Mechanical Property, Fatigue Strength and Clinical Trial of Dental Cast Ti–15Zr–4Nb–4Ta Alloy

Abstract

The mechanical properties and fatigue strength of Ti-15Zr-4Nb-4Ta castings were compared with those of Co-Cr-Mo and Ti-6Al-7Nb castings, which have been clinically used in Japan. The mechanical properties of buffed and chemically polished dental castings were almost the same. The 0.2% proof strength (ρ 0 . 2 % P S ), ultimate tensile strength (ρ U T S ) and total elongation (TE) of the buffed Ti-15Zr-4Nb-4Ta castings were 832 ′ 41 MPa, 964 ′ 69 MPa and 7 ′ 3%, respectively. The ρ 0 . 2 % P S , ρ U T S and TE of the buffed Ti-6Al-7Nb castings were 873 ′ 30 MPa, 982 ′ 27 MPa and 11 ′ 4%, respectively. The ρ 0 . 2 % P S , ρ U T S and TE of the buffed Co-Cr-Mo castings were 589 ′ 23 MPa, 773 ′ 19 MPa and 10 + 2%, respectively. The fatigue strength of the Ti alloy castings at 1 x 10 7 cycles was lower than that of the Co-Cr-Mo castings. The fatigue strengths of the Ti-Al-7Nb and Ti-15Zr-4Ta-4Nb castings at 1 x 10 7 cycles were approximately 100 and 80 MPa, respectively. Clinical trials were carried out for complete and partial dentures made of the Ti-15Zr-4Nb-4Ta alloy. Clinical observation was conducted over a one year period for patients wearing complete or partial dentures. During the clinical observation, all five patients felt comfortable with the dentures, and fracture of the clasp was not observed.