Abstract: An assembly for practicing sinus membrane elevation in the process of dental implant surgery comprising a balloon made of an elastomeric material and having a rounded head portion, an elongated, tubular sleeve portion and a flanged rim portion. Further provided is a balloon probe member having a stem portion with an outer screw-thread and a bore freely fitting the external diameter of the balloon tubular sleeve. A connector member is threadably receivable in the probe member and connected to a flexible pipe with a manually operable valve. For inflating the balloon a pump supplies a pressurized fluid through the pipe.