RCT : Access Cavity Openings

∆ Methods of Determining Anatomic Configurations :

• If canal suddenly stops in apical region, bifurcation into much smaller diameters may be assumed, to confirm use SLOB.

• Lateral radiolucencies indicates precence if lateral/ accessory canals.

• Abrupt ending of a large canal signifies a bifurcation.

• Knoblike-image indicates an apex that curves towards or away from the beam of x-ray machine.

✓✓✓ Maxillary Central Incisor (11/ 21) :

• Average Length : 22.5 mm

• Shape : Roughly Triangular.

• Multiple canals are rare.

• Incidence of accessory and lateral canals is high.

• Apical foramen is usually found laterally within 2mm and not always at exact root apex.

✓✓✓ Maxillary Lateral Incisor (12/ 22) :

• Average Length : 22.0 mm

• Shape : Ovoid.

• Root tends to turn towards the curvature, usually towards distal, in it's apical position.

• Anatomic apex may be found lateral within 1-2 mm of apex.

✓✓✓ Maxillary Canine (13/ 23) :

• Average Length : 26.5 mm

• Shape : Ovoid.

• Do not reduce incisal edge excessively to gain excess.

• The apex will often curve any direction in the last 2-3 mm.

✓✓✓ Maxillary 1st PreMolar (14/ 24) :

• Average Length : 20.6 mm

• Shape : Ovoid.

• Canal orifices will be found below and slightly central to the cusp tips.

• Radiographic division of roots, will often indicate tooth rotation.

• Distal curvature may be present.

✓✓✓ Maxillary 2nd PreMolar (15/ 25) :

• Average Length : 21.5 mm

• Shape : Ovoid.

• Accessory/ Lateral canals may be present.

• Apical curvature may be present.

✓✓✓ Maxillary 1st Molar (16/ 26) :

• Average Length : 20.8 mm

• Shape : Ovoid???????

• Palatal root is often curved buccally in it's apical third,

° it has a sharp angulation away from midline.

• DistoBuccal root always has 1 canal.

• MesioBuccal root may have 2 canals (2nd canal lies somewhat between the mesio-buccal and palatal orifices).

✓✓✓ Maxillary 2nd Molar (17/ 27) :

• Average Length : 20.0 mm

• Shape : Ovoid???????

✓✓✓ Maxillary 3rd Molar (18/ 28) :

• Average Length : 17.0 mm

• Shape : Ovoid????

✓✓✓ Mandibular Central Incisor (31/ 41) :

• Average Length : 20.7 mm

• Shape : Ovoid, with attention given to lingual approach (Ovoid-Truangular Shape).

• To avoid perforation, use but contacting the incisal edge in lingual direction.

✓✓✓ Mandibular Lateral Incisor (32/ 42) :

• Average Length : 21.1 mm

• Shape : Ovoid?????

• Apic curvatures and lateral canals are common.

• Minimal flaring is to be done to avoid ripping(perforate) through proximal walls.

✓✓✓ Mandibular Canine (33/ 43) :

• Average Length : 25.6 mm

• Shape : Ovoid, may be extended incisally for labial-limgual accessibility.

✓✓✓ Mandibular 1st PreMolar (34/ 44) :

• Average Length : 21.6 mm

• Shape : Ovoid. 

✓✓✓ Mandibular 2nd PreMolar (35/ 45) :

• Average Length : 22.3 mm

• Shape : slightly Ovoid, wider MesioDistally.

✓✓✓ Mandibular 1st Molar (36/ 46) :

• Average Length : 21.0 mm

• Shape : Ovoid-Rectangular

• Distal root canals are larger than Mesial root canals.

• Multiple accessory foramina are located in the furcation area.

✓✓✓ Mandibular 2nd Molar (37/ 47) :

• Average Length : 19.8 mm

• Shape : ???????

• Most susceptible to vertical fracture.

✓✓✓ Mandibular 3rd Molar (38/ 48) :

• Average Length : 18.5 mm

• Shape : ????

✓∆✓  Errors in access cavity when the anatomic crown is missing :

• Perforation of root, due to negligence of angulation of tooth. (Can be corrected by taking radiographs before starting)

∆✓∆ Perforation Repair :

• Perforation is made.

• Use paper/ adsorbent points to control haemorrhage.

• Butt end of paper point is rolled and freshly prepared amalgam bullet is placed on its top.

• Place it at the Perforation and remove paper point.

• Contour it, let it dry and set and continue with RCT.