Principles of Operative Dentistry Flashcards
What is operative dentistry?
Treatment of disease/defects of hard tissues of teeth THAT DO NOT REQUIRE FULL COVER 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 & brittle
Enamels rods are _____ diameter near the surface & _____ 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 lamella
Enamel lamella extend from ____ toward ____
Enamel; DEJ
Odontoblastic process crossed into enamel:
Enamel spindles
Hypomineralized zone where dentin meets enamel:
Dentino-enamel junction (DEJ)
The DEJ, where 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 restoration?
- 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 comprised 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 located between dentinal tubules
Intertubular dentin
Dentinal tubules are lined with ____ & _____ is between the dentinal tubules
Peritubular dentin; intertubular dentin
Where is the diameter of dentinal tubules the largest?
Largest at pulp
In dentinal tubules, the number 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 protection to the underlying pulp by decreasing dentin permeability:
Reparative 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 & fills with calcified material
Dentin hardness compared to enamel:
Dentin is 1/5 as hard as enamel
Dentin is harder near the ____ than 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 & fluid in dentin tubules
When enamel/cementum is removed during preparation, the _____ is lost, causing ____ resulting ____
Seal is lost; causing small fluid movements in tubules which distorts nerve endings; dentin sensitivity/pain
Created whenever tooth is cut/prepared:
Smear layer
The smear layer plugs:
Dentinal tubules
Enamel vs. Dentin color:
Enamel:
- Grey & semi-translucent
- Color depends on the underlying dentin
- Becomes temporarily whiter when dehydrated
- shiny
Enamel vs. Dentin color:
Enamel becomes temporarily white when:
Dehydrated
Enamel vs. Dentin color:
Dentin:
- Yellow/white
- Dull/opaque
Covers the root surface:
Cememtum
Cementum is ____ compared to dentin
Softer
Describe the formation of cementum:
Formed cotinually
Curve or shape of something:
Contour
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 as _______
- ______ when chewing
- Restore _____ & ______
- Resistance form, retention form, convenience form
- Defects
- Protection to pulp
- As conservatively as possible
- Resist fracture
- Esthetics & function
Tooth preparation should be _____ especially for ______
Precise; amalgam
Tooth preparation should follow the:
GV Black- design & principles
Preparations for complete composite restorations incorporate:
Bonding
When preparing a tooth you should extend to:
Sound tooth structure in all directions
Preparation 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 ____
- Protect ____
- Minimize fracture
- Maximize retention
- Protect pulp
The last step in preparation of a tooth is:
Final cleaning, inspection & sealing prep
Factors to consider prior to restoring a tooth: (5)
- Esthetics
- Economics
- Medical conditions
- Age
- Caries risk
The dental anatomy to consider when restoring a tooth include: (4)
- Enamel rod orientation
- thickness of enamel & dentin
- Size & location of pulp
- Relationship of tooth to periodontium
When considering conservation of tooth structure, repair _____ but preserve _____
Damage; Vitality
Locations of primary caries:
- Pit & fissure
- Enamel smooth surface
- Root surface
Pit & fissures occur from:
Imperfect coalescence of developmental lobe
What area of the tooth is an area that is left unclean chronically (location of primary caries)
Enamel smooth surface
Carries 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 a the junction between the restoration and tooth may cause:
Recurrent caries
May progress under the restoration or behind it so it cannot be seen with a radiograph:
Recurrent caries
Type of carries that cannot be seen in a radiograph:
Recurrent caries
Reparative dentin is formed by odontoblasts at:
Ends of tubules & surface of pulp in response to irritation
Light color caries that appear dull & mushy:
Acute
Acute caries may also be called:
Rampant caries
Caries that are slow or arrested, a dark color & appear shiny/solid:
Chronic caries
Dentists formally practiced _____ meaning ____-
“Extension for prevention” - meant taking away unnecessary tooth structure & is no longer practiced
Instead of “extension for prevention” there are better preventative measures available including: (4)
- Enameloplasty
- Sealant
- Preventative resin
- Conservative composite restoration
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, mesial-occlusal-distal
Facial or buccal
Lingual
Internal walls in a tooth preparation include:
Axial wall
Pulpal wall (floor)
Label A & B in the following image:
A- Pulpal floor
B- Axial wall
The axial wall is ____ to the long axis of the tooth:
Parallel
Wall closest to the pulp:
Pulpal wall (floor)
The pulpal wall/floor is ____ to the long axis of the tooth in ______ preparations:
Perpendicular; class I & 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 line angle
H- Axio-buccal line angle
I- Axio-gingival line angle
Describe the floor in a preparation: (3)
- Prepared
- Flat
- Perpendicular to occlusal forces
The pulpal floor is _____ to occlusal forces
Perpedicular
The pulpal & gingival walls of a prep provide ______ for the restoration and _____ in the tooth
Provide stabilizing seats & 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 & EXTERNAL surface of the tooth:
Cavosurface angle/margin
Types of cavosurfaces (3):
- Bevel
- 90 degrees
- Chamfer
Where the cementum meets the enamel:
Cementoenamel junction (CEJ)
The enamel margin strength is formed by:
Full length enamel rods
Enamel rods’ inner end are on:
Sound dentin
When enamel rods are not supported by enamel:
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 invovled
A preparation on the occlusal surface of posterior teeth:
Class I
A class I prep on the occlusal surface of posterior teeth may include:
Lingual/buccal grooves & pits
A preparation on the proximal surface of premolars & molars:
Class II
A preparation on the proximal surfaces of incisors & canines THEY DO NOT INVOLVE THE INCISAL EDGE:
Class III
A preparation on the proximal surfaces of incisors & canines that INVOLVE the incisal edge:
Class IV
A preparation on the gingival 1/3 of buccal & lingual 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 & 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 restoration
- no occlusion on margins of prep
When considering the outline form of a prep:
- ______ on cusps & marginal ridges
- Minimize extensions _______
- Connect two preps that _____
- Preserve strength
- Faciolingually
- Less than 0.5mm apart
In a class I prep, the depth of pit & fissure maximum=
2.0mm (in lab setting)
In a class I prep, the depth should extend to:
Sound tooth structure
In a class I prep, extend when: (2)
- Fissures cannot be eliminated by enameloplasty
- Two cavities have less than 0.5mm between them
When considering outline form, do not terminate on:
Cusp height 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 preparation:
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 four 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?
- When margin exceeds 2/3 of the distance between the central groove
- When margins 1/2 the distance between the central groove and cusp tip
Resistance form is compromised when the margin extends 2/3 the distance of 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 weak cusps
-Internal line angles slightly rounded
-External line angles slightly rounded
-Flat floors
These all contribute to:
Resistance form
Slightly rounded external line angles leads to:
Less stress concentration
Flat floors 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:
- Remove unsupported enamel
- Reduce stress concentration
In order to contribute to resistance form, the margins in amalgam should be:
90 degrees
The objective of retention form is to:
Retain the restoration (keep restorations in the tooth)
Method contributing to retention form in which it prevents tipping and proximal displacement:
Dovetails
What is the goal of a dovetail?
Prevents tipping & proximal displacement
What are the three components of retention form?
- Wall length
- 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:
Microchemical retention between adhesive & tooth
Form that allows you to access the defect:
Convenience form
Convenience form allows you to:
See what you are doing
Once outline form, primary resistance, & primary retention form are complete, _____ may remain & 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 & retention form
- external walls & margins
- cleaning, inspecting & sealing
Affected dentin is _____ and usually _____ but NOT _____
Is this okay to leave or does it need to be removed?
Demineralized; discolored; soft
Ok to leave
Affected dentin is _____ while infected dentin _____
Okay to leave; must be removed
Describe infected dentin:
Microorganisms present
Soft
May or may not be stained
Must remove
Why must infected dentin be removed?
Because microorganisms are present
How do you tell the difference between affected & infected dentin?
Not always possible
Secondary retention includes:
Retention grooves & points
Areas for restorative material to “lock” into, resulting in improved retention:
Retention groove/points
Secondary retention includes having fewer _____
Extensions
A bevel for rounded axiopulpal line angles is an example of:
Secondary resistance
Allows for the increase bulk of restorative material & dispersal of concentration of forces:
Bevel for rounded axiopulpal line angles
Position slightly to the patients right & in front:
8:00
When should an 8:00 position be used?
- Buccal sides of patients UL
- Lingual sides of patient LR
Position slightly to the patients right & 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 & behind:
12:00-1:00
When should a 12:00-1:00 be used?
- Buccal sides of patients R & L anterior
- Lingual sides of patients R & L anterior
