Endo Test 1 Flashcards
1
Q
Endo is concerned with…
A
MORPHOLOGY, PHYSIOLOGY, PATHOLOGY of PULP and PERI-RADICULAR TISSUE
2
Q
Apical periodontitis
A
Detected by peri-radicular radiolucency – INCREASED OSTEOCLAST ACTIVITY
3
Q
NSRCT is to remove the __ and __ of microorganisms to pulpal and periradicular space
A
presence and access
4
Q
What three factors determine how fast Apical Perio heals?
A
Chemomechanical debridement and restoration, endo pathogens, host factors
5
Q
What two cytokines released by macrophages play an important role in bone resorption
A
IL1 beta and PGs
6
Q
5 things in NSRCT
A
Diagnosis coronal access instrumentation obturation final restoration
7
Q
Diagnosis is made up of 3 things
A
history (med and dent)
classification of pulpal and periradicular disease
treatment plan
8
Q
how many positive signs or symptoms do you need before starting RC treatment?
A
TWO
9
Q
What are the 3 goals of coronal access
A
straight line access
conserving tooth structure
unroof pulp chamber and remove pulp horns
10
Q
law of centrality
A
pulp chamber is always in the CENTER of the tooth
it is at the level of the CEJ
11
Q
Law of concentricity
A
walls of pulp chamber are concentric to the external surface of the tooth at the CEJ
Same amount of tooth lies between the outside and the pulp chamber
12
Q
Law of CEJ
A
CEJ is the most consistent, reproducible landmark for locating the pulp chamber
CEJ is easy to see, even on heavily restored teeth
roof of pulp chamber at CEJ usually
13
Q
law of symmetry I
A
EXCEPT FOR MAX MOLARS – orifices are equdistant from MD drawn on camber floor
14
Q
Law of Symmetry II
A
Except for MAX MOLARS – the orifices lie on a line PERPENDICULAR to the MD line
15
Q
Law of color change
A
Color of the floor of the pulp chambers is darker than the walls
16
Q
Law of orifice location I
A
orifices located at junction of wall and floor
17
Q
Law of orifice location II
A
Orifices are located at the terminus of the developmental fusion lines
**Champagne bubble test - helps you locate orifice
18
Q
what are the 2 major goals of instrumentations
A
cleaning and shaping
19
Q
what are some chemicals you can use to clean
A
NaOCL - irrigation
Ca(OH)2 - between appointments
20
Q
What kind of shape do you want to achieve through the shaping stage
A
continuously tapering conical shape from apical to coronal ends of the RC system
21
Q
What is the goal of obturation
A
create a fluid-tight seal int he entire length of the RD system and to entomb any residual pathogens
22
Q
Coronal seal
A
temporary and final restoration
prevent microleakage
23
Q
What are some indications for NSRCT
A
Irreversible pulpitis pulpal necrosis hyperplastic pulp prosthetics excessive supraeruption interna/eternal resortpion endo --> perio
24
Q
CONTRAINDICATIONS to NSRCT
A
tooth is unrestorable insufficient perio support massive root resorption non-strategic tooth canal instrumentation not practical
25
When do you evaluate NSRCT after you do it
6 months after
| then yearly after that
26
how do you know you were successful?
tooth is asymptomatic
tooth si functional and firmly seated in alveolus
soft tissue is normal
radiographs show normal lamina dura and no more PA radiolucency
27
How do you know NSRCT was unsuccessful
symptomatic tooth
soft tissue -- sinus tract plus palpation
PA radiolucency still there
28
Successful endo depends on
effective pain control and anxiety control
29
what is endo pain secondary to
inflammatory mediators on nociceptors
30
What are the THREE Ds to control endo pain
diagnosis
definitive dental treatment
drugs -- there are 3 drug classes that can act at CNS, act on axons, act on the inflammatory mediators
31
after you do NSRCT, how does the root grow back
SCAP -- stem cells from apical papilla
32
Pulp is from what origin
mesenchymal
33
pulp is mostly
CT -- highly vascularized and innervated
34
what are the functions of pulp
```
inductive
formatie
nutritive
sensory
protective
```
35
Pulp horns in incisors are
located MD
36
pulp horns in post teeth correspond to
cusp tips
37
pulp chambers tend to occuppy
crown center
38
dimensions of pulp chamber depend on
shape of crown and trunk
39
"pulp cavity" is divided into what two things
pulp chamber and root canal
| coronal part and radicular part
40
what kind of curve to most root canals have
FL -- so a curved canal is often undetectable on a facial projection radiograph
41
wide roots tend to have
more than one canal
42
root canal extends from what to what
orifice to apical foramen
43
the shape of the pulp system reflects
the surface outline of the crown and root
44
Weine canal classification - TYPE 1
one orifice - one canal - one foramen - (1-1)
45
Weine canal classification - TYPE 2
two orifices - two canals - one foramen (2-1)
46
Weine canal classification - TYPE 3
Two orifices - two canals - two foramina (2-2)
47
Weine canal classification - TYPE 4
one orifice - two canals - two foramina (1-2)
48
What are somet things that can alter the internal anatomy of a root
age, irritants (that stimulate increased dentin formation -- like caries, perio disease, etc)
calcifications
internal resorption - uncommon and not extensive
49
the apical foramen is usually...
NOT at the true anatomic apex of root
50
Apical constriction
if present, it is not radiographically visble and usually not detectable with tactile sensation
51
the apical constriction is usually how far away from the apical foramen
0.5 to 0.75 mm away from the apical foramen
52
the apical foramen is usually how far away from the anatomic apex?
3mm
53
Dens invaginatus
max laterals
infolding of enamel
leads to variation in root and pulp anatomy
could be a source of irritation
54
dens EVAGINATUS
seen in mand premolars
small tubercle on the occlusal surface -- has pulp
if the tubercle fractures, there is pulp exposure and it can lead to pulp necrosis
source of where bacteria enters
55
where do you see high pulp horns
mesio buccal of first molars
56
where do you see lingual groove
max laterals
| can lead to a deep narrow perio defect which can have pulpal communication
57
Dilaceration
complex root curves
58
info about the max central
```
triangular access
1 canal at apex
22mm long root
root is broad BL
labial/facial curvature apically
```
59
max lateral
Triangle -- oval access
1 canal at apex
Distsal curved root at apex
60
Max canine
oval access
LONGEST TOOTH - 26 mm
1 canal at apex
distal curved root at apex
61
Max first PM
```
oval access -- wide FL
1 canal - 26%
2 canals - 69%
3 canals - 5%
mesial concavity on crown and root at CEJ
```
62
Max 2nd PM
75% - 1 canal at apex*
24% - 2 canals at apex*
1% - 3 canals at apex*
63
Max 1st molar
```
Triangle access - base toward facial and apex toward lingual -- situated more on the mesial side of tooth
--the 2 MB canals are 1-3 mm apart
MB root: 82% has one canal; 18% has 2
DB root - 1 canal
Palatal root - 1 canal
```
64
Max 2nd Molar
MB root - 88% has 1 canal; 12% has 2
DB root - 1 canal
Palatal root - 1 canal
65
the palatal root is facially curved in...
55% of first molars
| 37% of second molars
66
Mandibular incisors
centrals - 3% have 2 canals
| laterals - 2% have 2 canals
67
Mandibular canine
oval access -- widest FL access
| 6% have 2 canals
68
Mand 1st PM
oval acces - wide
74% have 1 canal
25% have 2 canals
69
what is different about mand PM crown?
crown is at 30 degree angle to root
70
Mand 2nd PM
oval access - wide FL
97% have 1 canal
3% have 2 canals
71
Mand 1st molar
81% of mesial root has 2 canal orifices and 61% of those have 2 canals that exit the apex
Distal root -- 22% have 2 canal orifices and 15% of those heave 2 canals that exit the apex
72
mand 2nd molars
Mesial root - 64% have 2 canal orifices and of that 35% have two canals that exit the apex
distal root - 7% have 2 canal orifices and of that 5% have 2 canals at the apex
so the distal root of mand 2nd molar is usually 1 canal orifice and one canal at apex
73
what is a radix paramolaris
additional FACIAL root
74
Radix entomolaris
additional LINGUAL root
75
Principles of endo access are...
removal of all defective restorations and caries before entering the pulp
removing unsupported tooth structure
create access cavity walls that do not restrict straight or direct line passage of instruments tot he apical foramen
76
where do you want your straight line access to reach
apical third of canal or where the initial curve of the canal begins
77
proper access allows for three thing:
effective irrigation
cleaning and shaping
quality obturation
78
what are the two safe ended burs
endo-z and tapered diamond
79
what can you use the endo explorer to do
locate orifices and evaluate straight line access
80
what is the major etiologic factor of pulpal disease
bacteria
Bacterial-induced inflammation and necrosis of pulpal tissue.
--need to remove presence and access of bacteria
81
what are portals of entry for bacteria into pulp
```
attrition or other trauma
caries
failed restoration -- microleakage
anachoresis- bacteria gather in one spot
perio--> endo connections
```
82
what kind of bacteria invade pulp
polymicrobial = 5-8 diff types
the percent of obligate anaerobes increases over time
more G- than G+
83
Why does necrotic pulp favor anaerobes?
low O2 tension
rich in Polypeptides and AA
favors commensal interactions among microbes --- one bacteria's trash is another's treasure
84
successful NSRCT involves
disruption and removal of bacteria
85
AP is associated with what bacteria
Prevotella - pain and sinus tract too
Porphyromonas - pain and sinus tract too
Fusobacterium
Peptostreptococcus
86
Not all infection is caused by bacteria...
Yeast. Herpes. HIV also involved
87
if there is bacterial colonization, are you INFECTED?
NO. most of thse bacteria are NORMAL FLORA.
88
when can you call it INFECTION
when there is DAMAGE to the host with emergence of clinical signs and symptoms
89
where does most of the pathology of infections come from
release of bacterial compound ( LPS, capsules, enzymes etc)
Activation of HOST'S cytokine network
Destruction of host cells and microbes
90
How does the pulp respond to infection?
Non-specific: PMNS --> liquefactive necrosis --> abscess - or macrophages
Specific immune response: TH > Ts > Plasma
Secondary dentin formation
Vital pulp can help stop growth of bacteria.. but necrotic pulp is not resistant to infection
91
What are the major cell types in peri-radicular lesions
Macrophages, lymphocytes (T>B), plasma cells, PMNs, NK, eosinophils, mast cells
This infiltrate can comprise ~50% of all cells
92
increased osteoclast activity leads to apical perio... through what?
IL 1 - beta
| PGs
93
What if bacteria are present during obturation/
success drops from 94% to 68%
94
What is so special about Enterococcus faecalis
33-60% of NSRCTs have E. Faecalis
95
How far can microbes grow into dentinal tubules in 14-21 days?
300-400um
this is why uthscsa does a "crown down"
96
what is the best method of cleaning?
cleaning and shaping (instrumentation)
with 0.5% NaOCL and
Ca(OH)2 for 1 week
97
If there is pulpal necrosis with AP present, there is...
>90% chance of intraradicular infection
98
what are some techniques to reduce bacteria
Rubber dam
Chemomechanical debridement (modified crown-down, larger file size, copious NaOCl irrigation)
Inter-appointment medicament (Ca(OH)2 has best antibacterial effectiveness)
Quality of obturation
Seal of temporary and final restoration
99
what are some properties of an ideal irrigant
```
removes debris
antimicrobial
dissovles organic tissue
removes smear layer
disinfects areas not accessible to files
lubcricates files -- so you don't have separation
non-toxic
not altered by dentin
```
100
Rank the irrigants from most to least useful
```
4% NaOCl >
2.5% NaOCl >
2% chlorhexidine >
0.2% chlorhex >
EDTA >
citric acid >
0.5% NaOCl
```
do EDTA to remove smear layer
101
When do you prescribe abx?
systemic involvement: lymphadenopath, fever, malaise etc
Pt has compromised immune system: disease or drugs
if the signs/symptoms are rapidly increasing
if there is involvement of an anatomic danger zone
102
when you do use abx.. you should
check up on PT every 24 hrs
| use loading doses
103
Thee are 3 most common strains of pathogens
eubacterium (91 strains)
peptostreptococus (65 strains)
black-pigmented bacteroids (30 strains)
ALL ARE SUSCEPTIBLE TO PENICILLINS
104
what percent of the bacteria are susceptible to amoxicillin + clavulanic acid
99% -- it is the BEST
augmentin
105
what is the worst abx?
metronidzole -- only 42% are susceptible
106
list the abx in order of best to worst
```
amox + clavulanic acid >
clindo >
amox = clarithromycin >
penicilin >
metronidzole
```
107
3 stages of odontogenesis
Bud --> cap --> bell --> eruption
108
when is the enamel knot seen?
starts proliferating at cap stage -- it is where the CUSPS or incisal edge will be
109
where are the number of cusps defined
bell stage
110
As the tooth erupts, there are NO MORE AMELOBLASTS.. only...?
odontoblasts which persist though life
111
Hertwigs epithelial root sheath
epithelial origin
| communicates with the mesenchymal stem cells
112
enamel knot determines crown shape
| what determines root shape
hertwig's epithelial root sheath
113
what are some cells found in the pulp
```
Fibroblasts
Odontoblasts
Dendritic Cells
PMNs (neutrophils and macrophages)
Lymphocytes
Endothelial Cells and Neurons
Mesenchymal (Stem) Cells
```
114
what is the most numerous cell in the pulp
fibroblasts
what does fibroblasts make>
type 1 and 3 collagen
it degrades collagen fibrils (turnover)
and has secretory function -- growth factors
115
what is the most specialized cell in dental pulp
odontoblasts
-- make and sescrete DENTIN
makes type 1 collagen and proteoglycans for the ECM
secretes growth factors
believed to be able to detect antigens
116
what growth factors do fibroblasts secrete
NGF and NPY
117
what growth factors do odontoblasts secrete
dentin sialoprotein
| DPP
118
what is the ultimate APC>
dendritic cell
highly specialized immune cell
similar to Langerhans cell in skin
class 2 APC
presents it to T cells via MHC II
119
Macrohpages and neutrophils
move toward a chemokine [] gradient
has APC activity
can squeeze into dentinal tubules
releases inflammatory mediators -- IL1 and TNF alpha
120
which is the regulatory T cell
CD 4
| T HELPER
121
which is the effector t cell
CD 8
| CYTOTOXIC T CELL
122
what makes up the ECM
```
water
GAGs
Type 1 and 3 collagen
Non-collagenous proteins
----tenascin and fibronectin
```
123
what does fibronectin do
Substrate adhesion glycoproteins
| Involved in the attachment, spreading and migration of cells
124
why is the pulp considered MICROvascularized
the biggest artery that enters is an arteriole
| the biggest vein that exits is a venule
125
what is a C fiber
low conducting
THROBBING PAIN
dull ache
typical linflammatory pain
126
what is an A-delta fiber
sharp and quick pain
dentinal HSR
fluid moving up and down to cause a delta to go off
127
describe the pathosis in periradicular tissue
Breakdown of bone, PDL and possibly cementum
Loss of cementum may lead the root susceptible to resorptive processes
Periradicular lesion heals with successful Endo TX, if lesion is of endodontic origin.
128
what are the biologic objectives of cleaning and shaping
Progressively reduce the number of viable bacteria
Remove all tissues and debris
Avoid irritation of the periradicular tissues
129
what are the MECHANICAL objectives of cleaning and shpaing
Achieve a continuously Tapering Cone Shape
Smooth Canal Walls
Development of an apical stop (matrix)
Avoid Iatrogenic Preparation Errors
130
what are the 3 steps to cleaning and shaping
Preliminary Crown-Down (pre-flaring of the initial 2/3)
Final Crown-Down
Apical Preparation
131
what do you use when you crown down
shape root canal system
use different TAPER but SAME SZE
k3
25mm at tip -- but various tapers
132
what are the goals of PRELIMINARY CROWN DOWN === step 1
enlarge canal orifice
achieve straight line access to apical 1/3
gross debridgement of coronal 1/3
133
What are the goals for the FINAL crown down ------ step 2
improve line access to apical 1/3
maintains a glide path into the apical 1/3
gross debridement of the whole root canal system
134
3rd step - final apical prep
final debridement of apical 1/3
| creation of an apical stop (matrix)
135
how do you get the EWL?
subtract 1mm from the canal length
136
in the final crown down, what taper K3 file do you have to reach the working length with?
0.04 taper
137
what provides sensation to pulp
V2 and V3
138
what are the chemical properties of gutta percha
Soluble in chloroform and xylene
Slightly soluble in eucalyptol
Insoluble in aqueous solutions
139
what are the biologic properties of gutta percha
Minimally irritating to tissue
Non-biodegradable
Easily sterilized
140
the master cone is..
tapered
| ID'd by numbers - 30, 35, 40 etc
141
the non-standardized cone is
not tapered -- ID'd by name: fine, extra fine, med fine etc
142
why is gutta percha better than silver tips?
gutta percha adapts to canal walls
143
what does the thermafill carrier do
combines the properties of gutta percha and silver tips
144
WHAT ARE THE EFFECTS OF EDTA
```
Softens dentin.
Distinct antimicrobial properties.
Moderately irritating.
Suitable as irrigating agent.
Removes smear layer.
Demineralization proportional to time.
Partial demineralization.
```
145
what is cavit
most commonly used temporary sealer
but don't use in vital teeth because it needs water to set??
it dehydrates the dentin and causes more pain to PT
use only on non vitals
146
intermediate restorative material (IRM)
does NOT need water to set
147
a standard K file has
16 mm of screw area
| 25 mm length total
148
when do you use a barb broach
NOT IN A NARROW OR CURVED CANAL
only use for Gross tissue removal from the root canal space
Pulpectomy
Debridement
149
K# profiles have a
onstant tip size and varying taper
150
the colored ones... have
constant 0.04 taper but varying tip size
151
what ist he largest k file we use
20
152
what are the non-cellular defenses of pulp
outward fluid movement
tert dentin
AV shunts
153
what are the cellular mechanisms of defense for pulp
tert dentin
| robust immune response
154
what kind of pressure is in pulp from fulid movement
positive pressure
| outward movement
155
tert dentin
body's own restorative material
can be reactionary or reparative
less tubular than reg dentin
makes a hard tissue barrier -- dentin bridge
156
bacterial insult to pulp results in what three things
direct cellular damage
acute inflammatory response
chronic inflammatory response
157
what is allodynia
reduced threshold -- something that should not be painful is painful
158
what is hyperalgesia
increased signaling -- amplifies noxious stimulus
159
when there is an inward flow of noxious agents...
there is inflammation
then increased intra-pulpal tissue pressure
then outward flow of dentinal fluid
which REDUCES ITHE INWARD FLOW OF NOXIOUS AGENTS!
160
once you have carious exposure, the chances are
SLIM JIM.
| do not perform a direct pulp cap of carious exposed teeth
161
the master cone for gutta percha should be...
fitted in a dry canal
162
the master cone of gutta percha should be what when you withdraw it
slightly resistant
163
does the master cone extend to the working length?
yes
164
how do you confirm that the apical fit for the master gutta percha cone is good
radiographic
165
how do you dry the canal
sterile paper points
166
how do you pick a master cone size
same size as master apical file
| set it to the working length
167
a correct fit gutta percha cone should
be at the WL
| slightly resist removal
168
what if the master cone does not fit
inser the MAF again and make sure it goes down to the correct WL
clear the apex with a 10 file
irrigate and reinsert the master gutta percha cone to the WL or select another gutta percha cone of the same esize
169
what if you don't feel resistance?
the final prep is larger than originally believed -- operator error
test a larger cone then
only use the larger cone if it goes all the way down to the WL
170
what if the new master cone feels resistant but it doesn't reach the WL
you have to go back with the Profile and use one size larger than the origianl cone tested
171
How does one know when the root canal sealer is properly mixed?
```
When there is a dense, homogenous,
smooth, creamy mass which when the
spatula is raised three fourths(3/4) to
One(1) inch from the mixing slab, the
string of sealer holds 4-5 seconds before
breaking
```
172
How do you coat the canal walls with sealer
choose a profile instrument 2 sizes smaller than what your MAF was and set it to your WL and coat it with sealer
173
when do you use a counter clock wise rotation
straight canal when sealing canal
174
when do you use a wiggle motion when sealing canal walls
curved canal
175
WHAT DOES “LATERAL CONDENSATION” OF GUTTA PERCHA MEAN?
using spreaders and plungers to fill the root canal system
176
when do you use a yellow FF spreader
small canals
177
when do you use a red MF spreader
medium canals
178
when do you use a F blue spreader
large cnaals
179
how far from the WL do you need to be when you do lateral compaction
1-2 mm
| choose an acessory cone that matches the spreader size you chose
180
CAVIT can only be used with
```
non vital teeth
it needs water
and it will pull water from dentin
and dehyrate it
and cause more pain
if the tooth is vital
```
