Endodontics Flashcards
What are the methods of periodic-endo communications?
Perforations
Root apex
Lateral canals
Fractures
Dentinal tubules
What are the ideal properties of an obturation material?
Biocompatible
Dimensionally stable
Unaffected by oral fluid
Insoluble
Radiopaque
What is the composition of gutta percha?
20% GP
60% Zinc Oxide
10% Radiopacifiers
5% Plasticisers
What is the function of a sealer?
Seals space between dentine wall and core
Fills voids and irregularities
Lubricates obturation
What are the ideal properties of a sealer?
Good adhesion
Easily mixed
Bacteriostatic
Insoluble
Radiopaque
No shrinkage
Slow set
How does zinc oxide eugenol perform as a sealer?
Antimicrobial
Free eugenol can be toxic
How does glass ionomer perfom as a sealer?
Bonds dentine
Difficult to remove
Minmal antimicrobial
How does resin perform as a sealer?
Good sealer
Good slow
Slow set 8 hours
How does calcium silicate perform as a sealer?
High pH (12.8)
Biocompatible
Good seal
What are the 9 endo laws?
Centrality
Concentricity
ACJ
Symmetry 1
Symmetry 2
Colour
Orifice Location 1
Orifice Location 2
Orifice Location 3
What is the law of centrality?
Floor of pulp is central to the tooth at the ACJ
What is the law of concentricity?
Walls of pulp chamber are concentric to the external surfaces at the ACJ
What is the law of the ACJ?
The ACJ is the most consistent, repeatable landmark for locating the pulp chamber
What is the Symmetry Law 1?
Orifices of canal are equidistant from line drawn in mesio-distal direction through the pulp chamber floor
What is the exception to the symmetry 1 law?
Upper 6’s
What is the symmetry law 2?
Orifices of canal lie on perpendicular to a line drawn in a mesio-distal direction across the centre of the pulp chamber
What is the exception to symmetry law 2?
Upper 6’s
What is the colour law?
Colour of pulp chamber floor is darker than the walls
What is the orifice location 1 law?
Orifices are located at junction of walls and floor
What is the orifice location 2 law?
Orifices are located at angles in the floor wall junction
What is the orifice location 3 law?
Orifices are located at terminus of root development fusion lines
How can endodontic equipment be classified?
Manually operated
Low speed
Engine driven NiTi rotary
Engine driven adapts to canal
Engine driven reciproc
Ultrasonic
How can endodontic equipment be classified?
Manually operated
Low speed
Engine driven NiTi rotary
Engine driven adapts to canal
Engine driven reciproc
Ultrasonic
What is Nitinol?
Equiatomic alloy of nickel and titanium
What are the special features of nitinol?
Exotic material: does not conform to typical rules of mettalurgy
Superelasticity: application of stress does not result in usual proportional strength
What is the crystal structure of NiTI?
Temperature dependent structures of martensite and austenite:
Martensite= soft and ductile
Austenite= strong and hard
What is shape memory?
Material deformed at one temp then returns to original shape
What are the components of rotary instruments?
Taper
Flute ; groove to collect dentine and soft tissue
Cutting edge
Land; surface between flutes
Relief; reduction in land
Helix angle; angle formed by cutting axis and long axis of files
What is the purpose of irritants?
Remove debris
Lubricate
Dissolve organic and inorganic material
Penetrate to canal periphery
Kill bacteria/yeast
Disrupt biofilm
What does sodium hypochlorite ionise in water to form?
Na+ and OCl-
What is the effect of pH on sodium hypochlorite?
Acid/neutral: HOCl predominates
>9; OCl- predominates
What are the ideal features of obturation materials?
Easily manipulated
Seals canal laterally and apically
Unaffected by moisture/fluid
Sterile
Dimensionally stable
Non-irritant
Radiopaque
Easily removed
What are the ideal properties of sealers?
Tackiness
Easily mixed
Bacteriostatic
Insoluble in tissue fluids
Radiopacity
No shrink on set
Slow set
What is gutta percha?
Transiosomer of poly-isoprene
What are the design objectives
Continuously tapering funnel
Maintain apical foramen position
Apical opening as small as possible
What are the clinical objectives?
Remove infected hard and soft tissue
Prevent re infection
What is endodontic success improved by?
Hypochlorite irrigation
Dental dam
Why is dental dam used in endodontic?
Protects airway
Improves access
Improves efficacy and vision
Prevents contamination
Protects soft tissue
What are the pulpal diagnoses?
Normal
Reversible Pulpitis
Symptomatic Irreversible Pulpitis
Asymptomatic Irreversible Pulpitis
Pulp Necrosis
How does a normal pulp present?
Asymptomatic
Normal thermal response
Vital
How does symptomatic irreversible Pulpitis present?
Lingering pain to stimulus
Pain with postural change (night)
How does reversible Pulpitis present?
Inflamed
Pain to stimulus
Resolves with treatment
How does asymptomatic irreversible Pulpitis present?
No symptoms
Normal response to thermal tests
How does pulp necrosis present?
Negative pulp test
TTP
Radiographic osseous breakdown
May be asymptomatic
What are the apical diagnoses ?
Normal
Symptomatic apical periodontitis
Asymptomatic apical periodontitis
Acute apical abscess
Chronic apical abscess
Condensing osteitis
How does a normal apical diagnosis present?
Not TTP
Uniform PDL space
How does symptomatic apical periodontitis present?
TTP
Pain on biting
Periapical radiolucency
How does asymptomatic apical periodontitis present?
Asymptomatic
Periapical raidolucency
How does an acute apical abscess present?
Rapid
Swelling
TTP
Spontaneous pain
Systemic problems
How does a chronic apical abscess present?
Gradual
Asymptomatic
Periapicla radiolucency
Sinus (with or without pus)
How does condensing osteitis present?
Localised bony reaction to low grade inflammatory stimulus
Diffuse Periapical radiopacity
What are the aims of mechanical preparation?
Creates space to allow irritants and medicaments to more effectively eliminate micro-organisms
Remove infected hard and soft tissue
What are the stages of mechanical preparation?
Tooth preparation
Access cavity
Confirm straight line access
Initial negotiation, coronal flaring
Working length determination
Apical preparation
What are examples of irritants?
3% NaOCl
17% EDTA
0.2% CHX
What are the lengths of times for the final irrigation?
10 minutes NaOCl
1 minute EDTA
10 minutes NaOCl
What are the ideal properties of irritants?
Disinfect canal (remove micro-organisms)
Dissolve organic and inorganic material
Remove smear layer
Cheap
Non-toxic to Periapical tissues
What are the pros of sodium hypochlorite?
Dissolves organic material
Disrupts smear layer
Effective antimicrobial
What are the cons of sodium hypochlorite?
Doesn’t remove smear layer
Dissolves fabrics
Risk of hypochlorite accident
How are sodium hypochlorite accidents managed?
Copious irrigation
Analgesia
Review
What can be done to prevent a hypochlorite accident?
Bib/eyewash
Slow flow rate (1ml/15s)
Depress with index finger
Don’t lock needle in canal
Use a side vented Leur-lock 27G needle
Avoid excessive pressure
What is the smear layer?
Superficial (1-5um) layer of organic pulpal and inorganic dentinal material formed during prep
Prevents disinfection and sealer penetration
What can be used to remove the smear layer?
17% EDTA
10% citric acid
MTAD
What is an example of an intra-canal medicament?
Non-setting calcium hydroxide
What are the features of calcium hydroxide?
Antibacterial
Reduces inflammation
Kills mirco-organisms
Removes tissue debris
What are the purposes of chemomechanical prep?
Irrigate to remove microbes
Remove smear layer
Prepare shape for obturation to WL
Flush out debris
Allows delivery of irritants
What is estimated working length?
Estimated length at which instrumentation should be limited
1mm short of radiographic apex
What is estimated working length?
Estimated length at which instrumentation should be limited
1mm short of radiographic apex
What is corrected working length?
Actual length at which instrumentation should be limited
What is the master apical file?
Largest file taken to working length
Represents final prepared size of apical canal
What are the ideal properties of irritants?
Low cost
Reduction of friction
Temperature control
Good penetration within the root canal system
Killing of platonic microbes
Non-toxic to Periapical tissue
Doesn’t react with dental materials or weaken dentine
Washing action
Improve cutting of dentine by instrumentation
Dissolution of organic and inorganic
Killing of biofilm
Non allergenic
What is the optimum concentration of sodium hypochlorite?
0.5-6%
What percentage of sodium hypochlorite is used in GDH?
3%
How thick is the smear layer?
1-5um
What is the protocol for removing the smear layer?
3% NaOCl - 10 mins
17% EDTA- 1 min
3% NaOCL- final rinse
What is the cause of external infection related inflammatory root resorption?
Root resorption caused by PDL damage
Root canal toxin reaching external root surface causing resorption
Tooth is non-vital
What is vertucci type 1?
Single canal
What is vertucci type 2?
2-1
Two canals that join into one
What is vertucci type 3?
One canal that divides into two then merges into one
1-2-1
What is vertucci type 4?
Two separate canals
2
What is vertucci type 5?
One canal that separates into two
1-2
What is vertucci type 6?
Two canals that join then separate into two
2-1-2
What is vertucci type 7?
One canal leaves the pulp chamber, divides, rejoins and divides at the apex
1-2-1-2
What is vertucci type 8?
Three separate distinct canals
3
What are the benefits of nickel titanium files?
Superelasticity
What are the benefits of coronal flaring?
Reduces hydrostatic pressure
Reservoir for irrigants
What are the pulpal diagnoses?
Healthy Pulp
Reversible Pulpitis
Symptomatic Irreversible Pulpitis
Asymptomatic Irreversible Pulpitis
Necrotic Pulp
Previously treated
What is the management of reversible pulpitis?
Pulp therapy
What is the management of irreversible pulpitis?
Pulpotomy
Pulpectomy
Extraction
What is the management of necrotic pulp in a mature tooth?
RCT
Extract
What is the management of necrotic pulp in an immature tooth?
Pulpotomy
Pulpectomy
Extract
What are the periapical diagnosis’?
Normal
Asymptomatic Periapical Periodontitis
Symptomatic Periapical Periodontitis
Acute Apical Abscess
Chronic Apical Abscess
Condensing Osteitis
How does asymptomatic periapical periodontitis present?
No pain
Radiolucency
How does symptomatic periapical periodontitis present?
Pain on biting
Percussion
Palpation
How does acute apical abscess present?
Rapid onset
Spontaneous pain
Swelling
How does chronic apical abscess present?
Slow onset
Little/no discomfort
How does condensing osteitis?
Bony reaction to low grade inflammatory stimulus
How does reversible present?
Pain to cold (short lasting)
Hydrodynamic expression (microleakage)
No change in pulp blood flow
How does irreversible present?
Spontaneous pain
Sleep disturbance
Negative to cold
Pain to heat (c fibres)
Increased pulpal blood flow
How do non-vital teeth present?
Discoloured
Sinus
Gross caries
Large restoration
Radiographic (periapical radiolucency)
What is the aim of sensibility tests?
To test neuron/nerve function
Very subjective
What are examples of sensibility tests?
EPT
Thermal tests
Test drilling
What are the features of calcium hydroxide?
Bacteriocidal/Bacteriostatic
Highly alkaline pH 12.5; stimulates dentine formation
Stimulates pulpal cells to recalcify demineralised dentine
Neutralised acidic restorative material
What are the features of mineral trioxide aggregate?
High pH
Creates bacterial tight seal
Can act as a base for restorative material
What are the components of mineral trioxide aggregate?
Portland Cement (75%)
Bismouth Oxide (20%
Gypsum (5%)
What are the two types of MTA?
White
Grey (includes iron)
What are the disadvanatages of calcium hydroxide?
Weak cement
Very soluble if not protected
What are the disadvantages of mineral trioxide aggregate?
Prolonged set time
Discolouration
What is the aetiology of pulp disease?
Caries
Cracks
Trauma
Iatrogenic
Attrition
Restorations
Periodontal disease
Aggressive scaling
Orthodontic treatment
What are the layers of a carious lesion?
Soft (infected)- excavated
Firm (affected)- resistant to excavation
Hard (sound)
What do we completely remove caries?
Infected tissues
Complete elimination of chronic inflammatory infiltrates
Visualise
Better adhesion
What treatment should you do if there is no exposure following complete caries removal?
Indirect pulp capping
What treatment should you do if there is an exposure following complete caries removal?
Direct pulp capping
Partial pulpotomy
Complete pulpotomy
When is indirect pulp capping indicated?
In reversible pulpitis/traumatic exposure
Where there is a shadow of the pulp
What is the stages of indirect pulp capping?
Apply biomaterial- biodentine or theracal
Immediate final restoration
What is the aim of vital pulp therapy?
Aims to retain the pulp vitality after removing part of or all of the pulp that has been impaired due to trauma or caries
Indicated mainly for reversible pulpitis
What are the factors affecting the outcome of vital pulp therapy?
Type of exposure
Isolation
Coronal pulp amputation needed
Haemostasis and disinfection
Therapeutic agent
Coronal seal
What are the types of pulp exposures?
Carious
Traumatic
Iatrogenic
When is direct pulp capping indicated?
Actual exposure of pulp tissues during cavity preparation or after complete caries removal
Tooth should respond normally to EPT and sensibility tests
When is a partial pulpotomy indicated?
In reversible pulpitis/irreversible pulpitis/traumatic exposire
Removal of 1-3mm inflamed coronal pulp tissues
Haemostasis should be achieved within 5 minutes
When is a complete pulpotomy indicated?
Reversible/irreversible pulpititis
Complete removal of coronal pulp tissues
Haemostasis within 10 minutes
What are the uses of sodium hypochlorite?
Haemostasis
Disinfection
Biofilm removal
Clearance of dentine chips
What are the ideal features of therapeutic agents?
Sealing
Antimicrobial
Non-cytotoxic
Soluble
Anti-inflammatory
Handling properties
Radiopacity
Setting time
Application
What are the drawbacks of Calcium hydroxide?
High alkalinity (pH 12)
Poor quality of dentine bridge
Low resistance to microleakage
Lack of antibacterial longevity
Limited biocompatibility
What are examples of calcium silicate cements?
MTA
Biodentine
What are the indications for calcium silicate cements?
Direct and indirect pulp capping
Pulpotomies
Root canal filling material
Perforation repair
Regenerative endodontic procedures
What are the features of biodentine?
Antimicrobial
Bioinductive and osteoinductive
Non-cytotoxic
Provides hermetic seal
No discolouration
Setting time 10-13 minutes
Radiopacity similar to dentine (not good)
What are the features of mineral trioxide aggregate?
Antimicrobial
Bioinductive and osteoinductive
Non-cytotoxic
Better hermetic seal than CH
Crown discolouration
More radiopaque than dentine
What are the limitations in pulpal diagnosis?
Subjective nature of pain perception
Imaging
Lack of biomarkers
Clinical testing
Uncertainty in clinical presentation
What are the inflammatory biomarkers of pulp inflammation?
MMP9
IL-6
IL-8
IL-1
IL-2
TNF-alpha
TIMP-1
IFN-Y
What are the treatment options for permanent teeth with irreversible pulpitis?
Partial pulpotomy
Complete pulpotomy
RCT
What should you do if haemostasis is not achieved within 5 mins with NaOCl when carrying out a partial pulpotomy?
Complete pulpotomy
What should you do if haemostasis is not achieved within 10 mins with NaOCl when carrying out a complete pulpotomy?
RCT
What are the indications for vital pulp therapy?
Signs and symptoms of reversible pulpitis
Signs and symptoms of irreversible pulpitis
Incomplete root formation
Carious exposure
Traumatic exposure
Controlled bleeding within 10 mins
What are the contraindications for vital pulp therapy?
Uncontrolled bleeding (>10 mins)
Pulp necrosis/ negative to EPT and cold tests
Previous attempt of VPT
Presence of swelling, pus, sinus tract or fistula
Lack of experience and armentarium
What are the favourable outcomes of vital pulp therapy?
Sensibility tests within normal limits
Free of pain
Absence of swelling
Absence of apical periodontitis
Absence of root resorption
Formation of dentinal bridge
In immature teeth- complete formation
What are the unfavourable outcomes of vital pulp therapy?
Clinical signs and symptoms
Apical periodontitis
Unresponsive to EPT and cold
Incomplete root formation
Root resorption
