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stupid root canals Flashcards

1
Q

Why is a healthy pulp important?

A
  1. Completion of root formation in immature teeth - primary dentine
  2. Continued lifelong tooth development - secondary dentine
  3. Protection against infection - tertiary dentine
  4. Maintenance of sensory function
  5. Maintenance of elasticity of dentine
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2
Q

What is the aim of endo tx?

A

To prevent or treat periapical periodontitis by eliminating microorganisms from the root canal system and preventing re infection with a well sealed root canal filling and coronal restoration

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3
Q

List 4 sources of threat to the pulp

A

Carious attack
Trauma
Iatrogenic damage
Tooth surface loss

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4
Q

Where is the apical foramina found?

A

0.5-0.7mm from the anatomical and radiographic apex

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5
Q

Where is the apical constriction and why is it relevant?

A

0.5-0.7mm short of the apical foramina
Distance increases with age due to secondary cementum deposition
Electronic apex locators are used to find the position of it

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6
Q

What should a history include if trauma was involved?

A

Time, date and location of incident
Was there loss of consciousness or dizziness - refer to A+E for head investigations
Medical history
Was any emergency tx performed
Type, time and location of any other tx provided prior

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7
Q

What should be included in an E/O exam?

A

If acute facial swelling get a provisional diagnosis
Record body temp if difficulty swallowing, breathing and/or facial asymmetry
Palpate TMJ and LNs

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8
Q

What 8 things should be included in an I/O exam?

A

Dental pathology - caries, surface loss, fracture
Palpation
Discolouration (yellow or grey then pulp necrosis) (pink then internal resorption)
Pocketing
TTP
Mobility
Swelling or sinus
Is the tooth in occlusion

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9
Q

How many special investigations are needed for a diagnosis?

A

Two independent positive diagnostic tests

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10
Q

How is a cold test used?

A

Endo frost on cotton wool pledges
-50ºC
Use as first line - good for vital and non-vital teeth

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11
Q

How is a heat test used?

A

Useful if pt unsure which tooth is painful
Use a heated GP stick

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12
Q

How is an electric pulp test used?

A

Dry tooth and use toothpaste as conductive medium
Electric stimulus applied to tooth at variable intensities
Gives digital reading which can be compared to a contra-lateral tooth
Tests A delta fibres
Test the cervical margin of each root

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13
Q

Give 5 reasons for a false positive EPT response from a non-vital tooth

A

Anxious patient
Young patient
Partially vital teeth - multi-rooted
Canal full of pus
When in close contact with gingival tissues or metallic restorations

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14
Q

Give 5 reasons for a false-negative response from vital teeth

A

Any from:
- heavily restored teeth
- older patients due to secondary dentine deposition
- recently traumatised teeth
- partially vital teeth
- nerve supply damaged but blood supply intact
- teeth undergoing/recent ortho tx
- pt under the influence of sedative drugs/alcohol - increased threshold

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15
Q

Name 4 other tests used to aid in definitive diagnosis?

A

Palpation
Percussion
Mobility
Radiographs - periapical

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16
Q

Why are pre-op radiographs taken?

A

To identify pathology and aid diagnosis
To assess restorability
To identify estimated working length

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17
Q

What are the minimum standards and images for endo tx?

A

Pre-operative PA
Sometimes mid-operative PA to ensure correct length prior to obturation
Post-obturation
Review

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18
Q

Give 4 reasons to take supplemental radiographs?

A

Perforation
Negotiating calcified canals
Staged obturation
To check post-space preparation

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19
Q

Give 4 indications for a CBCT in endo

A

Analysis of complex root canal systems
Assessment of treatable resorption
Pre-surgical assessment before peri-radicular surgery
Identified of extensively obliterated canals

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20
Q

What is dentine hypersensitivity?

A

Exposed dentine tubules causing pulpal hyperaesthesia

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21
Q

What causes dentine hypersensitivity and how does it present?

A

Causes - TSL, internal bleaching, gingival recession
Sharp pain with cold
Lasts no longer than a few seconds after stimulus removed
Never spontaneous

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22
Q

How is dentine hypersensitivity managed?

A

Manage the aetiology
Fluoride varnish
OH and diet advice
Desensitising agents

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23
Q

What is reversible pulpitis?

A

Inflammation of vital pulp that returns to normal with the management of the aetiology

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24
Q

What causes reversible pulpitis and how does it present?

A

Causes - caries, TSL, trauma or fracture
Sharp pain with cold, sweet or hot
Lasts no longer than a few seconds after the stimulus is removed
Never spontaneous

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25
Q

How is reversible pulpitis managed?

A

Restorations (direct or indirect) to manage the aetiology

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26
Q

What is irreversible pulpitis?

A

Inflammation of vital pulp that is incapable of healing
Can be symptomatic or asymptomatic

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27
Q

What causes irreversible pulpitis?

A

Caries
TSL
Trauma
Fracture

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28
Q

What is the presentation of irreversible pulpitis?

A

Dull aching pain with hot or cold
Lasts for a prolonged period after stimulus is removed
Can be spontaneous
Postural changes make it worse
May keep pt awake
Painkillers may be ineffective
Pain may be referred

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29
Q

How is irreversible pulpitis managed?

A

RCT
XLA

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30
Q

How does symptomatic apical periodontitis present clinically and radiographically?

A

Clinical - pain on biting, TTP and well localised pain
Radiographically - may be PDL widening and apical radiolucency

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31
Q

How does acute apical abscess present clinically and radiographically?

A

Severe pain with rapid spontaneous onset
TTP
Suppuration, swelling and mobility likely
Possible systemic symptoms - fever, malaise
May have PDL widening and apical radiolucency

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32
Q

How does chronically apical abscess present clinically and radiographically?

A

Typically asymptomatic - may report mild discomfort
Sinus tract formation
Metallic or bad taste
Apical radiolucency

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33
Q

How is periodontitis and apical abscesses treated?

A

RCT
XLA

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34
Q

How does cracked tooth syndrome present?

A

Sharp pain on biting or dull ache on release of bite

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35
Q

What investigations should be carried out for cracked tooth syndrome?

A

Percussion and tooth sleuth
Mobility
Pocket depth
Transillumination to identify cracks
Occlusal assessment
Sensibility testing

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36
Q

What are the clinical findings or cracked tooth syndrome?

A

TTP and tooth sleuth positive
Deep, narrow isolated pocket
Sensibility can give hyper-response or negative

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37
Q

How may cracked tooth syndrome appear radiographically?

A

In acute cases may appear normal
In chronic cases, may be more evident - can see J shaped lesions with bone loss

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38
Q

How should a cracked tooth be assessed?

A

Extent of crack - if sub-gingival then unrestorable
Assess pulpal status and treat
Assess periodontal support - if extensive bone loss, deep perio pocket and excessive mobility then XLA

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39
Q

How should cracked teeth be treated in an emergency?

A

Occlusal reduction to relieve biting pressure
Composite splint to stabilise the cracked portion
Place an ortho band if unsure and then review - if symptoms have settled with band then likely crack present

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40
Q

What should a pt be informed of for valid consent?

A
  1. All tx options and risks and benefits
  2. Why you think tx is necessary
  3. Consequences risks and benefits of the tx you propose
  4. The likely prognosis
  5. Your recommended option
  6. Cost
  7. What might happen without tx
  8. Whether tx is guaranteed and if any exclusions apply
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41
Q

Give 8 indications of RCT

A

Irreversible pulpitis
Necrotic pulp
Acute or chronic apical periodontitis
Acute or chronic apical abscess
Non-vital cracked tooth
Pulpal exposure
Elective devitalisation
For the retention of a fixed restoration

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42
Q

Give 4 contraindications for RCT

A

Unrestorable tooth
Insufficient periodontal support
Vertical root fracture
Insufficient operator skill or unable to replace dam

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43
Q

What 4 things improve the outcome of primary RCT?

A

Pre-op abscence of periapical radiolucency
Root filling with no voids
Root filling extending within 2mm of the radiographic apex
Satisfactory coronal seal and restoration

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44
Q

List 3 biological objectives of RCT

A

Disinfect as much of the root canal system as possible
Remove potential nutrient sources that support microorganism growth
Prevent re contamination of the root canal system

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45
Q

Why is irrigation necessary?

A

Is it not possible to mechanically prepare the entire root canal system due to microorganisms adhering to the root walls

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46
Q

How does mechanically shaping the root canal system facilitate cleaning?

A

Allows direct removal of bacteria and nutrient sources
Enables penetration of active agents for disinfection

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47
Q

List 4 desired features that should be achieved in canal prep in order to produce an optimal seal in the root canal system

A

Continuous taper
Maintained canal axis position in the centre of the root
Maintained original position of the foramen, not enlarged
Sufficient space to deliver disinfecting solutions to the canal terminus

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48
Q

What should be included in an endo referral letter?

A

Pt details
C/O and HPC
MH, SH and DH
Examination findings including special tests results and a restorability assessment if possible
Diagnostically acceptable periapical
Provisional or definitive diagnosis
Justification for the referral based on the case difficulty assessment
Details of any failed attempts at tx

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49
Q

Describe the maxillary canal anatomies

A

1 - single canal
2 - single canal, often distal curve
3 - single canal
4 - 75% have 2 roots with 1 canal in each
5 - 75% have 1 canal, 24% have 2 canal orifices which converge to give 1 apical foramen
6+7 - majority have 3 roots, mesial root has 2 canals in 96% of cases

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50
Q

Describe the mandibular canal anatomies

A

1+2 - single canal, may have 2 separate canals which fuse in apical portion
3 - one root and one canal, 6% have 2 roots
4+5 - 20-30% of canals start coronally as one canal and divide into 2 or 3 and stay separate
6+7 - distal root 1 canal in 75% cases, 2 canals in 25% - mesial root usually 2 canals, rarely 3

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51
Q

What are the 9 steps of endo tx?

A

Rubber dam isolation
Access and canal location
Coronal/SLA
Irrigation and recapitulation
Working length
Apical gauging and determining Master Apical File (MAF)
Apical preparation
Inter-appointment dressing
Obturation

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52
Q

What are the 6 access cavity design principles?

A
  1. Allow removal of entire contents of pulp chamber
  2. Allow visualisation of the pulp floor and canal orifices
  3. Allow direct access to apical 1/3 of the canal for instrumentation
  4. Allow retention and support of a temp filling material - good seal
  5. Provide a reservoir for canal irrigant
  6. Be as conservative as possible
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53
Q

What can be used for canal location?

A

DG16 probe

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54
Q

How is coronal prep carried out?

A

If canal narrow, pre-flare with SS hand file using step-back technique up to a size 35
Prepare coronal 2/3 or up to point of curvature (whatever is less) with Gates glidden burs in a crown down technique (sizes 4, 3, 2)
Use pre-op radiograph to calculate estimated working length as a guide - approximation only

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55
Q

What should happen after use of every instrument in the canal?

A

Irrigate with sodium hypochlorite (0.5-2.5%)
Irrigation needle should be passive within canal and moved in a gentle up/down motion never passing beyond 2mm short of working length
Recapitulate with a small file (10)

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56
Q

What occurs in apical exploration?

A

Explore apical anatomy with pre-curved SS hand file (10, 8 or 6)

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57
Q

How is the working length ascertained?

A

Achieve a zero reading on the EAL with a hand file (largest file the canal will allow to seat passively, usually 15 or 20)
Take a radiograph with the file left at the length of the zero reading (measure and write down this length and the reference point)
Confirm position of file in relation to the radiographic apex
If happy with file position on radiograph, subtract 0.5mm from this length to get the working length
Confirm from radiograph you have straight line access
If unhappy, reconfirm apex locator readings or consider alt methods such as using paper points to help determine working length, repeat radiograph

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58
Q

How is apical gauging carried out?

A

Passively place progressively larger files to 0.5mm beyond the working length
The first file that will not pass beyond the working length is the first file to bind and estimates the size of the apical constriction

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59
Q

How do you determine the master apical file (MAF)?

A

Between 1 and 3 sizes larger than the first file to bind at the working length, normally dependent on the canal shape/curvature

60
Q

How is apical preparation carried out?

A

Prepare up to the MAF at working length using a watch winding motion
Prepare the canal using a step back technique from the working length with a watch winding motion
Patency at zero reading length
Increase the file size every 1mm you step-back, creating a 0.05 or 5 degree taper

61
Q

How can you gauge the canal taper?

A

Passively place files into the canal until they will go no further (from MAF to largest) and set the rubber stopper to the reference point
Measure each file to check your taper
Make any necessary adjustments to your preparation if needed

62
Q

What is a MAF radiograph?

A

A radiograph with the MAF at working length to radiograph confirm preparation length (the file should be 0.5mm shorter than the working length radiograph assuming the length was satisfactory)

63
Q

How is an inter appointment dressing placed?

A

Dry canals with paper points and place non-setting CaOH into the canals
Use the MAF file to apply the CaOH, gently rotating it out of the canal in an anti-clockwise motion
Repeat until canal is full
Place a barrier (CW) over CaOH and a temp restoration on top (GIC, Kalzinol), ensuring a thickness of at leath 3mm

64
Q

How is the final irrigation carried out?

A

Rinse with 17% EDTA for 1 minute followed by a thorough rinse with NaOCl
Can use a well fitting GP cone (same size as MAF) to perform manual agitation via a GP pumping technique to maximise effectiveness
Ideally dry the canals with paper points between using different irrigants

65
Q

What is needed for a master cone radiograph and how is it taken?

A

Select master cone (same size as MAF) and ensure it seats to working length and has adequate tug-back - if not then modify by removing 0.5mm from the tip with a scalpel until this is achieved
Place the master cones to working length and confirm their position with a radiograph

66
Q

How is obturation carried out?

A

Disinfect the master cones in NaOCl and dry with 3 in 1
Dry canals using paper points
Place a thin layer of sealer on the canal walls and seat master cone to length
Place a finger spreader up to 1mm short of working length
Place a matching accessory cone and repeat process until canal obturated
Cut GP at level of canal orifice or level of bony crest if this is lower

67
Q

Describe a post-op radiograph

A

Radiograph to check length and density of root filling as well as the restoration
If not confident about quality of obturation can take this before placing your definitive restoration

68
Q

How should RCT teeth be restored?

A

Consider placing an orifice barrier - act as a seal in case of future microleakage or loss of definitive restoration eg - GIC/RMGIC/flowable composite
Consider the most appropriate definitive restoration:
1. Direct (without cuspal coverage) eg - composite
2. Cuspal coverage (direct or indirect) eg - onlay, partial or full veneer crown
3. Post (only indicated to retain a core/restoration where resistance and retention form are deemed inadequate)

69
Q

When should a RCT be reviewed?

A

Clinical and radiograph review 12 months later and annually up to 4 years until radiolucency has healed

70
Q

Describe the make up of protaper rotary instruments?

A

Nickel-Titanium - gives a greater degree of flexibility so more curved roots can be treated
6% taper compared with 2% taper of hand files

71
Q

How are protaper rotary instruments used?

A

Prep of canal using crown down technique - starting with larger file first
This is opposite of the way the apical 1/3 is prepared by hand files
Prep starts with largest file, progressing to the smallest - file should be advanced about 1-2mm down the canal not forcing it down
A single file cannot be used to prep the whole canal - would cause too much stress in tooth - fracture risk
Consider finishing apical 1mm using hand files as the end of the rotary file is thin and fragile - prone to fracture inside the canal - called separation

72
Q

Give 4 advantages of rotary instruments?

A

Any from:
- increased debris removal
- less transportation of infected debris from coronal to apical
- reduced lodging
- they keep centred on the canal
- reduced canal transportation
- smoother preparation and shaping
- less operator fatigue

73
Q

Give 4 disadvantages of rotary instruments

A

Increased risk of fracturing an instrument
Reduced tactile feedback
They cannot adequately prepare the apical 1mm - requires hand files
Relatively high cost

74
Q

Describe the protaper technique

A

Scout canal with hand K files 10, 15, 20 until resistance
Measure length of number 20K file and transfer to S1
Take S1 to this length, brushing on withdraw
Negotiate with 10K file to length
Determine working length with EAL and confirm with PA
Work number 15 and 20 to working length
S2 to length
F1 to working length
Re-check working length and gauge
If tight canal use HP F1 to length, HP F2 (minus 0.5mm) and HP F3 (minus 1mm)

75
Q

Give 4 reasons to use rubber dam during RCT

A

To minimise risk of contamination of root canal system by oral bacteria in saliva and tissue fluids
To prevent ingestion or aspiration of dental materials, irrigants and instruments
To provide a controlled operative environment
To improve visualisation of the operating field

76
Q

What are the basic stages of RCT?

A

Assess tooth restorability
Prepare an access cavity
Identify straight line access
Initial canal negotiation and coronal 2/3 flare
Apical negotiation and working length determination
Apical preparation after working length confirmation

77
Q

How is access to the canal system gained?

A

Completely remove the roof of the pulp chamber and make sure no ledges or lips are present
Probe the canals with DG16 probe - the canal entrance will feel sticky
Identify the canals before placement of rubber dam to make sure that you are in the correct place

78
Q

What are Krasner and Rankows anatomical laws regarding the pulp chamber?

A

Law of centrality
Law of concentricity
Law of the CEJ

79
Q

What is the law of centrality?

A

The floor of the pulp chamber is always located in the centre of the tooth at the level of the CEJ

80
Q

What is the law of concentricity?

A

The walls of the pulp chamber are always concentric to the external surface of the tooth at the level of the CEJ

81
Q

What is the law of the CEJ?

A

The CEJ is the most consistent, reproducible landmark for locating the position of the pulp chamber
The distance from the external surface of the clinical crown to the wall of the pulp chamber are the same throughout the circumference of the tooth at the level of the CEJ

82
Q

What are Krasner and Rankows anatomical laws regarding the pulp chamber floor?

A

Law of symmetry 1
Law of symmetry 2
Law of colour change
Law of orifice location 1
Law of orifice location 2
Law of orifice location 3

83
Q

What is the first law of symmetry?

A

Except for maxillary molars, the orifices of the canals are equidistant from a line drawn in a mesial distal direction through the pulp chamber floor

84
Q

What is the second law of symmetry?

A

Except for the maxillary molars, orifices of canals lie on a line perpendicular to a line drawn in a mesial-distal direction across the center of the floor of the pulp chamber

85
Q

What is the law of colour change?

A

The colour of the pulp chamber floor is always darker than the walls

86
Q

What is the first law of orifice location?

A

Orifices of root canals are always located at the junction of the walls and the floor

87
Q

What is the second law of orifice location?

A

Orifices of the root canals are located at the angles in the floor-wall junction

88
Q

What is the third law of orifice location?

A

Orifices are located at terminus of development root fusion lines (DRFL) - commonly known as the dentine map or grey tracks

89
Q

What is a glidepath?

A

A smooth pathway from the coronal orifice to the anatomical foramen
Allows for larger instruments to follow

90
Q

How is canal negotiation carried out generally?

A

Start to negotiate canal with size 10 K file
Gain info on root canal system - is it wide or narrow, does it divide, is it full of pulp tissue or debris
Pre-flaring with progressively larger files is beneficial, especially in narrow canals

91
Q

How is a glide path created?

A

Systematic approach with small SS K files (6,8,10)
Watch winding motion to start opening the canal
Progress to larger SS hand files (15,20,25 etc) for pre-flare technique
Be cautious with larger files in challenging canals
Negotiation must be done with a manual SS instrument

92
Q

Why is coronal flare carried out?

A

To widen the canals coronally
Helps to locate canals better visually and aids straight line access

93
Q

How is a coronal flare obtained?

A

From PA, measure the length of the root to determine the working length - or apex locator
Divide the canal into thirds and measure 2/3 the length on to a Gates Glidden bur (size determined by tooth and canal size) - mark with a rubber stopper
Widen the coronal aspect of the canal with the bar and repeat the step with two more advancing size burs - known as a crown down (large to small bur)

94
Q

How does an apex locator work?

A

Electrical impedence - they emit a visual or audible sound when they reach the apex due to changes in tissue moisture

95
Q

What is the step back method?

A

Once the apical portion is prepared - the step back prep is used to create a greater taper of the canal
Successively larger instruments are used - each 1mm shorter than the previous one

96
Q

How is the step back method carried out?

A

MAF should extend to the length of 1mm short of the working length (WL1)
Select next size file up and subtract 1mm from WL1 (WL2)
Mark WL2 on the file using a rubber bung
Use this file in the canal until there is no resistance felt against the file
Repeat the above step twice more remembering to irrigate - use MAF as a reference in between subsequent files to ensure a tapered smooth, ledge-free canal
Clean the canal with saline and dry with paper points ready for obturation

97
Q

How is apical preparation carried out for vital pulps?

A

Use barbed roaches - looks like barbed wire
Made from SS
Place in canal, twist anti-clockwise and pull out the vital pulp

98
Q

What is recapitulation?

A

After use of a file and irrigation, a smaller file is used to loosen with a reciprocating motion ensuring the canal is patent

99
Q

How is apical patency ensured?

A

A size 10 file should be set at WL+1 and inserted gently just through the constriction at regular intervals to ensure the apex does not become blocked and remains patent

100
Q

Why is irrigation important during RCT?

A

Filing generates debris which can cause blockage if left - can then lead to inflammation
Irrigation helps loosen and clear the debris out and also aids instrumentation by helping to lubricate the canals

101
Q

How is irrigation carried out?

A

Using sodium hypochlorite (NaOCl) 2.5% in a blunt, side delivery needle syringe
Irrigate passively and take care not to advance the needle past the apex

102
Q

Give 5 advantages of NaOCl as an irrigant?

A

Effective antimicrobial agent
Excellent organic tissue solvent - ability to dissolve organic material from canal by oxidation
Lubricant
Quick effective agent
pH 11

103
Q

Give 3 limitations of NaOCl as a lubricant

A

Toxic
Not substantive
Ineffective in smear layer removal - why EDTA is recommended as a penultimate irrigant

104
Q

How does chlorhexidine differ as an irrigant from NaOCl?

A

Similar antimicrobial effect
Doesn’t dissolve the organic debris found in areas inaccessible to hand instrumentation eg - lateral canals

105
Q

How is EDTA used as an irrigant?

A

A chelating agent which is used as a lubricant
Softens the canals’ dentine walls and facilitates canal preparation
May also be used as an irrigant at the end of canal prep (penultimately) to remove the smear layer before placement of an inter visit dressing or obturation

106
Q

Name 3 intracanal medicaments?

A

Non-setting calcium hydroxide
Vitapex
Ledermix - steroid paste

107
Q

What pH is non-setting CaOH?

A

UltraCal - 11
HypoCal - 12

108
Q

When is vitapex indicated?

A

Deep-seated infections of the root canal

109
Q

When is ledermix indicated?

A

Dressing an inflamed vital pulp prior to commencing RCT
Intra-visit medicament if severe periradicular inflammation present

110
Q

List 9 ideal properties of an obturation material

A

Easily introduced into the canal
Doesn’t shrink after use
Bacteriostatic
Shouldn’t stain the tooth
Easy and quick to sterilise before insertion
Seal the canal apically and laterally
Impermeable
Radiopaque
Easily removed if necessary

111
Q

List 5 objections of obturation

A

To provide a 3D hermetic seal to the root canal to:
- prevent the ingress of bacteria - coronal seal
- incarcerate any microbes remaining in the root canal system
- prevent re-infection of the root canal system
- prevent diffusion of inflammatory exudate into the canal - as apical seal

112
Q

What are the components of GP?

A

GP - 15%
Zinc oxide - 65%
Radiopacifier - 15%
Plasticiser - 5%

113
Q

List 5 advantages of GP?

A

Any from:
- cheap
- easy to handle
- does not deteriorate
- radiopaque
- biocompatible
- non-supportive of microbial growth
- can be removed with heat or solvent

114
Q

List 3 disadvantages of GP?

A

Lack of adhesion to dentine
Shrinkage on cooling when heated
When exposed to air and light for long periods of time, it oxidises and becomes brittle - can be reconditioned with warm water

115
Q

What taper is found on GP?

A

2º

116
Q

What may happen if the master GP cone is too small or too long?

A

To small - apical construction
Too long - defective apical resistance - usually due to inaccurate determination of the working length

117
Q

Describe the cold lateral compaction technique

A

Dry canal with paper points
Coat walls of canal with sealer using hand file or finger spreader
Lightly coated master GP placed in canal
Spreader is measured and inserted into canal with vertical finger pressure for 20 seconds before removal when immediately a lightly coated accessory point is slid into the tract left behind
This is repeated until the spreader will reach no deeper than 2-3mm
GPs severed with heat and then firmly condensed with a cold instrument, usually a plugger
Since the GP isn’t softened with heat it will remain dimensionally stable

118
Q

Describe the warm GP technique

A

GP heated inside the root canal by use of a hot hand instrument (heat carriers)
Root canal given continuous taper - coronal parts designed wider to allow space for the instrument to heat and condense the GP
Non-standardised point used as the master GP due to greater flare
The point is cut 2-3mm short of WL
Sealer applied to walls of root canal and master GP placed and severed at canal entrance with a hot plastic instrument
Cold instrument then used to condense the warm GP apically
Heat carrier then heated and placed 3-4mm in GP
Warm GP again condensed with a cold plugger
This is repeated to 5-6mm short of working length when the apical part of the canal is filled
If a post is required, obturation is usually considered completed here

119
Q

When complication is commonly seen with the warm GP technique?

A

Overfilling

120
Q

Describe the injection mould GP technique?

A

GP is heated outside of the mouth until it is flowable and inserted into the canal by a syringe
The canal can be filled in seconds but shrinkage occurs
To help counteract shrinkage only 2-3mm of the canal is filled at a time and continuous condensation force is applied to the GP when cooling

121
Q

What complications are commonly seen in the injection mould GP technique?

A

Overfilling
Incompletely filling

122
Q

List 7 properties of root canal sealer

A

Provide a seal by good adhesion to the canal wall
Flow into irregularities
Lubricate glide path of GP
Bacteriostatic
Encourage hard tissue repair
Set slowly - allows longer working time for adequate GP compaction and
Flow during setting to counteract shrinkage forces

123
Q

Give 2 examples of sealers

A

Resin based eg - AH Plus
Zinc Oxide/Eugenol based eg - Tubliseal

124
Q

Describe AH Plus

A

Long working time
Easy to remove with solvent
Irritant until set

125
Q

Describe Tubliseal

A

Extended working time
Eugenol is antimicrobial
Doesn’t shrink
Soluble in tissue fluid
When used with GP a chemical bond forms between zinc in the oxide in the GP point - increasing the stability

126
Q

List 6 factors which reduce the success of RCT

A

Re-RCT
Complex root morphology - sclerosed canals, curved roots, furcation
Tooth mobility
Inexperienced clinician
Existing parafunctional habits
Poor OH maintenance

127
Q

What is the radiographic follow up criteria for endo (ESE)?

A

1 year post tx as a minimum

128
Q

Describe a favourable outcome for endo

A

Absence of pain, swelling and sinus with no loss of function
Radiographic evidence of normal PDL around root
No further follow up

129
Q

Describe an uncertain outcome for endo

A

Radiographic evidence of lesion that has remained the same or only diminished in size but is still present
Yearly radiographs for 4 years or until the lesion has revolved
Can become favourable or unfavourable

130
Q

Describe an unfavourable outcome for endo

A

Symptoms of pain and swelling
Radiographic evidence of lesion that has increased in size after 1 year or hasn’t completely healed after 4 years
Root resorption
Further tx is indicated

131
Q

What should the ideal post-op endo radiograph show?

A

GP should be 0-2mm from the apex
Good quality fill
Adequate taper
GP should reach the CEJ

132
Q

List 4 scenarios where surgical endo may be indicated

A

Clinical or radiographic evidence of apical pathology that can’t be accessed conventionally
Extruded apical material
Persistent pathology post RCT where re-RCT is not deemed appropriate
Perforation that can’t be accessed through the pulp chamber

133
Q

List 3 surgical endo procedures

A

Incision and drainage
Apicectomy
Root hemesection - removal of one root and the retention of the remainder of the tooth in multi-rooted teeth

134
Q

List 5 benefits of maintaining pulp vitality (vital pulp therapy)

A

Maintains tooth’s defence system
Maintains full proprioception function of the tooth
Enables continual development of tooth and de to-alveolar complex
Endo tx of necrotic pulp is challenging and not always successful
Mechanically weakened endodontically treated teeth are more prone to fracture

135
Q

When is an indirect pulp cap indicated?

A

Dentine is lose due to caries, trauma or previous iatrogenic intervention
Cavity exists close to the pulp
Dentine still remains over the pulp tissue

136
Q

How is an indirect pulp cap carried out

A

Isolate with rubber dam
Complete cavity prep as appropriate - careful approaching pulp floor
Disinfect cavity with wet CW with NaOCl - 30s to 1m
Cover deepest part of cavity closest to pulp with a CSC or CaOH (CaOH needs to be sealed with GIC or RMGIC)
Definitively restore the tooth
Clinical review in 6 months and periapical in 1 year

137
Q

When is a direct pulp cap indicated?

A

When dentine is lost due to caries, trauma or previous iatrogenic intervention and the pulp tissue is exposed
Symptoms if present are mild and not indicative of irreversible pulpitis

138
Q

How is a direct pulp cap carried out?

A

Isolate with rubber dam
Disinfect tooth with CW soaked with NaOCl until bleeding is controlled
If bleeding not controlled, perform a partial pulpotomy
Cover exposed pulp with a CSC or CaOH (CaOH needs to be sealed with GIC or RMGIC)
Definitively restore tooth
Warn patient of possibility of further tx if symptoms occur
Clinical review in 6 months and periapical after 1 year

139
Q

When is a partial pulpotomy indicated?

A

When dentine is lost due to caries, trauma or previous iatrogenic intervention and a cavity exists where soft tissue of the pulp is exposed and bleeding
Exposed pulp appears inflamed/contaminated or it is not possible to get haemostasis - may be symptomatic

140
Q

How is a partial pulpotomy carried out?

A

Isolate with dam
Remove superficial coronal pulp tissue and irrigate with sterile saline
Control bleeding with CW soaked in NaOCl
If bleeding not controlled within 5 minutes, remove further pulp tissue
Place CSC or CaOH (CaOH needs sealed with GIC or RMGIC)
Definitively restore tooth
Clinically review in 6 months and periapical after 1 year

141
Q

When is a full pulpotomy indicated?

A

Dentine is lost due to caries, trauma or previous iatrogenic intervention and a cavity exists where the soft tissue of the pulp is exposed and bleeding
Exposed pulp appears inflamed/contaminated or it is not possible to get haemostasis at a superficial level - may be symptomatic

142
Q

How is a full pulpotomy carried out?

A

Isolate with dam
Completely remove coronal pulp tissue ro canal orifice level
Control bleeding with CW soaked in NaOCl
If bleeding not controlled within 5 minutes, further pulp tissue should be removed until haemostasis achieved or until confirmed that pulpectomy should be carried out
Place CSC or CaOH, seal with GIC or RMGIC and definitively restore tooth
Clinically review in 6 months and periapical in 1 year

143
Q

What are the clinical effects of a hypochlorite injury?

A

If allowed to settle on vital tissues will result in a chemical burn
If exposure short then a minimal inflammatory response will be evoked
If exposure is more prolonged and/or a higher concentration of solution, a more pronounced inflammatory response will occur which will lead to necrosis of the affected tissue

144
Q

What are common symptoms of a hypochlorite accident?

A

Pain - acute and sudden onset
Bleeding/haemorrhage - from the root canal
Swelling - can occur minutes to hours after the accident

145
Q

List 7 other rarer symptoms from a hypochlorite accident

A

Irrigant discharge from nose
Bruising of head and neck region near the tooth
Paraesthesia - esp if near neurovascular structures eg - mental foramen
Cellulitis - may close the ipsilateral eye
Trismus
Ophthalmologist symptoms - blurred vision, diplopia
Extremely rare - airway obstruction due to swelling

146
Q

How should hypochlorite accidents be managed?

A

Explain to the pt what’s happened and reassure
Immediately irrigate canal with saline
Dress the tooth with CaOH and a temp filling
Pain management - LA and analgesics
Swelling management - NSAIDs, consider ABs if tooth grossly infected (Amoxicillin 250-500mg TTD)
Warn pt swelling may not peak until 5-7 days afterwards
Most cases resolve within 2 weeks - more complex can last 1-2 months

147
Q

How should you follow up a hypochlorite accident?

A

Make a telephone follow up call same day or that evening
Continue daily phone calls for first few days - then move to once or twice a week until happy things have resolved
Once settled, consider obturation of the tooth
Refer to OMFS should be considered if you are concerned

4 - misc (10 decks)

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