Exam 1 Flashcards
operative dentistry
the branch of dentistry that deals with the art and science of diagnosis, prevention, treatment, and prognosis of diseases or trauma of the dentition.
preventative dentistry
dental care that helps maintain good oral health.
biomaterials
man-made materials used to replace tissues or that function in intimate contact with living tissues.
Dental materials are biomaterials used in or around the oral cavity.
dental materials
Dental materials are biomaterials used in or around the oral cavity.
enamel
hard wear-resistant surface material
Dentin
bulk material of the tooth that acts as a cushion to enamel
pulp
provides nutrients to the dentin and responds to stimuli
periodontium
supports the tooth and provides feedback on forces placed on the tooth
gingival tissue
prevents noxious agents from accessing the periodontium
Class I
toothbrush and toothpaste
Class II
Composite and amalgam restoration materials
Class III
Bone graft materials
selection of dental materials
biting force, degradation of material, temperature change, biocompatibility, esthetic
biting forces
may fracture teeth and replacement materials
degradation of materials
corrosion of metal teeth and dental caries
temperature changes
that cause restorations to contract and expand differently than teeth, causing leakage around the restoration as well as tooth sensitivity
biocompatibility
the lack of harmful effects to the patient
esthetic
demand of the patient
classification of dental materials
classification by use, classification by location of fabrication, classification by longevity of use
impressions
are taken to make a replica of the tooth or structures that are being fabricated
Cast
a restoration is being constructed on the replica
study model or diagnostic cast
replica is used to study the size and position
luting
gluing two things together
luting agents
dental cements
dental cements
holds the crown onto a prepped tooth and fills the microscopic gaps between the tooth and the crown. Cements must flow like a liquid so the crown will fit. Cement is strong and insoluble in oral fluids.
base
implies a degree of strength and thermal insulation. It has greater bulk which serves to restore part of the missing tooth and provide thermal insulation.
liner
a relatively thin layer of material painted on to protect the underlying dentin from chemical irritation.
temporary materials
temporary crowns and restorations
preventative materials
pit and fissure sealants, mouthguards, fluoride trays
direct restorative materials
placed in the cavity preparation that was drilled by the dentist.
indirect restorative materials
fabricated outside of the mouth. They are made on a replica of the patient’s oral tissues.
gases
atomic bonds between gas molecules are very weak
liquids
strong attraction between molecules but not strong enough to carry a load or maintain shape without support
solids
crystalline solids have a consistent spatial relationship of atoms or molecules repeated hundreds to thousand to millions of time = long-range order
amorphous solids
have strong atomic bonds present in crystalline materials but have a short-range order. Glass in a window or dental mirror is an amorphous solid.
metals
Gold, ductile- bent easily without breaking and retains strength)
ceramics
Dishes, glass, ceramic materials (crowns) are strong when compressed – the atoms are forced together. However, they can be weak and brittle if pulled or bent)
polymers
Plastics, weak; resins, hard
Moldable polymers – bleaching or fluoride trays
composites
Made up of two or more different materials. (Fiberglass)
enamel
Composite of apatite, (a ceramic material and a protein (a polymer)
Thermal conductivity
Rate of heat flow through a material
Measured as heat flow over time
Thermal conductivity depends on
Distance heat travels
Area in which heat travels
Temperature difference between source and destination
pulpal sensitivity is likely if
conductive materials (metals) placed close to the pulp. If caries are deep and a metal restoration is used, an insulating base is placed beneath the metal filling to insulate the pulp from hot and cold stimuli.
heat of fusion
amount of energy required to melt a material
Coefficient of thermal expansion
Measure of the change in volume in relation to the change in temperature
percolation
Opening and closing of the gap between tooth structure and a restoration due to differences in coefficients of thermal expansion
electric conductivity
-Good electrical conductors
Metals
-Poor electrical conductors (insulators)
Polymers
Ceramics
galvanic shock
electricity flowing through a metal object (fork) to the amalgam and through the pulp
viscosity
ability of a material to flow, temperature dependent
High viscosity
high-contact angle- poor wetting
low viscosity
low contact angle- good wetting
wetting
a surface with an adhesive material like a sealant, brings the material into intimate association with the surface so that the chemical and micromechanical bonding can occur.
radiolucent
some ceramic materials, denture acrylic resin
radiopaque
metal restorations
hardness
a property that is measured by scientific instruments that press a special tip into the surface of the test material
abrasion resistance
resistance of dental restorations to food, opposing teeth, and other dental materials
solubility
ability to dissolve in water
water sorption
materials that absorb water
strain
is the change in length divided by the original length
stress
the load or the force divided by the cross sectional area of the object
compression
is pushing or crushing stress
tension
a pulling stress
shear
slip stress occurs when parts of an object slide by one another
torsion
stress is a twisting force
bending
common stress and is actually a combination of several types of stresses
creep
small movement of amalgam overtime caused by the compression, temperature, and more
stress relaxation
slow decrease in force overtime causing a change in shape
stress concentration
stress increase around defects
IRM
intermediate restorative material
uses for IRM
Cement a temporary crown while permanent one is being made
Create insulating base under permanent restorations
Provide sedative or obtundent (soothing agent) filling for sensitive teeth
It is used as an Insulating base! Protect the pulp from thermal trauma
Zinc Oxide-eugenol
organic liquid that is weak acid, component of oil of clove, phenol derivative and is antibacterial and obtudent (reduces irritation) to the pulp
zinc Phosphate cement
zinc oxide powder mixed with phosphoric acid
-consistency is determined by use luting or base
-luting- mix will be string like 1inch between spatula and slab
-base- thick putty like consistency
**cooled glass slab incremental mixing EXOTHERMIC
Glass ionomer 3 forms
powder and liquid, premeasured capsule, paste
glass ionomer use
most widely used, least soluble, used as luting, base, liner, core build up
FL releasing
bonds to teeth
Polycarboxylate (Durelon)
consistency determines use luting or base
-not very strong
Calcium hydroxide (Dycal)
secondary or reparative dentin
- Paste/paste system
-liner and base- used when micro pulp exposure is expected, direct pulp cap
-Setting reaction of calcium hydroxide is accelerated by water, moisture in dentin is sufficient to cause material to set in seconds of application
Temporary cement (Rely-X)
-Two paste system
-temp indirect (lab made)
-restorations- inlays, onlays, crowns, bridges
