Crown Contours

Current theories of crown contour, margin placement, and pontic design
• Curtis M. Becker, D.D.S., M.S.D., a, b, *,
• Wayne B. Kaldahl, D.D.S.a, b, **
• a University of Colorado, School ofDentistry, Denver, Colo., USA
• b University of Nebraska, School of Dentistry, Lincoln, Neb. USA

Abstract
Crown contours which promote favorable tissue response follow these guidelines: (1) buccal andlingual contours are flat; (2) embrasure spaces should be open; (3) contacts should be high (incisal one third) and buccal to the central fossa (except between first and second molars); and (4)furcations should be “fluted” or “barreled out.” Margins should be supragingival where possible. The pontic design of choice is the modified ridge lap for posterior spaces and the ridge-lap facing foranterior spaces.

Reprint requests to:DR. CURTIS M. BECKER 5055E. KENTUCKY DENVER, CO 80222.
*Clinical Assistant Professor, Department of Restorative Dentistry, University of Colorado, School ofDentistry.
Assistant Professor, Department of Periodontics, University of Nebraska, School of Dentistry.
Copyright © 1981 Published by Mosby, Inc.


Gómez Mira F, Ardila Medina CM.
Purpose: Secondarycaries at crown margins and the influence of preparation techniques are major clinical problems. It was therefore the aim of this study to compare natural caries lesions at crown margins withexperimental caries lesions.
Materials and Methods: Five extracted caries-free human molars were restored with gold cast crowns and afterwards covered with wax leaving a 3 × 3 mm window at the crown margin.These teeth were then incubated in acidified gel (pH 4.7) for 50 days. After incubation these teeth and five other crowned extracted teeth exhibiting natural caries lesions were embedded in Technovit9100. Serial sections with a thickness of 80 μm were cut through the lesions and investigated with polarized light microscopy (PLM) and scanning electron microscopy (SEM) combined with energy...