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Biomedical subjects

J K Sutherland

Publications and source records attributed to J K Sutherland.

11 recordsLinked to original sources
PubMed1990

Soldering technique for osseointegrated implant prostheses.

This article describes a method for making changes in the alignment of superstructures for osseointegrated implants. After a cast is made from a transfer impression, the teeth and plastic are removed from the framework. The framework is sectioned into as many pieces as necessary to realign it on the analogs in the cast. The pieces are held in soldering investment with guide pins and abutment screws for soldering in the new position. The prosthesis is completed, finished, and replaced in the mouth.

Dental Implantation, Endosseous↗
PubMed1989

Endodontic access of all-ceramic crowns.

This study determines the effects of access opening on all-ceramic (Dicor) crowns. Forty-two extracted permanent teeth were selected to represent the various types of human teeth. Crown preparations were completed, polysulfide impressions made, and stone dies poured. The dies were forwarded to a commercial dental laboratory for fabrication of the restorations. The crowns were luted to the prepared teeth and endodontic access openings were completed by using established criteria for access preparation. The crowns were removed and examined by direct vision, transillumination, stereomicroscopy, and scanning electron microscopy. Two crowns fractured during access preparation, seven crowns exhibited craze lines, and 29 crowns exhibited chipping of the ceramic material adjacent to the access opening. There was no significant difference in the extent of chipping with diamond or carbide instrumentation. However, carbide instrumentation caused more fractures and craze lines than did diamond instrumentation.

Ceramics↗
PubMed1988

A spreadsheet method for 90Sr and 89Sr interpretation.

A spreadsheet method of handling multiple data points is described for the interpretation of "radiostrontium" analyses. The method uses up to 10 or more counts on one sample, starting 1 d after the chemical separation. The unreliable "day-0" count on a relatively low activity sample is not used since it introduces too many uncertainties. The count data for each sample are compared against a spreadsheet-calculated matrix of ingrowth/decay curves from 0 to 100% 90Sr and at the analytical count intervals between about 24 to 650 h after the chemical separation to determine the best fit of the data set. This fit occurs where the decay/ingrowth characteristics of the sample, as defined by the changing counts, most closely match those of the matrix for all of the data points. At this fit, the 89Sr and 90Sr percentages are defined, and the best estimate of the "time-0" counts is calculated using all of the counts. Secondary separations and analyses are not required.

Software↗
PubMed1980

A photoelastic analysis of the stress distribution in bone supporting fixed partial dentures of rigid and nonrigid design.

Within the limitations of the experiment, the following conclusions can be made from this investigation: 1. Under conditions of vertical loading, the rigid fixed partial denture design does not permit independent response by either abutment. The nonrigid fixed partial denture design allows the abutments some independence in response to vertical loading 2. The stress distributions and concentrations produced in the supporting bone are favorably altered by the placement of a fixed partial denture of rigid or nonrigid design. 3. The distribution of stresses in the supporting bone varies with the number and location of the loading sites. 4. Under conditions of vertical loading, the Ney and Stern nonrigid fixed partial denture designs exhibit no significant differences in stress distribution or concentration.

Alveolar Process↗