1. Field of the Invention
The present invention relates generally to a handpiece for dental procedures, and more particularly to a disposable hand-held instrument for dental drilling.
2. Background
Common dental procedures involve the use of a drill to reduce at least a portion of a tooth prior to performing work on the area of the mouth on or near the tooth. In some instances, decayed enamel is removed from a tooth prior to replacement with a hardened substitute. In some instances, some or all of a tooth is removed with a dental drill prior to work beneath the gum line.
Typical drills used for such work have several components. First, a handpiece, typically constructed from stainless steel, or a steel alloy is used. An appropriate bit is selected for the work to be accomplished. Some bits have variable lengths and surface properties which affect the character of operation. The bit is then inserted into a rotating portion of the handpiece, and securely coupled to it. Finally, a source of pressurized air is connected to the handpiece, the flow of which is directed within the handpiece to rotate the turbine, which in turn rotates the bit at speeds useful for drilling.
After the handpiece has been used to perform a procedure on a patient, the handpiece is typically flushed with air or water for approximately 20 to 30 seconds in an attempt to discharge material that might have entered the turbine and/or air and water channels. The handpiece is then disconnected from the air source, and the bit is removed. Previously, the bit and handpiece have been sterilized, usually by steam or chemicals in an autoclave, requiring time between procedures or, in a busy office, the purchase of multiple handpieces and bits to allow for continuous use during sterilization.
The cost of the handpieces individually can be high. Moreover, the cost to refurbish reusable handpieces when the performance of certain features, such as bearings or light sources, degrades can be high. Additionally, handpieces may not be completely sterilized after use, or sterilized handpieces may not be properly sterilized or maintained in a sterile container after cleaning prior to use on a subsequent patient, increasing the exposure to potentially unclean environments. Although some disposable handpieces exist, they are often not provided in a sterile package and typically have inferior performance characteristics to reusable handpieces. Thus, the need exists for a sufficiently powerful, low-cost handpiece which can be assured of sterility for use on a single patient.
An aspect of at least one of the embodiments disclosed herein includes the realization that dental handpieces can be run with air, and that incorporating a structure which delivers air to the turbine blades of the handpiece in an efficient and high speed manner is advantageous.
Thus, in accordance with an embodiment, a disposable dental instrument driven by compressed air comprises an elongated body comprising a first shell half, a second shell half, and a core, the shell halves joined to form an exterior surface for manual manipulation, the shell halves additionally forming a cavity, the cavity having various passageways as fluid conduits. The dental instrument further comprises a base comprising a plurality of conduits, the base communicating with an outside source of light and fluid through the conduits, the conduits communicating with the passageways defined by the elongated body, and a head located at the opposite end from the base, the head comprising a turbine shaft rotatably mounted within the head. The dental instrument further comprises a turbine impeller, the turbine impeller connected to the turbine shaft, the turbine impeller being driven by an outside source of air through an air nozzle to rotate a dental bit, at least one opening located under the head configured to deliver fluid away from the dental instrument, at least one opening located under the head configured to deliver light away from the dental instrument, and wherein the air nozzle has a rectangular cross-sectional shape to create an airflow which more closely matches a rectangular cross section of a turbine blade.
Another aspect of at least one of the embodiments disclosed herein includes the realization that sealing two shell halves and a core together to form various conduits or passageways for light, air, and/or water can be difficult, and can lead to imperfections in the assembly. Including tapered mating portions on the core and left shell half can provide a gradually changing distance from the surface of the core for welding, thereby reducing or eliminating shape changes sufficiently sharp to cause imperfections in a sonic welding assembly.
Thus, in accordance with an embodiment, a disposable dental instrument driven by compressed air comprises an elongated body comprising a first shell half, a second shell half, and a core, the shell halves joined to form an exterior surface for manual manipulation, the shell halves additionally forming a cavity, the cavity having various passageways as fluid conduits. The dental instrument further comprises a base comprising a plurality of conduits, the base communicating with an outside source of light and fluid through the conduits, the conduits communicating with the passageways defined by the elongated body. The dental instrument further comprises a head located at the opposite end from the base, the head comprising a turbine shaft rotatably mounted within the head, a turbine impeller, the turbine impeller connected to the turbine shaft, the turbine impeller being driven by an outside source of air through an air nozzle to rotate a dental bit. The dental instrument comprises at least one opening located under the head configured to deliver fluid away from the dental instrument, and at least one opening located under the head configured to deliver light away from the dental instrument. The core comprises a flange extending away from a central face of the core, and a seam disposed along the edge of the flange, and wherein the first shell half comprises a wall extending towards the central face of the core, the wall having a tapered portion, the tapered portion being sized and shaped to mate with the flange.
Another aspect of at least one of the embodiments disclosed herein includes the realization that it is advantageous for dental instruments to direct light to a patient's tooth or interaction region, so as to better view what work is being done. Thus, it is desirable to have a reliable, stable light source attached to and within the dental handpiece to deliver light from the handpiece.
Thus, in accordance with an embodiment, a disposable dental instrument driven by compressed air comprises an elongated body comprising a first shell half, a second shell half, and a core, the shell halves joined to form an exterior surface for manual manipulation, the shell halves additionally forming a cavity, the cavity having various passageways as fluid conduits. The dental instrument further comprises a base comprising a plurality of conduits, the base communicating with an outside source of light and fluid through the conduits, the conduits communicating with the passageways defined by the elongated body. The dental instrument further comprises a head located at the opposite end from the base, the head comprising a turbine shaft rotatably mounted within the head, a turbine impeller, the turbine impeller connected to the turbine shaft, the turbine impeller being driven by an outside source of air through an air nozzle to rotate a dental bit. The dental instrument further comprises at least one opening located under the head configured to deliver fluid away from the dental instrument, and at least one opening located under the head configured to deliver light away from the dental instrument. The dental instrument further comprises a light rod configured to deliver light to one of the openings, the light rod comprising a tab extending from a body of the light rod, wherein the center core comprises at least one molded projection configured to engage the light rod tab and inhibit motion of the light rod in at least one direction.
Another aspect of at least one of the embodiments disclosed herein includes the realization that directing air to a turbine within the dental instrument can be made more efficient through the use of a flow deflector. The geometry of the flow deflector can increase air speed, reduce noise, and direct the air flow in a particular manner within the turbine area of the handpiece.
Thus, in accordance with an embodiment, a disposable dental instrument driven by compressed air comprises an elongated body comprising a first shell half, a second shell half, and a core, the shell halves joined to form an exterior surface for manual manipulation, the shell halves additionally forming a cavity, the cavity having various passageways as fluid conduits. The dental instrument further comprises a base comprising a plurality of conduits, the base communicating with an outside source of light and fluid through the conduits, the conduits communicating with the passageways defined by the elongated body. The dental instrument further comprises a head located at the opposite end from the base, the head comprising a turbine shaft rotatably mounted within the head, a turbine impeller, the turbine impeller connected to the turbine shaft, the turbine impeller being driven by an outside source of air through an air nozzle to rotate a dental bit. The dental instrument further comprises at least one opening located under the head configured to deliver fluid away from the dental instrument, and at least one opening located under the head configured to deliver light away from the dental instrument. The core further comprises a flow deflector located on the end of the core nearest the head, the flow deflector projecting further towards the first shell half than towards the second shell half, an edge of the flow deflector forming a part of the air nozzle.
Another aspect of at least one of the embodiments disclosed herein includes the realization that reducing the weight of a dental handpiece can save on cost, as well as make the handpiece easier to ship and use.
Thus, in accordance with an embodiment, a disposable dental instrument driven by compressed air comprises an elongated body comprising a first shell half, a second shell half, and a core, the shell halves joined to form an exterior surface for manual manipulation, the shell halves additionally forming a cavity, the cavity having various passageways as fluid conduits. The dental instrument further comprises a base comprising a plurality of conduits, the base communicating with an outside source of light and fluid through the conduits, the conduits communicating with the passageways defined by the elongated body. The dental instrument further comprises a head located at the opposite end from the base, the head comprising a turbine shaft rotatably mounted within the head, a turbine impeller, the turbine impeller connected to the turbine shaft, the turbine impeller being driven by an outside source of air through an air nozzle to rotate a dental bit. The dental instrument further comprises at least one opening located under the head configured to deliver fluid away from the dental instrument, and at least one opening located under the head configured to deliver light away from the dental instrument. The turbine shaft further comprises blades, the turbine shaft having cavities formed within the outer boundary of the blades.
These and other features and advantages of the present embodiments will become more apparent upon reading the following detailed description and with reference to the accompanying drawings of the embodiments, in which:
With reference to
With reference to
With continued reference to
With reference to
The head 90 is integrally formed with the body 50, as shown. In some embodiments the head 90 generally retains an air flow within its interior and inhibits air leakage to the ambient environment, thereby helping to minimize power loss and reduce noise levels.
With reference to
With continued reference to
With reference to
With reference to
With reference to
With reference to
With continued reference to
With continued reference to
With reference to
With reference to
With reference to
With continued reference to
With reference to
With reference to
Each of the base 11 and center core 16, and the shells 54, 56 are preferably composed from the same material to reduce manufacturing costs. Some suitable materials include plastics. In some embodiments, acrylonitrile butadiene styrene (ABS) can be used. The components can be injection molded. In some embodiments, the light pipe 18 can be formed from an acrylic resin or Lucite, though other plastics and materials with fiber-optic properties can also be used. Selection of material can be made to guarantee sufficient rigidity after manufacturing. Preferably, the material chosen does not easily deform, helping keep moving parts within tolerances.
With reference to
With reference to
With reference to
With reference to
With continued reference to
With continued reference to
With continued reference to
Although the nozzled entry area 112′ has been widened, the air impacting the impeller blades 96′ can arrive at the surface 114′ of the blade 96′ at the same angle. Thus, the substantially-tangential flow of air can be unchanged by the wider nozzled entry area 112′. In other embodiments, the shape of the entry can be altered sufficiently to redirect the flow of air away from a substantially-tangential course as well, including pointing further inward toward the center of the impeller assembly, or towards the inner wall, away from the center of the assembly.
With reference to
Assembly
Prior to assembly, central core 16 and base portion 11, and the right and left shells 54, 56 can be created from single-gate injection molding. The light pipe 18, and impeller blade/shaft turbine 96, 100 can be formed from injection molding as well. Preferably, the impeller blade/shaft turbine 96, 100 is formed from multi-gated molding to produce a balanced turbine. The number of gates for injection molding the impeller blade/shaft turbine 96,100 can be as few as 1, though preferably more. Any number of gates, including, without limitation, two, four, eight, twelve, or more can be used. For the shells 54, 56, center core 16 and base 11, and turbine 96, 100, ABS is preferably used to simplify manufacturing, though other plastics can be used.
Although ABS is used in some embodiments to facilitate ultrasonic welding, other methods of assembly, including without limitation, glues, heat sealing, thermal welding, other sonic welding, or mechanical fixtures such as screws can also be used to form components. Accordingly, other plastics can be used as appropriate for the material and cost requirements. One such example is a polyetherimide thermoplastic resins, which can include the commercial compound Ultem™.
During assembly of the impeller assembly 110, the center core 16 and coupled base 11 can be preferably placed atop the left shell 56, preferably aligning and coupling the seam 33 with the taper portion 60, and the protrusions 38 with the mating surfaces 61. The center core 16 can then be welded to the left shell 56. The light pipe 16 can then be disposed in one of the conduits 14 of the base 11 and engage the molded projections 22, with a second end 24 positioned at or near the light exit port 26. The impeller assembly 110 can then be assembled. The bearings 98 can be disposed around the turbine 96, 100 and coupled thereto. After the bearings are pressed onto the turbine, the grommets 122 are installed over the bearings. The impeller 110 can then be placed in the head 90. Subsequently, the protrusions 70 of the right shell 54 can be aligned with the flat face and mating area 19 along the core 16, as well as the flat mating surfaces 95 in the head region, and the right shell 54 can be welded to the core 16, closing the body 50.
Following assembly, the packaged handpiece 10 can be sterilized by exposure to ethylene oxide (EtO) gas, gamma rays, or electrons from an electron gun. EtO gas advantageously does not discolor plastic and is the preferred, but not exclusive, method of sterilization. Some embodiments of the handpiece 10 are packaged in a gas-permeable material, which inhibits the passage of pathogens through the material. After enclosure, the package can be exposed to EtO gas, which can sterilize the handpiece within the package and the surfaces of the package simultaneously. The handpieces 10 can then be shipped and stored.
Operation
The handpiece 10 is typically coupled with a fluid source providing air, water, and light to the conduits 14. Specifically, pressurized air can be provided to the conduit designated 64, light to the conduit designated 68, a vent can be coupled to the conduit designated 66, and a source providing water or pressurized water can be coupled to a conduit located beneath the wall 58. Thus, during use, light can be provided through the light pipe 18 to a point along or near the bit 92. Similarly, water can be selectively dispensed through the portion of the body 50 beneath the wall 58 and out the fluid port 62 to a point along or near the bit 92. In some embodiments, air is provided instead of water. Either can be used to clear tooth and other debris from the working area of the bit 92, as well as cool the portion of the tooth being drilled and the drill bit. Control can be exerted by the operator over the fluid source to control the use of water, air, and light.
During operation of the handpiece 10, pressurized air is provided from the fluid source to the conduit 64. This air travels through one side of the body 50 having an interior surface which is advantageously smooth to reduce friction. The air is then directed by the flow deflector 30 to a direction substantially tangential to the circular shape formed by the impeller assembly 110, particularly, the impeller blades 96. Thus, as the air passes through the nozzle entry area 112, it is directed to impact an engagement surface 114 of at least one of the blades 96. Air can be angled to preferably impact the flat surface 114 of an impeller blade 96 as the flat surface 114 is oriented along a line extending from the center of axis of rotation radially towards the exterior of the head, as shown in
Maximum power is typically achieved at approximately 50% of the free running rpm of the handpiece 10. The handpiece 10 can reach rotational speeds as high as 280,000 to 400,000 rpm when pressurized air of approximately 35 to 40 p.s.i. is supplied. Pressurized air preferably can be provided at approximately 40 p.s.i., though other pressures, for example as low as 15 p.s.i. or as high as 45 p.s.i. can also be used. Preferably, the handpiece 10 is operated at speeds of at least 160,000 rpm when coupled with an ISO-compliant source of pressurized air and light. In some embodiments, it has been found that the handpiece can have power equal to or greater than some of the leading metal reusable handpieces against which the embodiments were benchmarked. The speed at which peak power occurs is approximately one half of the free running rpm, although it could be more or less, depending on operating conditions and changes to the handpiece. Preferably, the handpiece 10 is operated to produce a noise level as low as possible. By way of specific examples, the noise level range is typically between 55 and 65 decibels. A noise level as low as 53 decibels has been observed. In certain embodiments, the noise level can be greater than 65 decibels as well.
After use on a single patient, the disposable dental handpiece 10 can be discarded, removing the need to re-sterilize it for the next patient. The foregoing description is that of preferred constructions having certain features, aspects, and advantages. However changes and modifications may be made to the above-described arrangements without departing from the spirit and scope of the invention. As one example, a hollow turbine having twelve straight blades made from four-gate injection molding can be used in one embodiment, while a solid turbine having eight curved blades made from two-gate injection molding can be used in another embodiment. In another example, either turbine could be disposed in a handpiece having a nozzle inlet such as that disclosed in
Although these inventions have been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present inventions extend beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the inventions and obvious modifications and equivalents thereof. In addition, while several variations of the inventions have been shown and described in detail, other modifications, which are within the scope of these inventions, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments can be made and still fall within the scope of the inventions. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventions. Thus, it is intended that the scope of at least some of the present inventions herein disclosed should not be limited by the particular disclosed embodiments described above.
This application is a non-provisional of and claims benefit under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 60/969,094, filed Aug. 30, 2007, which is incorporated in its entirety by reference herein.
Number | Name | Date | Kind |
---|---|---|---|
D110936 | Wiseman | Aug 1938 | S |
D121506 | Davis | Jul 1940 | S |
D162002 | Brown | Feb 1951 | S |
D174181 | Howie | Mar 1955 | S |
3120705 | Hoffmeister et al. | Feb 1964 | A |
3189999 | Reiter | Jun 1965 | A |
3310285 | Hawtin | Mar 1967 | A |
3418715 | Ellis | Dec 1968 | A |
3552021 | Graceffo et al. | Jan 1971 | A |
D219979 | Coss | Feb 1971 | S |
3589828 | Mosimann | Jun 1971 | A |
3727313 | Graham | Apr 1973 | A |
3893242 | Lieb et al. | Jul 1975 | A |
D239390 | Webb | Mar 1976 | S |
3946490 | Sotman et al. | Mar 1976 | A |
3955284 | Balson | May 1976 | A |
D241550 | Morin | Sep 1976 | S |
4014099 | Bailey | Mar 1977 | A |
D251304 | Leonard | Mar 1979 | S |
D254570 | McDonald | Mar 1980 | S |
D255929 | Austin, Jr. | Jul 1980 | S |
D255930 | Nilles et al. | Jul 1980 | S |
D257284 | Leonard | Oct 1980 | S |
4249896 | Kerfoot | Feb 1981 | A |
D261032 | Marucci et al. | Sep 1981 | S |
D261301 | Marucci et al. | Oct 1981 | S |
D263877 | Podszus et al. | Apr 1982 | S |
D264876 | Seid | Jun 1982 | S |
D267036 | Podszus et al. | Nov 1982 | S |
4370132 | Wohlgemuth | Jan 1983 | A |
D269122 | Seeley | May 1983 | S |
4406470 | Kataoka et al. | Sep 1983 | A |
4661060 | Strohmaier | Apr 1987 | A |
4795343 | Choisser | Jan 1989 | A |
4842516 | Choisser | Jun 1989 | A |
D305935 | Straihammer et al. | Feb 1990 | S |
4941828 | Kimura | Jul 1990 | A |
4978297 | Vlock | Dec 1990 | A |
5007831 | Bierbaum et al. | Apr 1991 | A |
5028233 | Witherby | Jul 1991 | A |
5040978 | Falcon et al. | Aug 1991 | A |
5096421 | Seney | Mar 1992 | A |
5156547 | Bailey | Oct 1992 | A |
5160263 | Meller et al. | Nov 1992 | A |
D335347 | McKeown | May 1993 | S |
D336517 | McKeown | Jun 1993 | S |
5217372 | Truocchio | Jun 1993 | A |
5231973 | Dlckie | Aug 1993 | A |
5263606 | Dutt | Nov 1993 | A |
5308242 | McLaughlin et al. | May 1994 | A |
5334013 | Meller | Aug 1994 | A |
5348473 | Kivlighan, Jr. | Sep 1994 | A |
5352118 | Franetzki et al. | Oct 1994 | A |
5352119 | Sakurai | Oct 1994 | A |
5374189 | Mendoza | Dec 1994 | A |
D355971 | Meller | Feb 1995 | S |
D356866 | Meller | Mar 1995 | S |
D370063 | Spreckelmeier | May 1996 | S |
5538425 | Reeves | Jul 1996 | A |
D373636 | Martin | Sep 1996 | S |
5562446 | Matsui et al. | Oct 1996 | A |
D378235 | Mark | Feb 1997 | S |
D378412 | Badoz et al. | Mar 1997 | S |
5674068 | Eibofner | Oct 1997 | A |
5681409 | Lin et al. | Oct 1997 | A |
5692901 | Roth et al. | Dec 1997 | A |
D389912 | Emerson et al. | Jan 1998 | S |
5733120 | Yao et al. | Mar 1998 | A |
5772436 | Matsui et al. | Jun 1998 | A |
5782634 | Lingenhole et al. | Jul 1998 | A |
5797743 | Bailey | Aug 1998 | A |
5807108 | Schwenoha et al. | Sep 1998 | A |
5810588 | Cohen | Sep 1998 | A |
5902108 | Nakayama et al. | May 1999 | A |
5911577 | Henrikson | Jun 1999 | A |
5921777 | Dorman | Jul 1999 | A |
5924206 | Cote et al. | Jul 1999 | A |
5924865 | Quinn | Jul 1999 | A |
5984654 | Mendoza et al. | Nov 1999 | A |
D425988 | Frank | May 2000 | S |
D426636 | Herring | Jun 2000 | S |
D427311 | Henrikson | Jun 2000 | S |
D427682 | Novak | Jul 2000 | S |
D428652 | Frezel et al. | Jul 2000 | S |
6099309 | Cardarelli | Aug 2000 | A |
6149430 | Nemetz et al. | Nov 2000 | A |
6186784 | Bailey | Feb 2001 | B1 |
D440817 | Armando et al. | Apr 2001 | S |
6305935 | Cardarelli | Oct 2001 | B1 |
6315560 | Krouglicof et al. | Nov 2001 | B1 |
6350124 | Wade | Feb 2002 | B1 |
D463556 | Bareth et al. | Sep 2002 | S |
D465279 | Etter et al. | Nov 2002 | S |
D472969 | Wilden | Apr 2003 | S |
6579093 | Bailey et al. | Jun 2003 | B2 |
6638068 | Lingenhole et al. | Oct 2003 | B2 |
6676374 | Hashimoto et al. | Jan 2004 | B2 |
D489134 | Nakanishi | Apr 2004 | S |
6716028 | Rahman et al. | Apr 2004 | B2 |
D495799 | Hirsch et al. | Sep 2004 | S |
6821119 | Shortt et al. | Nov 2004 | B2 |
D499486 | Kuhn et al. | Dec 2004 | S |
D504949 | Kuhn et al. | May 2005 | S |
D513927 | Chen | Jan 2006 | S |
7008224 | Browning et al. | Mar 2006 | B1 |
D520138 | Kuhn et al. | May 2006 | S |
D532907 | Feinbloom et al. | Nov 2006 | S |
D533276 | Nakanishi | Dec 2006 | S |
D533946 | Lintner et al. | Dec 2006 | S |
7214060 | Maitre | May 2007 | B2 |
D548342 | Cohen | Aug 2007 | S |
D550358 | Nakanishi | Sep 2007 | S |
D555972 | Rae | Nov 2007 | S |
D556323 | Nakanishi | Nov 2007 | S |
D572822 | Thomssen et al. | Jul 2008 | S |
D577824 | Thomssen et al. | Sep 2008 | S |
D579565 | Thomssen et al. | Oct 2008 | S |
D579566 | Thomssen et al. | Oct 2008 | S |
D580054 | Thomssen et al. | Nov 2008 | S |
D580055 | Thomssen et al. | Nov 2008 | S |
D580550 | Thomssen et al. | Nov 2008 | S |
D584411 | Thomssen et al. | Jan 2009 | S |
D588698 | Thomssen et al. | Mar 2009 | S |
D592308 | Thomssen et al. | May 2009 | S |
20020119420 | Bailey et al. | Aug 2002 | A1 |
20060121413 | Turner | Jun 2006 | A1 |
20060183073 | Browning et al. | Aug 2006 | A1 |
20060183074 | Brennan | Aug 2006 | A1 |
Number | Date | Country |
---|---|---|
686113 | Jan 1996 | CH |
0925762 | Jun 1999 | EP |
1023481 | May 1985 | GB |
2071913 | May 1998 | GB |
H1-145056 | Jun 1989 | JP |
1211559 | Aug 1989 | JP |
H9-70407 | Mar 1997 | JP |
2000-508951 | Jul 2000 | JP |
WO 9115160 | Oct 1991 | WO |
WO 9512361 | May 1995 | WO |
WO 96-12444 | May 1996 | WO |
WO 9740768 | Nov 1997 | WO |
WO 02076308 | Oct 2002 | WO |
WO 2004-082501 | Sep 2004 | WO |
Number | Date | Country | |
---|---|---|---|
20090061384 A1 | Mar 2009 | US |
Number | Date | Country | |
---|---|---|---|
60969094 | Aug 2007 | US |