Showa Yakuhin Kako Co., Ltd.

Gc Showayakuhin Corporation

Mitsuhiro Haraguchi

Yoshihiko Kawasaki

Fumio Tanaka

Mutsumi Shibuya

Renji Hayashi

Yoshinori Kato

Yukio Suzuki

Takashi Osada

Kazuhiro Ono

Yoshinori Katoh

Kiyoshi Wakabayashi

Ikuo Kitagawa

Yoshihiko (deceased) Kawasaki

Provided is an anesthetic solution-filled cartridge-type electric dental syringe, wherein the plunger has been shortened but the plunger can nevertheless be extended to the distance necessary to evacuate the anesthetic solution from the cartridge. The syringe comprises: an extension tube into which a plunger is movably inserted, the extension tube being movably disposed in the through hole of a support block and having racks formed in the side surface thereof that are coordinated with the racks of the plunger; and a means for the plunger to draw the extension tube to engage the racks of the extension tube with a pinion when the plunger reaches the middle of the distance corresponding to the anesthetic solution accommodation length of the cartridge. By the engagement of the racks of the extension tube with the pinion, the plunger moves together with the extension tube for the remainder of the distance corresponding to the anesthetic solution accommodation length of the cartridge.

Anesthetic solution-filled cartridge-type electric dental syringe

A motorized syringe for use with two types of dental anesthetic solution-filled cartridges, having a plunger plug in the 1.8 ml cartridge pushed by a push rod by a length required to push a plunger plug in the 1.0 ml cartridge. The syringe includes a cartridge holder for use with 1.0 ml and 1.8 ml cartridges, the push rod having a 1.0 ml position and a 1.8 ml position drawn back from the 1.0 ml position so that push rod movement can end at a common terminal position for both, a sleeve adapted to receive the push rod rear end when pushed back from the common terminal position, and to be not interfered with by the push rod's rear end when it is in the 1.0 ml position, the sleeve being pushed rearward with the push rod's rear end when pushed back to the 1.8 ml position.

Motorized syringe for use with two types of dental anesthetic solution-containing cartridges

A composition for local anesthesia which comprises a local anesthetic as an active ingredient and an agent for maintaining anesthetic action selected from the group consisting of acidic mucopolysaccharides such as sodium chondroitin sulfate and cellulose derivatives such as hydroxypropylmethylcellulose, and does not contain catecholamines, which has durability of anesthetic action suitable for minor dental operations such as tooth extraction, and can be used as a safe composition for local anesthesia used for oral surgery or dental treatment.

Composition for local anesthesia

A linear cartridge-type motorized dental syringe has a plunger rod aligned with a drive shaft of a motor, the externally threaded plunger rod movable longitudinally, but not rotatably, relative to the casing, a cylindrical body rotated by the shaft, a nut having arm-like nut halves with internal threads engaging external threads on the rod, a locking ring for rotation around an axis of the rod and for longitudinal movement between a rearward position where the ring forces the threads on the nut halves to engage the threads on the rod, and forward where the ring releases engagement of the threads, pusher pins for moving the ring rearward when the cartridge holder is inserted, and a spring for pushing the locking ring back to the forward position, with rotation of the cylinder body resulting in rotative motion of the nut around the rod to move it forward.

Linearly motorized dental syringe

Growing community of inventors

Shiraoka, Japan

Mitsuhiro Haraguchi