Principles of Operative Dentistry Flashcards
What is operative denistry?
treatment of disease/defects of hard tissue of teeth that DO NOT REAUIRE FULL COVERAGE RESTORATION
What does operative denistry restore?
Form, Function, and Esthetics
What varies in thickness by location and by tooth type?
enamel
What percent of the enamel is hydroxyapatite?
90-92%
What is the pattern of enamel rods?
- larger diameter near surface, smaller near dentin borders
- perpendicular to long axis, radiate outward (spokes on a wheel)
What can the grooves and fissures of the teeth lead to?
act as a food/bacterial trap and lead to decay
What are enamel tufts?
hypomineralized structures that extend into enamel from DEJ
What are enamel lamellae?
thin faults between enamel rod groups (extend from enamel toward DEJ)
What is the dentino-enamel junction?
hypomineralized zone where dentin meets enamel
Enamel ___________ in solubility as you approach DEJ
inreases in solubility
What can help to lower enamel acid solubility?
fluoride
What two characteristics describe pulp-dentin complex?
- strong and resilient
- living tissue
What is the largest portion of the tooth?
dentin (located in both coronal and root portions of tooth)
What does dentin form?
- walls of the pulp chamber
- formed immediately prior to enamel
Formation of what continues throughout life?
dentin
What are enamel spindles?
odontoblastic processes crossed into enamel (may serve as pain receptors)
What are dentinal tubules?
canals extending from DEJ/DCJ to pulp
What are dentinal tubules lined with?
peritubular dentin
The diameter of the peritubular dentin is largest at what?
the pulp
What forms reparative dentin?
secondary odontoblasts
What causes reparative dentin to form?
in response to trauma, chronic irritation, etc.
What is sclerotic dentin?
- primary dentin that has changed
What does sclerotin dentin fill with?
fills with calcified material after the peritubular dentin widens
What is the average hardness of dentin compared to enamel?
1/5 the hardness of enamel
What percent of dentin is hydroxyapatite?
50%
What allows for dentinal sensitivity?
fluid movement in tubules
What is the hydrodynamic theory of pain transmission?
- Odontoblastic process wrapped in nerves and fluid in dentinal tubules
- Enamel/cementum removed during preparation = seal is lost
- Causing small fluid movements in tubules= distortions in nerve endings = PAIN
What is a smear layer?
- created whenever tooth is cut/prepared
- plugs dentinal tubules
What is the color of enamel?
- gray, semi translucent
- depends of the underlying dentin
- becomes temporarily whiter when dehydrated
- shiny
What is the color of dentin?
- yellowish white
- dull, opaque
What are the characteristics of cementum?
- covers root surface
- softer than dentin
- formed continually
What is the definition of contours?
curve or shape of something
What is the definition of proximal contact?
where two adjacent teeth contact
What is the definition of embrasures?
an opening with sides flaring outward (v-shaped valleys between adjacent teeth)
What are the three forms when considering tooth preparation?
resistance form
retention form
convenience form
What are the objectives of tooth preparation?
- remove defects
- provide protection to pulp
- extend restoration as conservatively as possible
- resist fracture when chewing
- restore esthetics and function
Tooth preparation should be precise especially for…
amalgam
Preparations for composite restorations incorporate what?
bonding