Stomatology Technology Qualification (China) flashcards

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

Hunter-Schreger bands

Alternating light and dark bands in enamel seen in longitudinal section, caused by decussation of enamel prisms; they increase resistance to crack propagation.

Oblique PDL fibers

The most numerous principal fibers of the periodontal ligament, running from cementum obliquely to alveolar bone; they resist axial occlusal forces and convert them to tension.

Gamma-2 phase

The Sn7-8Hg phase in dental amalgam; it is the weakest and most corrosion-prone constituent, so high-copper alloys are formulated to reduce or eliminate it.

Addition silicone

Polyvinyl siloxane impression material that sets by addition polymerization with minimal shrinkage and high dimensional stability; it is preferred for precise fixed prosthodontic impressions.

Phosphate-bonded investment

Investment material with a phosphate binder and refractory filler, used for high-fusing alloys and metal-ceramic frameworks; it provides adequate expansion to compensate casting shrinkage.

Transformation toughening

Strengthening mechanism of zirconia in which tetragonal grains transform to monoclinic under stress, expanding and creating compressive stress that arrests crack propagation.

Balanced occlusion

Occlusal arrangement in complete dentures with simultaneous contacts on both sides in centric and eccentric positions, stabilizing the dentures during function.

Hanau's equation

L = H/8 + 12, relating condylar guidance (H), incisal guidance, cusp height (L), and compensating curve to achieve balanced occlusion on an articulator.

Tanaka-Johnston analysis

Mixed dentition space analysis that predicts the mesiodistal widths of unerupted canines and premolars from the widths of the four mandibular incisors, using sex-specific equations.

Leeway space

The difference in mesiodistal width between primary canines and molars and their permanent successors, greater in the mandible; it is preserved by a lower lingual holding arch.

Surgical obturator

An obturator placed immediately at the time of maxillary resection to support the surgical dressing, seal the defect, and allow speech and swallowing during early healing.

Platform switching

Use of a smaller-diameter abutment on a wider implant platform, which shifts the implant-abutment junction medially and reduces crestal bone loss.

Geobacillus stearothermophilus

A thermophilic spore-forming bacterium used as a biological indicator to verify steam sterilization efficacy because its spores are highly resistant to moist heat.

Amalgam waste recycling

Collection and recycling of amalgam scrap, filters, and traps to prevent mercury release into the environment, as required by dental waste regulations.

Dentinal tubule density

The number of dentinal tubules per unit area, greater near the pulp (about 45,000/mm²) than near the dentinoenamel junction (about 20,000/mm²), affecting dentin permeability.

A-delta fibers

Myelinated pulpal nerve fibers that conduct sharp, well-localized pain rapidly; they are activated by stimuli such as dentinal fluid movement and are blocked by local anesthetics.

Zinc phosphate cement

A dental cement formed by reaction of zinc oxide powder with phosphoric acid liquid; it has high compressive strength but no chemical adhesion and an initially acidic pH.

Water/powder ratio

The proportion of water to gypsum powder in a mix; increasing it reduces strength and setting expansion, while decreasing it increases both and shortens working time.

Total occlusal convergence

The angle between opposing axial walls of a prepared tooth; a smaller convergence (about 6-10°) increases retention and resistance form of a crown.

Passive fit

A condition in which an implant framework seats without strain or gap at all abutments; misfit can cause screw loosening, fracture, or peri-implant bone loss.

Record base

A temporary base adapted to the cast, used to support occlusion rims and record jaw relations before the final denture base is processed.

Tissue conditioner

A soft, temporary reline material that conforms to inflamed denture-bearing mucosa, providing cushioning and allowing tissue recovery before a definitive reline.

Adams clasp

A removable orthodontic clasp with two arrowheads that engage the mesial and distal undercuts of a tooth, providing retention for removable appliances and retainers.

Cervical vertebral maturation

A method of assessing skeletal maturity from the shape of cervical vertebrae on a lateral cephalogram, used to time orthodontic treatment during growth.

Hollow bulb obturator

An obturator design in which the defect-filling bulb is hollow to reduce weight while maintaining a seal, improving comfort and retention for the patient.

Locator attachment

A stud-type overdenture attachment with a self-aligning design that provides retention and some rotational freedom, available in different retention strengths.

Biological indicator

A preparation of known resistant spores used to monitor sterilization; growth after incubation indicates sterilization failure.

Material safety data sheet

A document providing information on the hazards, handling, storage, and emergency measures for a chemical, required for laboratory chemicals.

SNA angle

A cephalometric angle formed by the sella-nasion line and the line from sella to point A; it indicates the anteroposterior position of the maxilla.

Fluoride release

The ability of a material such as glass ionomer cement to release fluoride ions over time, which may inhibit demineralization and promote remineralization.

Solder flux

A substance applied during soldering to remove oxides and prevent reoxidation, allowing the solder to flow and bond to the parent metal.

Autoclave cycle

A sterilization cycle using saturated steam under pressure, typically 121°C for 15-20 minutes or 134°C for 3-4 minutes, monitored by indicators.