The chemical attraction between unlike molecules? (tape)
Adhesion
The chemical attraction between like molecules? (glue)
Cohesion
An index which indicates how one material reacts to temperature extremes in relation to another?
Coefficient of Thermal Expansion
The force at which a material breaks under pressure?
Compressive strength
Slow dimensional change caused by compression?
Creep
The ability to undergo change of form without breaking? (like the wire twistie on bread)
Ductility
A materials ability to recover its initial shape after undergoing a force?
Elasticity
An electrical current generated by dissimilar metals in an acidic environment?
Galvanism
The process of gelling? (solidification by cold) like jello in fridge
Gelation
The volumetric weight of one cubic centimeter of milliliter of water?
Gram
Absorption of a solvent by a gel?
Imbibition
A material's capacity to be shaped by force or pressure? (like play-dough)
Malleability
Passage of oral fluids/bacteria into and out of tooth structure due to marginal (restorative) seal?
Microleakage or Percolation
the linking, branching, or cross-linking of smaller molecules?
Polymerization
the force at which a material CANNOT return to its original shape?
Proportional limit
Contraction of a gel due to the loss of a solved? (ex. dried alginate)
Syneresis
The force needed to stretch a material to the point of fracture?
Tensile Strength
Resistance to flow?
Viscosity
Low viscosity-->water
high viscosity--> peanut butter
If you change a material's components, you change its properties?
Truisim
What 5 things make up amalgam?
-mercury
-silver
-copper
-tin
-zinc
3 desirable features of amalgam?
durable
similar compressive strength to enamel
relatively inexpensive
Undesirable features of amalgan? x7
-unattractive
*high thermal conductivity
*Dimensionally unstable (creep)
*delayed expansion if contaminated by saliva
*Requires tooth support
*Fracturable by excessive occlusion
*Susceptible to galvanism when new
When Polishing amalgams; what is final polish?
Tin oxide
How do you polish amalgam?
light touch with water and short burst to avoiding heat that will damage the odontoblasts
How do hygienist remove an overhang? because apparently boards thinks we can!
With a SCALER, not a curett
What establishes a mechanical retention with enamel or dentin and Dental Resins?
Phosphoric Acid
What does phosphoric acid increase?
surface area
What does BIS-GMA stand for?
bisphenol a-glycidyl methacrylate
Do sealant material have a low or high viscosity?
Low
Do composite have a low or high viscosity?
High
What are the 3 more common filler particles in composite?
Silicates
Quartz
Glass
What is added to composite for radiopacity?
Barium or stontium
What Resin-fill size is popular due to its high polishability and ease of handling, but requires tooth support?
MICROfills
Which resin-fill size is popular due to its COMBINED strength and beauty?
HYBRIDS
What resin-fill size increases surface area and, therefore, bond strength?
NANOFILLS
By adding what to composite increases polishability?
NANOFILLS
Is light cured (unmixed) or self cure (mixed) more porous?
Self cured is more porous, because when mixing it adds air, and that is bad
What do you polish composites with?
Tin oxide or diamond polishing paster
What is used to seal dentin or medicate the dental pulp?
Liners
What are 4 liners?
Varnish
Calcium Hydroxide
Zinc-oxide/eugenol
Resin-modified glass ionomer
What liner is fluoride releasing?
Glass-ionomer
What liner is CX with composites and why?
Zinc-oxide/eugenol because of the oil (IRM)
What Liner is placed over pulpal exposure to stimulate reparative dentin?
**
CALCIUM HYDROXIDE
**
What is used to proved thermal insulation or mechanical protection for the dental pulp (iusulate/protect like a Blanket)
Base=blanket to insulate, keep warm
Why are cements included as bases?
because cements are poor thermal conductors and have adequate compressive strength
What cement causes an EXOthermic reaction when mixing, a cool glass slab is needed, and uses a mechanical interlock between tooth and casting?
ZINC phosphate cement
What cement is a powder mixed with poly acrylic acid and has a high chemical affinity for enamel?
Polycarboxylate cement
What cement releases fluoride, binds to dentin, and can be used and a class V restoration?
Glass ionomer cement
What cement is tooth colored to use with esthetic restorations like veneers and onlays and ortho brackets, and pre-fab. post?
REsin cements
What cement is a resin modified glass ionomer and therfore releases fluoride and can be esthetic?
HYBRID (rely-X)
What cement is commonly used for temporary cementation?
Zinc-oxide/eugenol cement
What is uded to clean ZOE contaminated instruments?
Orange solvent, not alcohol
What are the 2 types of impression material?
Rigid and Flexible
What are the 2 types of flexible impression materials?
Aqueous and non-aqueous
What are the 3 stupid types of RIGID (inelastic) impression materials?
plaster, compound, and zinc-oxide/eugenol
What are the 2 types of Aqueous impression materials?
Reversible hydorcolloid or non-reversible hydrocolloid
What is another name for Reversible hydo-colloid?>
AGAR
What type of reaction does Agar undergo?
Physical, gelation; when cold id solidifies
Agar is susceptible to imbibition and syneresis, meaning what?
syneresis...smaller when loses water
Imbibition...larger with absorbing more water
What is another name for Irreversible hydrocolloid?
Alginate
What typer of reaction does alginate undergo?
Chemical reaction
Is alginate temperature dependant?
No; but setting time can be delayed/accelerated by it
Non-aqueous impression material is water-insoluble or ?
hydrophobic
What are 4 non-aqueous impression materials?
Polysulfide rubber
polyether rubber-unstable in moisture
Silicone rubber
Polyvinylsiloxane***crown prep impression
**
BOARD
**
Mixing times for impressions materials vary according to manufactures directions
Does Gypson shrink or expand as it sets?
Expands
What is Gypsum made out of?
Mineral, Calcium Sulfate di-hydrate
the more water needed in gypsum; the greater the setting expansion and lower the what?
Lower the compressive strength
Alpha/Beta? which one is superior?
Alpha is better, A's are better than B's, but C's get degrees!
What can be added to accelerate gypsum set time?
Potassium sulfate; potassium in banana's make you fast)
What can be added to slow the set of gypsum?
Borax; (borax is boring and slow)
Air incorporated into gypsum mix will result in what?
surface voids (bubbles/holes)
Model base is trimmed __________ to midline between central incisors.
Perpendicular
What is Inlay and casting wax best used for?
Cast restorative patterns
What is base-plate wax best used for?
removable prosthetic procedures
What is bite registration wax used for?
obtain occlusal records
What is boxing wax used for?
Used in pouring models
What is sticky wax used for?
attach models (hard when cool, sticky when heated) like when the wire retainer comes back from the lab attached to the model :)
B
What is utility wax used for?
modify the shape of impression trays and cushion brackets
For the greatest demensional accuracy, what should be done with wax?
invest wax pattern soon, avoid heat
How are casting alloys classified as?
Precious or Nonprecious
What 3 metals are used in dentistry and are Precious?
Gold
Platinum
Palladium
What 5 metals are Non-Precious used in dentistry?
Silver
copper
Nickel
Tin
Zinc
Which casting alloys tarnish and corrode?
Non-Precious
Intraorally, what can gold be polished with?
Tin Oxide
Extra-orally, what can gold be polished with?
Rouge; its a poison, so can't be used intra-orally
Pure gold is 24K (100%); how much is that in FINE?
1000 Fine
What is 18K in Fine?
18/24 = 3/4, 3/4 of 1000F is 750 Fine
What can opposing porcelain restorations cause?
Occlusal wear; use gold
What is the leading cause of Implant failure?
Mobility
What are 4 condra-indications for implant placement?
Inadequate bone
uncontrolled perio
smoking
Infection
Is an electric toothbrush contraindicated with implants?
NO
Can a air-powder polisher be used with implants?
Yes
What is the active ingredient in tarter control tooth-paste?
Pyrophosphate
What is the leading cause of dentinal hypersensitivity?
Pyrophosphate found in tarter control toothpaste
What is the active ingredient in gum care toothpaste?
Triclosan (antimicrobial agent)
What are 3 desensitizing ingredients in toothpaste?
Potassium nitrate
sodium citrate
strontium chloride
What are 2 desensitizing agents applied professionally?
Potassium oxalate and fluoride varnish
What are 2 active ingredients in vital bleach (home bleach)?
Carbomide peroxide and hydrogen peroxide
What does carbomide peroxide break down into?
hydrogen peroxide and urea