Dental Materials Final Flashcards
When a 2 paste system of ZOE is used how are the materials mixed?
Until a uniform color is achieved
Classifications of class 2 gold alloy?
Medium
Inlays and crowns
Medium yield strength
Medium wear resistance
What is a negative impression?
Impression of the patients mouth with alginate
Mixture of small and microfine particles
Micro hybrid
Composition of sealant materials
bis-GMA glycidyl methalacrylate UDMA urethane dimethacrylate
Microhybrid with nanosized particles added
Nanohybrid
How do we test for mercury levels?
Urine sample
What is 1 spill of mercury?
400 mg
How are the anterior borders of a diagnostic cast trimmed?
Symmetrical to the midline maxillary- runs distal of canine to midline mandibular- distal of canine to distal of canine
The act of mixing amalgam
Trituration
This is the color of a tooth or restoration. It may include a mixture of colors like yellow-brown
Hue
What does class 1 gold alloy consist of?
Soft
Inlays (not heavy in function)
Low yield strength
Low wear resistance
What materials are used for impressions?
Polysulfide
Polyvinyl
Alginate
Amount of lightness or darkness in the tooth
Value
What organs are affected by mercury?
Main organ is kidneys!
Brain kidneys and testicles retain mercury the longest
What is an alginate impression tray?
Metal perforated trays
Disposable
Stock
What makes ZOE biocompatible with tooth structures?
The neutral PH of 7
What stone is the choice of pouring impression materials?
Micro stone, less porous and gives better detail
What is a metallic impression material composed of silver based alloy with mercury?
Amalgam
What are the two ways elastic impression material can be classified by?
Irreversible and reversible
Fillers that are smaller averaging 0.04 in diameter 0.03 to 0.05
Microfilled
What was G.V. Black’s classification of cavities?
He and Frederick McKay determined drinking water was the factor of cavities
What is the anatomical portion of the cast?
Oral anatomy
2/3 of total height
What type of elastic material will not return back to its original state?
Irreversible (powder/liquid)
Class 2 of gypsum products
Model plaster (almost obsolete)
Indirect restorations
Fabricated outside of the mouth
These materials are expected to be long lasting replacement for missing damaged or discolored teeth
Permanent restorations
Steps for applying a sealant
Isolate the tooth Pumice with non fluoridated paste Rinse and dry Apply etchant for 60 sec Rinse and dry Apply sealant Light cure for 30-60 seconds Floss Check occlusion
What does TLV mean?
Threshold limit value
What are the sizes of mandibular impression trays?
20-25
20 is largest
What are veneers?
Thin layers of esthetic materials that are used to improve the appearance of the teeth. They are bonded to the fronts of the teeth. Can be used to lighten the color of teeth, cover stains, repair chips, lengthen worn down teeth, increase the size of small teeth, close spaces, or reshape crooked teeth
PFG
Porcelain fused gold
What are the classifications of impression materials?
Elastic and rigid
What are ZOE cements?
Zinc oxide eugenol cements
What is boxing wax?
Wraps around impression to make a base
What is a polyvinyl impression tray?
Stock disposable tri-tray
What is a polysulfide impression tray?
Custom tray
What are classification of compositions by filler size?
Macrofilled, microfilled, hybrid, microhybrid, nanohybrid, nanocomposites
Classifications of class 3 gold alloy
Hard
Inlays crowns bridges
High yield strength
High wear resistance
Positive replicas of teeth produced from impressions that create a negative representation of teeth.. commonly called study models and generally made from plaster or stone. Used for patient ed., treatment planning, and tracking progress
Diagnostic casts
What gauge material is used for fabricating mouth protectors?
0.080
Contains both large and small fillers
Hybrid
Aka provisional restorations used for short periods of time, several days to weeks
Temporary restorations
Class 4 gypsum products
Dye stone (made to pour dyes, used for ceramics/crowns)
What are ZOE cements used for?
Temporary cementation, temp or intermediate restorations, high and low strength bases, root canal sealers and perio dressings
Like provisional, placed for limited time however the time may extend from weeks to months
Intermediate
Resin bonded cement
Max-cem elite: this cement etches bonds and adheres to the tooth structure all in one. Has nano particles, contains quartz, lithium, and very compatible to tooth and crown bridge or veneer. No mixing!
Zinc polycarboxylate
Supplied powder liquid used for final cementation of indirect restorations. Long term, temp cements
What type of impression material is able to pick up undercuts?
Elastic
What material is reversible?
Rigid (thermoplastic)
What are ZOE cements suited for and why?
Temp restorations - their weaker tensile strength allows them to be easily removed at a second apt. when a temp restoration is to be placed
What are sealants?
Unfilled or lightly filled resin used to seal noncarious pits/fissures of deciduous and permanent teeth
The measure of gold content
Karat
The intensity of strength or color
Chroma
How do composite materials come supplied?
Delivery system
Single syringe
Two paste system
Holy fuck
This is taking forever
Which type of impression material will not pick up undercuts?
Rigid
Physical and chemical properties of gypsum
Dihydrate
(Cas04*2H2O)
Happens when water is mixed with powder
Hemihydrate
(Cas04*1/2H20)
Process called calciling to dry off powder
What gauge material is used to fabricate bleaching trays?
0.040
What are the sizes of max impression trays?
1-5
1 is largest
How are the lateral borders of a cast trimmed?
Parallel to buccal surface of posterior teeth
Distal of canine to distal of molar
What are the steps in fabricating mouth protectors?
Trim cast in horseshoe shape Insert material in frame Place max cast on platform Lower when heated and sagged Turn on vacuum Remove guard when cooled Trim excess material
Large particles ranging from 10-100 microns. Make composites difficult to polish and can become rough
Macrofilled
Filler particles ranging from 5-75 nanometers
Nanocomposites
Class 1 gypsum products
Impression plaster, almost obsolete
Classification of restorative materials
Temporary
Intermediate
Permanent
GC
Gold crown
What is the safe level for mercury in a 40 hr work week?
.005/m3
How are ZOE cements available?
Powder/liquid
And 2 paste systems
What is a positive impression?
When the impression is set in stone… diagnostic cast
How are the posterior borders of a cast trimmed?
Square with the midline, trim these with max and mand casts together
When the powder/liquid system of ZOE is used, how is it mixed?
Powder into liquid until heavy consistency is achieved
What is 2 spills of mercury?
600 mg
What is the art portion of the diagnostic cast?
Base of the study model 1/3 of total height
Glass ionomers
Capsule form now. Mixed in a Vari-mix. Should you have to mix any of these in powder/liquid ratio is now on the top of bottles
What type of elastic material will return to its original state?
Reversible(only 1 type of impression material is reversible)
Class 3 gypsum products
Dental stone (we use micro stone)
What are the types of permanent cements?
Resin bonded
Glass ionomers
Zinc
Polycarboxylate
What has eugenol been known for?
It’s sedative effect to the pulp largely caused by its antibacterial effects
Used of gypsum
Diagnostic cast, working cast, dye
Steps in fabricating a bleaching tray
Trim cast Apply blockout to teeth Light cure blockout resin Put thermoplastic sheet in vacuum former Place cast in center of platform Once it is heated and sags, lower frame and turn on vacuum Cool and remove cast Trim with scissors
How does mercury supplied?
In premeasured capsules known as mg spills
Composition of polysulfide impression materials
Sulfa 1:1 ratio used for dentures or crown and bridge
Classification of class 4 gold alloy
Extra hard
Partial denture framework bridges
High yield strength
High wear resistance
What metals are used to fabricate implants?
Titanium
What metals are used to fabricate partials?
Cobalt chromium alloy
What does a diagnostic study model contain?
Max and mand cast 3/3
What is 3 spills of mercury?
800 mg
What is the composition of polyvinyl impression material?
Polyvinyl siloxane used for crown and bridge
1:1
Direct restorations
Placed directly onto cavity preparations
Composition of ZOE
Power- zinc
Liquid- eugenol
What are the parts of the model trimmer?
Grinding wheel
Casing
Platform
What is the percentage of gold times 10
Fineness
Classification of cavities; Class I
Cavities located in pits or fissures. These are located in the occlusal surfaces of molars and premolars, the occlusal two-thirds of the buccal surfaces of molars, the lingual surfaces of upper incisors, and occasionally in the lingual surfaces of upper molars.
Classification of cavities; Class II
Cavities located in the proximal surfaces of molars and premolars.
Classification of cavities; Class III
Cavities in the proximal surfaces of canines, and incisors not involving the incisal angles.
Classification of cavities; Class IV
Cavities in the proximal surfaces of incisors or canines which also involve one or both of the incisal angles.
Classification of cavities; Class V
Cavities located in the gingival third of the labial, buccal, lingual, or palatal surfaces of any tooth.
Pontic
artifical tooth usually attached to a partial or bridge. Made of porcelain or ceramic
Maryland bridge
Commonly used to replace front teeth. A pontic is attached to metal bands that are hidden with white colored composide resin and attached to the backsides of the teeth on either side of the pontic
