The adherence of porcelain to implant gold cylinders with metal over-casting
Date
1995
DOI
Authors
Yip, Shing-Wai
Version
OA Version
Citation
Abstract
Branemark and ITI manufacturers both claim that porcelain should not be directly applied to their implant gold cylinder due to the lack of an oxide layer. It is recommended that the cylinder be over-cast with a metal-ceramic alloy to which the porcelain is subsequently applied. This may result in over contouring and with detrimental effects on the tissue and esthetics.
The purpose of this study is to investigate a technique to reduce this problem by over-casting the cylinders with ceramic alloy 0.8 mm short of the cylinder margin. Various metals and porcelain were used to provide a range of combinations of material with differing thermal expansion coefficients.
Sixty samples of 3i divided to six groups, forty samples of Branemark divided to four groups and thirty samples of ITI divided to three groups were processed in a special designed cylindrical pattern following the manufacturer’s recommended technique and equipments. Wax thickness was standardized to produce the same shape thickness of cast alloy. All specimens were mounted in a jig so that load applied with an Instron was directed on the marginal region. The load (kg) at which the porcelain began to crack is recorded.
Anova and Tukey statistical test revealed:
1. The failure load of porcelain on the Branemark cylinder was higher than the other two groups.
2. No significant difference among the 3i groups.
3. Both ITI and Branemark demonstrated significant differences between specific combinations of metal and porcelain.
This study found no spontaneous failure of porcelain using this over-casting technique and found that specific combinations of metal and porcelain produced maximum resistance to failure.
Description
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Thesis (D.Sc.D.)--Boston University, Henry M. Goldman School of Graduate Dentistry, 1995 (Prosthodontics).
Includes bibliographical references (leaves 117-125).
Thesis (D.Sc.D.)--Boston University, Henry M. Goldman School of Graduate Dentistry, 1995 (Prosthodontics).
Includes bibliographical references (leaves 117-125).
License
This work is protected by copyright. Downloading is restricted to the BU community. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.