抄録
The deficiency of the rigidity of the retainer causes the falling of the acid-etched fixed partial denture from the abutment teeth. It was reported in the previous paper that the adhesive strength of the bridge increased as the thickness of the retainer increasing and reached the plateau. Suitable thickness of the retainer, however, may be difficult to obtain due to the occlusal relation.
The purpose of this study is to look for the proper shape of the retainer.
The following conclusions were obtained.
1) Using cobalt-cromium alloy, the adhesive strength in the retainer of 1.0mm thickness was better than that of 0.5 mm on the same shape.
2) The extension of proximal wing portions and adding ledge-form were effective to gain higher adhesive strength in using cobalt-cromium alloy and Au-Ag-Pd alloy.
