88 terms

chapters 43,44,45

The ability to replace or bring something back to its natural appearance and function
artistically pleasing appearance
new dental material
1. must not be poisonous or harmful to the body
2. must not be harmful or irritating to the tissues of the oral cavity
3.must help to protect the tooth and tissues of the oral cavity
4. must resemble the natural dentition as closely as possible
5. must be formed and placed in the mouth's to restore mouth's natural contour
6. must conform and function despite limited access, wet conditions and poor visibility.
any push or pull on matter, creates stress and strain
the reaction within the material that can cause distortion
the change produced within materials that occurs as the result of stress
pulls and stretches
pushes toghether
ia the breakdown of material (sliding over the area)
contraction-material "shrinks" due to temp change
expansion-material "swells" due to temp change
microleakage-when restoration pulls away from the tooth
galvanic action
created when two different or dissimilar metals are present in the oral cavity
saliva contains salt, which makes a good conductor of electricity
reaction within a metal when it comes in contact with corrosive products, most corrosion is surface discoloration and can easily be removed with polishing agents
degree to which substance will dissolve in a given amount of another substance
allows material to fit into corners, boxes and pits of tooth
force that causes unlike materials to adhere to each other
ability of a liquid to flow over the surface and to come in contact with the small irregularities that may be present.
property of a liquid that causes it not to flow easily
ability to hold things firmly together when they will not adhere to one another
process of placing a paste type material in tooth preparation for adaptation, after material is in place, it is cured in place and perform its function
material hardens as the result of a chemical reaction of the materials being mixed together
dual cure
some curing takes place as a material is mixed, final cure does not occur until material is exposed to curing light
light cure
material does not harden until it has been exposed to a curing light , darker shades require longer curing time
amalgam indications
-stress bearing areas of the mouth
-small to moderate sized cavities in post
-severe destruction of tooth surface
-as a foundation for cast-metal, metal ceramic and ceramic restoration
-when a patient's commitment to a personal hygiene is poor
-when moisture control is problematic
-when cost is an overriding patient concern
restoration held in by retention grooves and pre
amalgam contraindications
-when esthetics is particularly important
-patient has history of allergy to mercury or other components
-when lg rest is needed, and the cost of another rest. material is not a significant factor in treatment decision
amalgam composition
mercury 43-54%
alloy powder 57-46%
silver- strength
copper-strength and corrosion resistance
zinc-suppress oxidation
amalgam ratio
1to 1 weight
eames technique
amalgam controversial issues
-harm to patients from the mercury within Ag placed in their teeth
-toxicity level of mercury vapors affecting dental personnel exposed over a long period of time.
amalgam preparation
capsules are supplied in sealed, single-use caps, alloy powder on one side, mercury on the other side seperated by a thin membrane
mercury and alloy powder are mixed together to form the mass of ag needed to restore the tooth
amalgam condensation
-ag is placed in increments into prep., each increment is condensed immediately
-condensation compacts ag into all areas of the prep and aids in remaining excess mercury from ag mix
amalgam carving/finishing
-carve back ag to the tooth's normal anatomy
-burnish to smooth ag
composite qualities
-withstand the environment of the oral cavity
-be easily shaped to the anatomy of the tooth
-match natural tooth color
-be bonded directly to the tooth surface
composite composition
-matrix-foundation in BIS-GMA
-macrofilled-lg filler particles, greater strength, rough surface
-microfilled-smaller particles than macrofilled, highly polished finished restoration, less strength
-hybrid-missed range of particle sizes, great strength with good polishability, excellent shading characteristics
composite application
-supplied in a single paste, light proof syringe
-placed and cured in layers for deep restoration
the process in which resin material is changed from a plastic state into a hardened restoration
composite finishing/polishing
-reduction is completed by the use of a white stone or a finishing diamond
-fine finishing is done with carbide finishing burs, then with diamond burs
-polishing the resin begins with med. discs and finished with the superfine discs
-finishing strips assist in the polishing of the interproximal surface
-polishing paste applied to a rubber cup completes the step
Glass ionomer applications
-final restoration in non stressed areas
-intermediate restoration
-core material for buildups
-provisional (longer-term temp) restoration
metal reinforcement
blend of spherical silver-tin alloy with glass ionomer produces a strong abrasion-resistant dental material
temp restorative material function
-reduce sensitivity and discomfort of a tooth to determine the diagnosis
-maintain the function and esthetics of a tooth until a permanent restoration can be placed
-protects the margins of a prep. tooth that will receive a casting at a later time
-prevent shifting of a adjacent or opposing teeth because of open space
temp rest. materials
provisional- cover major portion of the tooth or teeth for a longer period of time , must withstand biting forces and daily wear and tear or oral conditions
indirect restorations
types of restorations that the dental lab tech creates in lab
combined with noble and base materials to increase strength
noble-palladium and platinum
base-low value, iron, tin and zinc
alloys- combo of noble and base metal that combine to give the characteristics and hardness required of an indirect restoration.
Ceramic casting
type of material similar to that used in the dishes in your house
combination of metallic and non metallic elements
clay-like material with a glaze that has metallic components
ceramic is adhered to a metal casting, creating the best of both worlds in strength and esthetics
combines strength, translucence and ability to match natural tooth color
quality of ceramic castings
shading of colors matches tooth color well
improves the esthetic appearance of anterior teeth
has the strength of metal
good insulator
low co-efficient of thermal expansion
much to soft for cast restorations
gold alloys
combo of noble and base metals that combine to give the characteristics and hardness required of an indirect restoration
thermal changes or electrical energy (galvanism)
vibration from HP during prep, traumatic occ
result from acidic material coming in contact with pulpal tissues
result from bacteria from saliva coming into contact with pulpal tissues
-lines the deepest portion of the dental prep. to provide pulpal protection or dentinal regeneration
-health and condition of tooth determine what lining agent the DDS selects
Calcium Hydroxide
-protects the pulp from chemical irritation through sealing abilities
-stimulates production of reparative dent. or secondary dent.
-compatible with all types of restorative material
liner applications
-two paste system (base and catalyst)
-light cure
-placed only on dentin (floor prep), must avoid enamel or retentive grooves
a liquid consisting of one or more resins in an organic solvent
varnish function
-seals dent. tubules
-reduces leakage around restoration
-acts as a barrier to protect the tooth from highly acidic cements such as zinc phosphate
varnish application
-always placed after the liner, all surfaces of prep.
-interferes with the bonding and setting reaction of composite resins and glass ionomer restoration.
Fluoride varnish
professional topical fluoride application
treatment of hypersensitivity cervical areas
ortho patient
cavity varnish
dentin sealant
why is dental sealer(desensitizer) used?
-to treat prevent hypersensitivity
-no surface layer is formed which makes it ideal for use under all indirect rest.
placed when it is necessary to protect pulp before rest. is placed
placed deep in cavity prep. to protect tooth from thermal shock
helps sooth a pulp that has been damaged by decay or irritated during process of removing decay
zinc oxide phosphate
-thermal insulator
-place liner to protect against irritation from phosphoric acid in liquid
-protective and insulating base
-non irritating to pulp can be placed under all types of direct and indirect restorations.
bonding function
improved retenting properties through the creation of micromechanical retention between tooth and rest.
etching systems
maleic or phosphoric acid etchant is placed on either the enamel or dentin to remove the smear layers in prep. for bonding
enamel bonding
-used in placing sealants, bonded otho brackets, resin bonded bridges, veneers
-ensure surface is dry after etching
dentin bonding
success us dependent on removing the smear layer (thin layer of debris composed of fluids and tooth components remaining on the cavity prep) by etchant.
bonding available curing systems
available in self cure, dual cure, and light cure systems
bonding clinical applications
-perform steps precisely
-avoid expiration, contamination and thickening of liquids
-remove plaque or debris before bonding
-avoid over drying teeth, produce work best on slight moist tooth structure
-too much primer is better than too little, multiple layers work best
-solution should cover all surfaces
-avoid contamination with blood, saliva, debris
-allow as much time as possible for the bond to mature before completing restoration and removing cotton rolls or dental dam
3 classifications of cement
type1, type 2, type 3,
Type1 cement
luting agent includes permanent and temporary cements
type 2 cement
restorative materials like glass ionomer used as restorative material
type 3 material
includes liners/bases placed within cavity preps
luting agent
-a type 1 dental cement that acts as an adhesive to hold the indirect restoration to the tooth structure
-designed to be either permanent or temporary
cement mixing time/guidelines
-read and follow the manufacturer's directions
-determine use, then measure the powder and liquid
-place powder on one end of glass slab or paper pad and liquid toward opposite end (space allows room for mixing)
-any delay between completion of mix and seating will result in an initial setting process, and casting may not seat completely
to minimize loss of water from liquid or gain of water to powder, always dispense the powder first, then the liquid
powder to liquid ratio
-incorporating to much or to little powder will alter the cements consistency
-be sure to fluff powder in the bottle before dispensing
-always hold bottle or vial upright to ensure consistent size d drops
some cements put off an exothermic reaction, in such cases it is beneficial to cool the glass slab in fridge before mixing (wipe slab to remove condensation by mixing)
zinc oxide eugenol
liquid-eugenol, water, acetic acid, zinc acetat and calcium chloride
powder-zinc oxide, magnesium oxide, silica
zinc oxide eugenol function
type1 lacks strength and long term durability
-used for temp cementation or provisional coverage
-two system for temp cement (tempbond)
type2- for permanent cementation of cast rest. or appliances
zinc phosphate composition
liquid-50% phosphoric acid in water, buffered with aluminium phophate and zinc salts to control pH
powder-90% zinc oxide, 10% magnesium oxide
zinc phosphate function
type1 fine grain permanent cement of cast restorations
type 2 medium grain insulating base for deep cavity preps
use a laser, sealer or desensitizer to minimize the irritating factors
liquid-polyacrylic acid, itaconic acid, maleic acid, tartaric acid and water
powder-zinc oxide
polycarboxylate function
type1-permanent cement for cast restorations, S.S. crowns, and ortho bands
Type 2 used as a non irritating base under both composite or amalgam restorations
type3- used as an intermediate restoration
glass ionomer
liquid-itaconic acid, tartaric acid, maleic acid and water
powder- zinc oxide, aluminium oxide, calcium
glass ionomer function
type 1-cements metal restorations
type 2-restoring areas or erosion near gingiva
type 3- liner and dental bonding
glass ionomer characteristics
-one of the most versatile types of cement
-adheres to enamel, dentin, and metallic materials
-supplied in self-cure, light-cure, and pre measure caps
-powder is an acid soluble calcium, slowly releases Fl-inhibiting recurrent decay
-causes less trauma or shock to the pulp than many other types of cement
-low solubility in the mouth
-cament adheres to a slightly moist tooth surface
-very thin film thickness, excellent for ease of seating
-can be formulated for use as a dentin substitute
composite resin cement function
cement of ceramic or resin inlays and onlays
ceramic veneers
ortho bands
direct bonding of ortho brackets
all metal castings