ENDO Posttreatment Evaluation Flashcards
___ is a major cause of endodontic failure
- coronal leakage
- more endodontically treated teeth are lost because of restorative factors than because of failure of the root canal treatment itself
describe coronal leakage as a major cause of endodontic failure
- after RCT, the internal chambers of the tooth may become reinfected if coronal leakage occurs
- saliva contamination with bacteria and endotoxins can cause endodontic failure, a risk that increases with the duration of saliva exposure
do temporary restorations provide protection against occlusal forces?
- not complete protection
- when an immediate restoration is impossible, a bonded temporary restoration at the canal orifice can be used
why is it best to place permanent restorations as soon as possible after obturation?
to seal the internal aspect of the tooth from contamination
what is the course of action when the root canal space has been grossly recontaminated?
retreatment
T or F:
endodontically treated teeth become brittle
- false
- the moisture content of endodontically treated teeth is not reduced even after 10 years, so they do NOT become brittle
after endodontic treatment, why do teeth become weakened?
- loss of tooth structure
- loss of marginal ridges is a major contributor to reduced cuspal strength
what leads to a higher occurrence of fractures in endodontically treated teeth compared with vital teeth?
the loss of structural integrity with access preparation (rather than changes in dentin)
the most important part of the restored tooth is the ___
- tooth itself
- no combination of restorative materials can substitute for tooth structure
when a crown is needed, the axial walls of the crown engage the axial walls of the prepared tooth, forming the ___
- ferrule
- the ferrule is a band that encircles the external dimension of the residual tooth, similar to the metal bands around a barrel
- it is formed by the walls and margins of the crown
a longer ferrule increases ___
resistance to fracture
fracture resistance (to cervical tensile strength) increases significantly with increasing amount of ___
sound tooth structure
a ___ ferrule increases fracture resistance and resists lateral forces from posts and leverage from the crown in function
longer
crown preparations with ___mm coronal extension of dentin above the margin have double the fracture resistance compared with when the core terminates immediately above the margin
- 1mm
- the ferrule must encircle a vertical wall of sound tooth structure above the margin and must not terminate on restorative core material
insufficient remaining tooth structure to construct a ferrule should be evaluated for ___ or ___
crown lengthening surgery or orthodontic extrusion to gain access to additional root surface
what is the primary purpose of a post?
to retain a core in a tooth with extensive loss of coronal structure
the need for a post is dictated by ___
the amount of remaining coronal tooth structure
T or F:
posts reinforce the tooth
- false
- posts actually further weaken the tooth by additional removal of dentin and by creating stress that predisposes to root fracture
when placing a post in an endodontically treated tooth, at least ___mm of remaining gutta percha is recommended
5-7mm
what are 11 causes of endodontic failures?
- inadequate seal of the root canal system
- poor access cavity
- inadequate debridement
- missed canals
- vertical fractures
- procedure errors (perforation, ledging, loss of length)
- leaking temporary or permanent restoration
- periodontal involvement
- resorption
- compromised host factors (systemic conditions)
- misdiagnosis
in terms of long-term success and avoidance of endodontic failures, is coronal seal or apical seal more important?
coronal seal
historically, which endodontic step has been considered the most critical step and the cause of most treatment failures?
- obturation
- however, the two events are associated by not by cause and effect because poorly obturated canals are usually poorly debrided as well
what 4 main factors influence success rate of endodontics?
- apical pathosis
- bacterial status of the canal
- quality of endodontic work
- quality of coronal seal
how does apical pathosis affect endodontic success rate?
the presence of an apical lesion before treatment reduces the success rate of endodontic treatment by 10-20%
how does the bacterial status of the canal affect endodontic success rate?
the presence of bacteria in the canal before obturation results in a poorer prognosis
what are the 7 principles of successful endodontics?
- microbial disinfection
- debridement - key to success
- obturation
- diagnosis
- treatment plan
- knowledge of anatomy and morphology
- restoration
* factors 1-3 represent the traditional endodontic triad*
