CDT flashcards
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32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Vibrating line
- The imaginary line at the junction of the hard and soft palate where the soft tissue begins to move; the posterior palatal seal is placed at or near it.
- Freeway space
- The vertical distance between the occlusal surfaces of the maxillary and mandibular teeth when the mandible is in its rest position; it is typically 2 to 4 mm.
- Neutral zone
- The potential space between the tongue and the lips and cheeks where muscular forces are balanced; denture teeth placed within this zone are more stable during function.
- Combination syndrome
- A pattern of bone loss in which a maxillary complete denture opposes a mandibular bilateral distal extension partial denture, causing anterior maxillary resorption, papillary hyperplasia and posterior mandibular resorption.
- Retromolar pad
- A soft tissue pad at the posterior end of the mandibular residual ridge that must be covered by the denture base; it provides support and helps complete the peripheral seal.
- Balanced occlusion
- Simultaneous bilateral contacts of the opposing teeth in centric occlusion and in eccentric positions; it prevents tipping and dislodgement of complete denture bases during function.
- Residual ridge resorption
- Progressive loss of alveolar bone after tooth extraction; it is fastest in the first six months and is greater in the mandible than in the maxilla.
- Kennedy Class I
- A classification in which bilateral edentulous areas lie posterior to the remaining natural teeth, so the prosthesis is a bilateral distal extension supported by teeth and mucosa.
- Applegate's rules
- Rules governing application of the Kennedy classification; the classification is made after all extractions, and the most posterior edentulous area determines the class.
- RPI clasp assembly
- A clasp design of mesial rest, proximal plate and I-bar used on abutments next to a distal extension; the I-bar tip contacts the mesiobuccal surface below the height of contour.
- Indirect retainer
- A component placed on an abutment far from the distal extension, usually on the opposite side, that resists rotation of the prosthesis about the fulcrum line.
- Occlusal rest seat
- A spoon-shaped preparation with the deepest point at the marginal ridge and a floor sloping toward the tooth centre; it provides vertical support and directs forces along the long axis.
- Major connector
- The rigid component that joins both sides of a removable partial denture; the mandibular lingual bar should be at least 4 mm tall and 2 mm thick.
- Chamfer finish line
- A finish line with a rounded internal angle, usually 0.5 mm wide, used for cast metal and metal-ceramic crowns; it preserves more tooth structure than a shoulder.
- Ante's law
- A guideline stating that the total root surface area of the abutment teeth must be equal to or greater than the root surface area of the teeth replaced by the pontics.
- Ferrule effect
- A 1.5 to 2 mm collar of sound axial dentin encircling the core and crown margin; it resists fracture and improves retention of the restoration.
- Die spacer
- A coating applied to the die that creates 25 to 50 micrometres of space for cement; it improves seating and accommodates the film thickness of the luting agent.
- Convergence angle
- The total angle formed between two opposing axial walls of a preparation; about 10 to 20 degrees total provides good retention and resistance while allowing a path of insertion.
- Pier abutment
- A lone abutment tooth between two pontics in a fixed partial denture; a nonrigid connector is often used because the tooth otherwise acts as a fulcrum.
- Eugenol provisional cement
- A provisional luting agent containing eugenol; residues inhibit the polymerization of resin cements and composite core materials, so they must be removed completely.
- Hydrofluoric acid etching
- A surface treatment for glass-based ceramics that dissolves the glassy matrix and creates microporosity; 5 percent acid for 20 seconds is used for lithium disilicate.
- Silane coupling agent
- A primer applied to etched glass ceramic that forms chemical bonds between the silica of the ceramic and the resin cement, in addition to micromechanical retention.
- Transformation toughening
- The mechanism by which zirconia resists crack growth; tetragonal grains transform to monoclinic under stress, expanding and compressing the crack tip.
- MDP primer
- A phosphate ester monomer primer used on zirconia, alumina and metal because these surfaces cannot be etched; it bonds chemically to metal oxides.
- Leucite-reinforced ceramic
- A feldspathic glass ceramic containing dispersed leucite crystals; its flexural strength is roughly 100 to 160 MPa, and it is used for veneers and inlays.
- Lithium disilicate
- A glass ceramic with needle-like lithium disilicate crystals; flexural strength is about 360 to 400 MPa, and it can be etched and adhesively bonded.
- Angle Class II
- A molar relationship in which the mandibular first molar is positioned distally; the mesiobuccal cusp of the maxillary first molar occludes mesial to the buccal groove.
- ANB angle
- The angle formed between the nasion to A point line and the nasion to B point line; about 2 degrees indicates a skeletal Class I relationship.
- Leeway space
- The size difference between the primary canine and molars and their permanent successors; about 0.9 mm per side in the maxilla and 1.7 mm per side in the mandible.
- Anchorage
- Resistance to unwanted tooth movement used to move other teeth; it is classified as maximum, moderate or minimum depending on how much space the reactive unit may consume.
- Andrews six keys
- Six features of normal occlusion: correct molar relationship, crown angulation, crown inclination, absence of rotations, tight contacts and a flat occlusal plane.
- FMA cephalometric angle
- The angle between the Frankfort horizontal plane and the mandibular plane; a mean value of about 25 degrees indicates an average growth pattern.