Effect of metal design and technique on the marginal characteristics of the collarless metal ceramic restoration.
نویسندگان
چکیده
This investigation examined the marginal characteristics of the collarless metal ceramic restoration made with two commonly used direct-lift techniques: (1) a porcelain/wax paste and (2) a porcelain/liquid slurry. The metal copings touched the shoulder in half of the groups and were left 0.5 mm short in the other half to comprise the four experimental groups. Marginal seal was evaluated at facial and lingual surfaces on embedded and sectioned specimens for each group. Photo negatives were made of each specimen and projected at a constant magnification so that tracings could be made of the space between the die shoulder and corresponding porcelain. Composite surface measurements were made for each sample with a Zeiss Interactive Digital Analysis System instrument to evaluate porcelain adaptation to the shoulder. The porcelain/liquid groups demonstrated significantly smaller (p less than or equal to 0.05) facial marginal openings than the porcelain/wax groups. The group made with the porcelain/liquid technique with the metal on the die shoulder produced the most consistent overall results. The porcelain/liquid group with the metal off the shoulder had a statistically larger (p less than or equal to 0.05) mean marginal opening from the external margin to a point 0.75 mm to the interior than both techniques with the metal on the shoulder. Lingual marginal adaptation did not vary with each of the four experimental groups.
منابع مشابه
The evaluation and comparison of marginal adaptation in metal ceramic and all ceramic restorations fabricated by two methods: CAD/CAM and conventional
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متن کاملA study on the fracture strength of collarless metal-ceramic fixed partial dentures
PURPOSE The objective of this study was to evaluate fracture strength of collarless metal-ceramic FPDs according to their metal coping designs. MATERIALS AND METHODS Four different facial margin design groups were investigated. Group A was a coping with a thin facial metal collar, group B was a collarless coping with its facial metal to the shoulder, group C was a collarless coping with its f...
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ورودعنوان ژورنال:
- The Journal of prosthetic dentistry
دوره 65 5 شماره
صفحات -
تاریخ انتشار 1991