PubMed · 1103216
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
K Hoffmann. 1975. Drum splints through injection casting procedures--an alternative.. https://pubmed.ncbi.nlm.nih.gov/1103216/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
To achieve the complete three-dimensional (3-D) data retrieval of the shape of dentition, dental casts were measured from four directions; occlusal, right, left, and labial sides using a line laser scanner. Reconstruction of the entire shape, including undercuts and tooth crowding area, was attempted by applying a perceptual grouping algorithm, which is one of pattern-recognition theories. In the data measured from occlusal, right and left sides, the rows of measurements were parallel to the frontal plane, and three-directionally combined data (3-DC data) was accomplished by affine transformation. While, in the labial side, transformation to the frontal plane was done since rows of the measured data were parallel to the sagittal plane. To combine the labial data with the 3-DC data and reconstruct the complete image, rearrangement of the order of the data in the file was attempted by applying the perceptual grouping. That is, the minimum total length of data combining was examined by considering the factor of proximity and continuity between the data. The most appropriate order of data combining and recognition of islands were accomplished. Using a computer graphic (CG) with a wire-frame model, complicated regions such as anterior segments showing tooth crowding and undercut area were found to be successfully reconstructed without any data defects. The accuracy of reconstruction was ascertained by comparing the characteristic distances between apexes of molars in the reconstructed model with the real cast. The difference was within 0.3 mm, and present method for dental cast reconstruction is considered to be satisfactory for the present purpose such as orthodontics.
Explore the source record for details and available documents.
OBJECTIVE: To probe the clinical possibility of making incorporated keeper cap by high temperature casting. METHODS: The incorporated keepers were equally divided into two groups, and cast by applying medium and high temperatures respectively. The two groups were compared with the following items: the morphological changes and thickness of keeper's oxide film, the combining quality between keeper and alloy, and the magnetic retention force. RESULTS: The two different casting temperatures had the similar influence on the keeper's properties, such as the keeper's metallographical view, magnetic force (medium temperature casting group: 433.6 g; high temperature casting group: 433.8 g), and combining quality with alloy, except for the morphology and thickness of the keeper's oxide film. The oxide films of the high temperature casting group (surface: 7.59 microns combining surface of keeper and alloy: 6.17 microns) were thicker than those of the medium temperature casting group (surface: 4.65 microns; combining surface of keeper and alloy: 3.95 microns). CONCLUSIONS: The incorporated keeper could be made by using high temperature casting method instead of medium temperature one in clinic.