title: [A dynamic fitness test and a new method to measure the thickness of film using the digital subtraction system of X-ray photographic density].
abstract: It is impossible to show the dynamic fitness conditions of a denture base using White Silicone or other fitness test materials. In the present paper, materials and the measuring method for the dynamic fitness test were investigated. In order to choose the suitable materials for the dynamic fitness test, various kinds of ready made materials, such as wax or dynamic impression materials, were examined by load test and investigated the change on standing of flow character. EXPERIMENTAL WAX was made for dynamic fitness test, and was examined by load test and clinical test. EXPERIMENTAL WAX consists of DISCLOSING WAX (KERR), as a basic material, and the contrast medium. Extending the system of the conventional measuring method for White Silicone, DIGITAL SUBTRACTION SYSTEM (DSS) was developed as a new method of quantitative analysis for the thickness of wax film. In this system, thickness of wax film is measured from the X-ray photographic density and it's digital subtraction management. Accuracy of this system was also investigated. The summary of results is shown below. 1. It became evident that ready made materials had no useful characters for the dynamic fitness test. 2. EXPERIMENTAL WAX showed similar load effects with White Silicone when the load was 5 or 10kg. 3. Dynamic fitness and the mobility of the denture base during function were able to be shown by EXPERIMENTAL WAX, but it's operation was more complicated than White Silicone. 4. DIGITAL SUBTRACTION SYSTEM (DSS), a new method of quantitative analysis for the thickness of wax film, was developed. 5. Resolving power and measuring range of DSS were effected by quantity of subtraction. 6. DSS is not only useful to measure the thickness of EXPERIMENTAL WAX, but also has wide applications.
authors.forename: S
authors.initials: S
authors.lastname: Hanatani
mesh_terms: D003799:Dental Stress Analysis / Q000295:instrumentation / Q000379:methods*; D003819:Denture Bases; D003824:Denture, Complete; D006801:Humans; D011856:Radiographic Image Enhancement; D013382:Subtraction Technique