Handheld device for applying dental materials

Information

  • Patent Grant
  • 6319002
  • Patent Number
    6,319,002
  • Date Filed
    Thursday, August 24, 2000
    24 years ago
  • Date Issued
    Tuesday, November 20, 2001
    23 years ago
  • Inventors
  • Examiners
    • Wilson; John J.
    Agents
    • Ryan Kromholz & Manion S.C.
Abstract
A dental handpiece arranged to be coupled to a capsule containing a composite material and for delivering and/or retracting the composite material to and from the mouth of a patient. The handpiece includes an elongate tubular member having a hollow chamber for receiving a reversible electric motor, a battery for supplying electric power to the motor and a drive shaft coupled to the motor. The drive shaft is restrained from longitudinal movement but contains a threaded portion for engagement with a threaded bore of a longitudinally movable plunger. The plunger is arranged to force outward movement of the composite material from the reservoir of the capsule. A manually operated electric switch is preferably mounted in the wall of the handpiece with a portion extending internally and externally of the wall.
Description




BACKGROUND OF THE INVENTION




The present invention relates generally to a syringe and capsule therefore, and more specifically to a dental placement syringe and disposable capsule for use therewith.




Dental syringes and disposable plastic capsules for dispensing dental material are well known in the art. Disposable capsules, such as those described in U.S. Pat. Nos. 4,969,816; 5,165,890; 5,172,807; 5,306,147; and 5,336,088, are available in a number of sizes and shapes for dispensing a variety of dental materials. They essentially comprise a plastic body having an internal reservoir, a large diameter opening on one end and a small diameter discharge tip on the opposite end, as well as a separate piston or plug inserted into the large opening.




The internal reservoir is filled with dental material, and the plug seals the material within the reservoir. As the plug is pushed deeper into the reservoir, dental material is dispensed from the discharge tip. The capsules may be preloaded with dental material, or may be loaded on site as needed.




Dental syringes, such as those described in U.S. Pat. Nos. 5,061,179; 5,306,147; and 5,336,088, hold the disposable capsules in place, and have a longitudinally moving plunger that can push the plug into the reservoir, dispensing the dental material in a controlled fashion.




The longitudinally moving plunger is typically moved by squeezing or compressing a spring loaded handle or plunger. A full compression of the handle results in all the dental material being dispensed.




Although dental syringes and disposable capsules have become a convenient way to dispense a controlled amount of dental material into a patient's mouth, the size and shape of existing syringes can cause inconvenience. Syringes that are thin and fit easily into a patient's mouth, such as described in U.S. Pat. No. 5,129,825, must be held like a conventional manually operated syringe, using two fingers and the thumb to hold the device, with the thumb depressing the plunger. Positioning the hand with the thumb and fingers spread is uncomfortable and can quickly become tiresome. Holding the syringe by its rear portions also creates difficulty in controlling the exact location of the capsule tip and placement of the dental material.




Pistol grip syringes, such as described in U.S. Pat. No. 5,061,179, are more comfortable for the dentist's hand and can allow more precise placement of the dental material, but are bulky and difficult to fit in the small confines of an oral cavity.




Another difficulty in using conventional syringes is that once the dental material is dispensed, it cannot be drawn back into the reservoir. If too much material has been dispensed, the dentist must use another tool to pick up the excess. This is because the syringe's longitudinally moving plunger can only push the plug deeper into the reservoir. After an amount of material is dispensed, releasing the handle will allow the handle and longitudinally moving aperture to return to their original positions, but the plug will be left in the farthest forward position inside the capsule tip.




For the foregoing reasons, there is a need for a device that will allow a dentist to precisely dispense, and possibly recollect, a controlled amount of dental material into a patient's mouth in a manner that is comfortable for both the dentist and the patient.




SUMMARY OF THE INVENTION




The present invention is directed to a dental handpiece that satisfies the needs described above. The present invention preferably comprises a body with a hollow chamber, a reversible electric motor, a power supply, a retractable plunger, a drive shaft, a manual power switch, a removable nose cone and a disposable capsule tip.




The body of the handpiece is designed to fit comfortably in the dentist's hand, similar to the fit of a highlighting marker or soldering iron. Power is controlled by a sliding switch that normally rests in a neutral position and can move forward or backward, thus powering the electric motor in either forward or reverse operation. The sliding portion of the switch may be a ring that encircles the main shaft of the handpiece, allowing convenient switching operation by either the thumb, a finger, or both working simultaneously.




The hollow chamber of the handpiece holds the electric motor, rechargeable battery and drive shaft. The motor rotates the drive shaft, which is threaded and axially fixed. The retractable plunger tapers to a point at the front end, and has an internal longitudinal bore beginning at the rearward end and spanning most of its length. A portion of the longitudinal bore is threaded, and engages the threaded drive shaft. As the fixed drive shaft rotates in one direction, or the other, the plunger either advances or retracts longitudinally.




The detachable nose cone connects to the body and holds a disposable capsule tip filled with dental material. As the plunger advances forward, the tapered end enters the internal reservoir of the capsule tip, thus dispensing the material. The plunger is made of a somewhat flexible material that can bend around a curve in the capsule tip, but can still withstand high temperature sterilization. Because the plunger is retractable, and no separate insert plug is used, the device has the ability to draw excess material back into the capsule tip.




The overall shape of the device allows for precise control while comfortably fitting in the dentist's hand and the patient's mouth. The electric dispensing mechanism, as opposed to conventional manual operation, generates the same result with less physical effort, and allows greater precision and less fatigue during extended use. The tapered plunger reduces waste by eliminating the need for a separate disposable plug, and allows the device to recollect unneeded dental material if an excess is dispensed. The detachable nose cone and the plunger can be removed, sterilized, and reused. The present invention can also be connected to a battery charger without disassembly.











DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view of the present embodiment of the handpiece of this invention.





FIG. 2

is a perspective exploded view of the present embodiment of the invention.





FIG. 3

is a side elevational view of the present embodiment of the invention.





FIG. 4

is a longitudinal sectional view of FIG.


3


.





FIG. 5

is a fragmentary longitudinal sectional view depicting the plunger of

FIG. 4

, positioned in the handpiece, and shown in its starting position.





FIG. 6

is a fragmentary longitudinal sectional view depicting the plunger of

FIG. 4

, shown part way through its travel.





FIG. 7

is a fragmentary longitudinal sectional view depicting the plunger of

FIG. 4

, shown near the end of its travel.





FIG. 8

is a fragmentary longitudinal sectional view depicting the plunger of

FIG. 4

, shown retracting and recollecting dental material.





FIG. 9

is a side elevational view of an alternative embodiment of the manually operated power switch of this invention.





FIG. 10

is a fragmentary longitudinal sectional view of an alternative embodiment of the plunger, shown in its starting position.





FIG. 11

is a fragmentary longitudinal sectional view of the alternative embodiment of the plunger of

FIG. 10

, shown part way through its travel.





FIG. 12

is a fragmentary longitudinal sectional view of the alternative embodiment of the plunger of

FIG. 10

, shown near the end of its travel.





FIG. 13

is a fragmentary longitudinal sectional view of the alternative embodiment of the plunger of

FIG. 10

, shown in a retracted position.











DETAILED DESCRIPTION




Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.




Referring to

FIGS. 1

,


2


,


3


and


4


, an embodiment of a dental handpiece


20


capable of dispensing and recollecting a controlled amount of dental material is disclosed. The dental handpiece


20


includes a main body


22


, a manually operated power switch


70


, a detachable nose cone


40


, and a disposable capsule tip


30


. The main body


22


has an outer wall


23


, an end cap


26


and a hollow internal chamber


24


that contains a battery


76


, a reversible electric motor


60


, a drive shaft


62


and an extendable plunger


50


(see FIG.


4


). The battery


76


may be rechargeable, and the main body


22


may include an external electrical connection


27


for recharging the battery when the handpiece is not in use.




The manually operated power switch


70


controls an electrical connection


72


between the battery


76


and electric motor


60


. In the preferred embodiment of

FIG. 4

, inclusive, the switch


70


takes the form of a sliding ring encircling a portion of the main body


22


. The switch


70


is shown in

FIG. 4

normally resting in a neutral position, wherein the electrical connection


72


is open. Sliding the switch forward or backward along the longitudinal axis of the dental handpiece


20


engages the electric motor


60


in respective forward or reverse operation. The switch


70


may be momentary, and may include a potentiometer for variable speed operation of the electric motor


60


. The drive shaft


62


, which has a threaded portion


64


, is coupled to and rotated by the electric motor


60


, and is restrained from axial movement.




With particular reference to

FIGS. 2 and 4

, the retractable plunger


50


has a hollow internal longitudinal bore


54


beginning at its open end


53


and spanning most of its length. The opposite end is solid and has a cone shaped taper


52


. The plunger


50


has an internal threaded portion


56


that engages the threaded length


64


of the drive shaft


62


, as illustrated in FIG.


2


. The plunger


50


is prevented from rotation with respect to the drive shaft


62


by integrally formed webs


58


that slidably engage longitudinal grooves in the nose cone


40


, which remains stationary. As the drive shaft


62


rotates, the plunger


50


advances or retracts longitudinally, depending on the direction of motor


60


and drive shaft


62


rotation. As the plunger


50


advances, it will enter the disposable capsule tip


30


, thereby dispensing dental material from the handpiece


20


. In the preferred embodiment, the plunger


50


is made of a somewhat flexible material that can bend around curves in the capsule tip


30


and withstand sterilization in high temperatures, such as 135° C. The plunger threaded portion


56


may take the form of a threaded insert molded into the plunger


50


, although any method of formation may be used without departing from the present invention.




The nose cone


40


is fastened to the main body


22


with an easily detachable connection. Referring to

FIGS. 2 and 4

, a receiving opening


28


in the main body


22


is slightly larger than the connecting end


44


of the nose cone


40


, allowing a snug fit. A taper may also be designed into the receiving opening


28


, connecting end


44


, or both, to assure a proper pressure fit connection. It is to be understood that any detachable connecting means may be utilized, such as a push/twist locking action or other conventional design. The front of the nose cone has a threaded interior


42


for receiving the capsule tip


30


.




The disposable capsule tip


30


is conventionally available in many variations having a standard size full open end


37


and an array of front opening


38


diameters. A hollow chamber


42


holds the dental material to be dispensed. A flange


39


on the full open end


37


yields as the capsule tip


30


is twisted into the nose cone threaded interior


42


, thereby securing the tip


30


to the nose cone


40


.





FIGS. 5 through 8

illustrate the travel of the plunger


50


and the dispensing of dental material


36


.

FIG. 5

shows the plunger


50


in the typical rearmost starting position. A disposable capsule tip


30


had been filled with dental material


36


and attached to the nose cone


40


. As the electric motor


60


rotates the drive shaft


62


, the threaded length


64


of the drive shaft


62


engages the interior threaded portion


56


of the plunger


50


, thereby forcing the plunger forward (See FIG.


6


). As the plunger


50


enters the internal reservoir


32


of the capsule tip


30


, it creates a seal preventing any dental material


36


from escaping through the full open end


37


. Dental material


36


is forced out of the capsule tip


30


through the front opening


38


. As the plunger


50


extends farther into the internal reservoir


32


, it will flex to bend around any curves in the capsule tip


30


(See FIG.


7


). The taper


52


and flexibility of the plunger


50


allow all dental material


36


in the capsule tip


30


to be dispensed without using a separate disposable plug. If too much dental material


36


is dispensed, the electric motor


60


can be engaged in reverse, thereby retracting the plunger


50


. As the plunger


50


retracts, suction generated in the internal reservoir


32


will draw dental material


36


back into the capsule tip


30


.





FIG. 9

shows an alternative embodiment of the present invention, wherein the manual power switch takes the form of a two-way rocker switch


170


. Operation and circuitry of the rocker switch


170


may be momentary, and may include a potentiometer in accordance with known practice for variable speed operation of the electric motor


60


.





FIGS. 10 through 13

illustrate an alternative embodiment of the present invention, wherein the plunger


50


has a blunt end


152


that pushes a traditional plug


151


into the internal reservoir


32


of the capsule tip


30


. This embodiment of the invention is particularly well suited for use with conventionally available capsule tips


30


that are preloaded with dental material


36


and a traditional plug


151


. Although the use of a traditional plug


151


prevents the invention from recollecting excess dental material


36


, the invention is still superior to conventional dental syringes in the many ways described above.




The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.



Claims
  • 1. A dental handpiece arranged for delivery of a composite material, and including a hollow chamber having means for releasable support and communication with a capsule having an internal reservoir for containing said composite material;said hollow chamber containing: a reversible electric motor; a source of electric current arranged to supply electric power to said motor; a retractable plunger having a hollow internal longitudinal bore, said bore including a threaded portion thereof, said plunger having a forward end communicating with the internal reservoir of said composite-containing capsule and wherein said retractable plunger is flexible for at least a portion of its length, allowing said plunger to substantially conform to the contour of the capsule internal reservoir; a drive shaft including a threaded drive portion engagable with the threaded portion of said bore of said retractable plunger, said drive shaft being coupled to said electric motor and arranged for reversible rotation by said motor; and a manually operated electric switching means, at least a portion of which is positioned externally of said handpiece chamber and being arranged for controlling electric current for alternative rotational operation of said electrical motor and consequent forward and rearward longitudinal movement of said plunger.
  • 2. The dental handpiece according to claim 1, wherein said source of electric current is a battery enclosed within said hollow chamber.
  • 3. The dental handpiece according to claim 2, wherein said battery is rechargeable.
  • 4. The dental handpiece according to claim 1, wherein said manually operated switching means includes a potentiometer arranged for controlling electric current for variable speed rotational operation of said electrical motor.
US Referenced Citations (51)
Number Name Date Kind
D. 224655 Dragan Aug 1972
D. 289682 Dragan May 1987
D. 292825 Dragan Nov 1987
D. 315956 Dragan Apr 1991
D. 320852 Drumm Oct 1991
D. 334803 Discko, Jr. Apr 1993
D. 353673 Discko et al. Dec 1994
D. 359119 Dragan et al. Jun 1995
2381785 Thompson Aug 1945
2812765 Tofflemire Nov 1957
3164153 Zorzi Jan 1965
3208145 Turner Sep 1965
3581399 Dragan Jun 1971
3593423 Jones et al. Jul 1971
3624907 Brass et al. Dec 1971
3727310 Baker Apr 1973
3900954 Dragan Aug 1975
4019654 van Manen Apr 1977
4138816 Warden et al. Feb 1979
4215476 Armstrong Aug 1980
4340365 Pisanu Jul 1982
4397640 Haug et al. Aug 1983
4526573 Lester et al. Jul 1985
4569662 Dragan Feb 1986
4680026 Weightman et al. Jul 1987
4682950 Dragan Jul 1987
4684344 Brockway et al. Aug 1987
4767326 Bennett et al. Aug 1988
4768954 Dragan Sep 1988
4872837 Issalene et al. Oct 1989
4963093 Dragan Oct 1990
4969816 Drumm Nov 1990
5052927 Discko, Jr. Oct 1991
5061179 Dragan Oct 1991
5061180 Wiele Oct 1991
5083921 Dragan Jan 1992
5122057 Discko, Jr. Jun 1992
5129825 Discko Jul 1992
5165890 Discko, Jr. Nov 1992
5171146 Guerci Dec 1992
5172807 Dragan et al. Dec 1992
5306147 Dragan et al. Apr 1994
5336088 Discko, Jr. Aug 1994
5468148 Ricks Nov 1995
5474450 Chronister Dec 1995
5658144 Tinder et al. Aug 1997
5716210 Novak Feb 1998
5772433 Esrock Jun 1998
5899692 Davis et al. May 1999
6056165 Speranza May 2000
6093020 Pond et al. Jul 2000
Foreign Referenced Citations (2)
Number Date Country
197 00 480 A1 Jul 1998 DE
WO 9829054 Jul 1998 WO
Non-Patent Literature Citations (1)
Entry
Infodent International (p.13) Magazine Ad Saremco SR-J Tip Applicator Date currently not available.