Policies, Access & Working Length. Flashcards
More points are lost in Lab to — than anything else
Most FAILURES on WREBs & ADEC are due to —
POOR ACCESS
POOR ACCESS
Access Procedure - Outline
- You may draw your outline
form on the tooth - Create outline form just
through enamel with number
2 round or 330 bur HS - At this point bur is
somewhat perpendicular to
lingual surface of tooth - Stay shallow at this point.
Just through enamel < 1mm.
Access Procedure - Penetration
* Penetrate pulp chamber roof
with bur angled approaching
parallel to long axis of root in
center of outline form.
- You should reach the pulp in
most cases by — mm. – if not,
call for instructor help.
7
Confirm Pulp canal entry with
endodontic explorer DG16:
PUSH
Un-roof Pulp Chamber with
brushing out-strokes. Take
care not to gouge axial walls.
* Remove obstructions & smooth
the walls
- Irrigate well (NaOCl)
(3)
– Vision
– Remove Debris
– Begin Disinfection
Access Procedure - Refining
* Refine access prep with
Safe
ended diamond bur or Endo–Z
bur to help provide straight-line
access to mid-root. ( Mostly in
molar access).
* The non-cutting tip is simply a
pilot.
After ACCESS, your
next big task is
Working Length
The correct WL is:
1.0mm.
SHORT of the CANAL EXIT
If you DON’T get the WL
right; you will likely result
in a
POOR OUTCOME
How do you FIND the Canal Exit?
* In your HAND; Look at it
(3)
– Observe the canal exit
– Measure before you MOUNT tooth
– Measure before you MOUNT tooth
How do you FIND the Canal Exit?
* In the MOUTH; Start w/ Average Length
(3)
– Chart
– Apex Locator (if possible)
– Radiograph (with #15 file in canal)
APEX LOCATOR:
In use on a patient in the
Clinic
Apex Locator is not applicable in Lab
(No PDL in extracted teeth)
Place a #15 hand file in the
access and extend it in the
canal to the estimated canal
length
Take a radiograph and
adjust until you determine
the correct Working Length
Why do we use a #15 FILE to radiograph?
The GOAL for the WL is 1mm.short of the canal exit. This places the WL in close
proximity to the
natural Apical Constriction
WL
- Too SHORT:
The canal is NOT well CLEANED
WL
- Too LONG:
Even ¼ of a mm. long of the
constriction – we have created a
“BLOW-OUT” which guarantees
incomplete compaction at the apex
and an explosion of sealer in the
PA tissues.
About WL
* MUST HAVE a Reliable Reference Point
– Select a solid, reproducible location on the tooth
* Tip of incisal edge (anteriors)
* Tip of cusp for which the canal is named (molars)
– Don’t reduce it after WL is determined
– No need to reconfirm unless something
has changed.
Reliable Reference Point
when determined
write it down
Cleaning and Shaping:
– Access to the Pulp Chamber
FACILITATES:
(6)
– Locating the Canals
– Negotiating the Canals
– Gaining Patency
– Establishing Working Length
– Maintaining Apical Constriction
– A GOOD OUTCOME
***Proper — is arguably the single most
important requisite contributing to routine
endodontic success.
Access
skipped
Poor ACCESS yields PROBLEMS:
- You will NOT have a predictable result
- You will routinely miss canals
- You will NOT be able to clean properly
- You will NOT be able to shape completely
- You will NOT be able to fill adequately
- *** You will easily create problems and make your RCT far more difficult, dangerous and time-consuming than it needs to be.
Dr. Riley Mess-up
“Coke bottle” shape
Most simply defined, access involves drilling
a hole through coronal structure to gain
entrance into the pulp chamber.
* You are thinking: “Any fool can drill a hole
into the pulp” . . . But can they?
There is nothing so fool-proof that a
sufficiently talented fool cannot foul it up
