Janes' Wiggs Chapter 15 and 16 - Endodontics Flashcards
According to Wiggs Chapter 15 (endodontics)
What is contained within a normal dentinal tubule?
- Tubules contain tomes fibre, nerve ending, and fluid
- Tomes fibres are the odontoblast processes which perforate the dentin
N.B. Tomes process is something different - involved in enamel secretion by ameloblast
According to Wiggs Chapter 15 (endodontics)
What is the difference between reversible and irreversible pulpitis?
With reversible pulpitis, pulp can return to a non-inflamed state.
With irreversible pulpitis, tooth will progress to pulp necrosis.
Reversible pulpitis is generally a symptom of
pulpal inflammation caused by some form of short-term
irritation such as caries, dental treatment, or trauma.
According to Wiggs Chapter 15 (endodontics)
Describe anachoresis:
Anachoresis – infection of a tooth via bloodstream or regional lymphatics,
According to Wiggs Chapter 15 (endodontics)
Describe how trauma without pulp contamination may result in non vital tooth?
Trauma causes inflammation within the pulp.
Since it is in a confined space, as inflammation progresses, rather than classical swelling (enlargement of tissue) pressure within the pulp chamber develops
Leads to collapse of venules.
This prevents blood from draining away, and leads to pulp strangulation,
According to Wiggs Chapter 15 (endodontics)
How often does sterile pulp necrosis cause periapical periodontitis
in the absence of bacterial contamination this necrosis does not cause periapical periodontitis
According to Wiggs Chapter 15 (endodontics)
Describe this pathology:
CCF 108, hyperplastic pulpitis
According to Wiggs Chapter 15 (endodontics)
How is periapaical pathology definitively diagosed?
Histopathology
According to Wiggs Chapter 15 (endodontics)
What are the 5 categories of periapical pathology?
- acute apical periodontitis of pulpal origin,
- chronic apical periodontitis,
- periapical abscess with sinus,
- periapical abscess without sinus,
- radicular cysts
According to Wiggs Chapter 15 (endodontics)
What are the radiographic and clinical signs of acute apical periodontitis?
Rads may be normal, or slight widening of PDL at apex
Clinical signs are tenderness, pain on palpation/percussion (tough to see in our pts)
According to Wiggs Chapter 15 (endodontics)
What is the classic radiographic sign of Chronic Apical Periodontitis?
produces the classical periapical lucency seen on radiographs
According to Wiggs Chapter 15 (endodontics)
What are the radiographic signs of a periapical abscess?
May be no signs if acute
may be chronic signs of endodontic disease if an acute flare of a chronic process
According to Wiggs Chapter 15 (endodontics)
What is a phoenix abscess?
A periapical abscess which has arisen from a chronic apical periodontitis.
According to Wiggs Chapter 15 (endodontics)
What is a periapical abscess with sinus?
endodontic disease which has progressed and made a draining tract (sinus)
sinus tracts may be seen facially or suborbital, ventral‐mandibular, or within the oral mucosa, either gingival or at the mucogingival line
According to Wiggs Chapter 15 (endodontics)
What is a radicular cyst?
What are the two types?
What are radiographic features?
proliferation of cell rests of mallasez, which create an apical epithelium lined cyst cavity at the apex.
Pocket cyst is if it communicates with the pulp
true cyst is when cavity lining is complete and does not communicate with the pulp
appears as a classic radiolucency.
According to Wiggs Chapter 15 (endodontics)
How is a radicular cyst differentiated from a periapical granuloma?
On the basis of histopathology.
cysts are sack-like structures with a complete epithelial lining whereas granulomas only contain a mixed cell population including epithelial tissue
will both appear as a lucency on rads
According to Wiggs Chapter 15 (endodontics)
How does condensing osteitis appear radiographically and what is it’s cause?
Reactive bone formation and increased radiodensity of periradicular alveolar bone.
Pulp inflammation stimulates osteoblast activity
According to Wiggs Chapter 15 (endodontics)
How can condensing osteitis (pathological) be differentiated on radiographs from periapical osteosclerosis (non-pathological) seen in hard chewing dogs?
Can’t be differentiated on rads
According to Wiggs Chapter 15 (endodontics)
What are 4 signs of endodontic disease on radiographs?
Condensing osteitis
Radicular ankylosis
external root resorption occurs in some endodontic disease
Periradicular osteomyelitis (alveolar bone expansion) appears as osteopenia and expansion of the alveolus
According to Wiggs Chapter 15 (endodontics)
what are the most common radiographic findings in endodontic disease?
- Condensing osteitis
- Chronic focal sclerosing osteomyelitis
According to Wiggs Chapter 15 (endodontics)
What are classic features to differentiate perio-endo disease from endo-perio disease?
- Primary endo usually have a crown fracture. If it continues to a wide PDL can be called a J lesion
- Primary perio usually have deep pockets and wedge shaped periodontal lesions
According to Wiggs Chapter 15 (endodontics)
Describe class I, II and III Perio/endo lesions
Class I - Primary endo
Class II - Primary Perio
Class III - separate endo/perio component
Memory trick: alphabetical order - Endo, Perio, Separate
According to Wiggs Chapter 15 (endodontics)
What are group I Endodontic instruments?
Hand instruments like barbed broaches, K files and H files
According to Wiggs Chapter 15 (endodontics)
What are group II endodontic instruments?
Low speed attachments, with a latch grip
like gates glidden drills and peeso reamers
According to Wiggs Chapter 15 (endodontics)
What are group III endodontic instruments?
Engine driven Ni-Ti rotary instruments which adapt to curved canals
lightspeed etc.
According to Wiggs Chapter 15 (endodontics)
What are group IV endodontic instruments?
Engine driven instruments with 3d adaptation. self adjusting file is only current one.
Included a picture because it’s so cool
According to Wiggs Chapter 15 (endodontics)
What are group V endodontic instruments?
Enging driven reciprocatin instruments.
Think endo pulse, jack-hammer, woodpecker or…
According to Wiggs Chapter 15 (endodontics)
What are group VI endodontic instruments?
Ultrasonic instruments
According to Wiggs Chapter 15 (endodontics)
What is the main cause of ledging, gouging, zipping, stripping and translation?
Ledging, gouging, zipping stripping, and translation are all caused by straight–stiff files working in curved canals and trying to regain their straight shape
According to Wiggs Chapter 15 (endodontics)
What is the name and purpose of this instrument?
Barbed broach
for removing pulp tissue whole
Insert, twist 180 and remove
Will grab tooth walls and ruin everything/break - very fragile
According to Wiggs Chapter 15 (endodontics)
What is the name and purpose of this instrument?
How are they sized?
Gates glidden drill
enlarge access and flare coronal portion of access
sized in iso sizes, but go in increments of 20 starting at 50.
so smallest is iso 50, largest is iso 150
According to Wiggs Chapter 15 (endodontics)
How are K files and reamers made?
What is the difference between the two in terms of design, cutting, carrying and use?
Reamers and files are both meade the same way, from a triangle, square or rhomboid blank. Twisted to create a spiral - Files are twisted more than reamers (more flutes per mm)
•Reamers have <1/10- <1/4 spirals per mm
They are more aggressive at cutting, but poorer carrying
Used in a clockwise turning fashion
•Files have ¼ to >1/2 spirals per mm
Tend to carry better and give better tactile sense, but don’t cut as aggressively
•Used in a push-pull or in a ¼ turn and pull fashion
According to Wiggs Chapter 15 (endodontics)
What is this instrument?
How is it made?
H-File
Made by machine cutting a round blank to remove a triangular spiral and thus leaving a continuous spiral with a thin core
According to Wiggs Chapter 15 (endodontics)
What is this instrument?
How many turns is in a ‘cutting circle’ with a square, rhomboid or triangular blank?
K file
Square makes a cutting circle in 1/4 turn (90 deg turn will bring a new cutting face the position where adjacent one started)
Triangle makes a cutting circle in 1/3 of a turn (need to rotate a triangle 120 deg to bring another cutting flute into position of the adjacent one
Rhombus needs to turn 180 degrees because it’s asymmetrical, need to go halfway around to brig a new flute to the position of the adjacent cutting flute (which is on the opposite side)
According to Wiggs Chapter 15 (endodontics)
Compare and contrast H files with K files in regards to stiffness, cutting ability and fragility?
K file is Stiffer, has a lower cutting ability, and is less prone to breakage
H file is less stiff, more aggressive cutting, and more prone to breakage
According to Wiggs Chapter 15 (endodontics)
Why are H files use ONLY in a push-pull manner?
Will thread into dentin when rotated, and dethreading it will stress or break the metal.
Baically an H file is a long, skinny screw
According to Wiggs Chapter 15 (endodontics)
What is a standard taper and what does that mean?
standard taper is 0.02.
means for every mm of length of the file, it gets 0.02 mm wider.
According to Wiggs Chapter 15 (endodontics)
What is the colour sequence for files? What size does it start at? at what size does it begin going by 10’s in the iso sizes?
White
Yellow
Red
Blue
Green
Black
Begins at 15, and goes by 5’s until 60 then by 10’s for every colour.
N.B. Lightspeed does have a 65 file, it is also blue, like the 60. 70’s are green
According to Wiggs Chapter 15 (endodontics)
What does the file size mean, what size is a 50 at the tip?
it is the fraction of a milimetre in width at the tip of the file
ie. 50 ie 0.5 mm
15 is 0.15 mm
100 is 1.0 mm
According to Wiggs Chapter 15 (endodontics)
what modifications help to keep rotary instruments from causing stripping, ledging, gouging or transportation?
Blunt tips - will only follow a canal, won’t cut a new one
radial lands - spaced between cutting edges that are at the periphery of the file, but non cutting
negative rake angle - promotes scraping rather than cutting
According to Wiggs Chapter 15 (endodontics)
Which is a positive and negative rake angle, what action is represented by each?
According to Wiggs Chapter 15 (endodontics),
Will H or K files produce a smoother preparation?
K files
According to Wiggs Chapter 15 (endodontics),
In what particular situations are H files superior to K files?
For ribbon shaped canals, and for making a good coronal flare (used in a push pull manner only and more aggressive cutting.
According to Wiggs Chapter 15 (endodontics),
Spreaders are used for what type of compaction and have a _______ end
lateral compaction, have a pointy end
According to Wiggs Chapter 15 (endodontics),
Condensers/pluggers are used for what type of compaction and have a ______ end?
Vertical compaction, have a flat end
According to Wiggs Chapter 15 (endodontics),
Where does gutta percha come from?
made from the sap of the “palaquim” tree (Palaquim gutta)
According to Wiggs Chapter 15 (endodontics),
What are the 2 crystalline forms of gutta percha and what is different between them?
How does it change from one phase to the other?
alpha phase - sticky, pliable and will flow under pressure
beta phase - cones are beta phase, more rigid
Heat will transform from beta to alpha, cooling and condensing will shift it back
(VERY slow cooling will allow it to remain alpha, but this doesn’t usually happen with normal compacting and cooling)
According to Wiggs Chapter 15 (endodontics),
What is the composition of gutta percha cones used in endodontics?
18–22% gutta‐percha
59–76% zinc oxide
remainder being a combination of radiodense materials and plasticizers
Cohen’s lists:
Gutta-percha (19%–22%)
Zinc oxide (59%–79%)
Heavy metal salts (1%–17%)
Wax or resin (1%–4%)
According to Wiggs Chapter 15 (endodontics),
Which cones correspond to ISO sizes - Standard, or conventional?
What do the others represent?
Standard cones correspond to ISO sizes
Conventional cones manufactured to be similar in taper to spreaders for use as accessory cones
According to Wiggs Chapter 15 (endodontics),
What are 5 functions of irrigants in endodontics?
- lubricate the root canal,
- dissolve organic pulp and necrotic debris,
- soften dentin,
- destroy bacteria,
- flush debris from the canal
- remove the smear layer
According to Wiggs Chapter 15 (endodontics),
What are 3 main functions of EDTA (ethylenediaminetetraacetic acid)?
Lubricates
softens dentin
dissolves inorganic debris
bactericidal
According to Wiggs Chapter 15 (endodontics),
What are issues with 2% chlorhexidine as a canal irrigant?
not effective in removing the biofilm or dissolving necrotic organic tissue
According to Wiggs Chapter 15 (endodontics),
What are properties of an ‘ideal irrigant’ ?
What is the most commonly used irrigant meeting most of those criteria?
dissolve inorganic material,
dissolve organic tissue,
biocompatible,
antibacterial,
non‐toxic,
penetrate dentinal tubules,
easy to use
Bleach (NaOCL) either full strength (6%) or half strength (3%)
According to Wiggs Chapter 15 (endodontics),
Describe the balanced force technique?
What are the benefits?
•Instruments are passively placed in the canal and rotated 90° clockwise to engage canal wall dentin and then rotated counterclockwise as axial force is applied to the instrument
Helps K-Files remain centred with fewer complications
According to Wiggs Chapter 15 (endodontics),
Describe lateral compation obturation?
- Place fitted master cone in the canal with the sealant
- Pre-fit a spreader, and after master cone in place, jam the spreader in to 1-2 mm short of apex.
- Don’t split the root, and place an accessory cone.
- Repeat until 2/3 of canal is obturqated
According to Wiggs Chapter 15 (endodontics),
Describe use of a custom GP cone for obturation?
- Heat and roll together 2-3 large GP cones and place while warm.
- May help in very large canals which are challenging to instrument
- Can re-soften the tip for better adaptation with heat, eucalyptol or chloroform dip for 3-5 seconds
- Used in very large, immature canals.
According to Wiggs Chapter 15 (endodontics),
Describe use of a vertical compaction for obturation?
- Usually used with warm compaction
- Use a heated instrument (red-hot) to heat the GP core after in place with sealer. Withdraw the heated instrument and use a plugger to vertically compact the warm material
- Repeat with additional pieces of GP until filled
According to Wiggs Chapter 15 (endodontics),
Describe use of continuous wave for obturation?
- Measure plugger 5-7 mm short of the apex.
- Place a GP cone and sealer, and then put a plugger that can be heated.
- Push it to 2-3 mm from the measured point, and allow it to cool while maintaining the force
- Heat it again prior to withdrawl
- Fill remainder of canal with sealer and GP
According to Wiggs Chapter 15 (endodontics),
Describe use of simplifill plug for obturation?
- Plug made for use with lightspeed
- Place to 2-3mm from the apex for a test fit.
- Apply sealer with a lentulo and spread with a paper point.
- Place the plug, and check with a rad, unthread the carrier
- Place a GP cone and more sealer
- Remove excess with a heated plugger, and then vertically compact
According to Wiggs Chapter 15 (endodontics),
Describe use of flowable materials for obturation?
- Basically Guttaflow
- polydimethylsiloxane containing small particles of gutta‐percha
- No additional sealer
- Fill canals by injection, or lentulo
- Can use with a master GP cone, or above techniques for large canals
According to Wiggs Chapter 15 (endodontics),
Describe use of the thermoplastic method for obturation?
- Sealer applied
- Heated GP placed into canal and compacted while warm
- Will have shrinkage due to cooling,
- Compacting it while warm will compensate for the shrinkage
According to Wiggs Chapter 15 (endodontics),
Describe use of the thermomechanical method for obturation?
- Use a slowspeed handpiece at 10,000-12,000RPM and a compacting instrument
- Feed instrument in beside the GP
- As it rotates, heat is generated, and blades force the GP apically and laterally
- Feed in additional points as it’s withdrawn
- Not usually used in vet endodontics
According to Wiggs Chapter 15 (endodontics),
When describing obturation, what does over or under extended mean?
Over or under extended refers to the vertical dimension of the fill.
filled beyone the apex is termed over extended
filled short of the apex is underextended
According to Wiggs Chapter 15 (endodontics),
When describing obturation, what does over or under filled mean?
It refers to the fill in any dimension. overall quality of the obturation.
According to Wiggs Chapter 15 (endodontics),
What is the main reason for adding a glass ionomer intermediate layer?
some sealers (eugenol) will inhibit the polymerization of composites
According to Wiggs Chapter 16 (Advanced endodontics),
If you are struggling to find a canal entrance, what can be performed?
•If struggling to find a canal, expose the whole floor of the chamber in the region and then put a drop of bleach of hydrogen peroxide – will bubble over the canal
According to Wiggs Chapter 16 (Advanced endodontics),
What is the fundamental purpose of the access step?
to establish an unrestricted passageway from the crown and through the pulpal cavity to the apical terminus of the endodontic canal
According to Wiggs Chapter 16 (Advanced endodontics),
what can be done to help alleviate dystrophic calcification in the canal?
Chelating agents such as ethylene‐diamine‐tetra‐aceticacid (EDTA) can be used to aid in the dissolution of inorganic calcification within the canal
According to Wiggs Chapter 16 (Advanced endodontics),
What is gouging?
Damage to the floor of the pulp chamber, but not through to the PDL
According to Wiggs Chapter 16 (Advanced endodontics),
What is this procedural complication?
ledging or transportation
According to Wiggs Chapter 16 (Advanced endodontics),
how is ledging prevented and managed?
prevention: prebend stiff files, use flexible files, don’t use too much apical presssure
management: prebend a file at 45 deg and use with tip towards the trus canal, springiness should help direct it into place.
continue with bent files until filing complete
According to Wiggs Chapter 16 (Advanced endodontics),
What is this procedural complication?
Zipping or elliptication
According to Wiggs Chapter 16 (Advanced endodontics),
How is zipping managed?
Enlarge the whole canal to remove the elbow adjacent to the apical vault
According to Wiggs Chapter 16 (Advanced endodontics),
What is this complication called?
Stripping/lateral perforation
According to Wiggs Chapter 16 (Advanced endodontics),
What causes Stripping?
How is stripping prevented?
how is it managed?
- Caused by overzealous instrumentation in the mid root area.
- Prevent with judicious filing and anti-curvature pressure
Treat perforation with MTA. If it won’t stop bleeding, use an intracanal medicament CaOH for 2-3 weeks
According to Wiggs Chapter 16 (Advanced endodontics),
With cases of apical perforation, what technique is performed?
Backup technique is used to create a new apical stop.
According to Wiggs Chapter 16 (Advanced endodontics),
What techniques have been developed to treat endodontically compromised immature permanent teeth?
Vital pulp therapy
apexification/apexigenesis
(regenerative endodontics?)
According to Wiggs Chapter 16 (Advanced endodontics),
What is the goal of apexification?
The goal is to stimulate root end closure (or a hard tissue barrier to serve as a closed root end), so that eventually a standard endodontic procedure may be carried out.
According to Wiggs Chapter 16 (Advanced endodontics),
What is the expected timeline for apexigenesis to occur?
6-24 months
According to Wiggs Chapter 16 (Advanced endodontics),
Describe a unique role that EDTA plays in regenerative endodontics?
•EDTA is helpful because it may help to release growth factors involved in odontogenesis from dentin
According to Wiggs Chapter 16 (Advanced endodontics),
What are the goals of regenerative endodontics?
- Primary - Elimination of symptoms
- Secondary - Increased root wall thickness, increased root length
- Tertiary - Positive vitality testing
According to Wiggs Chapter 16 (Advanced endodontics),
What are the major requirements of regenerative endodontics?
stem cells
growth/differentiation factors
scaffolding
According to Wiggs Chapter 16 (Advanced endodontics),
What could failure of resolution of a periapical lesion after 9-12 months indicate, and what treatment could be performed?
periapical cyst (those pesky rests of mallasez) apicoectomy, curettage, and histopathology indicated
According to Wiggs Chapter 16 (Advanced endodontics),
What are the two MAJOR indications for performing surgical endodontics?
internal root apex inaccessibility
external root end complications
According to Wiggs Chapter 16 (Advanced endodontics),
What are the 4 categories of apical and periapical endodontic procedures?
Four categories of apical surgical intervention are:
periradicular drainage,
periapical curettage,
apical resection or apicoectomy, and
retrograde obturation or filling.
According to Wiggs Chapter 16 (Advanced endodontics),
What are the 2 main indications for apical resection?
- Removal of a diseased apex
- Allow access for retrograde filling.
According to Wiggs Chapter 16 (Advanced endodontics),
When performing a root end resection, what angle is currently recommended?
A flat resection
According to Wiggs Chapter 16 (Advanced endodontics),
Whay type of preparation is classically recommended for root ends?
Class I preparation
According to Wiggs Chapter 16 (Advanced endodontics),
In difficult to access root ends, what type of preparation can be used for the root end?
Slot of Matzuri
According to Wiggs Chapter 16 (Advanced endodontics),
What root end filling materials are currently recommended in vet med?
Zinc oxide cements or MTA
