Now composite resin restoration is clinically accepted in the repair of fractured PFM case, many mechanical surface treatment methods are performed to increase retentive force. The main purpose of this study was to compare the retentive force among the possible surface treatments and to insure the best method for the clinical application of the fractures porecelain and the exposed metal surface. To compare and to analyze the retentive force of repair resin, porcelain specimen were divided into 2 groups, etching group and non - etching group, and etching group were treated with 37% H3PO4, 1.23% APF. 10% HF and non - etching groups were treated with diamond bur, micro - sandblasasting. Also, metal specimens were divided by 2 groups : one was non - precious metal group which was treated with diamond but, micro - sandblasting and tin plating and electrolytic etching, the other was precious metal group which was composed of micro - sandblasting treatment only and tin plating treatment with micro - sandblasting. Each specimen had been restored for 48 hours and the bond strength of each specimen was calculated with Universal testing machine. @ES The results were as follows : @EN 1. Porcelain specimen had higher bonding strength than metal specimen for the repair resin(P<0.01). 2. In porcelain specimen, 10% HF etching group had the highest bonding strength among etching and non - etching group. 3. Metal specimen treated with micro- sandblasting had highest bonding strength among the non - sandblasting had highest bonding strength among the non - precious group, tin plating group had higher bonding strength than micro - sandblasting
group between the precious metal groups. 4. Bonding strength of tin plating was increased in precious metal group only.
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