principles of endo access- max anteriors

goals of access include:

• locate ________

• __________ access to canals

• removal of ________ and _________

• conservation of _______

• all canals

• straight-line

• chamber roof; coronal pulp tissue

• tooth structure

what is straight line access

unimpeded access of the instruments in the canals to the apical 1/3 of the canal or the first curve (if present)

is this an example of straight line access

NO: need to open orifice (where red arrow is pointing) to be able to get straight line access

_______ dictates shape of access

pulp chamber

the access should be as _____ as possible but as ______ as necessary

small; large

if access is too small, this can lead to… (3)

• difficulty locating canals

• missed canals

• difficulty achieving straight-line access

if access hole is too big…(3)

• unnecessary removal of tooth structure

• inc risk of fracture

• inc risk of perforation

the removal of pulp materials from the pulp horns/crown is necessary to prevent…

coronal discoloration

4 principles of access

• outline form

• convenience form

• caries removal

• toilet of the cavity

what is the outline for of access

• recommended shape of the access

• projection of internal tooth anatomy onto external root structure

• may change over time w calcification of chamber

what is convenience form for access

modification of ideal outline form to facilitate instrument placement and manipulation

reason for caries removal for access

• prevent contamination of root canal system

• assess restorability

• provide sound tooth structure for temporization/restoration

what is toilet of the cavity for access

keep it clean → prevent debris from blocking canal by frequently irrigating

out of the 4 principles of access, which is done first

caries removal

7 steps for access opening procedures

1. study pre-op radiograph

2. estimate depth of access from RG

3. remove all caries, may/may not remove restorations

4. access: use 701 fissure bur w high speed

5. use DG-16 endo explorer to detect chamber/canal orifice

6. re-eval as needed during access w tactile sensation to make sure you create straight-line access and open orifice

7. expose RG if needed

what is an orifice

opening of the root canal inside the pulp chamber

between a maxillary lateral and central, which is more bulky

central

maxillary anterior teeth have ___ (#) canal

1

in mandibular canines, 30% have ____ canals. from this, __% have the 2 canals join, and __% exit separate

2; 20%; 10%

shape of the root of a central incisor

usually straight

shape of root of a lateral incisor

usually apical curvature to distal or palatal

shape of root of a canine

long, usual apical curvature

w canines, it can be difficult to radiographically interpret the apical portion due to…

a small root root tip

what does the canal shape look like in the mid root vs the apical third of a maxillary central incisor

both are round

what does the canal shape look like in the mid root vs the apical third of a maxillary lateral incisor

can be round or ovoid

what does the canal shape look like in the mid root vs the apical third of a mandibular canine

usually oval, mid root can start separate and then join in apical third

what are some anatomical variations you may see in maxillary anterior teeth (would NOT want to choice these as exercise teeth)

• lingual developmental or palato-radicular groove

• dens invaginatus

• talon cups

the apical root of a maxillary central incisor may curve ____ or _____

distal; labially

canals of maxillary central incisors are usually ________

straight

when determining the access outline for maxillary incisors, you want to know the incisal limit, what does this mean

determined by incisal edge and cavoangle of the lingual so that you get underneath the incisal edge to obtain straight-line access

why is access always done on the lingual vs the incisal edge of anterior teeth

for esthetics

how would a worn maxillary incisors affect the incisal limit

incisal edge can be worn to or beyond the incisal limit

order of burs to complete access (but keep in mind the order is not definite)

1. initial access: 701/#1 round/ Endo Z

2. remove lingual shoulder/pulp horns/smooth: FG surgical length 2/4 bur

3. enlarge orifice/canal: slow speed w gates glidden #2/3/4

how to cut the cavo-surface outline

#701: about ~1.5 mm depth, hold perpendicular to tooth to get under incisal edge

how to access prep into the pulp chamber after cavo-surface outline has been cut

use surgical bur #2 (NOT short) to follow the long axis of the tooth

what you are feeling for when exploring the pulp chamber (w explorer)

what to find orifice, feel what you need to open more, if explorer doesn’t fit, need to open more

in maxillary incisors, it is important to remove the ____ (near the orifice) in order to get straight line access

lingual shoulder

what can you remove the lingual shoulder w

gates glidden #2/3/4 and hedstrom file

what should you be doing to check for pulp horns

use G2 explorer → if catching → use a small round bur at slow speed

if you’re having trouble opening the chamber and orifice, what questions can you ask yourself

• how far are you in the pulp chamber?

• are you under the incisal edge?

• is your access large enough to have illumination to help locate the pulp space?

what error happen here

gouge towards the facial → opening too far

what error happened here

pulp horn not incorporated w access (was not removed)