1. Piecing Together Endontic Excellence Dr. Ken Serota
Friday, November 19th, 2004

2. Piecing Together Endontic Excellence Dr. Ken Serota
Foramen Last
eliminates constrictions in the coronal region
cleans coronal 2/3’s of canal b/4 apical 1/3 is entered
limits the engagement of each file ~ 2-5mm
reduces the impact of canal curvature
better tactile awareness during apical shaping
allows greater volume of irrigant penetration
minimizes transportation, zipping, ledging
less irritants and toxins pushed through the foramen
working length less likely to change
less stress, minimizes breakage
Friday, November 19th, 2004

3. Piecing Together Endontic Excellence Dr. Ken Serota
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.
Friday, November 19th, 2004

4. Piecing Together Endontic Excellence Dr. Ken Serota
Apical Control Zone
Friday, November 19th, 2004

5. Piecing Together Endontic Excellence Dr. Ken Serota
.2 mm taper
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
Friday, November 19th, 2004

6. Piecing Together Endontic Excellence Dr. Ken Serota
Apical Gauging
Avoid apical parallelism
Objective - linear or point apical control zone
Friday, November 19th, 2004

7. Piecing Together Endontic Excellence Dr. Ken Serota
Distal Root
1 mm from Apex
Canal not debrided and shaped to the correct diameter
Necrotic Tissue
Friday, November 19th, 2004

8. Piecing Together Endontic Excellence Dr. Ken Serota
Distal Root
1 mm from Apex
Isthmus
Necrotic Tissue and Debris
Canals not debrided and shaped to the correct diameter
Friday, November 19th, 2004

9. What does the literature say about canal diameters?
Piecing Together Endontic Excellence Dr. Ken Serota
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
These are the average diameters of maxillary teeth one millimeter from the apex, ranging from .19 mm in the MB root of the molar to .45 mm in the lateral incisor.
Wu et al 2000
Friday, November 19th, 2004

10. What does the literature say about canal diameters?
Piecing Together Endontic Excellence Dr. Ken Serota
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
And in the mandibular teeth, there was no canal diameter smaller than a size 30 file. As the data suggests, instrumenting these canals with a small apical file size with a highly tapered instrument won’t adequately clean and shape the apical portion of these canals.
Wu et al 2000
Friday, November 19th, 2004

11. Piecing Together Endontic Excellence Dr. Ken Serota
Friday, November 19th, 2004

12. Piecing Together Endontic Excellence Dr. Ken Serota
Radiographic Terminus – NOT!!
Radiographic terminus alters throughout life – cellular cementum deposition
Apical foramen
Friday, November 19th, 2004

13. Electric Foramenal Locators
Piecing Together Endontic Excellence Dr. Ken Serota
Electric Foramenal Locators
In 1962 Sunada determined that the resistance between oral mucosa and periodontal ligament is a constant value 6.5 ohms (40/μAmp)
must turn unit on before attaching
probe to unit…
“might think in previous tooth”
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
Friday, November 19th, 2004

14. Piecing Together Endontic Excellence Dr. Ken Serota
Anatomic apex
PDL,
cementum & bone *
EAL = 0.0
Bleeding point
Friday, November 19th, 2004

15. Piecing Together Endontic Excellence Dr. Ken Serota
Working Length
Piecing Together Endontic Excellence Dr. Ken Serota
generic knowledge of root lengths
measure radiograph –
advantage of digital images
foramenal locators
USED REPEATEDLY
final WL determined after coronal debridement – lengths change with shaping
foramenal locators
USED REPEATEDLY
Friday, November 19th, 2004

16. Piecing Together Endontic Excellence Dr. Ken Serota
Friday, November 19th, 2004

17. Piecing Together Endontic Excellence Dr. Ken Serota
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
Friday, November 19th, 2004