revision of endodontic principles Flashcards
what is endodontology
it is concerned with the study form function and health of, injuries to and disease of the pulp and peri radicular region and their prevention and treatment and the principal disease being apical periodontitis caused by infection
what causes endodontic disease
microorganisms
host response
time
what is the difference in the apical region of the tooth than the coronal region
the apical region has less O2
nutrients from peri radicular tissues such as proteins and glycoproteins
lower bacterial count
the bacteria are less accessible to treatment measures
where is bacterial count higher in the tooth
in the coronal region
where does the bacteria get nutrients from in the apical region
from the peri radicular tissues such as proteins and glycoproteins
describe the bacteria in the coronal region
higher bacterial count
more accessible to treatment`tment
describe bacteria in the apical region
lower bacteria count
less accessible to treatment
more anaerobic bacteria
what do the bacteria feed off in the coronal region
nutrients from the oral cavity
what can be the nature of the root canal microflora
can be planktonic( free floating)
or bacterial biofilm
why is bacteria on a biofilm tricky to remove
as it is aggregated on a solid structure
complex community interactions
and it adheres to a wall
what can we use to help with diagnosis of endo treatment
SOCRATES
what else can we use for end treatment
special tests
radiographs
Cone bean CT
TTP- if it is TTP sign that the tooth is necrotic
what are the steps for isolation
1) Isolation
2) Access
3) Chemo mechanical prep
4) Irrigation
5) Temporisation
6) Obturation
what do we use for isolation
rubber dam! gold standard need to be used for medic legal purposes
what can happen if sodium hypochlorite touches soft tissues
can lead to soft tissue chemical burns, hemolysis, ulceration and necrosis o
what is important during chemo mechanical preperatoon
to try to achieve a smooth taper inside the canal to facilitate obturation and irrigation
why do we not mix Naclo and CHX
as it forms a precipitate called para chloralanine which blocks canals and is toxic and carcinogenic
which technique do we use to shape the canals
the double flare technique- flare the coronal third first and then the apical third and blend together
what is patency filing
using a size 10 file to clear any debris and aid irritant flow
what is recapitulation
checking that the master apical file still passes to the working length
what can be the issues with CBCT
higher dosage so needs to be justified
case by case basis
risk of false positives on PA pathology
what do we need to keep in mind when considering canals
they cross sectional area should be narrower as we go down the canal
should flow with the original shape
where should the apical foramen remain
in its original position
how can we manipulate the files
balance force- carries more risk
stem winding- more optimal
what are some errors caused by instrumentation
1) Dentine debris-removed by irrigation
2) Ledge-prevented by stem winding technique
3) Perforation-do not be aggressive with the files
Transportation
how do we prevent dentine debris
irrigation
how do we prevent ledges
by stem winding
how do we prevent perforation
do not be aggressive with files
how do we prevent transportation
do not force the files further than the apical constriction
what are the two types of automated instrumentation
rotary
reciprocation
what is rotary instrumentation
constant rotation in one direction
what is reciprocation
rotation in one direction and then rotation in the other direction
describe rotary files
made of nickel titanium used in crown down increased flexibility and resistance allowed them to bend often have press for rpm and torque eg pro taper gold
describe reciprocating files
used in crown down technique
made from NiTi
eg wave one
give an example of rotary interments
pro taper gold
give an example of reciprocating instruments
wave one
how can rotary files separate
by torsional failure and cyclic fatigue
what is torsional failure
occurs when the tip or any part of the instruments in locked in a canal while the shift continues to rotate
what is cyclic fatigue
as a file rotates in a curved canal it will undergo compressive and tensional stresses across the cross section eg like a paper clip back and forward and then it snaps
what is torque
a rotary force causing part of a structure to twist about the axis
how do we avoid cyclic fracture
altering the point of fatigue and never leave them in one place
how do we avoid this by using too much force
the motor has torque control and this means the file will simply stall
what are hand instruments made from
stainless steel
what are the automated files made from
ni-ti
and significantly more flexible
how do we manipulate files
balance force and stem winding
