34. Dental Materials/ Prostho (CD) Flashcards
Example of Inelastic Imp matl
Plaster of paris
used as impression plaster before
Example of ELASTIC Imp Matls
Colloidal soln
Zoe
Imp compound
Elastomers
Reversible hydrocolloids used in lab for duplication. From seaweeds.
Agar agar
BQ: Imp material that uses specialized equipment
Agar
Unique property of agar agar.
—ability of matl to change its form based on temperature
(Liquefaction/gelation)
Hysteresis
Property of agar agar to absorb water = expansion
Imbibition
Property of agar agar to release water = shrinks
Syneresis
BQ: Principal content of agar agar
Water
Hardener of agar agar
Borax
Least exp/cheapest imp matl
Fastest setting time
LEAST DIMENSIONALLY STABLE
Alginate or Irreversible hydrocolloids
BQ: Flexites is made of
Nylon
BQ: Major reactor of alginate
Sodium alginate or Potassium Alginate
Reactor of alginate
Calcium sulfate
BQ: Filler of Alginate
(Sa boards: SILICA!!!!)
* diatomaceous earth
Retarder of alginate
Sodium phosphate
BQ: Principal component of alginate
Diatomaceous earth
“Set alginate”
Calcium alginate
Ways to DECREASE SETTING TIME (faster set)
Inc water temp (hot/warm)
Mix rapidly (more friction=more heat)
Decrease water:powder ratio (thick)
BQ: what happens if you add a drop of liquid in ZOE
Decrease setting time (faster set)
BQ: Eugenol is derived from what oil?
Oil of cloves
Has obtundent effect on pulp; used for tx of dry socket
Eugenol
What are contraindicated with RESINS
Cavity varnish
Eugenol
BQ: How many coats of cavity varnish applied
1-2 coats
BQ: How long will the cavity varnish seal dentinal tubules
Short term
Imp compound or modelling compound/cake can be softened by:
Dry heat - torch—best
Water bath —most common
Examples of ELASTOMERS (PSP)
Polysulfide
Silicones
Polyether
Elastomers with longest setting time, foul odor, stains
Polysulfide
Stains and foul odor bec of lead peroxide
Least dimensionally stable AMONG ELASTOMERS
Condensation silicone
Least dimensionally stable Among ALL IMP MATLS
Alginate
Most dimensionally stable among elastomers
Addition silicones
Most expensive and accurate: used in FPD
Polyether
Chemical name of gypsum products
Calcium sulfate hemihydrate
Plaster of paris is aka
Beta calcium sulphate hemihydrate
Type I gypsum
Impression plaster
Type II gypsum
Model plaster
Type III gypsum
Dental stone
Type IV gypsum
High strength stone or die stone
Dental stone is aka
Alpha calcium sulphate hemihydrate
Open kettle
Irreg and porous particles
Plaster of paris
Closed kettle
Regular and lesser porous particles
Dental stone
+ Calcium Chloride
Larger regular particles and denser than dental stone
High strength or die stone
BQ: All of the ffg will happen when water:powder ration is increased, except:
A. Produce thinner mix
B. Slow setting time
C. Stronger mix
D. Dec expansion
C. Stronger mix
BQ: Among the 3 gypsum products, which has the highest setting expansion?
A. POP
B. Dental stone
C. Die stone
D. Same
A. Plaster
Gypsum retarder:
—delays setting time
⬆️ setting time (para hndi mabilis magset)
Borax
Na citrate
Gypsum accelerator:
⬇️ setting time = faster set
Gypsum
KSO4
NaCl
Investment for CAST GOLD
Gypsum bonded investment
Investment for cast cobalt chromium
Phosphate bonded investments
Binder in investing material = binds heat
Gypsum
Refractory material = resists heat
Silica
Process of ⬆️⬆️⬆️ temp
Burn out
Using centrifugal force = mold space
Casting process
Type of wax used in inlays, crowns, rpd wax, casting wax
Pattern wax
BQ: Principal component of pattern waxes
Paraffin
Type of wax used in master cast construction. Boxing wax, sticky wax, utility wax
Processing wax
Ideal thickness of base of the master cast
16mm
Type of wax: bite wax
Corrective wax
BQ: 3 most common natural waxes used in dental waxes are
Paraffin
Beeswax
Carnauba
BQ: Have the HIGHEST CTE among all dental materials
Waxes
Tendency of a molecule to expand or shrink depending on the temperature
HOT: expands / COLD: shrinks
Coefficient of thermal expansion = highest in waxes!!!!
Highest CTE among restorative materials
Unfilled resin (80)
CTE of teeth is close to GOLD
Teeth - 11
Gold - 14
Exposure of walls of preparation to a fluid or mov’t of fluid in a passageway
Percolation
BQ: The best way to PREVENT WARPAGE OF PATTERNS is to?
Invest immediately
BQ: If wax cannot be invested immediately within 30mins, what is the best thing to do to preserve its dimensions?
Refrigate
aka Precious metals
Ex. Silver, platinum, titanium, palladium
High noble
Aka semi precious metals
Noble
aka non precious metals
Base
resistance to breaking UNDER COMPRESSION
Compressive strength
resistance to breaking UNDER TENSION
Tensile strength
resistance to breaking UNDER HORIZONTAL FORCES
Shear strength
Maximum stress BEFORE FRACTURING
Ultimate tensile strength
Most important, resistant to permanent deformation
NiTi > Ss wires
Yield strength
Rigidity or stiffness
Modulus of elasticity
Important for WEAR CHARACTERISTICS and Finishing
Porcelain > Gold > Acrylic
Hardness
Process of joining two pieces of metal together through the use of lower fusing intermediate metal
Solder
Primary requirement para maging successful yung soldering
Cleanliness
Fusion temp in soldering
100-150 F
Optimal space for solder
0.25mm
Added to metal surface to IMPROVE FLOW of the solder, DISSOLVES OXIDES and prevent contamination
Flux
Placed around the area that is to be soldered to RESTRICT FLOW
Antiflux
BQ: Most common anti flux?
Soft graphite pencil
“Blue flame” ; excessive oxygen; produces oxides
Oxidizing flame
Low oxygen; produces CARBON in metal ( candle = black smoke)
Reducing flame
BQ: What flame is best to use with cast gold restorations?
Reducing flame
Principal component of porcelain; acts as matrix
Feldspar
Filler of porcelain;
Provides skeleton and strength
Quartz
Clay that acts as a binder, opaquer and flux in porcelains
Kaolin
Property of porcelain making it brittle
⬆️⬆️⬆️ Compressive strength = Brittle!!!!
Saturation of hue
Chroma
1/2/3
Lightness/whiteness or darkness/blackness
Value
1/2/3
Actual color
Hue
a, b, c
Darker = _ chroma Lighter = _ chroma
Darker = ⬆️ chroma Lighter = ⬇️ chroma
BQ: what is the phenomenon in which 2 objects appear to be the same color in a specific light source and appears different in another light source?
Metamerism
BQ: best light source?
Sunlight or natural light
BQ: Most important dimension of color in dental restorations?
Hueeee 💜
Gold standard of cements
Oldest and most commonly used
Zinc phosphate cements
Other name for Zn phosphate cements
“Zn oxyphosphate and bridge cement”
BQ: Frozen slab technique
To inc setting time of?
Zinc phosphate cement
BQ: Liquid component of zinc phosphate cements
Orthophosphoric acid (H3PO4)
BQ: Most acidic cement
Silicate cement
BQ: Only cement that is BASIC
Calcium hydroxide
BQ: pH of ALL CEMENTS WHEN FRESHLY MIXED
All cements are ACIDIC when freshly mixed
Once set= pH neutral
Setting time: 24-48hrs
Normal sensitivity 1-2days after cementation of restoration
Most soluble cement
Silicate cement
Least soluble cement
GIC
BQ: ADA spec of GOLD
Ada spec #5
BQ: Ada spec of Amalgam
ADA spec #1
Liquid has obtundent effect on pulp
Inhibits polymerization of resins
ZOE
BQ: First cement that bonds to tooth structure (CHEMICAL BONDING)
Zinc polycarboxylate
Retention of Zinc phosphate
MECHANICAL RETENTION
- FIRST cement to produce FLUORIDE
- MOST SOLUBLE / MOST ACIDIC
- First mat’l used in “ESTHETIC DENT”
Silicate cements
aka zinc silicate cement
Zinc silicophosphate cement
GIC is aka
“Aluminosilicate cement”
BQ: principal fluid of GIC
Polyacrylic acid
GIC is derived from what cements:
Fluoride releasing / chemical bonding
Silicate cement - Fluoride releasing
Zinc polycarboxylate - chemical bonding
Type I Gic
Luting
Type II GIC
Resto
Type III
liners and bases
Type IV GIC
PFS
Type V GIC
Orthodontic cement
Type VI gic
Core build up
Type VII gic
Fluoride release
Type VIII gic
ART
Type IX gic
Pediatric purpose
Class I articulator is aka
Simple hinge
Class II articulator is aka
Standard mean value
BQ: use average “ANATOMY LANDMARK” to approximate the actual hinge
Arbitrary
BQ: “ACTUAL HINGE” can be located using this facebow: more accurate
Kinematic
IOR made with wax
Bite registration
Most common IOR; mount the rel of mn cast to mx cast in Centric relation
Centric occ record
Most inferior portion of upper lip
Lip line
Location of incisal plane of maxillary teeth during SMILING;
Must follow the contour of lower lip
Smile line
Measured from base of nose to lip line
Lip length
horizontal reference for the orientation of maxillary teeth and incisal or occ plane
Interpupillary line
Ala tragus line is aka
Camper’s line
BQ: What part of tragus is used in ala tragus line
Superior part of tragus
BQ: Importance of Camper’s line
Esthetics
Starts from canine to molars
Seen in natural dentition only not in dentures (bec it may cause instability)
Convex - Mx
Concave - Mn
Curve of spee
Starts at distal of 1st molars
Seen in dentures
Compensating curve
Lingual inclination of Mandibular molars
Curve of wilson
Space between posterior teeth during protrusion
Christensen’s phenomenon
Motor speech production
Initiator = broca’s area
Improves quality of sound
Oral, nasal, pharyngeal cavities, sinuses
Resonators
Mechanism for speech production:
Initiator- broca’s area Motor - lungs Vibrator- vocal cords Resonators Articulators - lips, tongue, soft hard palate and teeth
FricatiVes
FV
linguoDeNTaL
D N T L
SibilantZ
S Z
Bilabial
BPM
BQ: What letter has the closest speaking space
S
Space in between maxilla and mandible when the mandible is at rest
Freeway space
Freeway space is aka
Interocclusal distance
VDR - VDO = FS
Ideal measurement of FS =
2 to 4mm
“Most posterior and superior” position of the condyle within the glenoid fossa
Centric relation
Centric relation is aka: (3)
Retruded contact position
Ligament guided position
Bone to bone contact
Complete intercuspation of opposing teeth independent of condylar position
Centric occlusion
Centric occlusion is aka (2)
Tooth guided position
Maximum intercuspal position
Position of mandible at physiologic rest
aka “Muscle guided position”
Resting position
“Ligament guided”
CR
“Tooth guided”
CO
“Muscle guided”
RP
Indicated for teeth without adequate tooth structure to develop a ferrule
Crown lengthening
Minimum exposed tooth structure to have FERRULE
1.5-2.0mm
Better than crown length because gingiva is still the same / using ortho
Forced eruption
Source of Autografts in the body? In the oral cavity?
Body: iliac crest
Oral cavity: tuberosity
Palatal tissue under a poor fitting denture base that is kept at night
Inflammatory papillary hyperplasia
Inflammatory FIBROUS hyperplasia is aka
Epulis fissuratum
BQ: Px wants to have a denture but does not want to have surgery to remove flabby tissue; what type of impression technique should you do?
Passive impression
Complication of torus palatinus removal
Nasal cavity penetration
Major conn used in RPD if px has torus palatinus
Horse shoe
Major conn used if px has Torus MANDIBULARIS
Labial bar or “swing lock major connector”
BQ: indication for labial bar
Severe lingually tilted tooth
Burning sensation in the mandibular ridge
Pressure on the mental foramen
Burning sensation on the palatal area
Pressure on the incisive foramen
Clicking of denture teeth
Excessive VDO
Porcelain teeth
Cheek biting
Not enough horizontal overlap of posterior teeth
Insuff VDO
Mucosal changes
Vit c def
“Accepts” dentist’s judgement and instruction
Philosophical
BQ: asks alot of “questions”; demanding
Exacting
Doesnt care about dental tx
Indifferent
Emotionally unfit to wesr dentures
Hysterical
Direction of ridge resorption in the MAXILLA
Superior and posterior
Direction of ridge resorption in the MANDIBLE
Inferior and anterior
“ah line” or “cupid’s bow” or BRA
Vibrating line
Imaginary line demarcating the movable and non movable tissues of the soft palate
(2mm anterior to fovea palatini)
Vibrating line
The posterior border of mx complete denture that puts pressure on the displacement tissue near the junction of the hard and soft palate (For: SEAL & RETENTION)
Posterior palatal seal (denture)
“Post dam” (cast)
Resistance of denture to LATERAL forces
Stability
Resistance of denture to forces DIRECTED AGAINST the tissues
Support
Resistance of denture to DISLODGEMENT from the ridge
Retention
Primary stress bearing area in the MAXILLA
Hard palate
Residual ridge
Primary stress bearing area in the MANDIBLE
Buccal shelf
Secondary stress bearing area in the MAXILLA
Rugae
Mx tuberosity
Secondary stress bearing area in the MANDIBLE
Slopes of the residual ridge
Denture that is delivered immediately following extraction
Immediate dentures
Disadv: Maluwag na
Reline after 6 months!
Denture Partially retained, supported, stabilized with natural teeth or implants
Overdentures
Tissues are compressed during impression to stimulate the same amount of pressure
Pressure / functional
Impression at rest without any pressure
Non pressure or mucostatic imp
BQ: Type of impression technique used in FLABBY TISSUE
Passive impression (a type of non pressure or mucostatic)
Best suited for withstanding forces of mastication (custom tray used)
Selective impression
Adding a new layer of material in the denture base
Relining
Replacement of entire denture base while keeping the same denture teeth in their current occ relationship
Rebasing
