SDLE (SPLE Dentist) cheat sheet

Resting membrane potential of a typical neuron is about -70 mV; threshold is about -55 mV; depolarization is driven by Na+ influx and repolarization by K+ efflux.

Cranial nerve VII exits the skull through the stylomastoid foramen; chorda tympani carries taste from the anterior two-thirds of the tongue, while the lingual nerve (V3) carries general sensation from the same region.

Collagen type I predominates in bone, dentin, cementum, and periodontal ligament; type II in cartilage; type III in reticular fibers and healing granulation tissue.

Intrinsic coagulation pathway involves factors XII, XI, IX, VIII; extrinsic pathway involves tissue factor and factor VII; both converge on factor X, then V, II (thrombin), and I (fibrin).

Acute inflammation is mediated primarily by neutrophils, histamine, bradykinin, and prostaglandins; chronic inflammation is dominated by macrophages and lymphocytes.

Normal arterial pH is 7.35-7.45; the bicarbonate buffer system is the main extracellular buffer, with a pKa of about 6.1.

Local anesthetics are weak bases that block voltage-gated Na+ channels from the intracellular side; in inflamed tissue the lower pH reduces the proportion of uncharged base and decreases efficacy.

Amoxicillin inhibits bacterial cell wall synthesis by binding penicillin-binding proteins; clindamycin binds the 50S subunit; tetracyclines bind the 30S subunit; metronidazole damages DNA in anaerobes.

Normal platelet count is 150,000-450,000/µL; INR reference is about 0.8-1.2 and aPTT about 25-35 seconds.

FDI system: permanent teeth are 11-48 and primary teeth 51-85; the first digit is the quadrant (1 upper right, 2 upper left, 3 lower left, 4 lower right) and the second is the tooth position from the midline.

Universal numbering: permanent teeth 1-32 begin with the maxillary right third molar and end with the mandibular right third molar; primary teeth use letters A-T.

The maxillary central incisor has the greatest mesiodistal crown width of all anterior teeth; the mandibular central incisor is the narrowest and most symmetrical.

Canines have a single cusp with the cusp tip located slightly mesial to the long axis; they possess the longest root of any tooth.

The maxillary first premolar typically has two roots and two cusps; the mandibular first premolar has a small lingual cusp and a mesial marginal groove.

The maxillary first molar has five cusps including the cusp of Carabelli, an oblique ridge, and three roots; the mandibular first molar has five cusps and two roots with a mesiobuccal groove.

Primary teeth have bulbous crowns, marked cervical constriction, and more divergent roots than permanent teeth; primary molars resemble permanent molars but are smaller.

Posterior contact areas are located in the buccal third of the proximal surface; anterior contact areas are located in the incisal third.

Enamel is about 96% inorganic hydroxyapatite by weight, is formed by ameloblasts, and cannot regenerate after eruption.

Enamel rods extend from the dentinoenamel junction to the surface; their direction is generally perpendicular to the DEJ and varies in decussation.

Dentin is about 70% inorganic; dentinal tubules contain odontoblast processes and dentinal fluid, and tubule density increases toward the pulp.

Pulp nerve fibers: A-delta fibers mediate sharp, well-localized pain; C fibers mediate dull, poorly localized pain.

Acellular extrinsic fiber cementum is found mainly in the cervical third and contains Sharpey's fibers; cellular intrinsic fiber cementum occurs more apically.

Principal periodontal ligament fibers are alveolar crest, horizontal, oblique, apical, and interradicular; oblique fibers are most numerous and resist axial loading.

Junctional epithelium is nonkeratinized and attaches to the tooth by hemidesmosomes; gingival sulcular epithelium is also nonkeratinized, while oral gingival epithelium is keratinized.

Resting salivary flow is dominated by the submandibular glands; stimulated flow is dominated by the parotid glands; total saliva production is about 1-1.5 L/day.

Taste from the anterior two-thirds of the tongue travels via chorda tympani (CN VII), posterior one-third via glossopharyngeal (CN IX), and epiglottis via vagus (CN X).

Dental caries involves acid production by Streptococcus mutans and Lactobacillus; enamel demineralization occurs when plaque pH falls below about 5.5.

Recurrent aphthous stomatitis most commonly affects nonkeratinized mucosa and heals in 7-14 days; minor ulcers are the most common type.

Leukoplakia is a white patch that cannot be scraped off and is not otherwise diagnosed; biopsy is required to assess dysplasia.

Oral squamous cell carcinoma is the most common oral malignancy; risk factors include tobacco, alcohol, and HPV 16; common sites are the lateral tongue and floor of the mouth.

Odontogenic keratocyst is lined by parakeratinized epithelium with palisaded basal cells and has a high recurrence rate; PTCH1 mutations are associated.

Ameloblastoma is the most common clinically significant odontogenic tumor; it often occurs in the posterior mandible with a multilocular 'soap bubble' radiolucency.

Pleomorphic adenoma is the most common salivary gland tumor, most often in the parotid; it is benign but recurs if incompletely excised.

Oral lichen planus is a T-cell-mediated chronic condition; reticular Wickham striae are the most common presentation.

Radiopaque structures are dense and absorb x-rays (enamel, metal, bone); radiolucent structures are less dense (air, soft tissue, caries).

Bisecting angle technique: the central ray is directed perpendicular to the line bisecting the tooth's long axis and the film; it is used when paralleling is not possible.

Paralleling technique: the film is parallel to the tooth's long axis and the central ray is perpendicular, reducing distortion and improving image accuracy.

SLOB rule: in two radiographs, an object that moves in the same direction as the tube head is lingual; one that moves opposite is buccal.

Intraoral film speeds: D, E, and F; F is the fastest and reduces patient dose, consistent with ALARA.

Panoramic radiography images the focal trough and is useful for gross survey but not for caries detection; dose is lower than a full-mouth series.

Cone beam computed tomography provides three-dimensional imaging at lower dose than medical CT and is useful for impacted teeth, implants, and endodontic anatomy.

Pulp vitality testing includes cold testing and electric pulp testing; percussion and palpation assess periapical inflammation rather than pulp vitality.

The SLOB rule and the buccal object rule are the same concept: same direction = lingual, opposite direction = buccal.

Amalgam contains silver, tin, copper, and mercury; high-copper alloys reduce gamma-2 phase and creep; amalgam is not adhesive and is generally avoided in esthetic anterior restorations.

Composite resin typically uses Bis-GMA or UDMA monomers with filler particles; polymerization shrinkage produces stress, especially in high C-factor cavities.

Phosphoric acid at 30-40% is used to etch enamel; etching creates microporosity for resin micromechanical retention.

Glass ionomer cement releases fluoride, bonds chemically to tooth structure, and is biocompatible; resin-modified glass ionomer adds light-cured resin components.

Zinc oxide-eugenol is a sedative temporary cement; eugenol inhibits polymerization of composite resin, so it should not contact resin during curing.

Addition silicone (polyvinyl siloxane) is the most accurate elastomeric impression material; alginate is an irreversible hydrocolloid used for preliminary impressions.

Crown preparation reduction: about 1.5-2.0 mm occlusal and 1.0-1.5 mm axial; finish lines include chamfer, shoulder, and knife-edge depending on material.

The hybrid layer is the resin-infiltrated demineralized dentin zone that provides micromechanical bonding; it is formed after acid etching and adhesive infiltration.

C-factor is the ratio of bonded to unbonded surface area; higher C-factor increases shrinkage stress and the risk of marginal gap formation.

Ante's law: the total root surface area of abutment teeth should equal or exceed that of the teeth replaced by the pontic.

Kennedy Class I is bilateral posterior edentulous area; Class II is unilateral posterior; Class III is unilateral posterior bounded by teeth; Class IV is anterior edentulous area crossing the midline.

A complete denture's posterior palatal seal improves retention by compressing soft tissue at the hard-soft palate junction.

Freeway space is the difference between vertical dimension at rest and at occlusion; it is typically 2-4 mm.

Balanced occlusion in complete dentures requires simultaneous bilateral contacts in centric and eccentric movements to stabilize the prosthesis.

Circumferential (C-clasp) clasps engage undercuts and provide retention; Roach (bar) clasps are used where esthetics or tissue contours limit C-clasps.

Osseointegration is direct bone-to-implant contact; healing typically takes 3-6 months depending on site and bone quality.

A ferrule of 1.5-2.0 mm of sound tooth structure improves resistance to fracture of crowned teeth.

Working length is measured from a coronal reference point to 0.5-1.0 mm short of the apical foramen.

Sodium hypochlorite (0.5-5.25%) dissolves organic tissue and is antimicrobial; EDTA chelates inorganic debris and aids smear layer removal.

Crown-down instrumentation moves from coronal to apical, reducing extrusion of debris and improving access to the apical third.

Reversible pulpitis shows provoked pain that resolves after stimulus removal; irreversible pulpitis shows spontaneous or lingering pain and requires pulp therapy.

Gingivitis is reversible inflammation limited to the gingiva; periodontitis involves attachment loss and alveolar bone loss and is irreversible.

Bleeding on probing indicates gingival inflammation; its absence is a strong predictor of periodontal stability.

Periodontal probing depth greater than 3 mm suggests sulcular deepening; attachment loss is measured from the cementoenamel junction to the base of the pocket.

Scaling and root planing remove plaque and calculus; adjunctive antibiotics may be used in aggressive or refractory periodontitis.

Alveolar osteitis (dry socket) presents 3-5 days after extraction with severe pain and an empty socket; treatment includes irrigation and medicated dressing.

Ludwig's angina is a bilateral infection of the submandibular and sublingual spaces with airway risk; management includes airway control and surgical drainage.

The inferior alveolar nerve block anesthetizes the mandibular teeth, lower lip, and chin; the lingual nerve is blocked separately for lingual soft tissue.

Le Fort I fracture is a horizontal maxillary fracture; Le Fort II is pyramidal; Le Fort III is craniofacial disjunction.

Mandibular fractures are the most common facial fractures; the angle and condyle are frequent sites.

Excisional biopsy is preferred for small lesions that can be removed entirely; incisional biopsy is used for large lesions or suspected malignancy.

Third molar assessment includes relationship to the inferior alveolar canal and lingual nerve; radiographic signs of proximity increase surgical risk.

Angle Class I: mesiobuccal cusp of the maxillary first molar occludes in the buccal groove of the mandibular first molar.

Angle Class II: mesiobuccal cusp of the maxillary first molar occludes mesial to the mandibular buccal groove; Class III occludes distal to it.

Primary teeth begin erupting around 6 months; the first permanent molar erupts around 6 years.

Space maintainers preserve arch length after premature primary tooth loss; band-and-loop and distal shoe are common designs.

Stainless steel crowns are used for severely decayed primary molars; pulpotomy preserves vital radicular pulp.

Orthodontic tooth movement requires light continuous force; heavy force causes hyalinization and undermines movement.

Cephalometric analysis assesses skeletal and dental relationships; cervical vertebral maturation estimates growth status.

DMFT counts decayed, missing, and filled permanent teeth; dmft is the primary dentition equivalent.

Fluoride varnish is typically 5% sodium fluoride (22,600 ppm); APF gel is 1.23% fluoride at pH 3.5.

Community water fluoridation is optimally about 0.7 ppm fluoride.

Primary prevention occurs before disease; secondary prevention detects and treats early disease; tertiary prevention limits disability.

Silness-Loe plaque index and Quigley-Hein index measure plaque; CPITN/PSR measures periodontal treatment needs.

Sensitivity is the probability of a positive test in diseased persons; specificity is the probability of a negative test in healthy persons.

The Ottawa Charter identifies health promotion actions: build healthy public policy, create supportive environments, strengthen community action, develop personal skills, and reorient health services.

Resin sealants are placed on pits and fissures after etching to prevent caries.

Informed consent requires capacity, adequate disclosure, understanding, voluntariness, and authorization.

Negligence requires duty, breach of duty, causation, and damages; all four elements must be proved.

Res ipsa loquitur allows negligence to be inferred when the injury would not ordinarily occur without negligence and the instrument was under the defendant's control.

Confidentiality may be breached when required by law, such as mandatory reporting of child abuse or certain communicable diseases.

Record retention periods vary by jurisdiction; many require adult records for 5-10 years and minors' records until majority plus a statutory period.

Abandonment occurs when a dentist unilaterally terminates care without adequate notice or referral.

Scope of practice is defined by licensure and law; performing procedures outside it may constitute unprofessional conduct.