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In this work, the effects of Ca content and extrusion temperature on the microstructures and mechanical properties of Mg–1Al– xCa alloys have been investigated. For Mg–1.0Al–0.4Ca (wt-%, AX10) dilute alloy, decreasing extrusion temperature from 290°C to 260°C can inhibit the dynamic recrystallisation (DRX) process, and the yield strength (YS) is also increased from ∼266 ± 6 MPa to ∼309 ± 3 MPa. When increasing the Ca content, Mg–1.0Al–0.8Ca (wt-%, AX11), a higher density of the Al2Ca phase is dispersed at the grain boundaries, which can further restrict the growth of DRXed grains, only ∼1.0 µm. Consequently, the higher YS of ∼330 ± 5 MPa can be obtained. The relevant results can shed light on designing other high-strength and low-alloyed Mg wrought alloys.

The influence of platform-switched abutment on stress distribution within the surrounding bone, fixture, abutment, and screw under various loading conditions were studied. Two 3-D finite element models representative of an implant-supported metal crown for the mandibular first molar and its surrounding bone were computed. Model A simulated the implant with non-platform-switched abutment and model B was for platform-switched abutment. A load of 100 N was applied vertically and obliquely at the center fossa, the tip of the buccal cusp and the distal fossa, respectively. The results show that the distribution of Von Mises stress in the two models is similar. When platform-switched abutment is used, the maximum Von Mises stress within the surrounding bone is lower; however, this value is higher within the fixture and screw.