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Biomedical subjects

H T Shillingburg

Publications and source records attributed to H T Shillingburg.

At least 19 recordsLinked to original sources
PubMed1993

Effect of luting media on the compressive strengths of two types of all-ceramic crown.

This study evaluated the effect of selected luting media on the compressive strength of two types of all-ceramic crown. Tooth preparation was standardized; each preparation had a shoulder width of approximately 1.2 mm, and all internal preparation angles were rounded. Hi-Ceram and Dicor all-ceramic crowns were fabricated and cemented into the preparations with zinc phosphate, glass-ionomer, or composite resin cement. Coronal compressive fracture strengths were determined, using a set of unrestored teeth as a control. There were no statistically significant differences among the mean compressive strengths of the three luting media, and there was no statistically significant difference between the mean compressive strength of Dicor and that of the natural tooth control.

Aluminum Oxide↗
PubMed1993

Pins, dowels, and other retentive devices in posterior teeth.

Devices used to increase retention of restorations to severely damaged posterior teeth are described, with an emphasis on pins and dowels. Advantages and disadvantages of different techniques and measures to help prevent and correct problems are presented.

Bicuspid↗
PubMed1991

A comparison of the abrasiveness of six ceramic surfaces and gold.

A type III gold alloy and six different ceramic surfaces were secured in an abrasion machine opposing extracted teeth to determine their relative abrasiveness and resistance to wear. The rankings of restorative materials from least abrasive to most abrasive were: gold alloy, polished; cast ceramic, polished; porcelain, polished; cast ceramic, polished and shaded; porcelain, polished and glazed; cast ceramic, cerammed skin shaded; and cast ceramic, cerammed skin unshaded. The ranking of materials from most wear-resistant to least wear-resistant was: gold alloy, cast ceramic cerammed, cast ceramic cerammed and shaded, porcelain polished, porcelain glazed, cast ceramic polished and shaded, and cast ceramic polished.

Analysis of Variance↗
PubMed1985

Effect of abutment mobility, site, and angle of impact on retention of fixed partial dentures.

Fixed partial dentures cemented to dies of adjustable mobility were subjected to repeated impacts at three different sites. Immobile abutments retained their prostheses longer than mobile abutments. Impacts that fell between the centers of rotation of the abutments were withstood longer than impacts that fell nearer the ends of the prostheses. This study failed to show a significant difference between the effect of impacts perpendicular to the occlusal plane and impacts angled 45 degrees toward the lingual plane. The results of this study suggest that (1) crowns that anchor rigid prostheses to mobile teeth require greater retentive ability than crowns on relatively immobile abutments and (2) occlusal impacts are best withstood when they fall on the areas of the fixed partial denture over and between the centers of rotation of the abutment teeth. If a fixed partial denture must withstand loading outside these areas, as is the case with cantilevered pontics and some tilted abutments, the retainer furthermost from the anticipated eccentric load must have exceptionally good retention.

Dental Abutments↗
PubMed1985

Preparation modifications for damaged vital posterior teeth.

The preservation of a severely damaged tooth with a cast restoration requires that the preparation be modified to make use of remaining tooth structure. Preexisting preparation features, such as boxes and isthmuses, and new ones, such as boxes, grooves, and pin holes, are employed to provide adequate retention and resistance. When destruction of coronal tooth structure exceeds one-half of the clinical crown, a pin-retained amalgam or composite resin core should be used to build up the tooth to receive a cast restoration.

Crowns↗
PubMed1983

Influence of preparation features on retention and resistance. Part I: MOD onlays.

Four variations of an MOD onlay preparation were studied for retention and resistance. Boxes were more effective than an isthmus in increasing retention value. The combination of boxes and isthmus showed the highest retention. The combination of boxes and isthmus also exhibited the highest resistance. There was no difference in resistance between boxes and the isthmus.

Crowns↗