s10-finals-Dental lab communication Flashcards
(35 cards)
What is the first step in disinfecting impressions before sending them to the lab?
Rinse under tap water, then dry and apply chemical disinfectants (gluteraldehyde or iodophore).
Why is inadequate tooth reduction in the cervical third problematic for metal-ceramic restorations?
It risks pulp exposure and compromises esthetics, leading to overcontoured restorations.
What happens if a tooth is underprepared for an esthetic restoration?
Technicians overcontour the restoration, increasing periodontal disease risk.
How should preparation margins be identified on a cast for the technician?
Outline them clearly with a colored pencil (minimal thickness but visible).
Can a collarless restoration be fabricated on a shoulder-bevel margin?
No—it requires a shoulder margin.
Why is proper articulation of opposing casts critical?
Discrepancies may require remakes or corrective grinding, compromising results.
List 5 essential components of a work authorization form.
G - General description of restoration
O - Occlusal scheme
L - Lab specs (Material, e.g., Type IV gold)
D - Design (RPD framework, substructure)
C - Connector type (cast/soldered)
R - Restoration type (crown, bridge, etc.)
S - Shade selection
P - Pontic design + tissue contact material
D - Date of next appointment
GOLD CROWN SPD
DELETED
DELETED
How should occlusal contacts be described in the work authorization?
Specify location (cusp-fossa/marginal ridge) and material (metal/porcelain).
What are the three types of connectors for fixed prostheses?
Cast, preceramic soldered, and postceramic soldered.
Why is wax contour evaluation important for pontic design?
Ensures proper framework design and reduces failure risk.
What is the recommended pontic material for tissue contact areas?
Highly polished porcelain or metal (hygienic design).
Why is shade selection challenging, and how can it be improved?
Due to color variability; use diagrams (cervical/incisal shades) and involve the lab.
What tool should match the ceramic system used by the technician?
A shade guide corresponding to the ceramic brand (e.g., Vita Classical).
How can a shade distribution chart aid the technician?
It maps multi-tonal shades (e.g., translucent incisal, cervical hue).
What is the purpose of diagnostic waxing?
To explore treatment alternatives and plan final restoration contours.
How do adjusted provisional restorations help the technician?
They guide final restoration contours for function/esthetics.
Why are colored photographs useful for the lab?
They provide accurate shade/characterization references.
What disinfectants are used for impressions?
Gluteraldehyde solutions or iodophore sprays.
What is the minimum cervical reduction for metal-ceramic crowns?
1.5 mm (unless risking pulp exposure).
What margin design is required for all-ceramic crowns?
Slightly rounded internal angle (glasslike smoothness).
Why must margins be “glasslike” for porcelain labial margins?
To ensure seamless ceramic adaptation and esthetics.
What error occurs if articulation is incorrect?
Remakes or excessive grinding, compromising occlusion.
What does the work authorization specify for RPDs?
Design (e.g., clasp type, major connectors).
