Endodontics Flashcards
1
Q
What are the methods of periodic-endo communications?
A
Perforations
Root apex
Lateral canals
Fractures
Dentinal tubules
2
Q
What are the ideal properties of an obturation material?
A
Biocompatible
Dimensionally stable
Unaffected by oral fluid
Insoluble
Radiopaque
3
Q
What is the composition of gutta percha?
A
20% GP
60% Zinc Oxide
10% Radiopacifiers
5% Plasticisers
4
Q
What is the function of a sealer?
A
Seals space between dentine wall and core
Fills voids and irregularities
Lubricates obturation
5
Q
What are the ideal properties of a sealer?
A
Good adhesion
Easily mixed
Bacteriostatic
Insoluble
Radiopaque
No shrinkage
Slow set
6
Q
How does zinc oxide eugenol perform as a sealer?
A
Antimicrobial
Free eugenol can be toxic
7
Q
How does glass ionomer perfom as a sealer?
A
Bonds dentine
Difficult to remove
Minmal antimicrobial
8
Q
How does resin perform as a sealer?
A
Good sealer
Good slow
Slow set 8 hours
9
Q
How does calcium silicate perform as a sealer?
A
High pH (12.8)
Biocompatible
Good seal
10
Q
What are the 9 endo laws?
A
Centrality
Concentricity
ACJ
Symmetry 1
Symmetry 2
Colour
Orifice Location 1
Orifice Location 2
Orifice Location 3
11
Q
What is the law of centrality?
A
Floor of pulp is central to the tooth at the ACJ
12
Q
What is the law of concentricity?
A
Walls of pulp chamber are concentric to the external surfaces at the ACJ
13
Q
What is the law of the ACJ?
A
The ACJ is the most consistent, repeatable landmark for locating the pulp chamber
14
Q
What is the Symmetry Law 1?
A
Orifices of canal are equidistant from line drawn in mesio-distal direction through the pulp chamber floor
15
Q
What is the exception to the symmetry 1 law?
A
Upper 6’s
16
Q
What is the symmetry law 2?
A
Orifices of canal lie on perpendicular to a line drawn in a mesio-distal direction across the centre of the pulp chamber
17
Q
What is the exception to symmetry law 2?
A
Upper 6’s
18
Q
What is the colour law?
A
Colour of pulp chamber floor is darker than the walls
19
Q
What is the orifice location 1 law?
A
Orifices are located at junction of walls and floor
20
Q
What is the orifice location 2 law?
A
Orifices are located at angles in the floor wall junction
21
Q
What is the orifice location 3 law?
A
Orifices are located at terminus of root development fusion lines
22
Q
How can endodontic equipment be classified?
A
Manually operated
Low speed
Engine driven NiTi rotary
Engine driven adapts to canal
Engine driven reciproc
Ultrasonic
23
Q
How can endodontic equipment be classified?
A
Manually operated
Low speed
Engine driven NiTi rotary
Engine driven adapts to canal
Engine driven reciproc
Ultrasonic
24
Q
What is Nitinol?
A
Equiatomic alloy of nickel and titanium
25
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
26
What is the crystal structure of NiTI?
Temperature dependent structures of martensite and austenite:
Martensite= soft and ductile
Austenite= strong and hard
27
What is shape memory?
Material deformed at one temp then returns to original shape
28
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
29
What is the purpose of irritants?
Remove debris
Lubricate
Dissolve organic and inorganic material
Penetrate to canal periphery
Kill bacteria/yeast
Disrupt biofilm
30
What does sodium hypochlorite ionise in water to form?
Na+ and OCl-
31
What is the effect of pH on sodium hypochlorite?
Acid/neutral: HOCl predominates
>9; OCl- predominates
32
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
33
What are the ideal properties of sealers?
Tackiness
Easily mixed
Bacteriostatic
Insoluble in tissue fluids
Radiopacity
No shrink on set
Slow set
34
What is gutta percha?
Transiosomer of poly-isoprene
35
What are the design objectives
Continuously tapering funnel
Maintain apical foramen position
Apical opening as small as possible
36
What are the clinical objectives?
Remove infected hard and soft tissue
Prevent re infection
37
What is endodontic success improved by?
Hypochlorite irrigation
Dental dam
38
Why is dental dam used in endodontic?
Protects airway
Improves access
Improves efficacy and vision
Prevents contamination
Protects soft tissue
39
What are the pulpal diagnoses?
Normal
Reversible Pulpitis
Symptomatic Irreversible Pulpitis
Asymptomatic Irreversible Pulpitis
Pulp Necrosis
40
How does a normal pulp present?
Asymptomatic
Normal thermal response
Vital
41
How does symptomatic irreversible Pulpitis present?
Lingering pain to stimulus
Pain with postural change (night)
42
How does reversible Pulpitis present?
Inflamed
Pain to stimulus
Resolves with treatment
43
How does asymptomatic irreversible Pulpitis present?
No symptoms
Normal response to thermal tests
44
How does pulp necrosis present?
Negative pulp test
TTP
Radiographic osseous breakdown
May be asymptomatic
45
What are the apical diagnoses ?
Normal
Symptomatic apical periodontitis
Asymptomatic apical periodontitis
Acute apical abscess
Chronic apical abscess
Condensing osteitis
46
How does a normal apical diagnosis present?
Not TTP
Uniform PDL space
47
How does symptomatic apical periodontitis present?
TTP
Pain on biting
Periapical radiolucency
48
How does asymptomatic apical periodontitis present?
Asymptomatic
Periapical raidolucency
49
How does an acute apical abscess present?
Rapid
Swelling
TTP
Spontaneous pain
Systemic problems
50
How does a chronic apical abscess present?
Gradual
Asymptomatic
Periapicla radiolucency
Sinus (with or without pus)
51
How does condensing osteitis present?
Localised bony reaction to low grade inflammatory stimulus
Diffuse Periapical radiopacity
52
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
53
What are the stages of mechanical preparation?
Tooth preparation
Access cavity
Confirm straight line access
Initial negotiation, coronal flaring
Working length determination
Apical preparation
54
What are examples of irritants?
3% NaOCl
17% EDTA
0.2% CHX
55
What are the lengths of times for the final irrigation?
10 minutes NaOCl
1 minute EDTA
10 minutes NaOCl
56
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
57
What are the pros of sodium hypochlorite?
Dissolves organic material
Disrupts smear layer
Effective antimicrobial
58
What are the cons of sodium hypochlorite?
Doesn’t remove smear layer
Dissolves fabrics
Risk of hypochlorite accident
59
How are sodium hypochlorite accidents managed?
Copious irrigation
Analgesia
Review
60
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
61
What is the smear layer?
Superficial (1-5um) layer of organic pulpal and inorganic dentinal material formed during prep
Prevents disinfection and sealer penetration
62
What can be used to remove the smear layer?
17% EDTA
10% citric acid
MTAD
63
What is an example of an intra-canal medicament?
Non-setting calcium hydroxide
64
What are the features of calcium hydroxide?
Antibacterial
Reduces inflammation
Kills mirco-organisms
Removes tissue debris
65
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
66
What is estimated working length?
Estimated length at which instrumentation should be limited
1mm short of radiographic apex
67
What is estimated working length?
Estimated length at which instrumentation should be limited
1mm short of radiographic apex
68
What is corrected working length?
Actual length at which instrumentation should be limited
69
What is the master apical file?
Largest file taken to working length
Represents final prepared size of apical canal
70
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
71
What is the optimum concentration of sodium hypochlorite?
0.5-6%
72
What percentage of sodium hypochlorite is used in GDH?
3%
73
How thick is the smear layer?
1-5um
74
What is the protocol for removing the smear layer?
3% NaOCl - 10 mins
17% EDTA- 1 min
3% NaOCL- final rinse
75
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
76
What is vertucci type 1?
Single canal
77
What is vertucci type 2?
2-1
Two canals that join into one
78
What is vertucci type 3?
One canal that divides into two then merges into one
1-2-1
79
What is vertucci type 4?
Two separate canals
2
80
What is vertucci type 5?
One canal that separates into two
1-2
81
What is vertucci type 6?
Two canals that join then separate into two
2-1-2
82
What is vertucci type 7?
One canal leaves the pulp chamber, divides, rejoins and divides at the apex
1-2-1-2
83
What is vertucci type 8?
Three separate distinct canals
3
84
What are the benefits of nickel titanium files?
Superelasticity
85
What are the benefits of coronal flaring?
Reduces hydrostatic pressure
Reservoir for irrigants
86
What are the pulpal diagnoses?
Healthy Pulp
Reversible Pulpitis
Symptomatic Irreversible Pulpitis
Asymptomatic Irreversible Pulpitis
Necrotic Pulp
Previously treated
87
What is the management of reversible pulpitis?
Pulp therapy
88
What is the management of irreversible pulpitis?
Pulpotomy
Pulpectomy
Extraction
89
What is the management of necrotic pulp in a mature tooth?
RCT
Extract
90
What is the management of necrotic pulp in an immature tooth?
Pulpotomy
Pulpectomy
Extract
91
What are the periapical diagnosis'?
Normal
Asymptomatic Periapical Periodontitis
Symptomatic Periapical Periodontitis
Acute Apical Abscess
Chronic Apical Abscess
Condensing Osteitis
92
How does asymptomatic periapical periodontitis present?
No pain
Radiolucency
93
How does symptomatic periapical periodontitis present?
Pain on biting
Percussion
Palpation
94
How does acute apical abscess present?
Rapid onset
Spontaneous pain
Swelling
95
How does chronic apical abscess present?
Slow onset
Little/no discomfort
96
How does condensing osteitis?
Bony reaction to low grade inflammatory stimulus
97
How does reversible present?
Pain to cold (short lasting)
Hydrodynamic expression (microleakage)
No change in pulp blood flow
98
How does irreversible present?
Spontaneous pain
Sleep disturbance
Negative to cold
Pain to heat (c fibres)
Increased pulpal blood flow
99
How do non-vital teeth present?
Discoloured
Sinus
Gross caries
Large restoration
Radiographic (periapical radiolucency)
100
What is the aim of sensibility tests?
To test neuron/nerve function
Very subjective
101
What are examples of sensibility tests?
EPT
Thermal tests
Test drilling
102
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
103
What are the features of mineral trioxide aggregate?
High pH
Creates bacterial tight seal
Can act as a base for restorative material
104
What are the components of mineral trioxide aggregate?
Portland Cement (75%)
Bismouth Oxide (20%
Gypsum (5%)
105
What are the two types of MTA?
White
Grey (includes iron)
106
What are the disadvanatages of calcium hydroxide?
Weak cement
Very soluble if not protected
107
What are the disadvantages of mineral trioxide aggregate?
Prolonged set time
Discolouration
108
What is the aetiology of pulp disease?
Caries
Cracks
Trauma
Iatrogenic
Attrition
Restorations
Periodontal disease
Aggressive scaling
Orthodontic treatment
109
What are the layers of a carious lesion?
Soft (infected)- excavated
Firm (affected)- resistant to excavation
Hard (sound)
110
What do we completely remove caries?
Infected tissues
Complete elimination of chronic inflammatory infiltrates
Visualise
Better adhesion
111
What treatment should you do if there is no exposure following complete caries removal?
Indirect pulp capping
112
What treatment should you do if there is an exposure following complete caries removal?
Direct pulp capping
Partial pulpotomy
Complete pulpotomy
113
When is indirect pulp capping indicated?
In reversible pulpitis/traumatic exposure
Where there is a shadow of the pulp
114
What is the stages of indirect pulp capping?
Apply biomaterial- biodentine or theracal
Immediate final restoration
115
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
116
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
117
What are the types of pulp exposures?
Carious
Traumatic
Iatrogenic
118
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
119
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
120
When is a complete pulpotomy indicated?
Reversible/irreversible pulpititis
Complete removal of coronal pulp tissues
Haemostasis within 10 minutes
121
What are the uses of sodium hypochlorite?
Haemostasis
Disinfection
Biofilm removal
Clearance of dentine chips
122
What are the ideal features of therapeutic agents?
Sealing
Antimicrobial
Non-cytotoxic
Soluble
Anti-inflammatory
Handling properties
Radiopacity
Setting time
Application
123
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
124
What are examples of calcium silicate cements?
MTA
Biodentine
125
What are the indications for calcium silicate cements?
Direct and indirect pulp capping
Pulpotomies
Root canal filling material
Perforation repair
Regenerative endodontic procedures
126
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)
127
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
128
What are the limitations in pulpal diagnosis?
Subjective nature of pain perception
Imaging
Lack of biomarkers
Clinical testing
Uncertainty in clinical presentation
129
What are the inflammatory biomarkers of pulp inflammation?
MMP9
IL-6
IL-8
IL-1
IL-2
TNF-alpha
TIMP-1
IFN-Y
130
What are the treatment options for permanent teeth with irreversible pulpitis?
Partial pulpotomy
Complete pulpotomy
RCT
131
What should you do if haemostasis is not achieved within 5 mins with NaOCl when carrying out a partial pulpotomy?
Complete pulpotomy
132
What should you do if haemostasis is not achieved within 10 mins with NaOCl when carrying out a complete pulpotomy?
RCT
133
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
134
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
135
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
136
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
137
