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With use of dental implants on the rise, there is also a tandem increase in the number of implant fracture reports. To the end of investigating the stress occurring in implants, elasticity and plasticity analyses were performed using the finite element method. The following results were obtained:(1) With one-piece type of implants of 3.3 mm diameter, elasticity analysis showed that after applying 500 N in a 45-degree direction, stress exceeding 500 MPa -which is the proof stress of grade 4 pure titanium -occurred. This suggested the possibility of fatigue destruction due to abnormal occlusal force, such as during bruxism. (2) With two-piece type of implants that can tolerate vertical loading of 5,000 N, plasticity analysis suggested the possibility of screw area fracture after applying 500 N in a 45-degree direction. (3) On the combined use of an abutment and a fixture from different manufacturers, fracture destruction of even Ti-6Al-4V, which has a high degree of strength, was predicted.

An unsupported platinum(III) dimer having added chloro ligands at equatorial sites and novel axial-equatorial chelate ligands, [Pt2Cl2(phpy)4] (Hphpy = phenylpyridine) was obtained from an oxidative addition reaction of [Pt(phpy)2] with [AuCl(SMe2)].

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