reading Flashcards
what should all contact after occlusal adjustment
3 anterior and 3 posterior
what part of the tooth should be adjusted in occlusal adjustment
deepen the opposing fossa
what are aliginates made of
hydrocolloids of sodium or potassium salts of alginic acid in water that reacts with calcium sulfate to produce a calcium alignate
how heavy should you adjust
adjust the indicating mark, don’t remove the entire mark
how is CR taken
in the terminal hinge position where opening and closing are purely rotational movements
what is defined as a CR
defined as the maxillomandibular relationship where the condyles articulate with the thinnest avascular portion of their respective disk
why do CR mounting
has more diagnostic value compared to those mounted in MI
what are excursive movement
laterotrusive
protrusive
how is the upper member of an articulator moved for A right laterotrusive movement
upper moved to the left
does CR depend on tooth intercuspation
independent of tooth contact
what do you do to put into CR if mandible is difficult to manipulate
deprogramming device is useful
Bio considerations for the tooth prep
conservation of tooth avoidance of over contour supragingival margin Harmonious occlusion Protection against tooth fracture minimize damage to surrounding dental tissue look at future dental health prep
mech considerations for the tooth prep
affect the integrity and durability of the restoration
Retention
Resistance
Deformation
esthetic considerations of the prep
mini display of metal
maxi thickness of porcelain
porcelain occlusal
subgingival margins
what are so considerations affecting future dental health
Axial reduction for development of good axial contours
margin located supragingival
margin adaptation (junction between restoration and tooth)
Margin geometry
problem with subgingival margins
hard to clean
major factor in periodontal disease
what outranks lack of retention as a cause of failure of crowns
dental caries
porcelain failure
factors concerning retention form
magnitude of dislodging forces
taper (slight, but not parallel cuz won’t be able to seat)
surface area (long walls more retentive)
stress conecetrations ( rounded line angle reduce stress concentration)
types of prep
roughness of surface to be cementeed
material to be cemented ( base metals better retained than less reactive high-gold metals)
types of luting agent
how do lateral movements affect a restoration
displace the restoration by rotating around the gingival margin
good resistance depends on
magnitude and direction of dislodging force
geometry of prep( follows the same rule as retention)
partial coverage has less resistance ( U shaped grooves and boxes help)
luting agents
decresing the temp
what preformed provisional looks the most natural
Polycarbonate( can even be relined to look nicer)
how are polycarbonate crowns supplied
Incisor
Canine
Premolar
why are methyl methacrylates highly exothermic
due to the low molecular weight leading to many reactions
why use sand disks with methacrylates and thermoplastic materials
will melt if you use diamond burs
what is the core of a dental crown
Dentin
how does cement keep the crown on
increases friction
most don’t bind/adhere to the tooth
ideal tapper
6 degrees
how rotation of the prop is stopped
compressive areas called resistance areas
how is prep height related to difficulty of displacement
linear
Roll of silicate glasses
controls shrinkage
strengthens
esthetics
How is zirconia keep stable in its tetrogoneal possition
substituting some Zr4+ with larger ones
when some of the zirconia in dense sintered zirconia is replaced with larger ions
stabilized zirconia
How is all zirconia made
must be milled,
can’t be pressed from wax
