crown and bridge

Curve of Spree

Concave curve on mandible and convex on maxilla.

Curve of Wilson

Curved line from buccal to lingual, with lingual cusps shorter than buccal cusps.

Height of Contour

Positioned at 1/3 from the gingiva.

Extension of Height of Contour

Extends 0.5mm past the CEJ, except for lingual mandibular posterior which is 0.75 - 1.0 mm.

Inlay Wax

Exhibits thermal expansion, flow increases towards melting range, and strain release can lead to distortion.

Molding Wax

Features low shrinkage, hard non-elasticity, high surface tension, and good carving properties.

Cervical Wax

Shows low shrinkage, stability, good carving properties, residue-free burning, and hardness.

Matrix

Records tooth surfaces from all angles, typically made of silicon.

Mixing Matrix

Requires an equal amount of base and catalyst.

Laws of Casting

Consist of 17 laws to prevent issues like porosity, miscasts, short margins, tears, investment ring issues, nodules, voids, and distortion.

law 1

-attach sprue to the thickest part of wax

law 2

margins should face down and to the right

law 3

position pattern in cold zone

law 4

reservoir must have a sufficient molten alloy

law 5

dont use runner bar

law 6

eliminate turbulence

law 7

select proper casting rings

law 8

reduce surface tension by spraying picosilk

law 9

measure appropriate water powder ratio depending on metal

law 10

use vacuum mixer

law 11

allow investment to set benchset

law 12

select appropriate time and temperature depending on the metal and investment

law 13

melt alloy with heat

law 14

use reducing zone of the flame to melt alloy

law 15

make sure u r using enough force (winded properly)

law 16

cast towards the margins of the wax pattern

law 17

do not quench immediately after casting

Expansion Adjustment

Increase by adding special liquid, warm water, using softer wax, and extending spatula time; decrease by reducing special liquid, using cooler water, harder wax, and decreasing spatula time.

Porcelain Thickness over Metal

Typically 1.0 - 2.0 mm.

Minimum Wax before Casting

0.5 mm.

thinnest metal can be

0.3 mm.

Maximum Metal Thickness

No specific limit.

Base Alloy Burnout Temperature

1550 degrees Fahrenheit.

Final Burnout Time Determinant

Number of rings used.

Metal Calculation

Weight of pattern + sprue x specific gravity of metal = weight of metal needed.

what is the base alloy we used in school called

d.SIGN 30

what is the density of base alloy

7.8

whats the burn out range of base alloy

800-850C 1550F

whats the melting range of the base alloy

1145-1165C

whats the casting range of the base alloy

1240 - 1350C

true or false - do we sandblast our coping after framework

true

whats supragingival

above the gingiva

whats equigingival

at the gingival

whats subgingival

underneath the gingiva

knife edge

used when not enough space for metal - porceline lays above the gingiva

chamfer

curved shape - more space for metal and prceline is able to come down at the gingiva

shoulder

sharp 90*angle

bevel

use to hide subgingival

shoulder with bevel

Thought to provide internal support of
shoulder margin