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 limits the engagement of each file ~ 2-5mm reduces the impact of canal curvature better tactile awareness during apical shaping 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 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 minimizes transportation, zipping, ledging less irritants and toxins pushed through the foramen working length less likely to change less stress, minimizes breakage less stress, minimizes breakage allows greater volume of irrigant penetration minimizes transportation, zipping, ledging minimizes transportation, zipping, ledging less irritants and toxins pushed through the foramen working length less likely to change less stress, minimizes breakage less stress, minimizes breakage

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.

Apical Control Zone

0.0 mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm 46 David Rosenberg David Rosenberg

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

Distal Root 1 mm from Apex Distal Root 1 mm from Apex Canal not instrumented to the correct diameter Necrotic Tissue

Distal Root 1 mm from Apex Distal Root 1 mm from Apex Canals not instrumented to the correct diameter Necrotic Tissue and Debris

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 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

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 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