Dr. Özkan ADIGÜZEL

2. Foramen Last
 eliminates constrictions in the coronal region
allows greater volume of irrigant penetration
 cleans coronal 2/3’s of canal b/4 apical 1/3 is entered
minimizes transportation, zipping, ledging
 limitsirritants and toxins pushed through the foramen
less the engagement of each file ~ 2-5mm
 reduces the impact of canal curvature
working length less likely to change
 better tactileminimizes breakage
less stress, awareness during apical shaping

3. Apical Control Zone
The ‘Apical Control Zone’ is a matrix-like region created in
the apical third of the root canal space. The zone
demonstrates an exaggerated taper from the clinician
defined apical constriction whether this is spatially a linear
or point determination. This enhanced taper in the apical
control zone provides resistance form against the
condensation pressures of obturation and acts to prevent
the extrusion of the filling material during obturation.

4. Apical Control Zone

5. 0.0 mm 20
0.25 mm 25
0.5 mm 30
0.75 mm 35
1.0 mm 40
2.0 mm 42
3.0 mm 44
4.0 mm 46
David
Rosenberg

6. Apical Gauging
Avoid apical parallelism
Objective - linear or point apical control zone

7. Distal Root
1 mm from Apex
Canal not debrided and shaped
to the correct diameter
Necrotic Tissue

8. Distal Root
1 mm from Apex
Necrotic Tissue
Canals not debrided and shaped
to the correct diameter and Debris

9. What does the literature say
about canal diameters?
Median of maxillary canal diameters 1mm from apex
 Mx. cent. incisor .34mm
 Lateral incisor .45mm
 Canine .31mm
 Premolar .37mm
 MB1, MB2 (molar) .19mm
 DB .22mm
 Palatal .33mm
Wu et al 2000

10. What does the literature say
about canal diameters?
Median of mandibular canal diameters 1mm from apex
 Md. central incisor .37mm
 Lateral incisor .37mm
 Canine .31mm
 Premolar .35mm
 MB (molar) .40mm
 ML .38mm
 Distal .46mm
Wu et al 2000

12. Radiographic Terminus – NOT!!
Radiographic terminus
alters throughout life –
cellular cementum
deposition
Apical foramen

13. Electric Foramenal Locators
In 1962 Sunada determined that the
 must turn unit on before attaching resistance between oral mucosa
probe to unit… and periodontal ligament is a
“might think in previous tooth” constant value 6.5 ohms (40/μAmp)
 canals can be wet, but chamber must
be dry…
no shared fluid between canals
 instrument must be free in access
opening…
no contact with metal

14. Anatomic apex
PDL,
cementum & bone
* EAL = 0.0
Bleeding point

15. Working Length
 generic knowledge of root lengths
 measure radiograph –
 advantage of digital images

foramenal locators
foramenal locators
USED REPEATEDLY
 USED REPEATEDLY
 final WL determined after coronal
debridement – lengths change with
shaping

17. Guru Conclusions
Several trends are increasingly evident:
 most NiTi techniques are hybrid rotary file protocols
 most operators create tapered apical preparations, ranging
from .06 to .2 or more
 most use a thermolabile technique
 most use patency files all the time
 all use foramenal locators as primary length determinant
 not all take WL x-rays and some use paper points for
length confirmation
 presence of an ACZ is dependent on operator’s technique