Principles of Operative Dentistry Flashcards
1
Q
What is operative denistry?
A
treatment of disease/defects of hard tissue of teeth that DO NOT REAUIRE FULL COVERAGE RESTORATION
2
Q
What does operative denistry restore?
A
Form, Function, and Esthetics
3
Q
What varies in thickness by location and by tooth type?
A
enamel
4
Q
What percent of the enamel is hydroxyapatite?
A
90-92%
5
Q
What is the pattern of enamel rods?
A
- larger diameter near surface, smaller near dentin borders
- perpendicular to long axis, radiate outward (spokes on a wheel)
6
Q
What can the grooves and fissures of the teeth lead to?
A
act as a food/bacterial trap and lead to decay
7
Q
What are enamel tufts?
A
hypomineralized structures that extend into enamel from DEJ
8
Q
What are enamel lamellae?
A
thin faults between enamel rod groups (extend from enamel toward DEJ)
9
Q
What is the dentino-enamel junction?
A
hypomineralized zone where dentin meets enamel
10
Q
Enamel ___________ in solubility as you approach DEJ
A
inreases in solubility
11
Q
What can help to lower enamel acid solubility?
A
fluoride
12
Q
What two characteristics describe pulp-dentin complex?
A
- strong and resilient
- living tissue
13
Q
What is the largest portion of the tooth?
A
dentin (located in both coronal and root portions of tooth)
14
Q
What does dentin form?
A
- walls of the pulp chamber
- formed immediately prior to enamel
15
Q
Formation of what continues throughout life?
A
dentin
16
Q
What are enamel spindles?
A
odontoblastic processes crossed into enamel (may serve as pain receptors)
17
Q
What are dentinal tubules?
A
canals extending from DEJ/DCJ to pulp
18
Q
What are dentinal tubules lined with?
A
peritubular dentin
19
Q
The diameter of the peritubular dentin is largest at what?
A
the pulp
20
Q
What forms reparative dentin?
A
secondary odontoblasts
21
Q
What causes reparative dentin to form?
A
in response to trauma, chronic irritation, etc.
22
Q
What is sclerotic dentin?
A
- primary dentin that has changed
23
Q
What does sclerotin dentin fill with?
A
fills with calcified material after the peritubular dentin widens
24
Q
What is the average hardness of dentin compared to enamel?
A
1/5 the hardness of enamel
25
What percent of dentin is hydroxyapatite?
50%
26
What allows for dentinal sensitivity?
fluid movement in tubules
27
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
28
What is a smear layer?
- created whenever tooth is cut/prepared
- plugs dentinal tubules
29
What is the color of enamel?
- gray, semi translucent
- depends of the underlying dentin
- becomes temporarily whiter when dehydrated
- shiny
30
What is the color of dentin?
- yellowish white
- dull, opaque
31
What are the characteristics of cementum?
- covers root surface
- softer than dentin
- formed continually
32
What is the definition of contours?
curve or shape of something
33
What is the definition of proximal contact?
where two adjacent teeth contact
34
What is the definition of embrasures?
an opening with sides flaring outward (v-shaped valleys between adjacent teeth)
35
What are the three forms when considering tooth preparation?
resistance form
retention form
convenience form
36
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
37
Tooth preparation should be precise especially for...
amalgam
38
Preparations for composite restorations incorporate what?
bonding
39
Prep walls are designed to...
- retain restoration
- resist fracture
40
What doing a preparation you should follow these steps...
1. remove remaining caries or old restorative material
2. protect pulp
3. minimize fracture, maximize retention
4. finish walls and margins
5. final cleaning, inspection, sealing prep
41
What are some factors that should be considered for preparations and restorations?
esthetics
economics
medical conditions
age
caries risk
42
What should you consider when thinking about dental anatomy for preparation?
- enamel rode orientation
- thickness of enamel and dentin
- size, location of pulp
- relationship of tooth to periodontium
43
Where are the locations of primary caries?
pit and fissure
enamel smooth surface
root surface
44
What are residual caries?
caries left by operator (intentionally or by accident)
45
When can residual caries be acceptable (very rare instance)?
to avoid pulp exposure
46
What are recurrent caries?
microleakage present at the junction between restoration and tooth
47
Why can recurrent caries sometimes not be seen on radiograph?
the caries can progress under the restoration or behind it
48
What are the characteristics of acute caries?
- rampant
- light color
- appears dull, mushy
49
What are the characteristics of chronic caries?
- slow or arrested
- dark color
- appears shiny, solid
50
What is the idea of conservative dentistry?
using better preventative measure available such as enameloplasty, sealant, and preventative resin
51
What does "extension for prevention" mean?
taking away unnecessary tooth structure to prevent spread of caries (this is no longer practiced)
52
What do the following abbreviations mean for tooth preparation?
O
MO or DO or MOD
F or B
L
- O = occlusal
- MO or DO or MOD = mesial occlusal or distal occlusal, mesial-occlusal distal
- F or B = facial or buccal
- L = lingual
53
What are the two terms for the internal walls?
axial wall
pulpal wall or floor
54
The axial wall is _________ to the long axis of tooth
parallel
55
Cavosurface is a (noun, verb, or adjective)
adjective
56
What is the definition of cavosurface?
margin (edge) where the prepared (cut) tooth meets the unprepared tooth
57
What is the definition of cavosurface angle?
angle where prepared wall and unprepared tooth surface meet
58
What wall is closest to the pulp?
pulpal wall/floor
59
The pulpal wall/floor is _________ to the long axis of the tooth in class I and II preps?
perpendicular
60
What are the characteristics of the floor?
- prepared (cut) walls
- flat
- perpendicular to occlusal forces
61
What do the pulpal and gingival floors/walls provide?
- stablizing seats for restoration
- distribute stresses in tooth
62
What is a line angle?
Junction of two walls/surfaces along a line
63
What is a point angle?
junction of three surfaces
64
What are the three types of cavosurface angles?
- bevel
- 90 degrees
- chamfer (not in this class)
65
What is the CEJ?
where cementum meets enamel
66
What is unsupported enamel?
when enamel rods are not supported by sound dentin
67
What is a class I prep?
- Occlusal surface of posterior teeth
- May include lingual/buccal grooves and pits
68
What is a class II prep?
Proximal surfaces of premolars and molars
69
What is a class III prep?
Proximal surfaces of incisors and canines (do not involve in incisal edge)
70
What is a class IV prep?
class III but the incisal edge instead
- Proximal surfaces of incisors and canines
71
What is class V prep?
Gingival 1/3 of smooth surfaces
◦ Buccal, lingual
72
What is class VI prep?
incisal edge or cusp
73
What are the stages of tooth prep?
- GV Black principles
- know what your restorative material needs for adequate strength
- initial stage
- final stage
74
What is the initial stage of preparation?
- outline form
- initial depth
- priary resistance form
- primary retention form
- convenience form
75
How should the outline form look?
- smooth and flowing
- undermined enamel removed
- margins placed where you can finish restoration
- no occlusion on margins of prep
76
What are the rules of outline form?
- preserve strength
- minimize extensions faciolingually
- connect two preps that are <0.5 mm apart
77
What are the rules for a class I prep in outline form?
- Extend to sound tooth structure
- Extend when (Fissures cannot be eliminated by enameloplasty and Two cavities have <0.5mm between them)
- Do not terminate on cusp height or ridge crest
- Allow sufficient access for placement and finishing
78
What are the rules for a class II prep outline form?
extend gingival margins apical to contact, extend interproximal margins to embrasures
79
How is axial wall depth measured?
Class II - measured from proximal marigin to axial wall
Class V - measured from marigin to axial wall
80
What is an enameloplasty?
- remove shallow enamel fissure or pit and create a smoother shape (self-cleansing)
- no more than 1/3 enamel thickness removed
81
What does resistance form mean?
resistance to fracture against occlusal forces
82
When is the resistance form compromised?
margin exceeds 2/3 of the distance between central groove
83
What should the resistance form have?
- internal line angles slightly rounded
- external line angles slightly rounded
- flat foors
84
What does the resistance form allow for?
suffiecient thickness of restorative material
85
What is the minimum thickness for amalgam, gold, porcelain?
amalgam - 1.5 mm
gold - 1-2 mm
porcelain 2.0 mm
86
What should the margins of the resistance form be for amalgam?
90 degrees
87
What are the objectives for the retention form?
- retain the restoration
- dovetail to prevent tipping and proximal displacement
88
What are the key aspects of the retention form?
- wall length
- convergence
- parallellism
89
What type of wall is better for retention (tall or short)?
tall
90
What are the final stage steps of tooth prep?
* Remove remaining infected dentin
* Remove remaining old restoration
* Pulp protection
* Secondary resistance and retention forms
* Finish external walls and margins
* Final cleaning, inspecting, and sealing
91
What does affected/demineralized dentin appear like?
- usually discolored by not soft
- ok to leave in rare circumstances
92
What does infected dentin appear like?
- soft
- may or may not be stained
- MUST BE REMOVED
93
What is secondary retention?
- retention grooves, points
- areas for restorative materials to "lock" into
- results in fewer extensions
- increase bulk of restorative material to disperse forces
94
Where should you position yourself to do lingual side of patients lower right and buccal side of patients upper left?
8:00
95
Where should you position yourself to do lingual side of patients lower left and buccal side of patients upper right?
11:00
96
Where should you position yourself to do buccal side of patients anteriors and lingual side of patietns anterior?
12:00-1:00
