NDLE flashcards

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

Enamel composition

Enamel is about 96% mineral by weight, mostly hydroxyapatite, with little organic material and water. It is avascular and cannot regenerate after eruption.

Dentin tubule direction

Dentinal tubules run from the pulp to the dentinoenamel junction in an S-shaped course in coronal dentin. Tubule density is highest near the pulp, increasing sensitivity.

Pulp nerve fibers

A-delta fibers are myelinated and mediate sharp, well-localized pain. C fibers are unmyelinated and mediate dull, poorly localized pain associated with prolonged noxious stimuli.

Periodontal ligament fibers

The principal fibers include alveolar crest, horizontal, oblique, apical, and interradicular groups. Oblique fibers are most numerous and resist axial occlusal forces.

Salivary buffering

Bicarbonate is the main salivary buffer, with phosphate and proteins contributing. Stimulated saliva has higher flow and buffering capacity than resting saliva.

Foramen ovale

The foramen ovale in the sphenoid bone transmits the mandibular division of the trigeminal nerve (V3) and the accessory meningeal artery.

Lingual nerve contents

The lingual nerve carries general sensation from the anterior two-thirds of the tongue and joins the chorda tympani, which carries taste and parasympathetic fibers.

Facial nerve exit

The facial nerve exits the skull through the stylomastoid foramen and divides within the parotid gland into temporal, zygomatic, buccal, marginal mandibular, and cervical branches.

Muscles of mastication

Masseter, temporalis, medial pterygoid, and lateral pterygoid are all innervated by V3. The lateral pterygoid depresses and protrudes the mandible.

Leukoplakia definition

Leukoplakia is a white patch or plaque that cannot be rubbed off and cannot be diagnosed as another disease. Biopsy is required to assess dysplasia.

Odontogenic keratocyst

Odontogenic keratocyst has a parakeratinized lining with a palisaded basal layer and satellite cysts. It recurs frequently and is associated with PTCH1 mutations.

Ameloblastoma features

Ameloblastoma shows odontogenic epithelium with reverse polarity and stellate reticulum-like areas. It is locally aggressive, common in the posterior mandible, and treated by resection.

Lichen planus

Oral lichen planus presents with bilateral white striae and a band-like lymphocytic infiltrate with basal cell degeneration. Erosive forms require biopsy and management.

Caries bacteria

Streptococcus mutans and S. sobrinus are acidogenic and aciduric and synthesize glucans. Lactobacilli contribute to caries progression.

Red complex

The red complex includes Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola. These species are strongly associated with periodontitis.

Autoclave parameters

Steam autoclaving uses 121 degrees Celsius at 15 psi for 15 to 20 minutes or 132 degrees Celsius for 3 to 4 minutes. Geobacillus stearothermophilus spores are the biological indicator.

Secretory IgA

Secretory IgA is the dominant immunoglobulin in saliva and mucosal secretions. It neutralizes pathogens and prevents adherence to mucosal surfaces.

Local anesthetic pKa

Higher pKa means more drug is ionized at tissue pH, slowing onset. In inflamed acidic tissue, more anesthetic remains ionized and efficacy is reduced.

Lidocaine maximum dose

The maximum dose of lidocaine is 4.4 mg/kg without epinephrine and 7 mg/kg with epinephrine. A 1.8 mL cartridge of 2% lidocaine contains 36 mg.

Epinephrine dilution

A 1:100,000 epinephrine concentration equals 0.01 mg/mL. A 1.8 mL cartridge therefore contains 0.018 mg of epinephrine.

Endocarditis prophylaxis

Amoxicillin 2 g orally 30 to 60 minutes before the procedure is standard prophylaxis for high-risk cardiac patients. Clindamycin is no longer recommended.

Composite shrinkage

Composite resin polymerization shrinkage is about 2 to 3 percent. Incremental layering reduces shrinkage stress and improves curing depth.

Enamel etching

Phosphoric acid at 35 to 37 percent applied for 15 to 30 seconds creates microporosity in enamel for micromechanical retention. Dentin etching is shorter.

Glass ionomer properties

Glass ionomer bonds chemically to tooth structure and releases fluoride. It has low fracture toughness and is used in low-stress areas or as a base.

Zinc oxide-eugenol

Zinc oxide-eugenol is sedative to the pulp but inhibits composite polymerization. A non-eugenol base should be used under composite restorations.

Working length

Working length is typically 0.5 to 1.0 mm short of the radiographic apex. Electronic apex locators detect impedance changes at the apical constriction.

Irrigant interaction

Sodium hypochlorite dissolves organic tissue and is antimicrobial. It must not be mixed directly with chlorhexidine because a precipitate forms; flush with saline between them.

Maxillary first molar canals

The maxillary first molar typically has three roots and four canals: mesiobuccal, mesiobuccal second, distobuccal, and palatal. The MB2 canal is commonly present.

Periodontitis diagnosis

Periodontitis requires clinical attachment loss and radiographic bone loss, not probing depth alone. The 2017 classification uses staging and grading.

Peri-implant mucositis

Peri-implant mucositis is reversible inflammation of peri-implant soft tissue without bone loss. Peri-implantitis adds progressive bone loss and requires treatment.

Posterior palatal seal

The posterior palatal seal is placed at the junction of the hard and soft palate near the vibrating line. It improves retention of complete dentures by creating a seal.

Inferior alveolar block

The inferior alveolar nerve block targets the mandibular foramen using landmarks such as the coronoid notch and pterygomandibular raphe. A 25-gauge long needle is used.