Thesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Endodontics

The aim of this study was to evaluate the adaptation of the obturation materials to the root canal walls, and its ability to conform to different canal irregularities in three techniques of obturation; namely: Thermafil (core carrier technique), Soft-Core system (core carrier technique) and System B (continuous wave of obturation). A recently extracted human maxillary central incisor with straight, completely formed root was used in this study. A split-tooth model was constructed and four alignment holes were drilled perpendicular to the long axis of the tooth, apical to the level of cementoenamel junction.These holes were drilled on the facial side of the root, and the other two on the palatal side.The block with the tooth was then longitudinally, buccolingually sectioned through the center of the root canal using a low-speed diamond disc. The two halves of the block could then be re-approximated and secured with four nuts and bolts placed in the alignment holes. Straight-line endodontic access preparation to the root canal was then made with a size #6 round bur in a low speed hand piece. The working length was established by visually placing the tip of a size #10 K-Flexofile 1 mm short of the anatomical root apex on one of the halves. The two halves of the root were reapproximated and secured with the four alignment nuts and bolts. The root canal was cleaned and shaped using K- Flexofiles, with the standard step-back preparation, up to size #60 master apical file. Saline irrigation was used throughout the whole instrumentation phase.Canal irregularities were artificially produced with size #1 round bur, making three shallow depressions (less than 0.5 deep) on the distal side of the canal at 1, 3, and 5 mm from the working length, and two similar depressions on the mesial half at 2 and 4 mm from the working length

Issued also as CD