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Biomedical subjects

R W Hession

Publications and source records attributed to R W Hession.

6 recordsLinked to original sources
PubMed1977

Endodontic morphology. IV. A comparative study.

One hundred sixty-four extracted human teeth of all denominations were subjected to radiographic study after their canal systems were prepared with endodontic instruments and perfused with a water-soluble, radiopaque contrast medium. The same specimens had been studied prior to endodontic instrumentation by means of the same technique, and a comparison of the two sets of radiographs was made. Results of this comparative study were combined with information gained during the instrumentation procedures, and an analysis of the success rate for each group of specimens has been given. The over-all rate of success was high (92 per cent), being highest in the case of maxillary incisors and canines (100 per cent) and lowest in mandibular incisors and canines (81.8 per cent). The belief that the canals of molars present more difficulties than those of other teeth was not substantiated in this experiment, with the success rate for maxillary and mandibular molars being 92.1 per cent. Discussed were the potential for the packing of debris into the apical ends of root canals during instrumentation, the presence of residual traces of alloy within canals after canal preparation, and the known and unknown fracturing of endodontic instruments.

Contrast Media↗
PubMed1977

Endodontic morphology. II. A radiographic analysis.

Radiographs of 164 extracted human teeth were examined under magnification subsequent to the infusion of a radiopaque contrast medium under vacuum into their empty canal systems. An analysis of the results was made from the recorded statistics, and some conclusions have been drawn from these. The form and number of canals generally conformed to those of the roots which housed them, with some exceptions. The presence of two canals in the mesiobuccal roots of maxillary first molars and the incidence of lateral, accessory, and furcation canals have been noted. The role of the endodontist in the treatment of teeth with such anatomic features was discussed.

Bicuspid↗
PubMed1977

Endodontic morphology. III. Canal preparation.

Three hundred nine root canals in 164 extracted human teeth were prepared with endodontic instruments for obturation by the lateral condensation technique. Variations in tooth lengths for each group of teeth were marked, pointing up the need for adequate control of instruments through careful assessment of tooth lengths in clinical practice. In most cases the canals were prepared to the desired depth and flared coronally with the assistance of chelates. Some instrument failures were noted, along with the tendency for files to force debris in an apical direction during instrumentation.

Dental Cavity Preparation↗
PubMed1977

Endodontic morphology. I. An alternative method of study.

Several techniques have been reported for the demonstration of canal systems in vitro. An additional technique has been developed which allows for the study of the internal anatomy of teeth prior to and after instrumentation on the same specimens. The use of a water-soluble contrast medium infused into root canal systems provides for easy removal of the contrast medium without alteration of the internal anatomy of the teeth. The pulps were eliminated from 164 extracted human teeth by enzyme action; the pulp chambers and root canal systems were filled under vacuum with a water-soluble, radiopaque contrast medium; and each tooth was radiographed from three angles with the contrast medium in situ. The contrast medium was cleared and an additional radiograph was taken. The potential for this procedure in the evaluation and assessment of the technique of canal preparation has been projected.

Contrast Media↗