Dr. Seet's Endo workshop Flashcards
Why MTA on immature teeth?
Very alkaline and very biocompatible. Kills the bugs and keeps the tissues alive. Good for hard tissue formation (dentinal bridge) via coagulation necrosis.
Apexification. They used to do it with CaOH. However, CaOH tends to lose alkalinity over time hence needs to be replaced. The problem with this is patient compliance. Also, long term placement of CaOH increases susceptibilty to root fractures. MTA stays there for a long time. Normally can obturate after 24 hours. Also, MTA releases CaOH over the next 3 months after.
The other advantage is that the dentinal bridge formed with MTA tends to be harder than the one formed using CaOH.
When to use a rigid splint?
Generally a flexible splint. No one knows for sure as to the use of rigid splint.
However, refer to Taylor and Heithersay. With luxations, all flexible.
For root fractures and alveolar fractures, no agreement was found but a cap splint resulted in the worst result. The most useful was a Kevlar splint. If solely alveolar fracture, maybe a rigid splint. HOwever, if theres trauma to the teeth (luxations), a rigid splint is contraindicated.
Generally, splint up to 4 months would be ideal but it depends a lot on hygiene.
WHat are the uses of MTA on immature teeth?
1) Regenerative endodontics (i.e. apexogenesis). Basically instrument past the apex to get blood to flow into the apex. Eventually it clots and forms a scaffold for pluripotent cells (stem cells from the apical papilla). Hopefully, this repopulates the pulp and revascularisation. Hopefully, you get continued root development.
Triple antibiotic paste can be placed after the blood clot is formed.
However, most of the literature is based on case reports. Also, have a look at the regenrative enddodontics guidelines of the AAE.
2) Root fractures. MTA used as a plug at level of fracture.
3) Pulp capping. Forms a good dentinal bridge.
4) AFter Cvek pulpotomy. Layer over amputated pulp and restore over.
5) For perforations. Depends on the size and level of the amputation.
What is the concentration of chemicals used to bleach teeth?
35% hydrogen peroxide. Thiourea can scavenge free radicals released by hydrogen peroxide which can inccrease chances of invasive ccervical resorption.
Which file to use when watchhwinding doown a calcified canal?
Hedstroem files cut more efficiently. However, not designed to be twisted into the canal. Its designedd to cut with an up-down stroke. As the shape is cut into the metal, theyre a bit weaker.
However, use a K-file with a watchwinding motion, it will unwind if theres resistance. Hedstroems tend to snap. If a big file isnt working, go smaller, not larger.
What is the appropriate length of time to use medicaments.
Leddermix -> know the ingredients
Ledermix for trauma and if patient in severe pain. Otherwise dont use this. Other ocasion if theres a lesion thats become symptomatic. Rarely ever use 50/50. Good bcs Ledermix released very quickly (within 24 hours) and its beliveed that CaOH slows this down. Also, want to kill the bacteria with corticosteroidd at the same time. However, the high pH of CaOH tends to negate the effect of triamcinolone. Tetracycline is bacteriostatic. A lot of enddodontic bugs are resistant to tetracycline.
How does odontopaste compare to ledermix?
Doesnt cause staining in anterior teeth. However, not a lot of studies published on Odontopaste.
May be indicated for symptomatic anterior teeth.
In an avulsion, up to a month and then change to CaOH.
Why is it recommended that CaOH be ussed about 10 days post trauma?
Can induce inflammation and result in resorption.
What tissues to worry about in trauma tissues?
1)PDL
- keep in an appropriate medium
2)Pulp
Not too much of a worry in adult ffully formed teeth.
How long should an avulsed imature tooth be monitored prior to endo?
Monitor for as long as there arent any signs of infection. Dont start endo unless there are signs of infection. Unless the tooth discolours and patient not happy about this.
When is emdogain indicated?
Enamel matrix derivative.
For avulsed teeth: coat the root surface with emdogain hoping that this will preserve PDL cells. However, Andreason 2005 showed that it didnt really do anything.
With re-implantations of teeth, its suggested that topical Ab can be used to reduce the chances of resorption. What is the prognosis?
Its basically Minocycline.
Whats the TCA for invasive cervical resorption?
Tissues are normally periodontal in origin. TCA is supposed to get rid of this tissue. This tissue is very vascular and bleeds like crazy hence the TCA. Coagulation necrosis and haemostasis.
