Endo obturation of cleaned and shaped RCS Flashcards
size matched cone/cold lateral compaction Tx sequence
Place GP in damp canal to corrected working length
- Should be some tug back – attempt to displace some desire for cone to stay in canal
Grab at reference point
- Remove and measure on ruler – should be at CWL
Now dry RCS
- Paper points
- R25
- End is firm and dry when RCS dried completely
Take already confirmed master cone
- Grasp at CWL
- Press on cone to make indent to ID
- Coat GP cone in sealant lightly
- Excess = risk of extrusion
- If doesn’t go to length may need to modify prep, too long – trim the cone so doesn’t extend beyond CWL
B spreader
- Rubber stop at CWL
- Insert alongside master cone
- Apical and lateral pressure to make space for accessory cone
- Rotation to free spreader – allow removal of spreader without displacing master cone
- Take accessory cone, lightly coated with sealant
- Place into space created by spreader
- Remember where placed spreader to assist placement of accessory cone
- Place into space created by spreader
- Super endo alpha
- Heated
- Sever the coronal mass of GP
- Place the tip
- Adjacent at orifice
- Activate and swipe across orifice
- Allow us to separate GP
- Whilst still hot take endo plugger and plug coronal aspect of GP lying in orifice
- Should have mass of condensed GP just below level of orifice
VItrebond and then coronal restoration
objective of RCT
to prvide an environment that allows healing of periradicular tissues so that the tooth is retained as a functional unit in the dental arch
theories of biologic basis of endodontic disease
“Triad” of preparation, disinfection, obturation
Historically, emphasis on obturation
- “Hollow tube” theory
- “Stagnation” theory
importance of obturation
- Study by Ingle et al (1965) indicated 58% of failures due to incomplete obturation
- This and other studies highlighted apical seal
- Driven development of materials and methods
suggesting healing reliably occurs in the presence of a defective obturation underestimates the important roles played by canal obturation in preserving the environment created by shaping and cleaning and preventing microbial reinfection of the canal space.
endo success =
periradicular regularity
not just about the white line
european society of endo steps on obturation
- Apical/lateral Seal
- Sealer/core Materials
- Timing of Obturation
- Length
- Assessment
- Coronal Seal
filling of RCS
Prevent the passage of microorganisms and fluid along the root canal and to fill the whole canal system
- Chemomechanical disinfection
Not only block the apical foramina but also the dentinal tubules and accessory canals
In some cases it might be recommended that prior to filling, the completion of root canal preparation is verified by taking a radiograph with the root canal instrument(s) (or filling cones) inserted to the full working length. The end-point of the inserted instrument (or cone) and the apex should be visible on this verification radiograph
working length
- Preparation should end at the junction of pulpal and periapical tissue
- WL should be as close as possible to CDJ
- This is usually the narrowest part of the canal – apical constriction
Determination
- electronic apex locators - Want 0/red
- radiographs
radiographically determined working length
Distance is from 0-3mm
- Varying constriction anatomy
- Increasing with age
Root resorption is a complicating factor
- If filled to apex then over-filled?
- Amongst others length was a prognostic determinant
- >2mm short of apex harboured bacteria
- If negotiated to length 74% success rate
what areas are important to be blocked in RCT
apical foramina but also the dentinal tubules and accessory canals
kill off microbes
when is filling done
Filling should be undertaken after the completion of root canal preparation and when the infection is considered to have been eliminated and the canal can be dried.
timing of obturation depends on (6)
- Signs
- Symptoms
- Pulp Status
- Periapical Status
- Difficulty
- Patient Management
materials used to fill RCS should be (7)
- biocompatible
- dimensionally stable
- able to seal
- unaffected by tissue fluids and insoluble
- non-supportive of bacterial growth
- radiopaque
- removable from the canal if retreatment needed.
filling of RCT shuld consist of
(semi-) solid material in combination with a root canal sealer to fill the voids between the (semi-) solid material and root canal wall
gutta percha
- Most common core material
- One of oldest dental material in use today
- Produced from juice of trees of the sapodilla family
- Natural rubber and gutta percha are polymers of same monomer - isoprene
- Trans isomer of polyisoprene
GP components
20% Gutta-percha
65% Zinc Oxide
10% Radiopacifiers
5% Plasticizers
GP obturation technique
build up of GP steadily
cold lateral compaction
Most commonly taught and practiced filling technique
- Regarded as the benchmark against which other obturation techniques are evaluated
- Low cost and ability to control the length of the fill
- Voids, spreader tracts, incomplete fusion of gutta-percha cones, and lack of surface adaptation
sized matched cones
- Sized-matched cones complement file size and shape
- Leave very little space for accessory cones (tight space)
- Is this a single point obturation technique?
thermal techniques - warm vertical compaction and continuous wave obtruraion
- Schilder introduced this as method to achieve three dimensional obturation
- Required a continuously tapering funnel and minimal apical diameter
Cone of GP in, sever, heat to GP and plug apically, pass on canal and sequentially repeat
Warmed GP flowed readily into the space (RHS) better obturation
warm GP =
effective fill
good for long curved canals not straight wide as lack apical curve
thermal techniuqes caution
apical control
mental nerve and deep facial nerve
what happens when conditions change
Not faced with funnel shaped prep with good apical diameter LHS – large open apex
biocermaic cements used
- Materials that can be used to fill spaces with large apical diameter
tissue response to obturation
MTA – is osteoinductive, cementum will start to grow along side to prevent damage
factors for endo materials sealing abilities (5)
- dye penetration
- isotope penetration
- salivary penetration
- bacterial penetration
- electromechanical technique
resilone
thought to be the next best thing in obturation
- Resin-based system
- Dentine bonding technology
- Thermoplastic synthetic polymer based on polymers of polyester containing bioactive glass and radiopaque fillers
- “Mono-block”
- 7 times greater chance of failure compared with teeth obdurated with GP
* removed from US mark 2014
sealers in RCT
root canal filling should consist of a (semi-) solid material in combination with a root canal sealer to fill the voids between the (semi-) solid material and root canal wall.
sealer functins (3)
- Seals space between dentinal wall and core
- Fills voids and irregularities in canal, lateral canals and between gutta-percha points used in lateral condensation
- Lubricates during obturation
properties of an ideal sealer (11)
- Exhibits tackiness to provide good adhesion
- Establishes a hermetic seal
- Radiopacity
- Easily mixed
- No shrinkage on setting
- Non-staining
- Bacteriostatic or does not encourage growth
- Slow set
- Insoluble in tissue fluids
- Tissue tolerant
- Soluble on retreatment
zinc oxide eugenol based sealers
- Zinc Oxide effective antimicrobial and may afford cytoprotection
- Resin acids affect lipids in cell membrane thus strongly antimicrobial/cytotoxic
- Although toxic, may overall be beneficial with longlasting antimicrobial effect combined with cytoprotective effects
- Free eugenol which remains can act as an irritant
- Lose volume with time due to dissolution – resins can modify this
glass ionomer sealants
- Advocated due to dentine bonding properties
- Minimal antimicrobial activity
- Greater solubility
- Removal upon retreatment is difficult
- Little clinical data to support use
resin sealers
Long history of use – development of AH26
- Epoxy Resin
- Paste-Paste mixing
- Slow setting - 8 hours
- Good sealing ability
- Good flow
- Initial toxicity declining after 24 hours
EndoRez (UDMA resin based sealer)
hydophillic
good penetration into tubules
biocompatible
good radio-opacity
calcium silicate sealers
- High pH (12.8) during the initial 24 hours of the setting
- Hydrophilic
- Enhanced biocompatibility
- Does not shrink on setting
- Non-resorbable
- Excellent sealing ability
- Quick set - three to four hours – requires moisture
- Easy to use
what sealers should never be used
containing aldehydes - toxic
how should the quality of the filling be checked
radiograph
radiograph should show the root apex with preferably at least 2–3 mm of the periapical region clearly identifiable.
- The prepared root canal should be filled completely unless space is needed for a post.
- The prepared and filled canal should contain the original canal.
- No space between canal filling and canal wall should be seen.
- There should be no canal space visible beyond the end-point of the root canal filling
assessment of obturations
Primarily based on post-op radiograph
- Length (2mm of radiographic apex)
- Taper
- Density
- Gutta-percha and sealer removal to facial CEJ in anteriors and canal orifice in posteriors
- Somewhat subjective
- Errors of obturation may be corrected early on before fully set
what is the best radiograph to use to assess if obturation success
Buccal lingual look good
Proximal more accurate at assessing obturation standard
how filled should RCT teeth be
should be adequately restored after root canal filling to prevent bacterial recontamination of the root canal system or fracture of the tooth.(vitrebond, GIC)
coronal seal Vs apical seal
“Technical quality of coronal restoration significantly more important for apical periodontal health than the technical quality of the root canal treatment”
Equally good for best outcome possible
orifice closure
- Finish obturation at orifice or just below orifice level
- Gutta percha rapidly becomes infected if exposed directly to oral bacteria
- ZnO/Eugenol materials are cytotoxic and form effective antibacterial barrier
- RM-GI or flowable composite
Develop a primary seal so even if provisional restoration does fail, able to develop an adequate seal even if restoration fails Best to place restoration as soon as practicable
regenerative endodontics
future
‘‘Biologically based procedures designed to replace damaged structures, including dentin and root structures, as well as cells of the pulp dentin complex’’ Recruit cells, differentiation and dentine formation Disinfectants to recruit stems from papilla into pulp space to start regeneration
5 factors for overall verdict on obturation
- Complete obturation contributes to success
- Assays not always reliable or relevant
- Outcome studies important but not uncomplicated
- Anecdotal evidence often has been adopted
- Classic materials have stood the test of time
