P2-ENDO LEC-CHAPTER 7

to achieve a sterile environment

what is the purpose of removing all caries in access prep?

access cavity prep

coronal pulp tissue is removed through what kind of prep?

biomechanical prep

radicular pulp tissue is removed through what prep?

jacket crown

what is the most acceptable resto of choice in endodontically treated teeth?

onlay

what is the minimally acceptable resto choice for endodontically treated teeth?

Straight line access

what provides the best chance of debridement of the entire canal space and reduces the risk of file breakage?

funnel

how are the line angles of an ideal access formed?

visualization of the likely internal anatomy

first step in preparing an access cavity

palpation of attached gingiva

what aids in locating root direction?

because morphology can change as it is destroyed by caries or replaced by restorations

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why is complete reliance of occlusal anatomy dangerous?

Krasner and Rankow

who found that CEJ is the most important landmark of identifying the location of pulp chambers and orrifices?

Krasner and Rankow

who proposed the nine guidelines?

maxillary molars

the first and second law of symmetry is applicable to all teeth except?

lingual surface

anterior teeth is prepared via what surface?

occlusal surface

posterior teeth is prepared via what surface?

incisal surface

mandibular incisors are prepared via what surfaces in selected areas?

better access to the lingual canal and improves debridement

why us mandibular incisors prepared via incisal surface in selected areas?

wall must be repaired immediately with a temporary filling

what will you do if chamber wall is perforated during carious removal?

crown lengthening

if removal of extensive restorations or carious dentin leads to less tooth structure available for placement of a rubber dam clamp, what should be done before root canal procedure?

to prevent tooth fracture

why do we need to remove unsupported structure?

crowded and rotated

fractured to free gingival margin

heavily restored and calcified,

part of a fixed prosthesis

what situations can possibly pose difficulties in placing a dam?

#.04 & #.06 Micro-Openers

what are the excellent instruments for locating orifices when dental dam has not been placed.

Sharp endodontic explorer

what are used to locate canal orifices and to determine their angle of departure from pulp chamber?

to make instrument placement easier

why are canals need to be flared?

small, precurved K-files (#6, #8, or #10)

what are used to explore canals?

Congealed (Calcified) pulp tissue

it may form a collagen plug that blocks the apex

Surgical loupes, endodontic endoscopes, DOM

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what are the instruments used for magnification and illumination?

tapering walls with widest dimension at the occlusal surface

what is the proper access cavity?

Prevents forces from pushing temporary restoration into the cavity and disrupt the seal

what is the purpose of tapering walls of the cavity prep?

3.5 mm

how much of temporary filling material is needed to provide an adequate coronal seal for a short time?

DOM

what is preferred for magnification and illumination?

highspeed handpiece

what type of handpiece is used for most phases of access preparation?

low-speed handpiece

what type of handpiece is used after penetration of dentin is done?

round carbide burs (sizes #2, #4, and #6)

what are the most extensively used burs in access cavity prep?

round carbide burs (sizes #2, #4, and #6)

what burs are used for initial external outline shape and for penetrating the roof of pulp chamber?

Fissure carbide and diamond burs with safety tip

what instrument has no cutting edge which is why it is safe to used for extending axial walls?

Round diamond burs

what burs are used for endodontic access of porcelain or ceramometal restorations?

carbide bur

clinician switches to what kind of bur after penetrating porcelain so metal and dentin can be cut efficiently?

Transmetal bur

what bur is used for metal restorations (amalgams, all-metal cast restorations, or metal copings of PFMs?

Mueller bur

example of an extended shank bur

extended shank bur

Used to cut into root to locate, identify the canal orifices

Used if tooth has a receded pulp chamber and calcified orifices

Munce Discovery bur

similar to Mueller but stiffer shaft and available in smaller head sizes

Gates Glidden burs

what burs are used to flare, enlarge, and blended orifices into the axial walls of the access cavity once they are located?

#.12 tapered rotary endodontic files

what more recently, have been used for the flaring and blending procedure?

DG-16 endodontic explorer

what is used to identify canal orifices and to determine canal angulation?

JW-17 endodontic explorer

it is used with the same purpose as that of DG-16 endo explorer, but thinner, stiffer tip for identifying calcified canals

Endodontic spoon

what is used to remove coronal pulp and carious dentin?

17 operative explorer

what is used for detecting any remaining pulp chamber roof, particularly in pulp horns?

Ultrasonic tips

what instruments are used to trough and deepen developmental grooves to remove tissue and explore for canals and provide outstanding visibility compared with conventional handpiece heads?

Fine ultrasonic tips

what instruments are have abrasive coatings that allow clinicians to sand away dentin and calcifications conservatively when exploring for canal orifices?

#2 or #4 round or tapered fissure bur

what burs are used to penetrate through the enamel and slightly of a dentin (1mm)?

drop-in effect

what is felt which means penetration is accomplished?

small broach coated with a chelating agent- introduced into the canal, rotated to amputate radicular pulp in a more apical level

what will you do if the hemorrhage still continues after amputation of canal pulp tissue?

17 operative explorer

what is used to confirm complete roof removal?

endodontic explorer

what instrument penetrates or dislodges calcific deposits blocking an orifice?

endodontic explorer

what instrument is used to evaluate straight-line access?

avoid placing a bevel

what is avoided when removing the lingual shoulder?

rotary nickel-titanium orifice openers

what instrument is used at slow speeds and low torque?

endodontic file

what instrument can approach the apical foramen or the first point of canal curvature undeflected?

loss of instrument control

Unnecessary deflection results to

more susceptible to separation during the shaping and cleaning

lack access to critical areas

do not shape and clean effectively

what are the 3 complications associated in deflected instruments?

file deflects in a facial direction

what is the indication if there is an inadequate removal of the lingual shoulder?

access cavity should be extended further incisally until the file is not deflected.

If lingual shoulder is adequately removed but file still binds on incisal edge, what will you do?

functional tooth surface

composite resin restoration will be placed on a

Butt joint margins

_________________ are indicated rather than beveled margins that can fracture and result in coronal leakage

1. remove all caries and permanent resto

2. initial external outline form

3. penetrate pulp chamber

4. complete roof removal

5. identification of all root canal orifices

6. removal of lingual shoulder & coronal flaring

7. straight-line access determination

8. visual inspection of the access cavity

9. refinement and smoothing of resto materials

the proper sequence of anterior access cavity preparation procedures

triangular

what is the final outline shape of molars if they have 3 canals?

rhomboid

what is the final outline shape for molars if they have 4 canals?

canal orrifices

what dictate the position of the corners?

aggressive probing

what kind of probing with endodontic explorer help locate the pulp chamber?

round bur, tapered fissure bur, or a safety-tip diamond or carbide

what is used for the complete roof removal in molars?

safety-tip diamond or carbide bur

what is used to funnel the corners of the access cavity in molars?

FALSE!

entire axial wall is shaped AT ONE TIME with little chance of gouging

true or false

entire axial wall shaped one at a time with little chance of gouging

internal underextension and impedes straight-line access

what does the mouse hole effect indicate?

#.10 or #.12 tapered engine-driven nickel titanium file

what is the alternative method in removing the natural coronal canal constriction in molars, to establish upper canal shape?