Influence of polishing on cast clasp properties.
During the polishing of clasps, two possible changes that could affect their properties are thinning of the clasp and work hardening of the alloy. Two distinctly different clasp pattern forms were selected and 20 samples of each were cast. They were then divided into two groups, polished and unpolished, in an effort to determine the total influence of the polishing procedure on clasp behavior. The results indicate that polishing produces a slightly more flexible clasp. Any influence resulting from possible work hardening is offset by the reduction of clasp thickness. Effects of width/thickness ratios and magnitude of deflections on finishing and polishing techniques may also alter clasp flexibility in the polished clasp.
Stress-relaxation testing. Part I: A new approach to the testing of removable partial denture alloys, wrought wires, and clasp behavior.
Presented at the meeting of the American College of Prosthodontists, San Diego, Calif. *Chief, Dental Service, Veterans Administration Hospital, Allen Park, Mich., and Associate Professor, Biomaterials, University of Detroit. **Professor, Department of Dental Materials, University of Michigan; Consultant for Dental Research, Veterans Administration Hospital, Allen Park, Mich. ***Research Associate, Department of Dental Materials, University of Michigan.
Numerical system of clasp design
Abstract Many terms necessary in clasp construction such as strength and retention can be expressed numerically. However, by suitable choice of definitions, they can also be made additive so that calculations are reduced to the simplest procedures of addition and subtraction. The strength of the clasp, for example, can be assessed as the sum of contributions from three components—the clasp, the material, and the tooth. The quality or value of Q of the clasp measures clasp performance and, like strength, is the sum of three quality components, from the clasp, the material, and the tooth. This method gives a means of assessing not merely the over-all performance but, more especially, the relative merits of shape and tapering in clasp design and the suitability of different materials for clasp work. The Q value of the material, Q m , can be calculated from published data and offers a framework for future research on clasp materials.