Principles of Operative Dentistry Flashcards
What is operative dentistry?
treatment of disease/defects of hard tissues of teeth THAT DO NOT REQUIRE FULL COVERAGE RESTORATION
Operative dentistry restores:
- form
- function
- esthetics
Enamel thickness varies by:
- location
- tooth type
Enamel is ____% hydroxyapatite
90-92%
Enamel can be described as both:
strong and brittle
Enamel rods are ___ diameter near the surface, and ____ near the dentin borders
larger; smaller
Enamel rods are ____ to the long axis and radiate ___
perpendicular; outward
Can act as food/bacterial traps, leading to decay:
grooves & fissures
- hypomineralized
- extend into the enamel
enamel tufts
- thin faults between enamel rod groups
enamel lamellae
Enamel lamella extend from ___ toward ____
Enamel toward DEJ
Odontoblastic process crossed into enamel:
enamel spindles
Hypomineralized zone where dentin meets enamel:
dentino-enamel junction (DEJ)
The DEJ, dentin meets enamel can be described as:
hypomineralized
Enamel becomes more soluble as you approach the:
DEJ
____ lowers acid solubility:
fluoride
What is important to remember when considering caries AND bonded restorations?
- fluoride lowers acid solubility
- enamel is more soluble as you approach the DEJ
Describe the pulp-dentin complex: (2)
- strong & resilient
- living tissue
The largest portion of the tooth is made up of:
dentin
Dentin is located in both ___ & ____ portions of the tooth
coronal & root
Forms the walls of the pulp chamber:
dentin
Dentin is formed immediately:
prior to enamel
Describe dentin formation: (timeline)
continues throughout the life of the pulp
Canals extending from DEJ/DCJ to pulp:
dentinal tubules
Dentinal tubules are canals extending:
from DEJ/DCJ to pulp
Dentinal tubules are lined with:
peritubular dentin
____ is between dentinal tubules
intertubular
Dentinal tubules are lined with ____ and ____ is between tubules.
pert tubular denin; intertubular dentin
Where is the diameter of dentinal tubules the largest?
At the pulp
In dentinal tubules, the # of tubules/square mm is greatest at:
the pulp
Reparative dentin is formed by _____ in response to ____.
secondary odontoblasts; moderate irritant
secondary odontoblasts form:
reparative dentin
Provides protecting to the underlying pulp- by decreasing dentin permeability
dentin
How does reparative dentin provide protection to the underlying pulp?
by decreasing dentin permeability
Primary dentin that has changed
sclerotic dentin
Process of sclerotic dentin formation:
peritubular dentin widens and fills with calcified material
Dentin hardness compared to enamel:
dentin 1/5 as hard as enamel
Dentin is harder near the ___ than near the ___ by ____x
DEJ than near pulp 3x
Dentin is ___% hydroxyapatite
50%
What causes dentinal sensitivity?
fluid movement in tubules
Describe the hydrodynamic theory of pain transmission:
odontoblastic process wrapped in nerves and fluid in dentinal tubules
When enamel/cementum is removed during preparation, ____ is lost, causing ____ resulting in ____
seal is lost; causing small fluid movements in tubules which distorts nerve endings; pain
Created when ever tooth is cut/prepared:
smear layer
The smear plugs ____
dentinal tubules
Enamel vs. dentin color
Enamel =
- gray, semi-translucent
- color depends on underlying dentin
- becomes temporarily whiter when dehydrated
-shiny
Enamel vs denin color:
Enamel becomes temporarily whiter when:
dehydrated
Ename vs. dentin color:
Dentin =
- yellow-white
- dull/opaque
Covers the root surface:
cementum
cementum is ____ compared to dentin
softer
Describe the formation of cementum:
formed continually
Curve or shape of something:
contours
Where two adjacent teeth contact:
proximal contact
An opening with sides flaring outward:
embrasures
V-shaped valleys between adjacent teeth, typically filled with gingiva:
Embrasures
Objectives of tooth preparation:
- ____ form, ___ form, ___ form
- Remove ____
- Provide necessary ____
- Extend restoration ___
- ____ when chewing
- Restore ____ & ____
- Resistance form, retention form, convenience form
- Defects
- Protection to pulp
- Conservatively as possible
- Resist fracture
- Esthetics and function
Tooth preparation should be ____ especially for ____
Precise; amalgam
Tooth preparation should follow the:
GV Black design and principles
Preparations for composite restorations incorporate:
bonding
When preparing a tooth, you should extend to:
sound tooth structure in all directions
Prep walls are designed to: (2)
- Retain restoration
- Resist fracture
The first step in a preparation is to:
remove remaining caries or old restorative material
Three important aspects of preparation include:
minimize ____, maximize ____, and protect ____
minimize fracture, maximize retention, protect pulp
The last step in preparation of a tooth includes:
final cleaning, inspection, and sealing prep
Factors to consider prior to restoring a tooth:
- esthetics
- economics
- medical conditions
- age
- caries risk
The dental anatomy to consider when resorting a tooth: (4)
- enamel rod orientation
- thickness of enamel and dentin
- size & location of pulp
- relationship of tooth to periodontium
When considering conservation of tooth structure, repair ____ but preserve ____
repair damage but preserve vitality
Location of primary caries: (3)
- pit & fissure
- enamel smooth surface
- root surface
Pit and fissures occur from :
imperfect coalescence of developmental enamel lobe
What area of the tooth is an area that is left unclean chronically (location of primary caries)
Enamel smooth surface
Caries left by the operator - may be intentionally or accidental:
residual caries
It is never ideal to leave caries especially when:
Left at DEJ or on prepared enamel wall
It may be acceptable to leave caries in a rare instance to:
avoid pulp exposure and when left as affected dentin near the pulp
Microleakage present at the junction between restoration and tooth causes:
recurrent caries
May progress under the restoration or behind it so it can not be seen with the radiograph:
recurrent caries
Type of caries that cannot be seen in a radiograph:
recurrent caries
Reparative dentin is formed by odontoblasts at:
ends of tubules at surface pulp in response to irritation
Light colored caries that appear dull and mushy:
acute
Acute caries may be also called:
rampant
Caries that are slow or arrested, dark color, and appear shiny/solid
chronic caries
Dentists formally practiced ____ meaning ____.
“extension for prevention”- meant taking away unnecessary tooth structure and is no longer practiced
Instead of “extension for prevention” there are better preventative measures available including:
- enameloplasty
- sealents
- preventative resin
- conservative composite resotration
Surfaces involved in restoration:
____= one surface involved
____= two surfaces involved
____= three or more surfaces involved
simple
compound
complex
Abbreviations:
O:
MO, DO, MOD:
F or B:
L:
Occlusal
Mesial occlusal, distal occlusal, medial-occlusal distal
facial or buccal
lingual
Internal walls in a tooth preparation include:
axial wall and pulpal wall (floor)
Label A and B:
A: pulpal wall
B: axial wall
Axial wall is ____ to the long axis of the tooth
parallel
Wall closest to the pulp:
pulpal wall/floor
The pulpal wall is ____ to the long axis of the tooth in ____ preparations
Perpendicular; Class I and Class II
Label the following image:
A: Pulpal floor
B: Axial wall:
C: Gingival floor
D: Buccal wall
E: Lingual wall
F: Axio-lingual line angle
G: Axio-pulpal ling angle
H: Axis-buccal line angle
I: Axioginigival line angle
Describe the floor in a preparation: (3)
- prepared
- flat
- perpendicular to occlusal forces
The pulpal floor is ____ to occlusal forces
perpindicular
The pulpal and gingival walls of a prep provide ____ for the restoration and ____ in the tooth
Provide- stabilizing seats and distribute stresses
Junction of two walls/surfaces along a line:
line angle
In a ____ line angle, the apex points AWAY from the observer
Internal
In a ____ line angle, the apex points TOWARDS the observer
External
Junction of three surfaces:
point angle
Junction of PREPARED cavity wall and EXTERNAL surface of the tooth:
Cavosurface angle or margin
Types of cavosurfaces:
- bevel
- 90 degrees
- chamfer
Where cementum meets enamel:
cementoenamel junction (CEJ)
Enamel margin strength is formed by:
full length enamel rods
Enamel rods’ inner ends are on:
sound dentin
When enamel rods are not supported by sound dentin:
unsupported enamel
Unsupported enamel can:
fracture easily because its brittle
Why operative dentistry?
- diagnosis
- treatment
- repair
Classifications of tooth preps are named based on:
anatomy involved
A preparation on the occlusal surface of posterior teeth:
Class I
A class 1 prep on the occlusal surface of posterior teeth may include:
lingual/buccal grooves and pits
A preparation on the proximal surfaces of premolars and molars:
Class II
A preparation on the proximal surfaces of incisors and canines, THEY DO NOT INVOLVE THE INCISAL EDGE
Class III
A preparation on the proximal surfaces of incisors and canines that involve the incisal edge
Class IV
A preparation one the gingival 1/2 of buccal and lingual smooth surfaces:
Class V
A preparation on the incisal edge or cusp:
Class VI
List the components of the initial stage of tooth preparation: (5)
- outline form
- initial depth
- primary resistance form
- primary retention form
- convenience form
When visualizing the outline form, the prep should appear:
smooth and flowing
List what aspects make up the outline form of the initial stage of tooth preparation: (3)
- undermined enamel is removed
- margins placed where you can finish the restoration
- no occlusion on margins of preparation
When considering the outline form of a prep:
- _____- on cusps and marginal ridges
- minimize extensions ____
- connect two preps that are ___.
- preserve strength
- faciolingually
- less than 0.5 mm apart
In a class 1 prep, the depth of pit and fissure maximum =
2.0 mm (in lab setting)
In a class I prep, the depth should extend to:
sound tooth structure
In a class I prep, extend when:
- fissures cannot be eliminated by enameloplasts
- two cavities have less than 0.5 mm between them
When considering outline form, do not terminate on:
cusp heigh or ridge crest
In a class II prep, extend gingival margins ____ , extend interproximal margins to ___.
apical to contact; embrasures
What is the axial wall depth in a class II prep:
0.2-0.8mm INTO DENTIN
How is axial wall depth measured?
From edge of tooth (proximal surface) to axial wall
Is not a typical depth measurement from the top of something to the bottom
axial wall depth
Removes shallow enamel fissure or pit, creating a smooth, saucer shaped surface
enameloplasty
A smooth saucer shaped surface created by an enameloplasty is:
self-cleansing
In an enameloplasty, no more than ___ enamel thickness should be removed:
1/3
List the 4 aspects of resistance form:
- resistance to fracture
- need to resist or withstand occlusal forces
- conservative extension- leave tooth strong
- preserve cusps and marginal ridges
When is resistance form compromised? (2)
- when margin exceeds 2/3 of the distance between the central groove
- When Marin ends 1/2 the distance between central groove and cusp tip
Resistance form is compromised when the margin extends 2/3 of the distance between the central groove, and you:
must cap weak cusps
Resistance form is compromised when the margins end 1/2 distance between central groove and cusp tip and you:
consider capping cusp tips
- Internal line angles are slightly rounded
- External line angles slightly rounded
- Flat floors
These are all aspects of:
Resistance form
Slightly rounding external line angles leads to:
Less stress concentration
Flat floor of a preparation prevent:
movement
Resistance form includes allowing for sufficient ____ of restorative material
thickness
In order to contribute to resistance form, bevels are needed to: (2)
- remove unsupported enamel
- reduce stress concentration
In order to contribute to resistance form, the margin in amalgam should be:
90 degrees
The objective of retention form is to:
retain the restoration (keep restorations in the toooof)
Method contributing to retention for that prevents tipping and proximal displacement:
dovetails
What is the goal of a dovetail?
prevents tipping and proximal dispacement
What are the three components of retention form?
- wall length
2, convergence - parallelism
Having a taller wall in a preparation will:
resist pull of sticky foods
Describe convergence in retention form:
Walls slant toward each other, especially important with amalgam
Describe retention form in bonded restorations:
microchemcial retention between adhesive and tooth
Form that allows you to axis the defect:
convenience form
Convenience form allows you to:
see what you’re doing
Once outline form, primary resistance, and primary retention form are complete, ___ may remain and its important to ___.
caries may remain; remove the caries
In the final stage of tooth preparation:
- remove remaining ____
- remove remaining ____
- ____ protection
- ____ & ____ forms
- Finish ___ & ___
- FInal ___, ____ & ____
- infected dentin
- old restoration
- pulp
- secondary resistance and retention forms
- finish external walls and margins
- final cleaning, inspecting and sealing
Affected dentin is ____ and usually ____ but not ___.
Is this okay to leave or does it need to be removed?
demineralized. usually discolored but NOT soft
OK to leave
Affected dentin is ____ while infected dentin ___
okay to leave; must remove
Describe infected dentin:
- microorganisms present
- soft
- may or may not be stained
- must remove
Why must you removed infected dentin?
Bc microorganisms are present
How do you tell the difference between affected and infected dentin?
Not always possible
Secondary retention includes:
retention groove and points
Areas for restorative material to “lock” into, resulting in improved retention
retention groove and points
Secondary retention includes have fewer ____
extensions
A bevel for rounded axiopulpal line angles is an example of:
secondary resistance
Allows for the increase bulk of restorative material and disperses concentration of forces:
bevel for rounded axiopulpal line angle
Position slightly to the patients right and in front:
8:00
When should an 8:00 position be used?
- buccal sides of patient UL
- Lingual sides of patients LR
Position slightly to the patient right and behind:
11:00
When should an 11:00 position be used?
- buccal sides of patients UR
- Lingual sides of patients LL
Position slightly to the patients left and behind:
12:00-1:00 position
When should a 12:00-1:00 position be used?
- buccal sides patients R and L anterior
- Lingual sides of patients R and L anterior
