Re-Endodontics Flashcards
How to diagnose post-treatment disease?
may not be straight forward as you may be dealing with partially treated pulp canals, missed canals or procedural mishaps. These should be included in the diagnostic description.
What is included to enable you to gain a good pain history?
When RCT was fine and if any problems arised
Rubber dam used?
Check for:
- swellings/sinus
- TTP
- Mobility
- PPD > 3mm
- tenderness on buccal palpation
Special tests:
- hot and cold sensitivity
Remember the SLOB radiography rule?
SAME lingual
Opposite Buccal
If you move the x-ray head medially the two roots will move dismally but the buccal one will be the opposite direction of the movement and the lingual will be the one in the same direction
Name the 3 diagnostic categories for post treatment disease?
Previously treated:
- (a)symptomatic PRP
- chronic apical abscess
- acute apical abscess
Name the 4 causes of post treatment disease?
Intraradicular microorganism
Extraradicular infection
Foreign body reaction
True cyst
Name the 9 possible reasons for the canal to have intra-radicular microorganisms?
Poor access cavity design
Untreated major or minor canal
Poorly prepared canals or poorly obturated
Procedural complications
Ledges
Perforations
Separated instrument
Newly introduced microorganisms
Coronal leakage
Name the 8 main reasons for endodontic treatment failure?
- Leaking around intubation
- Non-treated canals
- Underfilled
- Complex canal system
- Overfilled
- Iatrogenic
- Apical biofilm
- Cracks
What is the definition of an extraradicular infection?
Microbial invasion and proliferation into the preriradicular tissues.
- perio endo lesion where pocketing extends to the apical foramina
- extrusion of infected dentine chips during instrumentation
- overextended instrumentation/filling material
Biofilms which grow through the apical constriction and form an external apical biofilm
Extraradicular microbes
What is the defintion of a foreign body reaction?
In the periradicular tissue have been associated with a chronic inflammatory response:
- vegetables
- cellulose fibres
- onturatiob material (sealer or GP)
What is the defintion of a true radicular cyst?
Form when retained embryonic epithelium begins to proliferate due to the presence of chronic inflammation
Can’t tell between abscess, granuloma or cyst - radiographically
Cystic characteristics in a radiograph?
The larger it is, the more likely it’ll be cystic
However, treatment is still the same
Name and deacribe the 2 types of radicular cysts?
True radiculsr cyst:
- an enclosed cavity totally lined by epithelium
- no communication with RCS
- not heal after RCT
Periapical pocket cyst:
- epithelium is attached to the margins of the apical foramen
- cyst lumen is open to the infected canal and hence can communicate directly
- heal after RCT
Name the 7 things beware of when treating a tooth for an RCT?
History of bruxing
History of frequent decementing
Occlusal wear facets
Large/wide RCT/Posts
Large, narrow perio pockets
Can also indicate a perio endo lesion
Look for vertical root fracture
What is the most common cause of failed RCT?
Persistent or secondary infection of the RCS
Secondary intraradicular infections
Microbes are not present in the primary infection but have been introduced later
What species of bacteria can be found as a secondary intraradicular infection?
Propionibacterium
Actinomyces
Prevotella
E.faecalus
Streptococcus
Candida albicans
Fusobacterium nucleatem
Spirochaetes
Different combinations of bacterial can cause different ways of treatment failure
What are the 4 options after diagnosing a treated tooth with lost- treatment disease?
Nothing
Nonsurgical
Extraction
Surgical
When should Do Nothing be suggested for a patients failed RCT tooth?
No signs nor symptoms form the tooth and the radiolucency is not increasing in size
Evidence shows that it has little chance of becoming symptomatic
When should extraction be suggested?
When tooth has an obvious hopeless outlook
When should non-surgical re-treatment be suggested for a failed RCT?
The safer option that surgical
Most benefit with lowest risk
Greatest likelihood of eliminating most common cause (intraradicualr infection)
But could be more costly than surgical treatment and longer
When should surgical treatment be suggested for a patients failed RCT?
Surgery is chosen when no surgical re-treatmebt is not possible, or where the risk to benefit ratio is outweighed by surgery
RCTs can be improved, but somethings can be rectified
What are the aims of root canal re treatment?
Re treatment aims to regain access into the apical 1/3 of the the root canal system and create an environment conductive to healing
Need:
- coronal access (remove restorations)
- remove all previous obstruction material
- manage any complicating factors
- achieve full working length
- eliminate microbes
Should you remove the crown/bridge or not? Advantages and Disadvantages of keeping/removing?
Decision is easier if it is defective or replacement is required
Advantages of retaining the restoration:
- cost for replacement avoided
- isolation is easier
- occlusion preserved
- aesthetics maintained
Disadvantages of retaining indirect resto:
- removes dentinal core reduction retention and strength
- increased change of iatrogenic mishap as restricted vision
- removal of canal obstructions more difficult
- may miss something important
Name the 2 techniques to remove the crown without destroying it?
WAMKEY - dentsply maillefer
Metalift system
What influence the difficulty of post removal?
Fairly predictable
Depends on the post, location in mouth and material cemented with
How to remove a post?
What it was cemented with and when the last time it came out
Bonded restorations are more difficult to remove
Consider the types of post material? Name 2
Dentatus screw
Quartz fibre - more time consuming
What arenthe initial considerations when thinking about how to remove a post?
Location in the arch of the tooth that requires post removal
The more anterior in the arch, the more difficult to remove due to accessibility
To remove a post firt remove all restorative materials all around- use ultrasonics
Explain the way in which you’d remove the metal posts?
Ultrasonics
- eggler post remover
Ruddle/Gonon post remover
- masseran kit
If metal threaded, can often unscrew using Spencer Wells or similar
Quartz fibre posts
- pilot hole then piezo reamer
Zirconia and ceramic post
- often irretrievable
Explain the process of post removal with ultrasonics?
Rubber dam
Magnification and illumination
Aim to reduce the retention sing ultrasonics at the interface between the post and the tooth
Constantly move it around the circumference of the post to disrupt the cement along the post/canal wall interface
Use copious coolant spray
Owing to the heat that can be generated, stop every 15s
What to do if ultrasonics don’t work?
A post puller is required
Explain the Eggler post removal system?
Post puller
Device consists of two sets of jaesnrhay work independently
- first jaw grips the core
- the other jae pushes away from the tooth in line with the long axis
A cast core may need reduced with a high speed hand piece
- not recommended for the removal of screw posts
Explain the Ganon/Ruddle post removal system?
Effective for removing parallel or tampered non-actice preformed posts
Hollow trephine bur played over the trimmed down post
Trephine domes off tip of post to allow specific, matched size extraction mandrel to create a thread onto the exposed portion of the post
The extraction mandrel is attached to the post, the extraction vice is applied to the tooth and post
Turning the screw applies a coronal force
But vice large access in molar/crowded incisors is difficult
Explain how to remove fibre posts?
Often come with drill for removal
Need magnification
Can drill a pilot hole in the long access
Set a silicone stop at the depth of the post on the reamer and slowly take to this length
LN burs v useful
Speed at 600-900rpm
How to remove a fractured post?
Masseran Kit
Name the 6 potential complications of post removal?
Inability to remove
Tooth is unrestroable
Head transmission to PDL from ultrasonics
Tooth/root fracture
Perforation of root
Fracture of post and inability to remove
How to gain access to the RCS on a RCT tooth?
Once coronal access is gained remove any residual cement using an ultrasonic blocking access jntonthe RCS
What should happen if the tooth has limited access?
If not possible to remove lost, surgery can often be performed
Name 3 types of ways to remove GP?
Solvents:
- chloroform, halothane and oil of turpentine
Thermal
- ultrasonic
- system b
Mechanical
- rotary NiTi files (ProTaper D)
Explain how to use chemical solvents to remove GP?
Very small amount in luer lock syringe
Toxic if extruded
Leave in canal for a minute then working into HP with a C+ file or a 15 or 20 hedstrom
When all GP removed, add more solvent into canal and wick out paper points
Explain how to mechanically remove GP from the canal?
Rotary Notice files
- Mtwo R
- ProTaper D
Use at 600rpm
Always crown down
Active tip to penetrate GP
In which order should you use the ProTaper D files?
D1 16mm
D2 18mm
D3 22mm
Removing carrier based systems?
Much more difficult with more errors chance
Guttacore
New
What to do after bulk of GP is removed?
Flood canals with solvent
Use paper points to wicj out remains GP and sealer
Carefully use hedstroms
Explain the irrigant protocol?
NaOCl
EDTA or citric acid
Povidone iodine soak
NaOCl
Use copious irrigation
Once working length is reached progressively larger diameter hand files are rotatwd passive, nonbinding, clockwise direction to remove the remaining GP until the files come out of the canal clean
Explain why silver points are bad for RCTs?
Poor success rate of RCT with points
Not adaptable ti canal, limited seal and toxic products
Do not retreat in single visit as risk of flare up
Explain how to remove a silver point?
Never apply ultrasonic energy directly on point - will disintegrate
Difficult to remove
Grippable using stieglitz
Don’t twist
Apply ultrasonic indirectly to the stieglitz and vibrate out
Name the 4 options to fill the canals for retreatment?
Insoluble resin
GP
Silver points
Soluble pastes
How effective are electronic aplex locators for retreatment cases?
Frequently misread the working length
Regain accuracy when clean
How successful is retreatment?
Reduced success compared to de novo
What is the defintion of endodontic success?
If survival is used as the outcomes, longer is better
If bony infill is taken as successful the more infill the better
What does retreatemnt rely on?
Maginficaiton and illumination and successfully removing all obtruation material
Name the 3 ways in which there is communication between the pulp and periodontium?
Dentinal tubules
Apical foramen
Lateral/accessory canals
How can dentinal tubules becomes exposed?
Developmental defects
Disease processes
Surgical procedures
Trauma
Name the 4 types of morphology of the CEJ?
I: cementum iver enamel
II: Edge to edge
III: gap
IV: enamel over cementum
What is the defintion of the apical foramen?
Is the principle route of communication between pulp and periodontium
Pulpal inflammation can cause localised inflammatory reaction in the peridontium
May be exposed due to severe LoA
Where are most lateral canals found?
Middle 1/3
30-40% have lateral canals - found apically
Contain CT and BVs
Furcal canals
Explain the problem of potential for exposed furcal canals?
All teeth with furcation involvement can potentially have exposed fiscal canals
Lesions suggested radiographically may be due to infectious products from a necrotic pulp diffusing down a furcal or lateral canals
Remember sensitivity testing:
- lower 46 and 36 DL root
- Upper and lower premolars can have between 1-3 roots
- Canines have can 2 roots
Bacteria found in chronic/asymptomatic PRP and chronic peridontitis?
Aggregatibacter actinimycetesmcomitans
P gingivalis
Eikenella
Fusobacterium
P intermediate
Treponema denticola
Name the 4 iatrogenically occurring communication between pulp and periodntium.
Developmental malformations
Resorption lesions
Perforations
Cracks
Mucosal fenestration
Name 3 types of developmental malformations?
Palatogingival grooves
- upper incisors
- maxillary lateral incisors
If the epithelial attachment is breached, grooves becomes contaminated
Self-sustainjng infrabony pocket develops
LoA can quickly extend to the apical foramen causing pulapl necrosis
Treatment:
- difficult
- scaling and RSI don’t work
- bur out grooves and use regenerative techniques
Name 3 types of responsive lesions?
External inflammatory
Internal inflammatory
Cervical inflammatory
What are the requirements of resoprtive lesions?
An injury
A stimulus
Describe an internal inflammatory root resorption?
Only associated with increased probing depths and BOP when resorptive process has perforated through root
Describe an external inflammatory root resorption
Associated with increased probing depths and BOP
In late stages, can interfere with gingival sulces and result in periodontal abscesses
Describe a cervical inflammatory root resorption?
Starts where the JE attaches to root surface
Microbes in the giving sulcus situate and sustaon the resorptive process
Associated with increased probing depths, gingival swelling and BOP
What is the defintion of a perforation?
Caused pathological by caries or iatrogenically by procedural errors
Present with perio abscess - pain, swelling, pus draining and with infrabony pocket developing
Having perforated an acute inflamamltry action will occur
Closer to the gingival sulcus, increased likelihood of apical migration
What affects the prognosis of a perforation?
Location - mid to apical third better outlook as bounded by bone, but advanced perio bad
Time
Ability to seal
Chance of new attachment
Accessibility to RCS
Describe a horizontal root fracture?
Horizontal
Pocket formation may occur - coronal 1/3 root fracture
Can present with perio abscess or Deeping of perio pocket
Describe a vertical root fracture?
Vertical
Microbial colonisation of crack space = periodontal inflammation = breakdown of CT and alveolar bone leading to deep infrabony pocket
How to diagnose vertical root fracture?
Parallax x-ray
J shaped radiolucency
Perio abscess or deepening periodontal pocket
Deep, narrow pocket, pain on biting pain, abscess and chronic sinus
Surgical exploration but hopeless prognosis
What is the defintion of a mucosal fenestration?
Pathological condition characterises by the perforation of the alveolar bone playe and overlying mucosa by the roots of the teeth
Name the 4 aetiologies of mucosal fenestration?
Root prominence
Develolmenral anomalies
Chronic periradicular
Orthodontic tooth movement
Treatment for mucosal fenestration?
Generally asymptomatic but are plaque retentive factors
Causes of exposed root end further periodontal destruction ingress of bacteria into the RCS
Treatment:
- endodontic treatment
- surgery
- CT graft
What is the defintion of a furcation?
horizontal loss of bony support in areas where roots of multi-rooted teeth conerge
What is the aetiology of furcations?
result of plaque indcued inflammation
worse in elderly patients
PRFs
Which teeth affected?
All multi-rooted teeth
All molars, 14 and 24
Check from radiographs
How to investigate a furcation for a maxillary molar?
Mesio=-palatally, buccally and then distally
How to investigate a furcation for a maxillary premolar?
Check mesially and distally
root bifurcation loacted at the mid-apical third
- unsuitable for root resection
How to investigate a furcation for a mandibular molar?
Check buccally and lingually
Mesial and Distal root
More around the 6s as hinner buccal bone
What difference does a furcation have on a mandibular or maxillary molar?
Mandibular:
- even if severe only buccal and lingual bone plates affetced
- as long as no interproximal bone loss
Maxillary:
- potential for severe damage to the mesial and distal bone areas, affecting adjacent teeth
- needs more aggressive strategies
How to diagnose a furcation involvement?
If you can prod it with your probe
Radiographs can confirm your suspicisions and confirm amount of bone loss
Differential diagnoses for furcation?
Occlusal trauma widens the PDL and causes bone loss
Do a sensibility test to identify vital or non-vital
How to treat a furcated tooth that is non-vital?
Endo treatemnt always prior to periodntal treatment
How to treat a furcated tooth that is vital?
TRreat as plaque induced periodontal disease and review for further sensibility testing
How to clinically assess a furcation?
Probe around circumference
Determine extent
Factors attributing to it
Morphology
Factors affecting treatment
Best tool for furcations?
Nabers
Root trunk length affecting RCT?
shorter can be exposed but more accessible
Root length affecting RCT
SHort roots may have little root left invested in bone, reduce functional demands
Root form affecting RCT?
awkward shapes can make access difficult
What part of the furcation anatomy can make RCTs harder?
Concaviities
Accessory canals
Bifurcational ridges
What is the definition of cemento enamel projections
Enamel below gingival margin
What is the defintion of an enamel pearl?
Enamel below gingival margin in a pearl shape
Name the 3 grades of furcation severity?
I
II
III
Describe Degree I furcation?
Horizontal loss of peridontal support not exceeding 1/3 width of tooth
Describe Degree II furcation?
Horizontal loss of peridontal support exceeding 1/3 width of tooth, but not encompassing the tota width of furcation area
Describe Degree III furcation?
Horizontal loss through and through destruction of periodontal tissues in the furcation area
Name the potential consequences of furcation involvement?
Caries
Pulpal exposuire
Pulpal necrosis
FUrcal/accessory canal microbial invasion - pulpal death
Name the 2 objectives for RCT in furcated teeth?
Eliminate microbial plaque from the exposed root surface
Establish an anatomy condutive to effective plaque control
Need a plaque free zone
Name the 5 treatment options for a degree I furcation?
Repeated scaling
Mechanical non-surgical debridement
Furcationplasty
Elimate plaque trap via smoothing
Pokcet elimination surgery
Non-surgical therapy for furcation treatment?
OHI
Needs furcation access
Scaling and RSI
Wht is the defintion of furcationplasty?
a surgical resective treatment to eliminate the interradicular defect
B or lingual furcations
Tooth substance removed and alveolar crest remodelled at furcation level entrance
Name the treatment options for a degree II furcation?
Furcationplasty
Tunnel prep
Root resection
Guided tissue regen
Enamel matrix derivative
Tooth extarction
Name the treatment options for a degree III furcation?
Tunnel prep
root resection
extraction
What is the definition of tunnel preps?
surgical treatment for DII and III furcations
Needs unfused roots
Flap reflectyed and granulation tissues removeed, root surfaces scaled and RSI
Widened furcation area - allow easy teepee access
Flaps replaced in more apical area
High risk for sensitivity
What is the defintion of root resection?
Surgical division and removcal of roots of multi-rooted teeth
Good for uneven bone support
Must seal root
Must devitalise tooth
Bets to RCT before
Max amount of dentine saved
Direct resto after obturation
Which root to remove for resection?
The root or roots that will elimnate the furcation
Greatest amount of bone loss of LoA
Save better roots, lose worse roots
What is the ideal goal for regenaration?
regenrate lost attachment
new formation of cementum, functionally orientated PDL, alveolar bone and gingiva
PDL cells have ability to regen
