endodontic access

Endodontic Access Cavity Preparation

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* The main function of an access cavity is 1- To create an unimpeded pathway to the pulp space and the apical foramen of the tooth. 2- Straight-Line Access 3- prevention of iatrogenic problems and avoidance of technical failure of root canal treatment. 4- Give good vision 5- To locate all root canal orifices 6- To conserve sound tooth structure

Endodontic Preparation of Maxillary Anterior Teeth

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Access cavity preparation

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Endodontic Preparation of Maxillary Anterior Teeth

Adult tooth
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* Cavity Access. Canine

Extensive ovoid shape inciso-cervical, funnel shaped coronal preparation The canal is usually straight but may show a distal apical curvature.

* The pulp chamber is quite narrow M- D, and there is one pulp horn pointed to the incisal angle. The pulp space is much wider labiopalatally and the pulp space follows the outline. Oval root canal in cross section.

Maxillary Anterior TeethERRORS in Cavity Preparation

* In case of 1-crowned tooth 2-miss understanding of the tooth anatomy 3-tited teeth.

In crown 1-Missed canal 2-Labial perforation 3-Lateral perforation In root 4-Ledge formation 5-Ziping 6-Apical transportation 7-Apical perforation
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Maxillary Anterior TeethERRORS in Cavity Preparation

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Endodontic Preparation of MandibularAnterior Teeth

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Mandibular Anterior TeethERRORS in Cavity Preparation

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Mandibular Anterior TeethERRORS in Cavity Preparation

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* Should be removed to avoid stressed instrument And discoloration

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* Factors affecting the access cavity design: 1- Age of the patient 2- Number of canals 3- Curvature of the canal 4- Tooth type or number
tapered or cylindrical fissure burs, ISO 010 or ISO 012, are used in the initial stages of access preparation to establish the correct outline form. For penetrating ceramic or composite materials, diamond-coated burs are needed.


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* Round burs, normal and extra-long, in a contra-angle hand piece are used to lift the roof off the pulp chamber and eliminate overhanging dentine. If a standard length bur is too short, burs with longer shanks, up to 28 mm, are available. The longer and smaller sizes of burs may be used to remove dentine when opening calcified canals.
Safe-ended burs following initial access to the pulp space, a safe-ended or non-cutting tip, tapered diamond can be used to remove the entire roof of the pulp chamber. The non-cutting tip prevents perforation of the pulpal floor.

Maxillary First Premolar

Generally has 2 root with 2 canals, but in the case of 1 root has 2 canals which open in a common apical foramen. Many types of canal configurations. The pulp chamber is wide B-P with 2 distinct pulp horn. M-D, the pulp chamber is much narrower.

Endodontic Preparation of Maxillary First premolar Teeth

Young tooth Adult tooth
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Maxillary Second Premolar

The typical second premolar has one root and one canal and sometimes has an apical distal curvature. The pulp chamber is wider B-P and narrower M-D and has 2 well define pulp horns. The canal orifice is directly in the centre of the tooth.


Endodontic Preparation of Maxillary Second premolar Teeth
Young tooth Adult tooth
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Endodontic Preparation of Maxillary Premolar Teeth

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Maxillary Premolar TeethERRORS in Cavity Preparation

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Endodontic Preparation of Mandibular premolar Teeth

Young tooth Adult tooth
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Cavity Access

Because of 1-the inclination of the crowns of mandibular teeth 2- the smaller lingual cusp, the access opening should be placed buccal to the central fissure. The preparation is made oval, corresponding to the shape of the root and canal.

Endodontic Preparation of Mandibular Premolar Teeth

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Mandibular Premolar TeethERRORS in Cavity Preparation

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Mandibular Premolar TeethERRORS in Cavity Preparation
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Endodontic Preparation of Maxillary and mandibular Molar Teeth

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Maxillary First Molars

Generally three rooted with 3 canals. Additional canal is located in the MB root. Large pulp chamber, triangular in shape, with the base toward the buccal and the apex toward the lingual surface. Slightly curved buccal roots. DP curvature of the MB root. Apical-buccal curvature of the palatal root (55%)

It is very important to preserve the developmental lines that connect with the canal orifices. It’s dark lines in the floor of the pulp chamberof teeth. *

It has 3 or 4 pulp horn, the MB is the longest. The floor of the pulp chamber is normally just apical to the cervix and is rounded and convex to the occlusal. The MB canal opening is closer to the buccal wall than is the DB orifice mostly 2 canal MB1 + MB2. The DB canal is closer to the middle of the tooth than to the distal wall, and is the shorter and finest of the 3 canals.

Maxillary First Molars

Operating microscope is used to locate the canal orifices
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Endodontic Preparation of Maxillary First molar Teeth

Young tooth Adult tooth
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* Always seek for accessory canal in any teeth and every were

Maxillary Second Molar

It is similar of the first molar:Large pulp chamber.Mesiobuccal, distobuccal, and palatal roots, each with one canal.Gradual curvature of all three canals.“Flattened” triangular outline form.The DB canal orifice is nearer the centre of the cavity floor. Some time 2 canals

Endodontic Preparation of Maxillary Second Molar Teeth

Young tooth Adult tooth
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Endodontic Preparation of Maxillary Molar Teeth

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Locate canal orifices & obtain Straight-Line Access

Probing the Canal Entrances After the roof of the pulp chamber has been penetrated and the access cavity prepared, the entrances to the pulp canals must be probed. A hooked explorer can be used to determine if enough dentin has been removed The canal entrances are found by feeling with a thin, stiff explorer. If the explorer sticks in a spot, a size 8 or 10 file is used to verify that the spot is indeed the entrance to a root canal and not a perforation. Then is the opening gently enlarged. Narrow root canals must first be enlarged coronally with a Hedstrom file before the deep preparation with Gates-Glidden burs can be started.

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Maxillary Molar TeethERRORS in Cavity Preparation

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Maxillary Molar TeethERRORS in Cavity Preparation
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Mandibular First Molar

Usually has 2 roots one mesial and one distal. The Distal root is smoller and vertical. Distal curvature of the mesial root (84% of the time) which has two canals. The distal canal is larger and more oval. The MB is the most difficult canal to instrument because its tortuous path and narrow.

Triangular outline form in case of 3 canals, square to rectangular in case of 4 canals reflects the anatomy of the pulp chamber, with the base toward mesial and the apex toward the distal surface.
The cavity is primarily within the mesial half of the tooth but is extensive enough to allow positioning of instruments and filling materials.

Endodontic Preparation of Mandibular Molar Teeth

Young tooth Adult tooth
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Endodontic Preparation of Mandibular Molar Teeth

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Mandibular Molar TeethERRORS in Cavity Preparation

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Mandibular Molar TeethERRORS in Cavity Preparation

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Thank you

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