| Objective:The purpose of this study was to develop a inter-joins zirconia abutment and assess its mechanical properties.Methods:The zirconia abutments were made from nanometer zirconia powder by injection molding technology. (1) zirconia abutments and titanium abutments of the 10 which were separately attached to Osstem GSⅡSystem implants were divided into half by wire cutting machine along the plant axial length, then the microgap at interface were measured by scanning electron microscope. (2) 20 zirconia abutments and 20 titanium abutments were separated into four groups; each group included five zirconia abutments and five titanium abutments. Three groups which were chosen randomly were separately attached to Osstem GSⅡSystem implants. Set them to abutment-implant assembly group. In order to simulate the different loading conditions of anterior teeth and molar teeth, the abutment-implant assembly group were grouped by different stress angle:forced the abutments along the plant axial length to 30°(Group A),90°(vertical, Group B), and 0°(parallel, Group C) angles. Then the fracture resistance of the specimens was separately tested and compared. (Speed=0.5 mm/min). The rest group (Group D) was chosen for single abutment. The fracture resistance of the specimens was tested and compared when forced the abutments along the plant axial length. (Speed=0.5mm/min).Results:The prepared zirconia abutments had good shape and fit the plant smoothly. (1) The internal hexagonal microgap of connected interfacial of the zirconia-plant and titanium-plant respectively were 16.90±0.86μm and 11.76±0.50μm, There was statistical differences between the two groups (P <0.05). The minimum microgap of the Moore's taper place of zirconia-plant and titanium-plant respectively were 5.45±0.68μm and 4.94±0'.66μm; the maximum microgap was 33.85±2.98μm and 9.63±0.94μm. No statistical difference was observed in minimum microgap of the two groups (P>0.05), while there was statistical differences in maximum microgap of the two groups (P<0.05). (2)The compression strength of zirconia abutments and titanium abutments:When the angle was 30°(Group A), the compression strength of zirconia abutment and titanium abutment respectively were 434.66±36.07N and 1073.12±73.96N, there was statistical differences in the two samples (P<0.05). When the angle was 90°(Group B), the compression strength of zirconia abutment and titanium abutment respectively were 301.46±15.38N and 736.36±120.10N,it also had statistical differences (P<0.05). The angle was 0°(Group C), when the mean fracture load was in 1300～2000N, all of the plants had been "s" shape, while both zirconia abutments and titanium abutments had not happen any form of damages. The compression strength of Group D (zirconia abutment and titanium abutment) was 2882.28±164.37N and 1934.14±89.30N, there was statistical differences in the two samples (P<0.05).Conclusions:The zirconia abutments which were made from nanometer zirconia powder by injection molding technology can fit the plant smooth, both the adaptability of abutment-plant connected interfacial and the compression strength under multi-angle load can meet clinical application requirements. |
