Dental instrument

The dental instrument includes a syringe and a topical anesthetic dispenser that is slidably attached to the syringe. The topical anesthetic dispenser can include a dispenser plunger, a dispenser barrel that slidably engages the dispenser plunger, a dispenser tube, and a needle cover affixed to the dispenser tube. The syringe can include a syringe plunger, a syringe barrel that slidably engages the syringe plunger, and a hollow needle having a beveled front end and a rear end extending toward the syringe barrel. A first carpule containing topical anesthetic can be loaded in the dispenser barrel. A second carpule containing injectable anesthetic solution can be loaded in the syringe barrel.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a dental device, and particularly to a dental instrument including a dental syringe and a topical anesthetic dispenser.

2. Description of the Related Art

While anesthetic solutions are typically administered to minimize pain associated with a particular dental procedure, the process of injecting the anesthetic solution itself can be very painful. Various topical agents are employed to minimize the pain that would otherwise be experienced by the injection. Topical anesthetics, for example, in the form of gels (Benzocaine), sprays (Tetracaine), patches (Lidocaine, EMLA made of lidocaine and prilocaine), and creams (EMLA) can be used to provide relief from pain associated with the injection.

Traditionally, administration of the topical anesthetic and the injectable anesthetic has been a cumbersome process, requiring the use of separate instruments and preparation measures. The prescribed protocol for sterilizing the target zone, preparing the instruments, and applying the topical anesthetic can significantly increase the overall time a caregiver must spend with each patient prior to administering the anesthetic injection. Oftentimes, multiple caregivers can be required to topically apply the anesthetic and administer the injection. In addition, a caregiver using a needle for injecting the anesthetic solution must take extra care to avoid accidental needle pricks and infectious needle stick injuries. The risk of an accidental needle stick injury is particularly high when a caregiver attempts to recap the needle after injection.

Thus, a dental instrument solving the aforementioned problems is desired.

SUMMARY OF THE INVENTION

The dental instrument includes a syringe and a topical anesthetic dispenser that is slidably attached to the syringe. The topical anesthetic dispenser can include a dispenser plunger, a dispenser barrel that slidably engages the dispenser plunger, a dispenser tube, and a needle cover affixed to the dispenser tube. The syringe can include a syringe plunger, a syringe barrel that slidably engages the syringe plunger, and a hollow needle having a beveled front end and a rear end extending toward the syringe barrel. A first carpule containing topical anesthetic can be loaded in the dispenser barrel. A second carpule containing injectable anesthetic solution can be loaded in the syringe barrel.

When not in use, the needle cover can be positioned to extend circumferentially around the needle and protrude beyond the needle tip to avoid accidental needle pricks. In use, a user can push the dispenser plunger in the direction of a target area to thereby slide the barrel dispenser barrel forward and/or eject the topical anesthetic from the first carpule through the dispenser tube to the target area. After the topical anesthetic is administered, the user can pull the dispenser plunger (together with the dispenser tube and needle cover) in the opposite direction to expose the needle tip. Pushing the syringe plunger can move the rubber stopper through the second carpule and thereby eject fluid from the carpule through the needle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIG. 1, the dental instrument10includes a syringe12and a topical anesthetic dispenser14that is slidably mounted on the syringe12. The topical anesthetic dispenser14can include a dispenser plunger16, a dispenser barrel18to which the dispenser plunger16is slidably attached, a dispenser tube20, and a needle cover22affixed to the dispenser tube20. The syringe12can include a syringe plunger24, a syringe barrel26to which the syringe plunger24is slidably attached, and a hollow needle28having a beveled front end33defining an injection opening and an opposite rear end extending toward the syringe barrel26. The syringe24can further include two grip handle rings38aand38b, respectively, through which a user's index finger and middle finger can be inserted to hold the dental instrument10in place. A first carpule30containing topical anesthetic can be loaded in the dispenser barrel18. A second carpule32containing injectable anesthetic solution can be loaded in the syringe barrel26. The first and second carpules30and32, respectively, can include a generally cylindrical glass vial having openings at first and second opposing ends. The first end of each of the vials is covered by a rubber membrane that is held in place by a cap58and59, respectively, made of metal foil. The metal cap58,59of each vial has a circular opening at its center that exposes a portion of the rubber membrane. The rubber membrane of the first carpule30and the second carpule32can be pierced by a rear end of the dispenser tube20and the needle28, respectively. The second end of each vial is closed by a movable rubber stopper34and36, respectively.

The dental instrument10can be made from chrome-plated brass, stainless steel, or any suitable material known in the art.

The syringe12and the dispenser14can be slidably connected in any suitable manner. As shown inFIG. 2, for example, an attachment bracket40can be provided which can be fitted within the syringe barrel26, e.g., over the carpule32, and slidably attached to the dispenser barrel18. The attachment bracket40can include ring-like opposing ends for receiving opposing ends of the carpule32. A bottom surface of the dispenser barrel18can, for example, include guide rails which slidably engage corresponding grooves defined in the attachment bracket. Alternatively, the dispenser barrel18can include grippers which slidably engage side edges of the attachment bracket. As is further shown, the dispenser barrel16can include a cylindrical protrusion14athat receives an end portion of the syringe barrel26. As such, the cylindrical protrusion14acan have a diameter that is slightly larger than the end portion of the syringe barrel26.

The syringe plunger24can include a shaft42having a ring handle44at one end and a piston46at an opposing end. A cylindrical housing member48can be positioned adjacent the piston46. The cylindrical housing48can have a peripheral wall defining two opposing open ends. A compression spring50and a push knob52can be positioned within the cylindrical housing48. A harpoon member54having a pointed or angled sharp edge can be at least partially disposed within the housing48. The harpoon member54can be configured to engage a surface of the rubber stopper34of the carpule32. For example, the harpoon54tip can be configured to hook into a top surface of the rubber stopper34. A separating member56can be provided to separate the housing member from the syringe barrel26.

The syringe plunger24can be configured to include an activating/locking mechanism that facilitates locking the compression spring50in a compressed state and/or releasing the compression spring50. For example, the piston46can be rotationally constrained relative to the housing member48. The piston46and the housing member48can, for example, include corresponding first and second threads, whereby twisting the syringe plunger24in a first direction compresses the compression spring50, and twisting the syringe plunger24in an opposite second direction releases the compression spring50. Upon release of the compression spring50, the push knob52is pushed toward the carpule32, which causes the harpoon54to latch into the rubber stopper34and the needle28to pierce the rubber membrane of the carpule cap58. In other words, the push knob52can transmit load from the plunger24via the compression spring50to the rubber stopper34.

As shown inFIG. 3, the first carpule30containing topical anesthetic can be loaded in the dispenser barrel18such that the rubber membrane of the cap59is penetrated by a rear end of the dispenser tube20, and the rubber stopper36is in communication with the dispenser plunger16. The front end of the dispenser tube20defines a dispenser opening or spray nozzle for dispensing topical anesthetic on the injection site. The second carpule32containing injectable anesthetic solution can be loaded in the syringe barrel26such that the cap58is proximate the rear end of the needle28and the rubber stopper34is proximate the harpoon54of the syringe plunger24.

When not in use, the needle cover22can be positioned to extend circumferentially around the needle28and protrude beyond the needle tip30, as shown inFIG. 1, to avoid accidental needle pricks. In use, a user can push the dispenser plunger16in the direction of a target area to thereby slide the dispenser barrel18forward and position the dispenser tube20(together with the attached needle cover22) proximate a target area. Additional pressure on the dispenser plunger16can eject a spray of the topical anesthetic from the first carpule30through the dispenser tube20and to the target area. After the topical anesthetic is administered, the user can pull the dispenser plunger16(together with the dispenser tube20and needle cover22) in the opposite direction to expose the needle tip30. In other words, the dispenser tube20and needle cover22can slide in the direction of the user to expose the needle when the dispenser plunger16is pulled. The syringe plunger24can then be manipulated to release the compression spring50. As described above, release of the compression spring50can advance the harpoon54forward to embed the harpoon tip54in the rubber stopper34and cause the rear end of the needle28to penetrate the rubber membrane of the cap58. The needle tip30can then be inserted into a target area and the syringe plunger24can then be pushed forward to move the rubber stopper34through the second carpule32and eject fluid from the carpule32through the needle28.

It should be noted that a user can, after inserting the needle tip30into a target area and prior to ejecting fluid from the carpule32, withdraw a small amount of fluid from the target area by pulling the syringe plunger24in the direction of the user. Pulling the syringe plunger24can allow the harpoon54that is embedded in the rubber stopper34to elevate the rubber stopper34and thereby draw fluid into the carpule32. Blood in the carpule32can indicate to a user that the needle28has penetrated a blood vessel and must be repositioned.