Endo Test 2 Flashcards
Endo infections are…
polymicrobial
Bacterial profile changes in endo disease as the…
disease progresses
Debridement relies on..
chemical and mechanical action (cleaning and shaping)
Successful root canal therapy depends on a lot of things
Correct Diagnosis
Adequate Access
Adequate working length determination
Adequate Progressive Disinfection of the Root Canal System(Cleaning)
Adequate Shaping (minimal deviation from the original anatomy)
Adequate Obturation (bacterial-tight seal)
Adequate Coronal Seal (bacterial-tight seal)
Poor access leads to
proceudral accidents and poor chemomechanical debridement
Poor chemomechanical debridement leads to
persistent infections and poor obturation
What is the BEST way to decrease bacterial load
Mechanical + Chemical + Ca(OH)2 decreases the bacterial load the most
Order of best irrigants
4%, 2.5% NaOCl > Chlorhexidine > EDTA > Citric Acid > 0.5% NaOCl
Properites of the ideal irrigant
Removal of particulate debris Antimicrobial Dissolves organic tissue Removes smear layer Disinfects areas not accessible to files Lubrication of files (reduces separation) Non-toxic Not altered by dentin Organic tissue solvent Inorganic tissue solvent Antimicrobial action Nontoxic Low surface tension Lubricant
What are the BIOLOGIC objectives of cleaninga nd shaping
Progressively reduce the number of viable bacteria
Remove all tissues and debris
Avoid irritation of the periradicular tissues
Keep instruments and irrigants inside the tooth
Never bind the needle in the canal or you will push the Clorox through the foramen
What are the MECHANICAL objectives of cleaning and shaping
Achieve a continuously Tapering Cone Shape
Smooth Canal Walls
Development of an apical stop (matrix)
Avoid Iatrogenic Preparation Errors
What are the 3 steps to cleaninga nd shaping
Preliminary Crown-Down (pre-flaring of the initial 2/3)
Final Crown-Down
Apical Preparation
Describe the K3 instruments
same tip size (25) different taper (note differences in thickness)
same tip size (25) different taper (note differences in thickness)
used in preliminary and final crown down
Size at D0=25 Different Taper (0.12 to 0.02)
what RPM do you use
280-300
What is recapitulation
Hand files (K-files) should always be used in between rotary instruments
What are the goals of PRELIMINARY CROWN DOWN
Enlarge canal orifice - Allows for easier access of subsequent instruments and irrigants
Achieve Straight Line Access to the Apical 1/3
Decreases procedural accidents (ledges, broken instruments and etc)
Increases accuracy of working length determination
Gross-debridement of the Coronal 1/3
Avoids extrusion bacteria and their toxins into the periapical region
What are the goagls of the FINAL CROWN DOWN
Improves Line Access to the Apical 1/3
Decreases procedural accidents (ledges, broken instruments and etc)
Increases accuracy of working length determination
Maintains a glide-path into the apical 1/3
Gross-debridement of the whole root canal system
What are the goals for the FINAL APICAL PREP
Final debridement of the apical 1/3
Creation of an apical stop (matrix)
What instruments do you use in step 3 (final apical prep
Use Profile Instruments
Refer to the apical size table in your manual for the most adequate final apical size preparation for the tooth being treated
Profiles are ALL THE SAME TAPE (0.4) but different lengths
What taper must you reach on step 2
0.04 because the profiles are all this taper
Instrumentation goal is?
continuous taper from coronal access to apical foramaen
what is the apical matrix
Narrowest Portion of the Preparation
Artificial Barrier Ideally Created at the CDJ
Barrier / Stop Beyond Which Smaller Files Cannot Pass
3 things to evaluate cleaning and shaping
smooth walls
positival apical matrix
adequately enlarged while maintaining original shape and giving an even taper
Ideal filling material
Easily introduced into the canal. Seal laterally and apically. No shrinkage after insertion. Impervious to moisture. Bacteriocidal or discourage growth. Radiopaque. Non-staining to tooth structure. Non-irritating to periapical tissue. Sterile or easily sterilized. Easily removed from canal.
What are the four things in GP
GP
Zinc oxide
heavy meal salts
wax or resin
What is GP soluble in?
chloroform and xylene
Slightly soluble in eucalyptol
what is GP NOT soluble in
NOT soluble in aqueous solutions
what are the BIOLOGIC properties of GP
minimal irritation to tissue
NON-BIODEGRADEABLE
easily sterizlized
which is the master cone of GP
standardized named by NUMBERS refer to MAF first one you put in tapered
which is the non-standardized GP cone
named by fine, med fine,fine fine etc
accessory cones
go in second
no taper
what are the advantages of GP
Can fill canal in 3 dimensions (adapts to canal walls very well)
Can be removed in retreatment or post preparation
what are the DISadvantages of GP
Doesn’t seal canal wall
Doesn’t come in precision sizes
ad/dis-ad of silver points
Advantages: they are rigid, easy to put into the right place
Disadvantages: they do not adapt to canal wall (this is why we use gutta percha – bc it adapts to the canal wall)
thermafil
combines silver points and GP
Disadvantages: bc it is so easy to place into the root canal, you may mishape or not completely clean the canal – you will have a higher instance of failure
If there is a curve, the carrier can go around the curve and it might strip the gutta percha off and lead to a source of leakage
why do we need sealers?
bc no obturation material can SEAL the canal
what is the IDEAL sealser
Excellent seal when set. Adheres to tooth and obturating material. Radiopaque. Non-staining. Dimensionally stable. Easily mixed and introduced into the canal. Easily removed. Insoluble in tissue fluid. Bacteriocidal or discourage growth. Non-irritating to periapical tissue. Slow setting.
Kerr Sealer
has silver
stains tooth
Grossmans sealer
we use at UTHSCSA
non-stainign
What decreases working time of sealer
heat and humidity
over spatulation
what does sealer have that increases working time
small particle size of zinc oxide
What does EDTA do?
Softens dentin. Distinct antimicrobial properties. Moderately irritating. Suitable as irrigating agent. Removes smear layer. Demineralization proportional to time. Partial demineralization.
properites of ideal temporary filling material
Impervious to bacteria and oral fluids. Hermetically seal. No pressure on dressing. Harden rapidly. Withstand mastication. Easy to manipulate. Harmonious color.
Cavit
dont use on vital teeth
Hedstrom file
machined, not twisted instrument
Filing motion, more aggressively cutting than k-file
Used to prepare middle & coronal 1/3rds
Reamer file
Triangular twisted piece of stainless steel
Reaming motion = place into canal at given length, then turn clockwise ¼ turn to engage flutes, then bring out
K file
Square stainless steel wire twisted to form flutes
Used in filing motion = place in canal to given length, then apply lateral pressure against wall & bring out – do 360 deg around canal
what is the pulp-dentin complex highly innervated with
primarily pain sensing fibers
A mineralized encasing susceptible to damage by trauma or microbes is…
pulp-dentin complex
what is some etiology of pulpal insult
caries
trauma
what are the NON-CELLULAR defense mechanisms of the pulp
Outward fluid movement
Deposition of tertiary dentin (reactionary vs. reparative)
AV shunting mechanism
what are the CELLULAR defense mechanims of the pulp
Deposition of tertiary dentin (reactionary vs. reparative
Dental pulp is capable of robust immune responses.
in pulpal blood flow, what leads to vasoconstriction
sympathetic fibers
in pulpal blood flow, what leads to vasodilation
injury trigeminal afferent fibers inflammatory mediators: PGs, bradykinin, free radicals LPS and other bacterial products parasympatthetic fibers
what is the formula for pulpal blood flow
Pa - Pv / Rt
Describe outward fuid movement
There is a constant outward fluid movement from the dental pulp to the enamel layer.
This positive pressure is increased with edema of the dental pulp resulting in the extravasation of immunological active substances such as immunoglobulin towards the site of invasion.
Bacteria and toxin come from the carious lesion, travel down dentinal tubules, and the fluid moves in the opposite direction as the pulp becomes inflamed.
Primary dentin
first layer of dentin deposited during tooth development
Secondary dentin
Subsequent layer of dentin deposited with aging thoughout the life of an individual as long as the pulp is still vital
Tertiary dentin
localized layer of dentin deposited as a response to insult
Reparative Dentin
Teritiary dentin deposited by newly recruited odontoblast-like cells as result of an insult so severe that damaged the overlaying odontoblastic layer
So tertiary dentin can be…
BOTH Reactionary or Reparative
Tert dentin – body’s own restorative material – no restorative material is better than tert dentin
Tert dentin is less tubular (sometimes even Atubular) – it only accumulates in areas where it is needed.
SO the most desireable outcome as a response to injury is formation of tert dentin
What are the three things that can result from insult?
direct cellular damage
acute inflammatory response
chronic inflammatory response
Pulpal irritants can be…
microbial
mechanical
chemical
what ist he MAIN etiology of pulpal disease
MICROBES
they clog up the dentinal tubules
Pulpal tissue may remain inflamed for long periods of time and may undergo eventual or rapid necrosis. This depends on several factors:
the virulence of bacteria,
the ability to release inflammatory fluids to avoid a marked increase in intrapulpal pressure,
the host resistance
the amount of circulation, and most importantly
the lymph drainage.
what does direct cellular damage lead to
tissue destruction
Host Elicits Defense Against Invaders
May be Overwhelming to the Pulp
what are the cardinal signs of inflammation
Redness (Rubor) Heat (Calor) Pain (Dolor) Swelling (Tumor) Loss of Function
what are the normal immune cells in the normal pulp
Dendritic cells
Macrophages (more centrally positioned)
Circulating T cells
Other resident immune cells
what are the cells in INFLAMED pulp
Activated Dendritic cells and macrophages
Increasing numbers of PMNs
T, B, NK cells
Plasma cells (IgG, IgA specific against invading microroganisms)
what do PMNs do during acute inflammation
Polymorphonuclear Leukocytes (aka PMNs):
Move towards a chemokine concentration gradient.
Have phagocytic activity
Can squeeze though vascular endotelial cells and into dentinal tubules
Which is the first to recognize antigen
dendritic cell
so it is the first to release chemokines
Describe chronic inflammation
PMNs are still present in great numbers
But, more T-lymphocytes and plasma cells are now present
Immunoglobulins (IgM, IgG and IgA) are now present.
what is the first line of defense
PMNs
they squeeze into tubules
what can Mediate Immune Attachment and Migration
cell adhesion molecules
which cell adhesion molecules SLOW DOWN leukocytes
P selectin E selectin PSGL1 PNad MAd CAM VCAM
which cell adhesion molecules STOP leukocytes
ICAM2
ICAM1
VCAM1
MAdCAM1
Allodynia
reduced nociceptive threshold. Non-noxious stimulus evoke pain – like when you tap a tooth (it shouldn’t hurt) but if there is a lesion/inflammation in a tooth, tapping the tooth would hurt. Stimulus causes pain when it shouldn’t
Hyperalgesia
increased nociceptive signaling. Amplifies the noxious stimulus = more pain – elevated response to a painful stimulus – pulp test to test vitality of tooth – it is cold and sharp and hurts the PT – if the tooth is inflamed, it will hurt more than usual.
Reduced firiing threshold
Sensitization occurs in both peripheral and central sites
when the dentin exposed
infward flow of noxious agents –> inflammation
leads to increased intra pulpal tissue pressure
leads to outward flow of dentinal fluid
leads to reduced inward flow of noxious agents
what is the results of the barthel experiment
Do not perform a direct pulp cap of a carious exposure!!
401 carious exposures capped: Asymptomatic Exposure less than 1mm2 Rubber dam isolation Calcium Hydroxide dressing Permanent restoration
what happened if there is chemical etiology
iatrogenic
hypochlorite by dentist
Periradicular pathosis: ACUTE
Etiology: microbial (early), trauma (e.g. occlusion), chemical (accidental injection of chemical into the periradicular tissues)
No radiographic lesion seen, perhaps just widening of the PDL
Same inflammatory infiltrate profile as seen in the pulp
Periradicular Pathosis: CHRONIC
Etiology: Microbial (well-established infection)
Lesion is evident on the radiograph
Chronic inflammatory infiltrate as seen in the dental pulp is observed
There is activation of osteoclasts
which periradicular pathosis is evident on radiograph
chronic
Which periradicular pathosis has activation of osteoclasts
chronic
what is present in chronic periapical pathosis
canal-periodontium communication
What is obliterating the root canal space in three dimensions
obturation
What are the proper cleaning and shaping characterisitcs
SMOOTH WALLS –WITHOUT ROUGHNESS, BLENDING FROM APICAL CONSTRICTION TO THE ACCESS PREP
POSITIVE APICAL MATRIX-TESTED WITH THE MASTER APICAL INSTRUMENT, SOMETIMES ONE SIZE SMALLER
ADQUATELY ENLARGED-ESTIMATED FROM THE DIAGNOSTIC RADIOGRAPH FOR ORIGINAL CANAL SIZE
What are the criteria of fitting a GP master cone
THE MASTER CONE MUST FIT IN A DRY CANAL
Master cone must extend to WL
Have slight resistance to withdrawal
Radiographic confirmation to verify
how many drops of eugenol when mixing sealer
2 dropos
how much powder when mixing sealer?
size of quarter
how do you know you’ve mixed the sealer correctly?
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
How do you coat the canal walls?
Select a Profile instrument 2 sizes smaller set it to WL and coat it with sealer
If you have a curved canal, how do you coat the walls with sealer?
A wiggling motion
What is indicated when coating the canal walls on a straight canal
a counterclockwise rotation into the straight canal
what is lateral condensation
a technique which involves the use of spreaders and pluggers(condensers) to fill the root canal system.
What does the spreader do in lateral condensation?
is used to force the master cone laterally against the canal wall to make room for accessory cones by insertion with apical force
The spreader makes space for what?
accessory cone
When kind of force is used when you compact the GP?
both lateral and vertical
what is the smallest size spreader
FF yellow
what is a medium spreader
MF Red
what is the largest spreader
F blue
Accessory cones need to reach how far from WL?
1 - 2 mm
how much cavit is needed for a good seal
4mm
can you use cavit on a vital tooth
NO!
cavit needs water to set
it will dehydrate the dentin
what happens if you over extend the sealer
it is an irritant
so usually cause transient discomfort
What happens if you over extend GP
it is usually more irritating than if you over extend sealer and is not desirable
5 criteria that are essential to proper obturation of the root canal
PROPERLY CLEANED & SHAPED CANAL
A GOOD APICAL MATRIX
A CONTINUOSLY TAPERING CANAL PREPARATION FROM ORIFICE TO APICAL FORAMEN
A SOLID CORE FILLING MATERIAL SUCH AS GP THAT OBTURATES THE CANAL SPACE IN ALL DIMENSIONS AND A FILM OF SEALER BETWEEN THE CANAL WALL AND GUTTA PERCHA MASS
SKILL OF THE OPERATOR
always remember
Regardless of the type of obturation technique used, the quality of the obturation will be no better than the ________.
canal prep
what are the 5 diagnostic components
CC History Extra and Intraoral exams Pulp tests Radiographic exam
what does physical tapping reveal
periapical irritation
indicated by a painful response to physical tapping
what can palpation pick up
incipient swelling
determines tenderness
when assessing mobility… getting a 1 means?
barely and perceptible horizontal movement
when assessing mobility… getting a 2 means?
LESS THAN 1mm of horizontal movement
when assessing mobility… getting a 3
means?
MORE THAN 1mm of horizontal movement
what is the purpose of doing a peril exam
may discover a vertical root fracture or sinus tract
establish periodontal prognosis
make sure to explore the entire sulcus
how can lighting up a tooth help see a fracture?
A fracture will disrupt the transmission of light through the tooth, exhibited by loss of illumination on the side of the fracture opposite the light source
SO… light it up… and then the part you don’t see lit up has a fracture somewhere
darkened part is on the other side of the fracture plane
when taking radiographs, why is it imporant for correct angulation
you need to see the separation of multirooted teeth
come in at an angle to see
like we did 15 degreees off on max premolar
when you do a pulp test, why do you select a control tooth
to establish what is “normal” to the PT
where do you apply the thermal testing agent
mid facial area of facial crown surface
what are some reasons for getting a false negative on the electric pulp tester
Patient heavily premedicated Inadequate contact with tooth Recently traumatized tooth Excessive calcification in the canal Recently erupted tooth with immature apex Partial necrosis Dead batteries in pulp tester
what is a reason to get a false POSITIVE on the electric pulp tester
Conductor / electrode in contact with a metallic restoration or gingiva
Patient very anxious
Failure to isolate and dry tooth
Liquefaction necrosis
what are some plans of treatment?
No treatment Emergency treatment Root canal treatment Other Tentative restorative plan Extraction
what are the clinical APICAL diagnoses?
Normal Symptomatic Apical Periodontitis Asymptomatic Apical Periodontitis Acute Apical Abscess Chronic Apical Abscess
what are the clinical PULPAP diagnosis
Normal Reversible Pulpitis Irreversible Pulpitis ----Symptomatic ----Asymptomatic Pulp Necrosis Previously Treated Previously Initiated Therapy
What makes endo infections complex?
the bacteria are more ANAEROBIC as you move deeper in the canal
but the majority of the bacteria are found in the coronal 1/3 of the canal
by how much does the taper of a file increase
0.02mm of taper per each 1mm length
what are the 3 non-cellular defense mechanisms of pulp
AV shunting
tert/reparative dentin
outward fluid movement
what is reparative dentin
Reparative dentin (3) deposited by newly recruited odontoblast like cells as a result of severe insult that has damaged the overlaying odontoblastic layer. Is it atubular dentin
what is reactionary dentin
deposited by odontoblasts (they react) when there is moderate insult. It is tubular dentin continuous with other dentin layers
what ist he difference between reparative and reactionary dentin
reparative dentin is ATUBULAR to a SEVERE insult
Reactionary is TUBULAR DENTIN to a MODERATE insult
tertiary dentin can be ___ or ___.
reactionary or reparative
How do we know that Microorganisms are the main etiology of pulpal disease??
RAT STUDY
Kakehashi, Stanley and Fitzgerald 1965
cleaning and shaping will disrupt the bacterial _____.
biofilm
how do you get the periradicular lesion?
bacterial invasion –> necrosis –> lesion
PMNS follow a chemotactic gradient:
Detect a chemical signal (chemostasis)
Roll Attach Migrate Attack
how do you develop chronic apical periodontitis
• Cellular mediator activate osteoclasts and they destroy the surrounding apical bone
what is central sensitization
when a tooth pain is around for a while and the other adjacent teeth will also feel painful
if the PT breaks off parts of their crowns, is there a good prognosis?
yes.
just bond the teeth back on
do osteoclasts get activated in acute periradicular pathosis
no
in anterior teeth, where do you cut off the GP?
1.0 mm apical to cervical line
1mm apical to CEJ
in posterior teeth, where do you burn off the GP?
at the root canal orifice
what is central sensitization
when a tooth pain is around for a while and the other adjacent teeth will also feel painful
if the PT breaks off parts of their crowns, is there a good prognosis?
yes.
just bond the teeth back on
do osteoclasts get activated in acute periradicular pathosis
no
do osteoclasts get activated in acute periradicular pathosis
no
do osteoclasts get activated in acute periradicular pathosis
no
in anterior teeth, where do you cut off the GP?
1.0 mm apical to cervical line
1mm apical to CEJ
in posterior teeth, where do you burn off the GP?
at the root canal orifice
surviving odontoblasts will lay down?
reactionary dentin
to a moderate/minor insult
newly recruited odontoblasts will lay down?
reparative dentin
to a major big insult
