Materials In Relation To Endodontics Flashcards
Endodontic first principles
Diagnosis of failure- why did it fail
Restorability
Prevention of coronal fracture-if yes, hopeless prognosis
Microorganisms
Root canal filling materials
GP
Silver points-tend to corrode, SPAD- impossible to remove
Posts- metallic or non-metallic
Removal of GP
Termal- system B (heated wire that melts GP, risk of heat damage
Mechanical- Hedstorm, retreat files, ultrasonic
Chamical (solvents)- chloroform, halothane, eucalyptus oil, turpentine oils…
Can be difficult or easy. Does not cut cleanly so always need some sort of solvent to remove remnants. Or to soften it initially and then remove it mechanically.
Hedstroem files for removal of GP
Twisted files
Shape allows removal by back action
Two instruments are placed at the same time either side of the GP, then twisted and pulled coronally.
Good when a single point is in the canal
Retreat files for removal of GP
Made for this purpose
Non end cutting end
Very efficient in removal of GP
Used in sequence
Have back action and debris comes out coronally so no contamination apically
Ultrasonic instruments
Use on low power (30%of power) due to heat generation as reliable to fracture
Has cuting tip
Heat can soften the GP but also cause damage
Solvents as removal of GP
Chloroform - most effective and efficient, can be toxic. If spilled can melt rubber dam as well…
Halothane- less effective but also toxic…
Eucalyptus, turpentine oils-less potent, less toxic but less effective and efficient
Removal of thermafil
Metal or plastic points coated in GP
Cones are heated and inserted in canals.
Hard to remove
Removal of silver points
Difficult to remove as they are solid. Difficult to grasp and then to fracture due to corrosion
Removal of SPAD,
Very hard!
Difficult to see, access
Removal of posts
Depends if
metallic- usuall luted, so could be easier to remove. Can be removed with Eggler post remover. No LA before this as if painful- can be as beaks are not at the right place and holding the tooth that can lead to XLA. Good in the anterior region, due to its size-not so good in posterior teeth. Another example is Masserann Kit.
Ultrasonic can be used- vibrations are transmitted to the cement and post that will fracture and can be removed
non metallic- bonded into the root canal. Need to be cut out.
Tenax Kit is example- channel cut in the centre of post and then rest (fibres) can be removed- use microscope to distinguish cement from tooth and post.
Irrigation regimes in re RCT
Initial infection bacteria are different than in re infected endo tooth
More of gram positive aerobic and facultative anaerobic microorganisms. Examples- E. Faecalis; Candida Albicans
Those bacteria are organised into protective adhesive biofilms that need to be broken-down -chielating agent is used for that following by sodium hypochlorite for disinfecting.
Hypochlorite is only effective in high concentration against E. Faecalis.
Chlorhexidine is more effective against gram positive microorganisms such as E. Faecalis.-improved disinfection when combined with hypochlorite
But IMPORTANT not to use them together but rinse with sterile water after each or using paper points so they don’t react as could be carcinogenic.
Iodine potassium iodine- effective against E. Faecalis, can diffuse though dentinal tubules and kill bacteria; have short antimicrobial effect, it is antiviral. Some pt are allergic to iodine or seafood-so contraindicated
Other antimicrobial systems used in reRCT
Bacterial photo dynamic therapy -additional microbial effect. Have additional photo dynamic effect/light and photosensitizer that is taken up onto the cell membrane of bacteria/rapidly dividing cells and when light is switched on-oxygen is released and kills bacteria. No resistant strain against the light
Should be used as adjunct to conventional regime
Intervisit intracanal dressing materials
Non setting calcium hydroxide is first choice
E. Faecalis can survive this high pH produced by calcium hydroxide
Other materials:
Iodine potassium iodine-
Combination of above them…
