Operative dentistry Flashcards
Enamel thickness for dogs and cats
Dog .3-.6mm
Cats .1-.3mm
How many dentin tubules are present
JVD 2010- 75,000
Wiggs - 29,000-52,000
What happens when dentinal tubules are exposed
Pain is caused by rapid outflow of fluid
Outward - cold
Inward - hot
What is the difference between C and A delta fibers
A delta = myelinated, larger, rapid pain
C type = smaller, unmyelinated, slow dull pain
What are the two types of tertiary dentin
Reactionary - formed from pre existing odontoblast
Reparative - formed from new odontoblasts due to death of original
Tertiary dentin
Rapidly irregular deposited dentin
Sclerotic dentin
Highly mineralized and occurs when odontoblasts are lost leaving a dead tract
Difficult to bond
What are the 3 types of cavity classes
Simple - 1 tooth
Compound - 2 teeth
Complex - 3+ teeth
Class 1 cavity
I,PM,M
Pit/fissure commonly found on occlusal surfaces
Class 2 cavity
PM/M
Proximal surface of caudal teeth
Class 3 Cavity
I/C
Proximal surfaces of rostral teeth without incisive involvement
Class 4 cavity
I/C
proximal surface of rostral teeth with incisive involvement
Class 5 cavity
I/C/PM/M
Gingival 3rd surface
Class VI cavity
I/C/PM/M
defect of the incisal edge or cusp
Stress vs Strain
Stress- When a force acts on a constrained body, the body resists the force.
Strain- is described as the change in length (ΔL = L − Lo) per original length (Lo) of the body when it is subjected to a load.
Wetability and appropriate angle
Surface wettability, which is characterized by the contact angles of a water droplet on a solid surface, is used to describe the ability of a water droplet in maintaining contact with the solid surface. It is also used to indicate the water repellency of the surface.
Angle = 0
Ideal properties of restoration
Good esthetics
Biocompatible
Not dissolve in oral fluids
Strength and modulus similar to tooth
Good abrasive/wear resistance
Coefficient of thermal expansion similar to tooth
Minimal dimensional changes with setting
High polishability
Radiopaque
Adhere to tooth structure
Common restoration materials
*Composites
*Glass Ionomer Cements (GICs)
*Resin Modified Glass Ionomer Cements (RMGICs)
*Amalgam
*Compomers
*Giomers
What are the four major components of composite resin
Inorganic filler - quartz/glass
Organic resins - glue
Coupling agent - link
Initiator - accelerator
What is the main component of fillers
Quartz/silica
**increased amt of filler increases the strength and reduces polymerization
CR organic resins are
Methacrylates
**Bisphenol A glycidyl methacrylate (bis-GMA)
**Triethylene glycol dimethacrylate (TEGDMA)
**Urethane dimethacrylate (UDMA)
Silorane
**epoxy
What are the disadvantage of methacrylates
polymerization shrinkage
Micro-leakage
Silane is commonly used for as?
Coupling agent
What are the 3 types of initiator types
Chemical
Light activation
Dual (self/light)
Benzoyl peroxide is what kind of initiator
chemical
Camphoroquinone is what type of initiator
Visible light (460-480)
Benzoin methyl ether is what type of initiator
UV light cured (365)
What are the 6 types of composite classification
Macrofilled
Microfilled
Hybrid
Nanofills
Nanohybrid
Flowable
What type of composite is recommended for type III/V cavity restoration
Macro/micro
What are the four types of fluoride releasing materials
**Resin composites–Better mechanical properties, wear, least fluoride
**Conventional GI–Thermal expansion coefficient similar to tooth, lower wear resistance, high fluoride release
**RMGI–Prone to abrasion, decreased flexural strength, should not be used in occlusal load-bearing areas
**Compomers–More resin than RMGI
Better mechanical properties like resin composites
Moderate fluoride release
Acid etch is made of what
phosphoric acid 35-38%
30 sec = enamel
15 sec = dentin
What generation is etching required for bonding
4th = multiple bottle
5th = single bottle
What generation of bonding does not require etch
6th = 2 bottle
7th = 1 bottle
What are the 8 steps to cavity prep.
Outline form
Resistance form
Retention form
Pathology removal form
Wall Form
Preparation cleansing form
Margin placement
Pulpal protection
What class of cavity is amalgam recommended for
Class 1
What type of restoration requires beveling
Class III-VI
**not Class V if near CEJ
What is the difference between ferrous and non-ferrous metal
Ferrous–iron/steel
Non-Ferrous –Noble (gold, platinum, palladium, iridium, rhodium, ruthenium, and osmium)
What is the difference between precious metals vs alloy
Precious = noble + silver
Alloy = combination of several metals
What is a luting agent
dental cement connecting the underlying tooth to a fixed prosthesis
What is the difference between resistance and retention
**Retention- ability to be retained when subjected to tensile forces along the long axis of the tooth preparation
**Resistance- ability to resist dislodgement when apical or oblique forces are applied
Convergence angle PM4
43
Convergence angle MN M1
36
Ideal convergence angle
12
Cast vs die
Cast - stone positive reproduction model involving large area of oral tissues
Die - same as cast but only a single tooth is replicated
What do liners do
zinc oxide or calcium hydroxide that can be applied to help protect the pulp
**can use GIC, RMGIC
