L1- Policies, Access, and Working Length Flashcards
what are the objectives of endo
- correctly diagnose diseases as LEO
- perform quality NS endodontic therapy
- restore and document healed outcome
what is the extreme service to the patient in endo (goal)
- relieve acute pain
- retain otherwise lost natural tooth
most failures on WREBS and ADEC are due to:
poor access
what is the access procedure for the outline
- create outline form just through enamel with number 2 round or 330 bur high speed
- the bur is somewhat perpendicular to lingual surface of tooth
- stay shallow, just through enamel - less than 1mm
what is the access procedure for 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 7mm
- confirm pulp canal entry with endodontic explorerDG16: PUSH
describe the access procedure- un-roofing
- un-roof pulp chamber with brushing out-strokes. do not gouge axial walls
- remove obstructions and smooth the walls
- irrigate well (NaOCl): vision, remove debris, begin disinfection
what is the 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
the endo - Z bur is a ____ cutting instrument only
side
after access, your next big task is:
working length
what is the correct WL
1mm short of the canal exit
when do you measure the canal exit
before you mount the tooth
how do you find the canal exit in the mouth
- chart
- apex locator
- radiograph with a #15 file in canal
what is the average root length for central incisors
- max: 22.5
- mand: 20.7
what is the average root length for lateral incisors
- max: 22.0
-mand: 21.1
what is the average root length for canines
- max: 26.5
- mand:25.6
what is the average root length for first premolar
- max: 20.6
- mand: 21.6
what is the average root length for second premolar
- max: 21.5
- mand: 22.3
what is the average length for the first molar
- max: 20.8
- mand: 21.0
what is the average root length for the second molar
- max: 20.0
- mand: 19.8
what is the usual number of roots and canals for max incisors
1 and 1
what is the usual number of roots and canals for max canines
1 and 1
what is the usual number of roots and canals for max first premolars
2 and 2
what is the usual number of roots and canals for max second premolars
1 or 2 and 1 or 2
what is the usual number of roots and canals for max molars
3 and 3 or 4
what is the usual number of roots and canals for mand incisors
1 and 1 or 2
what is the usual number of roots and canals for mand canines
1 and 1
what is the usual number of roots and canals for mand premolars
1 and 1 or 2
what is the usual number of roots and canals for mand molars
2 and 3 or 4
why is the goal for the WL to be 1mm short of the canal exit
this places the WL in close proximity to the natural apical constrictin
what is the result if the WL is too short
the canal is not well cleaned
what is the result if the working length is too long
- BLOW OUT
- guaranteed incomplete compaction at the apex and an explosion of sealer in the PA tissues
where is the reliable reference point usually loated
- tip of incisal edge for anterior
- tip of cusp for which the canal is named
what is the next step after dx
access
access to the pulp chamber facilitates:
- locating the canals
- negotiating the canals
- gaining patency
- establishing working length
- maintaining apical constriction
- a good outcome
what problems can poor access cause
- you will not have a predictable result
- you will 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
what is access
drilling a hole through coronal structure to gain entrance into the pulp chamber
what is the objective of access
- to create effective shape that is:
- smooth
- constantly tapering
- respecting the shape of the natural canal
- constricting near the terminus of the root
what is the Coke bottle effect
the canal is bigger than the cervical access at some more apical point in the canal
what are the requirements of access
- visibility of pulp chamber and all canal orifices from a single vantage point
- straight line access to mid root for instrument placement
- complete removal of pulpal roof and pulp horns
- avoidance of unnecessary weakening of tooth
what is “Draw”
visbility of pulp chamber and all canal orifices from a single vantage point
straight line access to mid root is required for:
instruments and obturating materials without regard to the long axis of the tooth
what is the dentin triangle
cross hatched area of secondary dentin that should be removed to create better access to mesial root
what do you use to remove the dentin triangle
a .25/.12 rotary file
what are the steps of access
- outline form - 2D surface shape
- coronal access- extending into pulp
- radicular access- adjustments to allow easy straight line entry to mid-root of each canal
what bur should you use for outline form in molars? PM?
- molars: #4
- premolars: #2
what else influences access besides ideal
canal anatomy and tooth damage can determine shape, size, and location of initial entry
what is coronal access for
to allow unobstructed visualization of the pulpal floor and ALL canal orifices from a single vantage point
what do you do in coronal access
- reach pulp at 7mm and mark bur
- extend bur within the outline form to remove pulpal roof
- do NOT touch pulpal floor with access bur
walls of the coronal access should:
DIVERGE to the occlusal
why should the walls of the coronal access should diverge to the occlusal
- better light
- better visualization
- your temporary restoration which is placed between visits will not be easily dislodged to leak and contaminate
what is the purpose of radicular access
to allow straight line access to midroot for shaping instruments and obturation materials to observe canal path- not the long axis of the tooth
what do you do in radicular access
- flare into canals to remove obstructions and make instrument placement simple and foolproof without looking
- facilitates crown- down procedure
hand files generally require____ strokes/file before going to the next larger size file
100
what is the access shape for the maxillary central incisor
triangular access from lingual about 3mm on each side
what is the shape of access for the maxillary lateral incisor
triangular/oval access
what is the shape of maxillary canine access
triangular/oval
what is the shape of the access for mandibular incisors
oval
what is the shape of the access for mandibular canines
oval
how does inadequate access compromise shaping
- induces unnecessary bending of file
- creates apical transportation of canal
what is the shape of access in maxillary first premolar
thin oval - width of #4 bur
what is the shape for access of maxillary second premolar
thin oval- width of #4
what is the shape for access of the mandibular first premolar
thin oval
what is the shape of access of the mandibular second premolar
thin oval
what is the shape of access of maxillary 1st molar
triangle- apex to palatal
what is the shape for access of the mandibular first molar
trapezoid
what is the shape for access of the mandibular 2nd molar
trapezoi/triangle
