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Biomedical subjects

R A Tanquist

Publications and source records attributed to R A Tanquist.

11 recordsLinked to original sources
PubMed1989

Bone stress distribution for three endosseous implants.

Axisymmetric finite element models of three geometries were evaluated: a serrated solid with a 2-degree taper and a rectangular cross section; a cylindrical screw-type solid; and a finned solid with a 1 degree 9' taper and a circular cross section. Ten moduli of elasticity ranging from 0.348 to 74.96 psi x 10(6) were used for each geometry. Contour plots of the resulting Von Mises stresses were used to study the changing stress distribution patterns within the surrounding cortical bone. The results indicated that the serrated geometry led to high-stress concentrations at the tips of the bony ingrowth and near the neck of the implant. Low moduli of elasticity emphasized these concentrations. The nontapered screw-type geometry had high-stress concentrations at the base of the implant when high moduli were studied and at the neck of the implant when low moduli were studied. The conclusion of this study was that a tapered endosseous implant with a high elastic modulus would be most suitable for dental implantology. However, the design must not cause high-stress concentrations at the implant neck that commonly cause bone resorption.

Alveolar Process↗
PubMed1987

The influence of anterior coupling on mandibular movement.

The need for and use of anterior coupling in occlusal rehabilitation has been discussed. The anterior teeth can often be coupled to the posterior controls by modifying contours with selective grinding, full or partial coverage restorations, or composite. When anterior guidance is provided, the anterior teeth should harmonize with the TMJs so that the posterior teeth will disclude in excursive mandibular movements. Significant functional, esthetic, and phonetic alterations that change the anterior guidance must be carefully planned because the anterior guidance affects all excursive tooth contacts. Anterior coupling, as described, is often an overlooked entity in restorative dentistry. Evidence of its role in separating the posterior teeth, reducing parafunctional activity, and harmonizing the temporomandibular complex has been presented.

Cuspid↗
PubMed1985

Methods taught in dental schools for determining the posterior palatal seal region.

The following conclusions summarize the results of a survey sent to the chairperson of the removable prosthodontic department of 70 dental schools regarding the concepts and techniques taught for developing the posterior palatal seal. A combination of clinical methods was most frequently taught for locating the vibrating line. The phonation of the Ah sound was the most popular single method taught for locating the vibrating line. Seventy-five percent of the dental schools taught that there is one vibrating line per person. The posterior flexion line was related to the distal termination of the maxillary denture by dental schools that teach the concept of two vibrating lines. Most dental schools (80.4%) do not use the fovea palatinae for locating the distal termination of the maxillary denture. Most dental schools (87.5%) teach students to carve the posterior palatal seal on the maxillary master cast. Most dental schools (93.9%) take the compressibility of the palatal tissue into consideration when carving the depth of the posterior palatal seal in the maxillary master cast. The butterfly pattern was most frequently described to carve the posterior palatal seal in the maxillary master cast.

Dental Impression Technique↗