Comparative study in marginal fit of a pressed ceramic and feldspathic porcelain fused to metal restoration / 대한치과보철학회지

PURPOSE: The purpose of this in vitro study was to compare the marginal adaptation of a ceramic-pressed-to-metal restoration with traditional metal-ceramic restoration. MATERIALS AND METHODS: Duplicating the prepared resin tooth, 20 metal dies were fabricated. Twenty metal copings of 2 groups which were metal ceramic restoration and pressed to metal restoration were fabricated. The marginal opening of each coping was measured with Microscope (BX 60M-36E 41D(R): Olympus, Japan). After porcelain build-up, the marginal opening of metal ceramic restoration and pressed to metal restoration (PoM(R): Ivoclar vivadent., Liechtenstein) were also evaluated in the same method. The measurements were analyzed using Wilcoxon Signed Ranks test and Mann-Whitney U test. RESULTS: Within the limits of this study, the results were as follows. 1. Metal-ceramic restorations in coping state (64.93 +/- 12.48 microm) in compared with Metal ceramic restorations after porcelain build-up (63.43 +/- 12.86 microm) had no significant difference in marginal adaptation. 2. Pressed-metal-ceramic restorations in coping state (50.00 +/- 12.28 microm) in compared with Pressed metal ceramic restorations after porcelain build-up (56.72 +/- 13.80 microm) had no significant difference in marginal adaptation. 3. Metal-ceramic restorations in compared Pressed-metal-ceramic restorations had no significant difference in marginal adaptation. CONCLUSION: Pressed-metal-ceramic restorations have the advantage of being technically less change through using of the lost-wax technique and this allows for the convenience of a full-contour ceramic wax-up as opposed to the more technique-sensitive layering method. Pressed-metal-ceramic restorations may be considered in clinic on the basis of the result of this study and the advantage of this system.

Morphometrics of alveolar process and anatomical structures around inferior maxillary sinus for maxillary implantation / 대한치과보철학회지

STATEMENT OF PROBLEM: Following tooth loss, the edentulous alveolar process of maxilla is affected by irreversible reabsorption process, with progressive sinus pneumatization leads to leaving inadquate bone height for placement of endosseous implants. Grafting the floor of maxillary sinus by sinus lifting surgery and augmentation of autologous bone or alternative bone material is a method of attaining sufficient bone height for maxillary implants placement and has proven to be a highty successful. PURPOSE: This study was undertaken to clarify the morphometric characteristics of inferior maxillary sinus and alveolar process for installation of implants. MATERIAL AND METHOD: Nineteen skulls (37 sinuses, 10M / 9F) obtained from the collection of the department of anatomy and cell biology of Hanyang medical school were studied. The mean age of the deceased was 69.9 years (range 44 to 88 years). The distance between alveolar border and inferior sinus margin at each tooth, the height of alveolar process and the thickness of cortical bone of the outer and inner table of alveolar process and the inferior wall of maxillary sinus were measured. RESULTS AND CONCLUSION: 1. The septum of inferior maxillary sinus were observe 28 sides (76.%) and located at the third molar (52.6%) and the second molar (26.3%). The deepest points of inferior border of maxillary sinus were located the first or second molar. The distance between alveolar margin and the deepest point of inferior maxillary sinus is 9.7 +/- 4.9 mm. 2. The length of the outer table of alveolar process were 4.9-28.2 mm and the shortest point was between the first and the second molors. The thickness of them were 0.9-3.2 mm. The length of the inner table of alveolar process were 7.4-25.8 mm and the shortest point was between the first and the second molars. The thickness of the were 0.9-4.6 mm. The results of this study are useful anatomical data for installing of maxillary implants.