Obturation Flashcards
What is the purpose of obturation?
- Prevent micro organisms from entering and re-infecting the canal
- To prevent tissue fluid from percolating back into the root canal system and provide a culture medium for any residual bacteria
- Prevent anchoresis
What are the requirements before obturating a canal?
Dry canal
Abscence of pain of symptoms
Signs of resolution of infection
Abscence of signs of residual infection
What is the purpose of obturation?
3D hermetic seal to the entire root canal system in order to prevent micro leakage
Apical and coronal seal
What is anachoresis ?
Tissue fluid denaturing and becoming antigenic
the localisation of microbes from the blood stream in a damaged pulp
What materials are used for obturation?
Silver point
Cement
Pastes
Gutta percha
What are the issues with silver points?
Single point dependant sealer and corrosion
What is GP?
It is a trans isomer of rubber and produced from the latex tropical trees,
What taper do the new GP points have?
0.04 and 0.06 taper
To match the new taper files and should be used for the thermoplasticed technqiue and
not single point
When do we use root canal sealer? And what is the purpose?
With all systems Cements core arterial to the canal Helps fill voids Acts as as lubricant Acts and a bacterial agent Thermal insulator on placement of GP
What are the features of a good canal sealer?
- Non irritant
- hermetic seal ability
- insoluble to tissue fluid
- radiopaqye
- bacteriostatic
- non staining to dentine
- sticky and good adhesion to canal when set
- easily mixed
- good working time
- easily removed
What are the groups of sealers we use?
Zinc OxidenEugenol sealer: tubliseal Non eugenol group : CaOH Resin sealer: AH26 Mediated group: endomethasone GIC sealers
What are the obturation techniques ?
- Lateral condensation (warm and cold)
- single cone and sealer with thermomechcanical compaction
- Coated carriers
- Vertical condensation
- injection thermoplasticisdd
- hybrid technique
- chlorowrcha
What are the errors in obturation?
Inaccurate placement of master point Lack of snug fit of master point at apex Use of incorrect spreader and points Extrusion of filler or sealer through apex Use of excessive heat Use of expxcessive condensation pressure Inadequate coronal seal
How do you do cold lateral condensation?
- Select master GP
- Remove master GP and place sealer
- Select spreader A and mark it so that it does not pass more than 2mm short of master GP
- Apply firm pressure and leave for 5-10seonds and then rotate and place a point which should be marked 2mm short of GP.
- Coat only the tip of the accessory points
- When you start getting to the wider part of the canal use B points.
How can sealer be placed into the canal?
Using a k file which is at master apical file size
Use a spiral filler but need to use on slow rotation and careful not to wedge canal
What must be done to excess sealer?
Removed with paper point
What is the disadvantage of cold lateral?
Voids in condensation
Reliant on sealer
Voids not identified in clinical radiographic view often
T/F you can get GP points to match the different system?
T
How Does the thermomechsnically plasticed method work?
Frictional heat from the compactor plastices GP and then the blades drive the softened material down the canal
When is the thermomechsnically technqiue good for?
Internal resorption
In which part of the canal can the thermomechsnically compacted technique be used in?
Straight part only
What instrument is used to condense in the thermomechanical technique?
Maillefer Gutta condenser
What are the problems with the thermomechsnical compaction technique?
Lack of control of heated GP
Heat generation
Contraction of the GP on cooling
What is an example of the hybrid technqiue?
Tagger
How does the tagger technique work?
- Select the largest maillefer Gutta condenser that will fit to length in the straight part of the canal and must be 3mm from terminus
- Select the master GP
- Laterally condense a minimum of three accessory points and use the Gutta condensers in the straight part of the canal
When are coated carriers used?
Well flared canals
T/F coated carriers offer a quick obturation method?
T
What is the advantage and disadvantage to the coated carrier?
Dis: Challenging to remove for post or re treat, the size verifstion only matched to the 4% rotary GT files and not any other system, difficult to seat to full length, stripping of the GP, extrusion, canal shaping is critical, low viscosity medium condensation, a lot of heat can be generated with the thermacut bur.
AD:quick, good in curved canals, the plastic carrier is matched in apical size and all tapers
What is The process to thermafil coated carriers?
- Dry canal with paper point
- Match the thermafil to the file that reaches the correct length
- Place into thermaprel oven to heat
- Mean while mix and apply sealer in canal
- Insert carrier into the canal using firm seated pressure and maintain pressure for one minute at apex
- Confirm position radiographically
- Sparare the plastic carrier using thermacut but without water
What type of oven is the thermaprep oven?
Fast halogen
What is an example of the vertical condensation?
System B
How does the system B work?
- System B plugger selected which is the largest plugger that binds 5-7mm from apex
- Place master apical point
- Down pack to within 1mm of binding point by using continuous wave condensation
- Maintain apical pressure without heat
- Separation burst
- Condense with plugger
What is an example of an injection technique?
Thermoplasticed GP Obtura
How does the Obtura system work?
Injection delivery system
GP heated to 160 degrees in gun and delivered at a temp of 65
What is the Viscosity and flow rate of the Obtura affected by?
The temperature
What has been shown to enhance the seal of Obtura system?
The sealer
What other instruments can be used in the injection systems?
Machtou hear carrier
Machtou plugger
What are the disadvantage of the injection moulded thermo technqiue?
Lack of control of heated GP
Heat generated
Contradtion of GP on cooling
What is an example of the resin systems and how does it work?
Epiphany
Soft resin obturation system
It has a resin material that lookis and handles like GP and can be used with any conventions technique
It is a dual cure resin sealer with dentine primer
What are the advantages of the resin system?
It has been shown that there is increased resistance to root fracture
What is an example of the ZnO eugenol sealer? And what are the properties?
Tubliseal
Contents: majority ZnO
Most popular and gives satisfactory clinical results
BUT: forms weak porous material when set, decomposes in tissue fluid and is cytotoxic,
Good: good seal since small volumetric change on setting and extended working time variants eugenol is a solvent to GP and this increases it’s bond the the sealer, anti microbial,
What are the advantage of CaOH?
Developed on the assumption that stimulate healing and hard tissue formation and foremen
They have a sealing ability similar to that have ZnO eugenol group
Possible they Ca may leach out overtime and weaken the cement
What are the advantages of resin sealers?
They have good sealing and adhesive properties and antibacterial but they have an initial inflam response and also setting shrinkage
What are the advantage of Glas ionomer cements?
Adhere to dentine wall
Initial inflam response which then subsided
Not sure how good it is at sealing and short working time
