Taiwan Dentist Licensing Examination cheat sheet

Enamel rods run from the dentinoenamel junction toward the surface; rod direction reverses at the neonatal line, which marks birth.

Amelogenesis is appositional then maturation; maturation-stage ameloblasts are ruffle-ended (resorptive) or smooth-ended (leaky), regulating ion transport.

The four stages of wound healing: hemostasis, inflammation (neutrophils then macrophages), proliferation (granulation, angiogenesis), and remodeling.

Nerve action potential: depolarization from Na+ influx, repolarization from K+ efflux; the refractory period limits maximal firing frequency.

Michaelis-Menten: v = Vmax[S]/(Km+[S]); competitive inhibitors raise Km without changing Vmax, noncompetitive lower Vmax.

Lidocaine blocks voltage-gated Na+ channels from the cytoplasmic side; it is a weak base, so inflamed acidic tissue reduces its efficacy.

Gram-positive cell walls have thick peptidoglycan with teichoic acids; Gram-negative walls have thin peptidoglycan and an outer membrane with lipopolysaccharide.

IgG crosses the placenta and fixes complement; IgA is the predominant secretory antibody in saliva and mucosal surfaces.

The mandibular nerve (V3) exits the foramen ovale; its inferior alveolar branch enters the mandibular foramen and gives off the mental nerve at the mental foramen.

The maxillary artery's third (pterygopalatine) part gives the descending palatine, infraorbital, and sphenopalatine arteries; the middle meningeal artery arises from the second part.

The parotid gland is innervated by glossopharyngeal (CN IX) parasympathetic fibers synapsing in the otic ganglion; its secretomotor fibers travel with the auriculotemporal nerve.

The temporomandibular joint is synovial and bicondylar; the avascular fibrocartilaginous disc divides it into upper (translation) and lower (rotation) compartments.

The periodontal ligament is a dense connective tissue with principal fibers (alveologingival, dentogingival, dentoalveolar, transseptal) that resists occlusal and eruptive forces.

Gustatory fibers: anterior two-thirds of tongue via chorda tympani (CN VII) to the geniculate ganglion; posterior third via CN IX to the inferior ganglion.

The submandibular ganglion is suspended from the lingual nerve; postganglionic fibers supply the submandibular and sublingual glands.

The mandible grows mainly by endochondral ossification at the condylar cartilage and by appositional remodeling of the ramus and posterior border.

Amalgam sets by reaction of silver-tin alloy with mercury forming silver-mercury and tin-mercury phases; residual gamma-2 (Sn8Hg) phase is the most corrosion-prone.

Composite shrinkage stress depends on C-factor (bonded/unbonded surface ratio); higher C-factor cavities (Class I) increase contraction stress.

Glass ionomer bonds chemically to tooth via polyacrylic acid chelation to calcium; it releases fluoride but has low fracture toughness.

Zinc oxide-eugenol is an obtundent temporary material; eugenol inhibits polymerization of resin composites, so resin must not contact it.

Elastic modulus measures stiffness; the higher the modulus, the more rigid the material and the more it resists deformation under load.

Dental porcelain's coefficient of thermal expansion must closely match the metal substructure to prevent porcelain fracture from mismatched expansion.

Gypsum products: stone (alpha-hemihydrate) needs less water and is stronger than plaster (beta-hemihydrate); setting expansion decreases with lower water-to-powder ratio.

Bonding to enamel relies on acid etching (phosphoric acid) creating microporosity; dentin bonding requires removal or infiltration of the smear layer.

Cavity preparation principles: resistance form resists fracture of restoration and tooth; retention form resists displacement; both depend on remaining tooth structure.

Endodontic working length is typically 0.5-1.0 mm short of the radiographic apex; electronic apex locators measure impedance changes at the apical constriction.

The pulp is enclosed by rigid dentin; inflammation raises interstitial pressure, causing necrosis because there is no room for swelling.

Sodium hypochlorite dissolves necrotic tissue and is antimicrobial; it does not remove the smear layer, which requires EDTA or citric acid.

The four main canals in maxillary first molars are MB1, MB2, DB, and palatal; MB2 is the most frequently missed canal.

Dentin permeability is highest near the pulp and in the cervical region because tubules are wider and more numerous there.

Reciprocating or rotary NiTi files should be used with a crown-down sequence and copious irrigation to reduce torsional and cyclic fatigue failure.

Postoperative sensitivity to composite is reduced by using a self-etch or selective-etch adhesive and by controlling polymerization shrinkage.

The path of insertion for a fixed partial denture is determined by the parallel guiding planes of abutment teeth; a surveyor verifies parallelism.

Ante's law states that the root surface area of abutments should equal or exceed that of the pontic; it is a guide, not an absolute rule.

Occlusal vertical dimension is the distance between the maxilla and mandible at maximum intercuspation; loss of it causes reduced freeway space and angular cheilitis.

A removable partial denture's major connector distributes forces; maxillary connectors must cover the palate but avoid the gingival margin by at least 6 mm.

The neutral zone is the space between the lips, cheeks, and tongue where denture teeth are positioned to balance muscular forces.

Cement retention depends on preparation taper (ideally 6 degrees), surface area, and film thickness; excessive taper reduces retention.

The curve of Spee and curve of Wilson must be reproduced in complete dentures for balanced occlusion in eccentric movements.

Abutment selection for a fixed partial denture favors teeth with adequate crown-root ratio (ideally 2:1 or better) and healthy periodontal support.

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

The 2018 classification stages periodontitis by severity (I-IV) based on interdental clinical attachment loss and tooth loss, and grades by progression rate (A-C).

Pocket depth alone does not diagnose periodontitis; clinical attachment level is the reference for true attachment loss.

Scaling and root planing removes subgingival calculus and biofilm; it is indicated for pocket depths of 4 mm or more with bleeding on probing.

Risk factors for periodontitis include smoking, diabetes mellitus, and genetic predisposition; smoking impairs neutrophil function and healing.

The gingival sulcus depth in health is typically 1-3 mm; a depth over 3 mm with attachment loss indicates a periodontal pocket.

Regeneration of periodontal tissues requires a barrier membrane (guided tissue regeneration) or enamel matrix derivative to exclude epithelium.

Aggressive periodontitis (now stage/graded periodontitis) often presents with rapid attachment loss and molar-incisor pattern in younger patients.

The most common odontogenic cyst is the radicular (periapical) cyst; the most common odontogenic tumor is the odontoma.

Ameloblastoma is locally aggressive, typically in the posterior mandible, with a soap-bubble radiographic appearance; treatment is resection with margins.

Oral squamous cell carcinoma most commonly arises on the lateral border of the tongue and floor of the mouth; risk factors include tobacco and alcohol.

Leukoplakia is a clinical diagnosis of a white patch that cannot be rubbed off and cannot be classified as another disease; biopsy is required.

The inferior alveolar nerve block targets the pterygomandibular space; failure is often due to deposition below the lingula or accessory innervation.

Dry socket (alveolar osteitis) presents 2-3 days after extraction with severe pain and an empty socket; treatment is irrigation and a medicated dressing.

Ludwig's angina is a bilateral submandibular/sublingual cellulitis that can obstruct the airway; management is airway protection and surgical drainage.

Aphthous ulcers are recurrent, painful, shallow, non-keratinized mucosal ulcers; they are not infectious and heal within 1-2 weeks.

The mixed dentition period begins with eruption of the first permanent molar (around age 6); the leeway space is larger in the mandible than the maxilla.

Class II malocclusion (Angle) has the mandibular first molar distal to the maxillary; Class III has it mesial.

Eruption times: primary central incisors 6-10 months; permanent first molars and central incisors around 6-7 years.

Ankylosis of a primary molar causes infraocclusion; the affected tooth fails to erupt further and may require extraction or space maintenance.

Space maintainers preserve arch length after premature loss of primary teeth; a band-and-loop is used for a single missing primary molar.

Cephalometric analysis (e.g., SNA, SNB, ANB) assesses skeletal relationships; ANB > 4 degrees suggests a skeletal Class II pattern.

Early childhood caries affects maxillary primary incisors first; fluoride varnish and dietary counseling are preventive measures.

Serial extraction is considered when there is severe crowding with a predictable arch-length deficiency, typically in the mixed dentition.

Informed consent requires disclosure of diagnosis, proposed treatment, alternatives, and risks, obtained from a competent patient without coercion.

Universal precautions treat all blood and body fluids as potentially infectious; gloves, masks, eye protection, and gowns are indicated.

Sterilization by autoclave uses moist heat at 121 degrees C (15 psi) for 15-20 minutes or 134 degrees C for 3-4 minutes; biological indicators verify efficacy.

Dental unit waterlines can harbor biofilm; flushing and chemical treatment reduce microbial counts to acceptable levels.

The Taiwan Dental Law requires dentists to hold a valid license; practicing without a license is a criminal offense.

Confidentiality is a core ethical duty; disclosure requires patient consent or a legal exception such as mandatory reporting of communicable disease.

Epidemiological measures: incidence counts new cases in a period; prevalence counts existing cases at a point in time.

Needlestick injury protocol: wash with soap and water, report immediately, and assess post-exposure prophylaxis for HBV, HCV, and HIV.