 5 days after extraction with severe pain and an empty socket; treated with irrigation and medicated dressing, not routine antibiotics.

Tanaka-Johnston prediction

Mixed dentition analysis that adds half the summed mesiodistal widths of the four mandibular incisors to 10.5 mm for the mandible or 11.0 mm for the maxilla.

Leeway space

Difference in mesiodistal width between primary canine and molars and their permanent successors, about 3.4 mm total in the mandible and 1.5 mm in the maxilla.

Frankl behavior scale

Four-point rating of child cooperation: definitely negative, negative, positive, and definitely positive, used to document behavior and guide treatment planning.

Clinical attachment level

Distance from the cementoenamel junction to the base of the sulcus or pocket; the definitive measure of past periodontal destruction and the basis for staging.

Stage versus grade

In the 2018 classification, stage describes severity and complexity of periodontitis, while grade describes rate of progression based on bone loss and risk factors.

Necrotizing ulcerative gingivitis

Painful infection with punched-out papillae, pseudomembrane, bleeding, and halitosis caused by fusiform bacteria and spirochetes; treated with debridement and metronidazole.

Kennedy classification

Classifies partially edentulous arches by the most posterior edentulous area: Class I bilateral posterior, II unilateral posterior, III unilateral bounded, IV anterior crossing the midline.

Lingual bar requirements

Mandibular major connector needing at least 8 mm of floor-of-mouth clearance, 4 mm height, 2 mm thickness, and placement about 3 mm below gingival margins.

Ferrule effect

A 1.5 to 2 mm parallel dentin collar around a crown or core that resists lever forces and increases fracture resistance of endodontically treated teeth.

SLOB rule

Radiographic principle: when the tube head moves, an object moving in the same direction is lingual, while an object moving opposite is buccal.

ASA physical status

Preoperative classification from I (healthy) to IV (severe systemic disease) used to judge medical risk before dental treatment; class III means severe disease limiting activity.

Focal trough

Three-dimensional curved zone of sharpness in panoramic radiography; objects outside it appear distorted or blurred, and patient positioning determines where structures fall.

Aspirin mechanism

Irreversibly acetylates platelet cyclooxygenase, suppressing thromboxane A2 and platelet aggregation for the platelet lifespan of about 7 to 10 days.

Naloxone use

Competitive opioid antagonist given for respiratory depression from opioids; its short half-life may require repeat dosing because the opioid can outlast it.

MRONJ

Medication-related osteonecrosis of the jaw: exposed bone for more than 8 weeks in a patient taking antiresorptives or antiangiogenics, with no radiation history.

Erythroplakia significance

Velvety red patch that cannot be diagnosed as another disease; it has the highest malignant transformation rate of oral mucosal lesions, so biopsy is mandatory.

Ameloblastoma features

Benign but locally aggressive odontogenic tumor, often in the posterior mandible with soap-bubble radiolucency; treatment is resection with margins because recurrence is common.

Gorlin syndrome

Nevoid basal cell carcinoma syndrome with multiple odontogenic keratocysts, bifid ribs, palmar pits, and a calcified falx; inherited as an autosomal dominant trait.

Informed consent elements

Must include disclosure of risks and alternatives, patient capacity, comprehension, and voluntariness; documentation protects the clinician and respects patient autonomy.

Tell-show-do

Behavior guidance technique that explains a procedure in child-friendly words, demonstrates it, then performs it; reduces fear and is first-line for anxious children.

Mandatory reporting duty

Legal obligation to report suspected child abuse or neglect to designated authorities, overriding usual confidentiality; failure may carry criminal or civil penalties.

DMFT index

Counts decayed, missing due to caries, and filled permanent teeth per person; used to compare caries experience across populations and over time.

Sensitivity versus specificity

Sensitivity is the proportion of diseased people correctly identified; specificity is the proportion of healthy people correctly identified as free of disease.