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The purpose of this study was to compare the shear bond strength of adhesion bridge by various resin cements. One hundred and fourty 1st premolars were used. The teeth were cut below 2mm from CEJ and the coronal portions were used. The coronal portions were embeded with the acrylic resin and trimmed with sic paper until the flat plane with φ 4mm above acrylic resin sticks in height 5mm were casted with nonprecious metal and the using surfaces were treated with sic paper from ＃200 to ＃1200 and polished with alminum oxide paste.And then, the using surfaces were sandblasted and treated with the electrochemical etching. The teeth were divided into three groups of fourty two each. In group Ⅰ, teeth and specimens were cemented with Panavia 21 In group Ⅱ, teeth and specimens were cemented with Superbond In gruop Ⅰ, teeth and specimens were cemented with All-Bond ＆ composite resin cement Each group was subdivided into three subgroups according to the storage period；one-day storage, fifteen-day storage, and thirty-day storage. The special jig was made. Then, the specimen and jig were mounted to Instron Universal Testing Machine and the failure were measured. The results were as follows. 1. There was statisfically significant difference between the failure loads of group Ⅰ and group Ⅱ and Ⅲ after one day storage(P＜0.01). 2. There was statisfically significant difference between the failure loads of group Ⅱ and group Ⅰ and Ⅲ and between group Ⅰ and group Ⅲ at fifteen day storage(P＜0.01). 3. There was statisfically significant difference between the failure loads of group Ⅰ and Ⅱ and group Ⅲ after thirty day storage(P＜0.01). 4. There was statisfically significant difference between the failure loads of one day storage and fifteen and thirty days storages in group Ⅲ (P＜0.01).
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