Maxillary molar teeth Entrance is always gained through the occlusal surface of all posterior teeth The initial penetration is in the exact center of mesial pit With the bur directed to the lingual ID: 1010560
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1. Access opening of posterior teeth
2. Maxillary molar teethEntrance is always gained through the occlusal surface of all posterior teethThe initial penetration is in the exact center of mesial pitWith the bur directed to the lingual. The 702 U tapered fissure bur used toPerforate gold cast, enamel Amalgam penetrate by no. 4 or 6 round bur
3. If the chamber is well calcified, initial penetration is continued until the contra-angle rests against the occlusal surface. This depth of 9mm is the usual position of the floor of the pulp chamber, which lies at the cervical level According to the size of the chamber, a regular-length No.4 or 6 round bur is used to open into the pulp chamber The bur directed toward the palatal canal orifice OR mesiobuccal canal orificeBecause Greatest space in pulp chamber
4. Locate orifices of the palatal, mesiobuccal, and distobuccal canalsRound bur is used to remove the roof of the pulp chamberAll orifices positioned entirely on the pulp floor and should not extend into an axial wall. Extension of an orifice into the axial wall creates a mouse hole effect, which indicates internal underextension and prevent straight-line access. In such cases the orifice must be re-positioned onto the pulp floor without interference from the axial
5. removal of cervical dentin shelfShelves of dentin overhang (cervical bulges ) orifices . restricting access into root canals. Removed with safety tip bur…. Finishing with 702U fissure bur
6. Canal orifice positioned at each angle of the triangle
7. Maxillary second molar
8. locate orifices of the distal, mesiobuccal, and mesiolingual canalsThe bur should be directed toward the orifice of the mesiobuccal or distal canal, where the greatest space in the chamber exists Mandible molar teethInitial penetration is made in the exact center of the mesial pitBy no. 4 or 6 round bur
9. Remove the roofFunnelingFinishingWith 702U fissure burUnobstructed access
10. Square outline form.Mesial & distal wall slop mesially.For adult & newly erupted tooth the outline is sameFurther exploration for fourth canal
11. Error during access openingUnder extension White color dentin of roofOver extension White color dentin of roof
12. Perforation Furcation by using surgical burFailure to orient the bur with long axis of the molarUnder extended
13. Over extendedDisoriented occlusal outline only palatal canal.Preparation in full crown placed to straighten a rotated molar.Palpation for mesiobuccal root give the idea of the preparation. Inadequate vertical preparationFailure to recognize sever buccal inclination of molar
14. Thank you