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Biomedical subjects

D R Burns

Publications and source records attributed to D R Burns.

11 recordsLinked to original sources
PubMed1990

Stress distribution surrounding endodontic posts.

This study compared the stress distribution during insertion and function of three prefabricated endodontic posts with different designs using the criteria of post length and diameter. Test blocks of photoelastic material were prepared with simulated endodontic canals. Three posts for each design, diameter, and depth were cemented. Each specimen was examined and photographed without load, with 135 Newton (N) compressive force, and with 90 N and/or 135 N oblique force applied at 26 degrees by use of a circular polariscope. Para-Post and Para-Post Plus posts produced similar, evenly distributed patterns of stress using the criteria of diameter, depth, and load. Flexi-Post posts produced asymmetric stress patterns with concentration of stress at each thread. During compressive loading and after cementation alone, Flexi-Post posts displayed significantly higher shoulder stresses and substantially greater stresses along the coronal surface of the post's length than Para-Post and Para-Post Plus posts. Apical stresses were similar for Flexi-Post, Para-Post, and Para-Post Plus posts during compressive loading.

Dental Stress Analysis↗
PubMed1990

Three-dimensional numerical modeling of geoacoustic scattering from seafloor topography.

A three-dimensional (3-D), second-order finite-difference method was used to create synthetic seismograms for wave propagation in heterogeneous media in order to investigate the scattering of elastic and acoustic energy due to topography on the seafloor. The method uses a fully staggered grid in Cartesian coordinates as developed by Virieux [Geophysics 51, 889-901 (1986)]. Numerical results were generated for two models: a linear fault scarp on the seafloor, and a flat seafloor containing a rectangular channel. Wave-front snapshots allow the scattering and focusing of different wave modes with direction to be visualized. Compressional and shear wave backscattering from the sides of the features can be seen together with the trapped compressional wave energy propagating inside the channel. The results illustrate the effects of out of the plane scattering due to simple seafloor topographic features.

Acoustics↗
PubMed1990

The use of the splint bar in conjunction with removable partial denture treatment.

The use of a bar, joined to lone-standing abutment teeth, that spans an edentulous space is an important treatment option for many partially edentulous situations. The splint bar provides positive vertical support for the removable partial denture while rigidly splinting the abutment teeth. This article defines the situations in which this treatment should be considered and describes the technique to achieve a successful result.

Dental Abutments↗
PubMed1989

Removable partial denture design and fabrication survey of the prosthodontic specialist.

In an effort to better understand and define the present standard of practice for removable partial denture design and fabrication, a questionnaire was prepared and distributed to prosthodontic specialists and graduate students or residents attending the American College of Prosthodontists annual meeting in 1987. The survey was designed to determine the philosophies and techniques used by prosthodontic specialists in treatment involving the removable partial denture. There were 195 questionnaires completed and used in determining the results. The results indicate areas of general agreement. Comparison with other data shows areas of controversy, but prosthodontists tend to follow techniques and philosophies similar to what is taught in most U.S. dental schools and what is recommended by the Academy of Denture Prosthetics.

Adult↗
PubMed1989

The Transosteal implant in the prosthodontic reconstruction of the edentulous mandible.

It is the purpose of this article to review transosteal implants, specifically the Mandibular Staple Bone Plate and the Transmandibular Implant, in regard to their clinical prosthodontic applications. In addition, those aspects of prosthodontic treatment shared will be highlighted and the differences in the techniques will be reviewed.

Dental Implantation, Endosseous↗
PubMed1988

Template for positioning and angulation of intraosseous implants.

Presurgical planning for submerged implant location and angulation within bone relative to the opposing occlusion is important for the prosthodontist. This information is accurately communicated to the surgeon by using a surgical template. A technique for fabrication of the template is described.

Dental Implantation, Endosseous↗
PubMedDate not supplied

Dimensional stability of acrylic resin materials after microwave sterilization.

Microwave sterilization techniques have previously been discussed in the literature, but there is need for information regarding the stability of acrylic resins subjected to these techniques. The purpose of this investigation was to measure and determine the potential influence of microwave sterilization on the dimensional stability of polymerized acrylic resin denture base materials. Uniform samples of previously heat-polymerized, autopolymerized, and visible-light-polymerized acrylic resins were measured for changes in weight and length before and after microwave exposure. All three acrylic resin materials maintained excellent stability; all materials had shrinkage values in the range of 0.02% to 0.03%. This is clinically insignificant compared to polymerization shrinkage, which averages 0.2%.

Acrylic Resins↗
PubMedDate not supplied

A review of attachments for removable partial denture design: Part 2. Treatment planning and attachment selection.

Part 2 follows the initial review of attachment partial dentures presented in Part 1 and considers the analysis of specific treatment requirements to provide a rationale for appropriate attachment selection. The tooth/tissue-supported removable partial denture is carefully reviewed and several treatment philosophies for attachment use in this situation are discussed.

Dental Clasps↗
PubMedDate not supplied

Review of attachments for removable partial denture design: 1. Classification and selection.

An attachment is a mechanical device, other than a clasp assembly, that functions as a direct retainer. Attachments for removable partial denture treatment are reviewed and a method for classifying different types of attachments is provided. Attachments are categorized as precision or semiprecision, depending upon the method of manufacture; internal or external, according to their intracoronal or extracoronal location relative to the abutment tooth; and rigid or resilient, as determined by the amount of movement allowed between the component parts. They are also classified by design. The advantages and disadvantages of attachment use as well as indications and contraindications are considered. Additionally, the conventional clasp-type direct retainer is compared to attachments.

Dental Abutments↗