ABPros Prosthodontics flashcards
ABPros Prosthodontics · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Ante's law
- The total pericemental root surface area of the abutment teeth must equal or exceed that of the teeth being replaced for a fixed partial denture to be biomechanically sound.
- Crown-to-root ratio
- The ratio of the clinical crown height to the amount of root supported by bone; 1:1 is the minimum acceptable for an FPD abutment, and 2:1 or worse indicates a guarded prognosis.
- Furcation involvement
- Loss of periodontal attachment into the root furcation, graded I to IV by severity; Class III and IV furcations generally disqualify a molar as a fixed partial denture abutment.
- Freeway space
- The difference between the vertical dimension at rest and the vertical dimension of occlusion, normally about 2 to 4 mm anteriorly, used to evaluate occlusal vertical dimension.
- Diagnostic mounting
- Placing maxillary and mandibular casts on an articulator using a facebow record to replicate the hinge axis and evaluate occlusion before treatment planning.
- Questionable prognosis tooth
- A tooth whose retention is doubtful should be extracted before fabricating an adjacent prosthesis, because later loss would compromise the existing span design.
- Miller mobility grades
- A 0 to 3 scale of tooth mobility; Grade 3 means greater than 1 mm buccolingual movement with vertical depression, indicating inadequate support for a load-bearing abutment.
- Mounted cast analysis
- Evaluation of occlusal plane, curve of Spee, and interocclusal space on articulated casts to determine whether the planned restoration can be fabricated predictably.
- Chamfer finish line
- A finish line with a 0.3 to 0.5 mm rounded bevel used for metal and metal-ceramic crowns; it preserves tooth structure while providing an adequate margin for casting.
- Shoulder finish line
- A flat 90-degree finish line of about 1.0 to 1.2 mm used for all-ceramic crowns because it provides sufficient bulk of ceramic to resist fracture at the margin.
- Total occlusal convergence
- The combined taper of opposing axial walls of a crown preparation, ideally 10 to 20 degrees; excessive taper reduces retention and resistance form.
- Resistance form
- The feature of a preparation that prevents dislodgment under oblique or lateral forces; it generally requires a height-to-width ratio of at least 0.4.
- Axial reduction metal-ceramic
- Approximately 1.0 to 1.5 mm of axial tooth reduction is required for metal-ceramic crowns to provide adequate porcelain thickness and acceptable esthetics.
- Ovate pontic
- A pontic with a rounded tissue-contacting surface seated into a soft-tissue socket; it requires 2 to 3 mm of tissue depth and provides superior esthetics.
- Connector cross-section
- The cross-sectional area of the joint between pontic and retainer; about 9 mm squared is the minimum for metal-ceramic posterior spans to resist fracture.
- Knife-edge margin
- A thin, unsupported preparation margin that is contraindicated for cast or ceramic restorations because it provides no bulk and leads to marginal distortion or fracture.
- Denture support
- The resistance of a complete denture to vertical seating forces, derived primarily from the residual ridge and underlying bone rather than from border seal.
- Posterior palatal seal
- A valve seal placed at the junction of the hard and soft palate, terminating at or near the fovea palatini, that improves maxillary denture retention.
- Balanced occlusion
- Simultaneous bilateral occlusal contacts in centric and eccentric positions in complete dentures, preventing tipping of the bases and tissue soreness.
- Neutral zone
- The space where forces from the tongue, lips, and cheeks are in equilibrium; placing denture teeth in this zone improves stability and tolerance.
- Lingual bar height
- A mandibular lingual bar major connector requires at least 4 mm of lingual height from the gingival margin to the floor of the mouth for adequate rigidity.
- Akens clasp
- A circumferential retentive clasp used on molars and bounded saddles; it engages the undercut from the occlusal direction and requires a reciprocating arm.
- Roach clasp
- A bar-type retentive clasp approaching from the gingival direction, useful on premolars where esthetics or undercut location favors a tissue-ward approach.
- Border molding
- The process of shaping the denture border with modeling compound during functional movements to capture the full extent of the vestibule and sulcus.
- Insertion torque
- The rotational force measured during implant placement; values above 30 to 35 Ncm generally indicate sufficient primary stability for immediate loading.
- Inter-implant distance
- A minimum of 3 mm should separate adjacent implants, and 1.5 mm should separate an implant from a natural tooth, to preserve crestal bone and papilla.
- Lekholm and Zarb density
- A classification of bone from Type I dense cortical to Type IV low-density trabecular; Type IV sites show lower primary stability and often need delayed loading.
- Implant occlusal scheme
- Flat, shallow cusp inclines with narrowed occlusal tables and no working-side contacts in lateral excursion reduce off-axis load and screw loosening.
- Zirconia flexural strength
- Zirconia has a flexural strength of roughly 900 to 1200 MPa, the highest among common dental ceramics, allowing thinner sections and posterior use.
- Lithium disilicate strength
- Lithium disilicate glass-ceramic has a flexural strength of about 360 to 450 MPa, suitable for single crowns and short-span anterior fixed partial dentures.
- Resin cement indication
- Resin cement is indicated for etched glass-ceramic restorations and for implant crowns where retrievability is desired; it is not interchangeable with zinc phosphate.
- Implant success criteria
- Buser and Albrektsson criteria include annual bone loss under 0.2 mm after year one, no mobility, no pain or neuropathy, and absence of peri-implant radiolucency.