• Complete removal of a deep carious lesion could result in pulpal exposure
• An indirect pulp cap or stepwise excavation technique could be used to maintain pulpal vitality
• There must be no clinical or radiographic evidence of pulpal pathology for either technique to be considered

Stepwise Excavation:

Caries removal staged over 2 visits which are 6-12 months apart. This technique results in less pulpal exposure than single visit caries removal

Indirect Pulp Cap:

• Remove peripheral dentine and infected dentine (reducing bacterial numbers) but leave the stained dentine overlying pulp (affected dentine with no/little bacterial ingress)
• Apply hard setting CaOH – inducing tertiary dentine formation. Place RMGIC over the CaOH ,sealer followed by the restorations
• However, it is difficult to know how much tertiary dentine has been laid down and when to stop excavating carious dentine

Direct Pulp Cap:

• This is when a dressing placed directly on exposed pulpal tissue – attempting to preserve vitality of pulp
• Pulp exposure either due to caries/trauma
• Studies indicate direct pulp cap has better long term prognosis when placed after trauma compared to caries.
• Success rate of 81.5% (Fuks, 2008)

For a direct pulp cap to be effective, following criteria must be met:

• Pin point exposure
• Exposure < 1 hour old
• Can be either open or closed apex

HISTORY	PRE-OPERATIVE ASSESSMENT	CLINICAL FINDINGS
No recurring or spontaneous pain	Normal vitality test	Bleed on touch but not excessively
No swelling	Pink pulp
	Not TTP No periradicular radiolucency. Young Patient Radiographically obvious pulp chamber and root canal
	No periradicular radiolucency
	Radiographically obvious pulp chamber and root canal

Partial Pulpotomy:

• This involves removing part of the pulp immediately close to the exposure.
• Indicated for a tooth with incompletely formed apices or a fracture involving the pulp. (Used to maintain vitality and continue root development)
• Cvek reports 96% success rate when in response to trauma and (Fuks, 1982) reports a 92% success rate

For a partial (Cvek) pulpotomy to be effective, following criteria must be met:

• Size of exposure = 0.5-4.0mm
• Exposure 1-2, 160 hours
• Can be either open or closed apex

Partial (Cvek) Pulpotomy Technique:

1. LA
2. Place rubber dam
3. Remove coronal portion of pulp (1-2mm) adjacent to exposure
4. Achieve haemostasis- use saline soaked cotton pledget
5. Apply non hard setting CaOH (or MTA) then setting
6. Interim layer of Glass Ionomer
7. Restore with composite
8. Review regularly

Full Coronal Pulpotomy:

Indicated for exposures that are larger than pinpoint

• Removal of entire coronal pulp
• Flood the chamber with CaOH and interim dressing
• Restore tooth with composite

The correct diagnosis is necessary before undertaking any endodontic procedure

• It is impossible to ascertain histological status of the pulp from signs, symptoms or clinical tests
• The most important feature of the dental history relate to the commencement, duration and intensity of the pain
• The clinician must piece together the information provided by the patient and special test to provide a diagnosis

SIGNS AND SYMPTOMS	IRREVERSIBLE PULPITIS	REVERSIBLE PULPITIS
Response to hot/cold	Cold & Hot (mostly hot)	Cold
Character of pain	Lingering	Sharp shooting pain
Previous history of pain	YES	NO
Spontaneous	YES	NO
Intensity	Severe	Mild
TTP	Sometimes	Rarely

Intra-oral examination

Note particularly:     

• Oral Hygiene
• Quality and Quantity of restorations
• Caries
• Missing & unopposed teeth
• Perio-Status (general & local)
• Swellings
• Sinus Tracts
• Discoloured teeth
• Tooth Wear & Facets (characteristics)

Pulp Sensibility Tests

Electronic Test:

• Pulp testers stimulate nerve tissue, no correlation between nerve tissue existence and blood flow
• Patients pain threshold varies – always test adjacent teeth for comparison
• Actual reading is irrelevant however comparison to adjacent teeth is important in checking for pulp involvement

Method:

• Must NOT be used in patient with cardiac pacemakers
• Dry teeth and place conducting medium on tooth (prophypaste)
• Place tip of instrument onto the paste of the tooth
• Instruct the patient to hold the metallic part of the apex locator and advise to let go when tingling sensation felt
• Operator presses black button and records number shown when patient lets go (Repeat process on adjacent teeth)

Thermal Test:

• Cold is more useful and safer as uses constant temperature (ethyl chloride/Endo-Frost)
• Hot is good when the tooth doesn’t respond to cold, and you cant identify the tooth (Heated GP)

Percussion Test:

• Most reliable indication of significant peri-apical inflammation is that of tenderness to percussion
• Finger pressure applied to the tooth in question

Selective Analgesia:

• Useful at isolating affected areas (e.g upper/lower) rather than isolated teeth

Transillumination:

• Can be useful for diagnosing vertical crown fracture

Reasons for inaccuracies in pulp tests:

False Positives:

• Multi-rooted tooth with vital and non-vital canals
• Response from an adjacent tooth
• Apprehensive patient
• Pus with canal system

False Negatives:

• Recent Trauma
• Incompletely formed root apex
• Secondary Dentine
• Canal Sclerosis
• Neural Supply damage, blood supply intact
• Insulation of the pulp by large composites/non conducting restorations

Radiographic Assessment

• High quality periapical radiograph, taken with a film holder using long-cone paralleling technique is mandatory prior to endodontic treatment
• Radiograph should show the entire length of root & at least 2mm of periapical bone
• If lesion margins aren’t entirely visible on radiograph- then additional radiographs will be required

1. When examining a radiograph prior to treatment – note:

2. Number, length and shape of root

3. Any existing root filling

4. Amount of periodontal bone support

5. Shape, size and location of pulp chamber

6. Visibility of the canals on the radiograph

7. Presence of canal curvatures

8. Location and extent of any restorations

9. Presence of any caries

10. Secondary dentine formation

11. Pulp stones

12. Sclerosed canals

13. Presence/absence of lamina Dura around the root, noting the width of periodontal ligament space

14. Presence, size and location of periapical/lateral/furcal radiolucencies

15. Completed root development

16. External resorption

17. Internal resorption

18. Fractures

19. Adjacent anatomy

20. In crowned teeth, angle of crown to tooth

If you cannot get a rubber dam on a tooth and isolate it then endodontic treatment is contraindicated

Cone–beamed computed tomography

• Cone–beamed computed tomography (CBCT) gives the operator a 3D image of tooth and surrounding structure,
• (CBCT) is not used routinely due to high radiation exposure

Rubber dam = Mandatory – Why?

• Protects the airway and gastro-intestinal tract from instruments, irrigating fluids and infected debris
• Reduces contamination of root canal system by salivary micro-organisms
• Improved operator visibility
• Protection and retraction of soft tissues
• Improves cross-infection control of salivary and blood-borne infections
• Dry field for placing uncontaminated restorative materials
• High volume aspiration facilitated
• Reduced chair time
• Improved patient comfort

For root canal treatment only the tooth treated is isolated. Adding a caulking material (oroseal) around margin of the dam can improve moisture isolation

Application Techniques

• Dam with clamp – Place the clamp on the dam and then place on the tooth, then free the wings to ensure seal
• Clamp then dam – essential to use floss ligature on both sides of the clamp in this situation as clamp can fracture and be aspirated
• Dam before clamp – stretch dam over tooth and apply clamp after

When a tooth is too broken down to support a clamp – build up using orthodontic band or split dam technique

Split dam technique:

• More common on anterior teeth
• Two meeting holes punched into rubber dam and stretched over adjacent teeth at each side and secured with wedgets – Caulking can be applied to margins providing isolation

Before starting any treatment, it is important to have an understanding of pulp chamber anatomy and root canal morphology

Krasner and Rankow Pulp Chamber Anatomy Laws:

• Law of Centrality: the pulp will always be in the centre of the tooth
• Law of the CEJ: the pulp will always be at the level of the CEJ
• Law of Concentricity: the walls of the pulp chamber will be concentric (share the same centre) to the outer wall of the tooth
• Law of Symmetry: a mesio-distal line across the tooth can be imagined
  • If a canal from a particular root is found on this line it is NOT likely there is another canal
  • If it is lingual to the line it is likely there will be another canal buccal to the line equidistance
  • This rule does NOT apply to maxillary molars

An access cavity should meet the following objectives:

1. Remove the entire roof of the pulp chamber so the pulp chamber can be fully debrided and floor examined to locate canals
2. Facilitate root canal shaping by providing STRAIGHT LINE ACCESS to apical third of root canals
3. Enable temporary seal to be placed securely
4. Conserve as much tooth tissue as possible whilst meeting previous objectives

Straight Line Access:

• Having straight line access is extremely important
• Undue bending of instruments renders them more likely to fracture or distort and makes access to some parts of the pulp space problematic
• Forcing instrument around a curve makes perforation more likely
• Instrument freedom of movement permits effective cleaning

Resistance Form:

• Too much tooth tissue loss compromises strength and integrity of an already weakened tooth
• If tooth already has a large cavity and cusps still have opposing contacts = high risk of fracture.
  • Treat with crown to overcome the fracture risk
• However don’t compromise an optimum RCT for over-preservation of tooth tissue

Removal Of Infected Dentine:

• Ensure leaky restorations and caries are removed
• Allows evaluation of remaining coronal tooth tissue
• Allows complete visualisation especially if fracture/crack is detected

Technique:

Initial access is made in enamel with a fast hand piece, then switched to a slow hand piece to penetrate the pulp chamber

• Don’t use rotary instruments on floor of chamber to preserve landmarks for canal identification
• Open up cavity to allow smooth walled access to cornua (pulp horns)
• Extend cavity margins to allow file handles to lie against a reference point if required
• If prosthetic crown is placed check angulation against root as may not be aligned as expected (may need to remove crown)
• Refine cavity to create pulpally converging walls on at least 2 opposing surfaces.
• Clear pulp chamber of all hard and soft debris with irrigation with NaOCL

Root Canal Anatomy:

Upper Central Incisor

• Single canal
• Conical tapering root
• Triangular cross-section coronally and rounder apically
• Average length= 22.5mm

Upper Lateral Incisor

• Single canal
• Conical root: distal curvature apically
• Oval cross-section coronally and rounder apically
• Average length= 22mm

Upper Canines

• Single canal
• Apex can curve anywhere in the apical 2-3mm
• Ovoid cross-section
• Average length= 26.5mm

Upper First Premolar

• Commonly have 2 roots/ 2 canals
• 6% have 3 roots/ 3 canals
• Apical portion tapers rapidly ending narrow
• Frequently have a distal curvature
• Average length= 20.6mm

Upper Second Premolar

• Single canal or 2 canals (may be separate or unite)- Vertucci
• Frequently have apical curvature
• Average length= 21.5mm

Upper First Molar

• 3 roots (MB, DB & Palatal)
• Palatal= Longest root often curving buccally
• Disto-buccal = conical root with single canal
• Mesio-buccal = curves distal, 93% have 2 canals (MB1, MB2)
• Average length= 20.8mm

Upper Second Molar

• 3 roots (MB, DB & Palatal)
• Roots shorter
• Roots closer together with less curvature than upper first molars
• Average length= 20mm

Lower Central & Lateral Incisor

• Single canal mostly – 2 canals 41% of the time
• Apical Curves common
• Average length= 20.7mm

Lower Canines

• Usually single rooted (may have 2)
• Ovoid cross-section
• Average length 25.6mm

Lower First Premolar

• 74% have single canals, the rest have 2 canals
• round cross-section in single root teeth & ovoid in 2 canal teeth
• Average length= 21.6mm

Lower Second Premolar

• 97.5% have single canals
• Average length= 21.6mm

Lower First Molar

• Usually have 2 roots –rarely 3
• Mesial root= often curved with two canals MB & ML (MB has greater curvature)
• Distal root= is larger and usually have a single canal but 1/3 have 2 canals
• Average length= 21mm

Lower Second Molar

• 2 roots
• Mesial root has 2 canals- MB & ML
• Distal root has 1 canal
• Average length= 19.8mm

Cleaning and shaping does not remove all micro-organisms. One study showed 53% of the canal will not be reached by mechanical instrumentation alone. Therefore irrigants play a crucial role in destroying micro-organisms, neutralising endotoxins and removing organic tissue

Objectives of cleaning & shaping

• To create a continuously tapering preparation
• Maintain original anatomy
• Retain position of apical foramen
• Keep foramen as small as possible
• Mechanical debridement allows sufficient space for irrigation
• Irrigants do not flow past 1-2mm past the tip of syringe. A conventional 30 gauge needle corresponds to an ISO 30 file and therefore an apical preparation smaller than this may result in inadequate irrigation

Common techniques for mechanical instrumentation:

Stepback Technique:

Devised to overcome a curved root canal. The apical region is first enlarged to a final master apical file 25/30. Then using increasingly larger files at 1mm less depth (per file) the taper is formed. Between each instrument irrigation should take place and re-capitulation (insertion of master apical file) between each size increase

A disadvantage of this technique is apical extrusion of debris which can lead to post operative pain

Crown Down Technique:

Technique involves cleaning coronal part first and working down towards the apex. Advantages include:

• Removing debris and microbes coronally first preventing spread to apical tissues
• Removing coronal interferences, which may affect apical regions
• Larger volumes of irrigants can be held in canal facilitating debris removal and disinfection
• Eliminating canal curvatures early on helps to gauge an accurate working length
• Reducing contact of instruments with root walls minimising instrument separation and deviation

Instruments

Hand Instruments:

• Hand instruments are grouped according to ISO classification (International Organisation of Standardisation)
• Standardised by colour coding and properties
• The instruments have a constant taper of 0.02mm per mm (standard taper)
• The different sizes of the instrument relate to the diameter of the tip

Barbed Broach

Barbed broach

• Mainly used in wide canals – need to be freely moving to engage tissue with less risk of fracture
• Instrument is made of soft steel wire

Reamers

Reamer

• They are used with a half twist and pull motion
• This results in ‘shaving’ of the canal wall

Files – Files are the mainstay of endodontic hand instruments and most are made from stainless steel

K-Files

K-Files

• Twisting triangular/square cross-sectional blank
• Tight spiral series is created working by either reaming or push/pull action

K-flex file

• Rhomboid cross-section with alternating sharp and non-cutting edges
• The high and low flute configuration improved flexibility and provides a reservoir for debris

Flexofile

• More flexible than K-file

Haedstrom

Headstrom

• Appearance of a Christmas tree,
• The file is very sharp but prone to fracture
• Only use a push-pull motion and not rotated

Nickel-Titanium (NiTi)

• Advantages= super elasticity and memory
• Results in greater elastic flexibility and resistance to torsional force

Greater Taper hand files (need a picture here)

• Set of 4 NiTi handfiles with varying taper (0.12 – 0.06) all have a tip size of (ISO 20)
• Allow for creation of predetermined funnel with use of fewer files
• They are used in clockwise and anticlockwise rotations, moving progressively closer to the apex, without the need for stepback

Filing Techniques

Watchwinding & Circumferential filing:

• Continuous back and forth rotation with slight apical pressure
• Each slight turn engages the flutes of the file in the canal wall and removes dentine
• Only fine files used to the apex as danger of compacting pulpal debris ahead of the file
• Once file reaches desired length push/pull action used, moving circumferentially along canal walls on the outstroke, to minimise debris impaction

Increased risk of strip perforation of inner wall when circumferential filing

Balanced Force Technique:

• Popular technique in curved canal
• Technique requires flexible files with non-cutting tips
• File inserted into canal until slight resistance felt then rotate 60 degrees clockwise (cuts dentine), Then 360 degrees anticlockwise to pick up dentine in flutes prior to next cycle

File may fracture if over-rotated or excessive force used

Rotary Instruments

• Low speed motor (150-350rpm) and low torque
• Many also have auto-reverse feature and variable speed/torque settings.
• All files are NiTi used with crowndown technique and copious irrigation and lubricant
• Used as adjunct to hand files – still need hand files to recapitulate and create a glide path
• clean instruments and do not overuse

Design features of rotary files:

• Variable taper – reduces need to use as many files
• Flute design – determines cutting efficiency and debris removal
• Non-cutting tips – Helps reduce risks of apical transportation
• Radial lands – minimise instrument fracture

ProTaper File:

• Rotary shaping files aim to widen access in the coronal two-thirds of the canal then finish the apical- third
• Shaping file X (SX)= instrument used primarily to extend canal orifices and widen access
• Shaping file (S1, S2)= primarily to open and expand the coronal and middle thirds of the canal
• Finishing file (F1,F2,F3,F4,F5)= expand and finish the apical third of progressively larger canals
  • F1= 0.20mm
  • F2= 0.25mm
  • F3= 0.30mm

Technique:

• Light apical pressure removed every 5-10 seconds. As files cannot be precurved, require straight-line access which can be achieved with GG burs or orifice shapers
• Once coronal prep is complete, canal should be explored to full working length and opened apically with size 15 and 20 files BEFORE using rotary instruments

Endosonics

• Similar to periodontal treatment, the devices can be either piezoelectric or magnetostrictive.
• Some come with irrigation reservoir delivering NaOCL
• Specifically designed ones can be used to locate canals. Removing calcified tissue can free obstructed canals

Lubricant Containing EDTA

Essential on both hand and rotary files. This chelates and softens the dentine reducing friction of the instrument against canal walls

Determining Working Length

Radiographs are the mainstay of working length determination, but electronic apex locators have gained popularity

FGDP Selection criteria for Radiography states ‘unless there is confidence about working length derived from electronic apex locator, at least one good quality radiograph is required to confirm working length

Radiographs:

Root canal instrumented up to the apical constriction (0.5-1mm) from apical foramen

• Take peri-apicals using long-cone paralleling technique
• Use at least size 20 files; If multiple canals are present use different sizes to be able to differentiate
• Can use additional check before obturating with a GP point in situ, ensuring canal is filled to the correct length (Master cone radiograph)

Apex Locators:

• Electronic apex locators assume impedance between the periodontal membrane and oral mucosa is constant at 6.5k(Ohm’s)
• Modern devices measure voltage gradients and are divided into absolute and gradient impedence devices
• Newer devices are now more accurate in presence of irrigating fluids
• Faulty readings can be given in teeth with open or large apices, perforations or if file touches metallic restoration
• Must not be used in patients with cardiac pacemakers

Technique

• File inserted into canal and progressed apically with second electrode placed in patient’s oral mucosa (lip clip)
• Digital/Audible display shows where the instrument tip reaches the apical foramen

Irrigation

Mechanical instrumentation facilitates adequate irrigation. One study showed 53% of the canal will not be reached by mechanical instrumentation alone

Main functions of irrigation are:

• Remove debris, which could block canals or be extruded into peri-apical tissues
• To assist in lubricating the canal
• Dissolves organic material
• Softening and removing the smear layer
• Penetrating area inaccessible to mechanical instrumentation to maximise cleaning. (Accessory canals)

Sodium Hypochlorite

• Most commonly used is irrigant is NaOCL, in water ionizes producing Na+ and OCL-
• Used in concentrations of 0.5%-5.25%
• It is a potent anti-microbial agent, and effectively dissolves pulpal remnants and organic components of dentine.
• Used both as unbuffered solution (pH11, conc 0.5-5.25%) and buffered with bicarbonate buffer (ph9, conc 0.5%) – Dakin’s solution

Though increasing the concentration = greater antimicrobial ability it also leads to greater viscosity deeming it less able to flow into small canals and also increases its TOXICITY

Has the following properties:

• Strong antibacterial activity killing at low concentrations – (effective against gram negative, gram positive, fungi and spores)
• Dissolves pulpal remnants by oxidation
• Cytotoxic to surrounding tissues

If NaOCL is extruded into peri-apical tissues (hypochlorite accident) then severe inflammation and necrosis can occur. Therefore NaOCL must be handled with great care:

• Must use a side-vented needle
• Must be freely moving in the canal
• For effective irrigation FREQUENCY > CONCENTRATION

EDTA

• Commonly used as an adjunct to NaOCL as it has a chelating effect to remove smear layer allowing NaOCL to work more effectively
• Has virtually no antibacterial activity
• Don’t leave in the canal for prolonged periods as leads to decalcification

Chlorhexidine

• Chlorhexidine (CHX) has antimicrobial properties and low toxicity
• Its activity is pH dependant and is greatly reduced in the presence of organic matter
• It’s effective against gram-negative, gram-positive and yeasts
• Mycobacteria and spores are resistant
• It does not dissolve organic tissue and effect on microbial biofilms is less than hypochlorite therefore NaOCL is first choice
• However CHX has less cytotoxic effects to the surrounding tissues
• DO NOT mix CHX and hypochlorite– forms a precipitate which is carcinogenic

Intracanal medicaments are needed to suppress bacterial regrowth between appointments if it takes more than one visit. The aim to:

• Eliminate remaining bacteria
• Reduce inflammation
• Act as a barrier to entry of pathogens
• Dry ‘wet’ canals

Calcium Hydroxide:

• Calcium hydroxide is the gold standard for dressing root canals
• Between visits the canal system is dressed with non-setting calcium hydroxide (CaOH)
• High pH 12.5 therefore bactericidal
• Sodium hypochlorite and CaOH have a synergistic effect
• Apply with a spiral filler or size 10 K file
• The long term use of CaOH is not indicated (no more than 4-6 weeks) as it reduces the fracture resistance of dentine

Vitapex:

• Calcium hydroxide and lodoform paste (Disinfectant)
• For deep-seated infections in the root canal eg. Abscesses and cysts

Steroid Containing Paste:

• Ledermix is a steroid containing paste of (triamcinolone acetonide and tetracycline)
• Useful in irreversibly inflamed teeth (‘hot’) but extirpation and LA should still be provided
• Tetracycline during pregnancy is not recommended
• Odontopaste is an alternative to ledermix and is a zinc-oxide-based paste effective in helping reduce bacterial contamination and post-operative pain

Root Filling Material

Ideal properties:

• Easily introduced into the canal
• Seal the canal laterally and apically
• Not shrink after insertion
• Impervious to moisture
• Bacteriostatic/ not encouraging bacterial growth
• Radiopaque
• Not stain tooth structure
• Not irritate periapical tissue
• Sterile, or easily sterilized before insertion
• Easily removed from root canal if necessary

Core Materials

Gutta Percha:

• Derived from Sapotaceae tree. Crystalline gutta-percha (GP) may occur in α or β phase
• GP points consists of 20% GP & 80% ZnO
• Dye and metal salts are added for colour and radiographic contrast
• Can come in ISO standard taper 0.04 and 0.06 taper (corresponding to rotary NiTi files)

Silver Points:

• Single silver points with sealer used to obturate the canals
• High failure rate due to materials inability to seal the canal and corrosion of the point, causing toxic release of products from metal initiating or supporting inflammatory reactions

Resin Based Core Materials:

• “Resilon” = polyester core with bioactive glass, bismuth and barium salts as fillers.
• Used as cones for lateral condensation technique, or pellets for thermoplastic, vertical condensation technique
• Similar properties to GP
• main advantageof thermoplastic resin as core material will be the extent to which it will bond to the sealer used

Sealers

Sealers are responsible for principle function of root fillings: sealing off the root canal systems, entombing residual bacteria and filling irregularities in prepped canal

Zinc-Oxide Eugenol:

Have some antibacterial activity, however may show toxicity when placed directly on vital tissues E.g. Grossmans sealer or Tubli-seal

Properties of Zinc Oxide Eugenol:

• Extended working time
• Shrinkage on setting
• Soluble in tissue fluid
• Chemical bond form with Zinc-oxide in GP
• May negatively affect bonding of core material
• Can stain tooth structure
• Radio-opaque

Glass Ionomer:

• Rarely used now due to disintegration and leakage and difficult to remove

Resin Bonded:

• Long working time and easy to remove with solvents but irritating until set
• Used with resilon core aiming to produce a ‘mono-block’ of homogenized filling material
• Based on BisGMA or UDMA monomers e.g AH plus

Calcium Hydroxide:

• Biocompatible,
• Possibly osteoregenerative
• Worries over solubility e.g. Sealapex

Silicone based:

• E.g.Roekoseal

Obturating Techniques

Obturation aims to maintain the condition of microbial free / reduced canals by:

• Entombing residual microbes in the canal post-clean and shape and preventing nutrient supply to these bacteria
• Preventing entry and/or killing of any microorganisms entering root canal systems

Single cone and paste methods are now obsolete due to high failure rates

Cold Lateral Condensation:

• This method is commonly used
• Master cone should be checked to see it fits to FWL with ‘tug back’
• Master cone is then coated in sealer and placed to working length with a measure spreader used to compact it laterally
• Withdrawal of the spreader is with watch-winding motion to ensure that the master cone is not pulled free
• The next accessory cone is added to a reduced length and this is continued until spreader does not extend more than 2-3mm into the canal

For this method a CONTINUOUSLY TAPERING CANAL MUST BE PRESENT-Not suitable for canals with internal resorptive defects

Warm Vertical Compaction:

• This method uses heated pluggers to apply vertical pressure and compact GP into canals,
• It can either be a single wave or multiple wave procedure
• This produces a well condensed apical plug of material
• Remainder of canal is then filled with thermoplastic techniques, or pre-cut sections of GP which are heated and vertically compacted

CONTINUOSLY TAPERING CANAL MUST BE PRESENT WITH SMALL APICAL FORAMEN

Single Wave Technique

• procedure can be achieved with devices such as ‘System B‘

Multiple Wave Technique

• Multiple pluggers of various sizes heated with a Bunsen or electrically heated instruments
• When backfilling, increments of 4/5mm of GP are placed in the canal and packed down
• A popular thermoplastic device is ‘Obtura’ extruding GP heated to 200°c

The significance of the coronal seal has been increasingly recognised in dental literature and in more recent times, it has been suggested the most important factor leading to the failure of endodontic treatment

• Influx of microbiota following fracture, wearing down or loss of the coronal restoration leads to failure and perpetuation of periradicular disease
• Clinically once obturation is complete, Vitrebond is placed over canal openings preventing stagnation areas for saliva contamination and bacterial ingress post treatment
• Even if a temporary restoration is to be placed on top of this, the Vitrebond will seal the canal system if the temporary restoration leaks

Haapasalo M, Endal U, Zandi H, Coil J. Eradication of endodontic infection by instrumentation and irrigation solutions. Endodontic Topics 2005:10:77-102 https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1601-1546.2005.00135.x

Gulabivala K, Patel B, Evans G, Ng YL. Effects of mechanical and chemical procedures on root canal surfaces. Endodontic Topics 2005:10:103-122 http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.537.1354&rep=rep1&type=pdf

Whitworth J. Methods of filling root canals: principles and practices. Endodontic Topics 2005:12:2-24 https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1601-1546.2005.00198.x

Orstavik D. Materials used for root canal obturation: technical, biological and clinical testing. Endodontic Topics 2005:12:25-38 https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1601-1546.2005.00197.x