A new two-piece dental implant, having a replaceable thin titanium sleeve in its 5 mm crestal part was designed. The use of a sleeve of near 0.2 mm thickness reduces implant diameter by 0.4 mm. Narrower diameter implants may increase the likelihood of component fracture in dental implant systems. 14 two-piece dental implants, with 25 deg abutment angle were subjected to a dynamic fatigue test according to DIN EN ISO 14801. The highest load at which a runout (nonfailure) occurred at 5 × 106 cycles, amounted to 575 N. This load level was confirmed with n = 3 samples. The Wöhler curve was determined. Accordingly, the runout at 106 cycles can be anticipated as 625 N. The new two-piece Implant B™ design using a 0.2 mm sleeve is compatible with the DIN EN ISO 14801 standards for dimensions of 4.2 mm diameter and 13 mm length. It withstands dynamic fatigue test at least as good as any other standard endosseous implant.