Piecing Together Endontic Excellence Dr. Ken Serota Friday, November 19th, 2004 kendo@endosolns.com

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 kendo@endosolns.com

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 kendo@endosolns.com

Piecing Together Endontic Excellence Dr. Ken Serota Apical Control Zone Friday, November 19th, 2004 kendo@endosolns.com

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 kendo@endosolns.com

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

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 kendo@endosolns.com

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 kendo@endosolns.com

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 kendo@endosolns.com

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 kendo@endosolns.com

Piecing Together Endontic Excellence Dr. Ken Serota Friday, November 19th, 2004 kendo@endosolns.com

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

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 kendo@endosolns.com

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

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 kendo@endosolns.com

Piecing Together Endontic Excellence Dr. Ken Serota Friday, November 19th, 2004 kendo@endosolns.com

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 kendo@endosolns.com