Patent Description:
Traditionally, in endodontics, the irrigation process occurs by the clinician when placing irrigant (sodium hypochlorite (NaOCI), ethylenediaminetetraacetic acid (EDTA), Qmix, etc.) in a syringe which is then connected to an irrigation needle via a luer lock connection. The clinician thereafter depresses the plunger within the barrel of the syringe manually causing the irrigant to extrude from the irrigation needle within the root canal. The clinician then can use sonic, ultrasonic, manual motion, etc. to agitate the irrigant and facilitate dislodging of debris within the canal as well as allowing the irrigant to go in areas (e.g., tubules) within the canal (via pressurization) in order to disinfect the canal more thoroughly. It is becoming more evident, though, that it is more efficacious when the irrigation and activation occurs simultaneously such that the irrigant is replenished within the canal while the activation is occurring.

<CIT> discloses a method for both irrigating while applying motion within the canal via a metal "stent-like" design. The issue with this design is that the relatively large amount of opening within the stent does not allow for any pressurization of the fluid when exiting the device. Furthermore, since the device is made from Nickel Titanium and thus compressible, this prevents any high level of agitation (i.e. lower frequencies than desirable) due to the increased contact of the device to the canal wall. The "stent-like" design lends to increased fragility and increased risk for the device becoming damaged during use.

<CIT>and <CIT> describes a system for delivering irrigant under high pressure through a needle placed inside the canal. There is no discussion of the needle having any type of activation though which limits the efficacy of the device and requires much higher pressures of the irrigant to adjust for the lack of activation of the irrigant within the canal.

<CIT> discloses a method for delivering and evacuating irrigant within a root canal during a root canal procedure. There is no mention of any method for agitating the irrigant as the irrigant is being delivered within the root canal. This can again limit the efficacy of the irrigation unless the pressures are much higher which increases the risk of apical extrusion of the irrigant thus potentially introducing toxic chemicals into the blood stream.

<CIT> describes a dental tip to be used with a rotosonic scaler or air scaler with irrigating water for a periodontal or endodontic treatment. The device portion is metallic in order to function at ultrasonic frequencies while being hollow in order to deliver irrigant through it. Furthermore, ultrasonic energy from the tip is most effective when the tip is not dampened. When tips that operate at an ultrasonic frequency (> <NUM>) contact the canal wall, it causes the tip frequency to dampen as well as the tip contact creates ledging which means small notches can be created on the canal wall which further destroys the root canal when contacted by the ultrasonic tip.

<CIT> discloses an endodontic irrigating system that incorporates ultrasonic energy into the irrigating needle used in connection with the instrument for root canal debridement. The system comprises at least one solution reservoir. The reservoirs are connected to one or more handpieces, which have at least one fluid outlet.

<CIT> discloses a device for endodontics by means of continuous ultrasonic irrigation with negative apical suction, consisting of a body made of a rigid plastic material, a threaded steel connection socket attached to the body, a truncated rhomboid connection joint made of plastic, a hollow conduit having a cylindrical section, a circular plastic connection joint, a stainless steel coronal cannula and an apically bored Ni-Ti microcannula.

<CIT> disclose a system for use in simultaneous liquefaction and acoustic debriment of a tooth canal comprising a contra-angle tip assembly being connectable to an ultrasonic hand piece with ultrasonic activation (><NUM>).

<CIT> and <CIT> and <CIT> discloses an endodontic tool that includes a sonic driven activator. A snap-on coupler is adapted to attach the tool to a driver. The driver will vibrate, sonically or ultrasonically, the flexible activator within a root canal of a tooth. The tool can be provided with fluid passages which allow for irrigating reagents to be delivered through the activator. The design of this construct implies that the irrigant is delivered into the device via the handpiece but there is not any disclosure as to how this is accommodated.

<CIT> discloses a handpiece for delivering irrigant while agitating the irrigant. This design shows that the irrigant is delivered into the device via handpiece. The handpiece includes a reservoir to contain the stock of irrigation solution, a pumping and ejecting device with which the irrigation solution can be conveyed from this reservoir into the canal by way of an endpiece. It further also comprises an agitator device for setting in motion an endpiece designed to agitate the irrigation solution present in the root canal.

<CIT> discloses an irrigation and aspiration handpiece. <CIT> discloses a device for drilling of root canals. <CIT> discloses a device for cleaning tooth root canals. <CIT> discloses microperforated needles. <CIT> discloses a root canal flushing device. <CIT> discloses a rotating and/or vibrating surgical instrument adapted for delivering fluid continuously while activated in an endodontic application comprising:a hollow needle and a handle; wherein the hollow needle includes a distal end portion, an intermediate portion, and a connector portion (the portion inserted in the handle); the intermediate portion and the distal end portion together form a working portion; the working portion terminates in a tip and is configured to act on a root canal; wherein the handle at one end is configured to be affixed to the connector portion of the hollow needle (see <FIG>); wherein the handle at opposite end is capable of being attached to an endodontic handpiece or a sonic agitator for the activation, wherein the hollow needle includes a plurality of openings (two openings) on the connector portion (see <FIG> and <FIG>) and at least one opening (slit on <FIG> and page <NUM>, lines <NUM> to <NUM>) on the intermediate portion closer to the connector portion to allow fluid to be delivered through part of the hollow needle, wherein a removable modular fluid delivery connector is coupled to the hollow needle, wherein the connector includes fluid delivery conduits for communicating the fluid to at least one opening of the plurality of opening of the hollow needle, wherein the modular fluid delivery connector is assembled to the device by at least partially enveloping the connector portion of the needle to allow fluid communication from the modular fluid delivery connector to the hollow needle.

There is a continuing need for a device in endodontic root canal treatment wherein the irrigation and activation occurs simultaneously. Also it is desirous, to provide the irrigant pressurized such that a higher velocity of the irrigant contacts the canal walls and enter into more of the irregular anatomy which allows for a more thorough disinfection of the canal.

The claimed invention relates to a dental device for delivering fluid continuously while activated in an endodontic application as defined in claim <NUM> Preferred embodiments of the claimed invention are defined in the dependent claims.

The above-mentioned aspects, as well as other aspects, features, and advantages of the present disclosure are described below in connection with various embodiments, with reference made to the accompanying figures.

The term "irrigant" and "fluid" are used interchangeably.

The dental device according the present claimed invention is designed to perform the function of both continuous irrigation and activation simultaneously or intermittently in an endodontic application. The irrigant is replenished within the root canal walls while the activation is occurring.

The dental device includes a hollow needle (<NUM>) having a tip end (<NUM>) and a connector portion (<NUM>); and a handle (<NUM>). The connector portion includes at least one tube connector (<NUM>) as shown in <FIG> that is integral part of the connector portion of the hollow needle or a plurality of openings on the connector portion (<NUM>) as shown in <FIG> and <FIG>. The handle on one end is configured to be affixed to the connector portion of the hollow needle. While the handle on the opposite end is capable of being attached to an endodontic handpiece (14a) or a sonic agitator (14b) for the activation. The hollow needle is connected to a connector. The connector is a modular fluid delivery connector, which is removable from the needle such that it can be reused. The hollow needle may be constructed of plastic, metal (superelastic or non-superelastic), or a composite of both. Preferably, the hollow needle is substantially or completely plastic, though not required.

A hollow needle with different handle configurations assembled to it, is illustrated in <FIG> and <FIG>. The hollow needle (<NUM>) comprises a distal end portion (<NUM>), an intermediate portion (<NUM>), and a connector portion (<NUM>). The distal end portion may have a diameter ranging from <NUM> to <NUM>. The working portion (<NUM>) includes the intermediate portion and the distal end portion. The working portion may be tapered or non-tapered. The taper may be a constant taper or variable taper along its length. The taper range may be from <NUM> % to <NUM> %. The working portion terminates at the tip end (<NUM>) and is configured to act on a root canal. The length of the needle for the working portion (<NUM>) is a length ranging from <NUM> to <NUM>. The distal end portion, intermediate portion and connector portion are molded together as one piece. The handle is affixed to the connector by methods such as friction fit, ultrasonic welding, overmolding, or adhesive. The needle includes a plurality of openings on the connector portion (<NUM>) and at least one opening on the distal end (<NUM>) to allow fluid to be delivered through needle. The hollow needle is coupled to a connector; and the handle is capable of being connected to a handpiece (for rotation, reciprocation, and/or otherwise) or a sonic agitator for the activation.

The number of openings on the needle to accept the fluid from the connector may range from approximately <NUM> to <NUM>. The openings on the needle may have geometries including but not limited to circular, elongated or oval. The diameter of the circular opening may range from <NUM> to <NUM>. The elongated or oval openings may have a different width than length; for example, a length range from <NUM> to <NUM>.

The number of openings along the distal and intermediate areas of the needle may range from <NUM> to <NUM>. The openings along the distal and intermediate areas of the needle may have geometries including but not limited to circular, elongated or oval. The diameter of the circular opening may range from <NUM> to <NUM>. The elongated or oval openings may have a different width than length; for example, a length may range from <NUM> to <NUM>.

In some embodiment of the device, the working portion of the irrigation needle includes a plurality of linear fins, a plurality of spiral fins or multiple ports.

In one embodiment of the irrigation needle, the plurality of linear fins (<NUM>) may extend radially and longitudinally from a circumferential surface along the intermediate portion and terminating at the tip end of the distal portion as shown in <FIG>.

In one particular embodiment of the irrigation needle, the linear fins may be made of be same material as needle or overmolded with a different material that is more flexible.

In one embodiment of the irrigation needle, the plurality of radially extending, spiral fins (<NUM>) may extend on an outer surface of the working portion of the irrigation needle as shown in <FIG>.

In one embodiment of the irrigation needle, the irrigation needle may have multiple ports (<NUM>) along the working portion where a center channel within the irrigation needle delivers fluid simultaneously at these multiple ports as shown in <FIG>. The advantage to having multiple ports in the needle is that different areas of the canal can be cleaned simultaneously without having to move the needle up and down within the canal. Furthermore, by having the irrigation ports closer to the canal wall, it allows for higher fluid velocities and pressures to be applied to the canal wall for a more thorough cleaning of the root canal.

In one embodiment of the irrigation needle, the working portion of the irrigation needle includes brushes (<NUM>). The brushes are located on the outer surface of the distal portion of the needle. The bristles on the brush may be made from nylon, polyester, acrylonitrile butadiene styrene (ABS), polyacetal, or any other moldable plastic, or any combination thereof.

In some embodiments, both the handle and needle may be made from the same type of material (e.g., plastic) and bonded together via different methods such as ultrasonic welding, adhesive, threads, etc..

In one particular embodiment of the disclosure, the plastic material made for the needle and handle may be the same. The needle and handle may be injection molded with materials such as polypropylene, polyethylene, nylon, polyoxymethylene, etc..

In one embodiment of the irrigation needle, the irrigation needle generally extends along an axis <NUM>. The working portion of the irrigation needle includes an elongated non- linear portion <NUM>. The elongated non-linear portion includes an offset portion <NUM>. At least a portion of the non-linear portion extends along an axis different from the needle axis thereby becoming generally non-linear.

In one particular embodiment, which does not form part of the claimed invention, the non-linear portion extends within a two-dimensional space as shown in <FIG>.

More particularly, in one specific embodiment, the working portion of the irrigation needle is offset from the needle axis resulting in a general C-shape. The offset portion may include a section of the non-linear portion that generally extends between two locations along the needle axis. For example, the offset portion may extend between a first location where the non-linear portion begins to extend away from the needle axis and a second location wherein the non-linear portion returns to the needle axis. The offset portion may include a crest. The crest may be an outermost point within the corresponding offset portion along the non-linear portion having the greatest distance from the needle axis. This distance between the crest and the needle axis may be defined by the crest displacement distance. Furthermore, the tip end may remain offset from needle axis <NUM> or may return to axis <NUM> and extend therefrom.

In another embodiment, the non-linear portion <NUM> extends within a three-dimensional space, that is, offset to the needle axis <NUM> in multiple planes as shown in <FIG>. More particularly, the non-linear portion <NUM> may extend from the needle axis in at least two different planes (for example cork-screw like shape). The non-linear portion may include at least one offset portion including a first offset portion and a second offset portion, each of the first offset portion and the second offset portion being displaced from the needle axis such that the first offset portion of non-linear portion and the needle axis <NUM> defines a first plane and the second offset portion defines a second plane different from the first plane. Each offset portion may include a crest and a corresponding crest displacement. The crest displacement decreases from one offset portion to another offset portion, the closer the offset portion may be relative to the tip end of the irrigation needle.

The nonlinear portion <NUM> may be displaced from the needle axis <NUM> along the offset portion <NUM> in an amount greater than about <NUM>, preferably less than about <NUM> and more preferably about <NUM>-<NUM>.

In one embodiment according to the present disclosure the connector is a modular fluid delivery connector. The modular fluid delivery connector is removable from the needle such that it can be reused.

<FIG> show the modular fluid delivery connector and its relationship to the irrigation needle. <FIG> shows the modular fluid delivery connector (<NUM>) assembled to the device over the connector portion (<NUM>) of the needle when in use for delivering fluid. Specifically, <FIG> depicts modular fluid delivery connector. <FIG> provides a cross-section of the modular fluid delivery connector (<NUM>) having an inner housing (<NUM>), an outer housing (<NUM>); at least two sets of O rings (<NUM>) and at least two ball bearing assemblies (<NUM>). The at least two set of O rings includes a smaller ID O ring set and a larger ID O ring set. A smaller ID O'ring set is configured to seal the irrigation needle to the inner housing of the modular fluid delivery connector. As depicted in <FIG>, that is the cross-section of the modular fluid delivery connector with needle inside it, (with arrows pointing to the grooves (<NUM>) where the smaller ID O' rings are located), the smaller ID O' rings seal the irrigation needle to the inner housing. <FIG> depicts that the hollow needle includes grooves (<NUM>) configured to accept the smaller ID O rings in the inner housing of the modular fluid delivery connector. The larger ID O'ring set is configured to seal the inner housing and outer housing. At least two ball bearing assemblies are used to align the inner and outer housing and allow them to freely rotating about each other. The ball bearings help keep the compression of the O'rings and seal between the inner and outer housing consistent. If the ball bearings are not present, the inner housing may become cantilevered to the outer housing thus compromising the O'ring compression causing leaking of irrigant in the connector. As shown in <FIG>, the outer housing has a luer lock connection (<NUM>) which allows irrigant to be delivered from within the luer lock connector to the outer housing and then to the inner housing. As shown in <FIG>, tubing containing a male luer lock connector (<NUM>) is attached to the female luer lock connector (<NUM>) of the outer housing. The inner housing (in <FIG>) further includes a fluid chamber (<NUM>) configured to deliver pressurized fluid through the number of opening within the irrigation needle.

<FIG> illustrates connector portion (<NUM>) of irrigation needle inside of the modular fluid delivery connector. Small holes (<NUM>) in the irrigation needle accept the irrigant from the inner housing. The handle (<NUM>) includes a stop (<NUM>) helps align the connector with the needle by preventing the user from placing the modular fluid delivery connector any higher past the handle when the modular fluid delivery connector is assembled to the hollow needle. In doing so, the fluid delivery conduits (<NUM>) of the modular fluid delivery system from the inner housing is aligned (and sealed) to one or more holes (<NUM>) of the needle.

In certain embodiment of the dental device, the inner and outer housings of the modular fluid delivery connector may be made from stainless steel metal or plastic injection molded or a combination of both.

In embodiments, the method to deliver irrigant to the connector can be a number of different ways including: manually via a syringe connected to tubing which is connected to the connector, a syringe within a syringe pump where the flow rate of the irrigant can be dictated by the syringe pump, or a reservoir with tubing connected to the device. The reservoir or syringe or syringe pump can be activated manually or electronically. If electronically activated, there is a pump or motor that drives and pressurizes the fluid to be delivered to the device at a given flow rate.

<FIG> show various examples of the irrigation needle with modular fluid delivery connector connected to an endodontic handpiece (14a) with irrigant being delivered from the irrigation needle. The handle is connected to the handpiece using a standard connector where the handle is designed per ISO <NUM>-<NUM> and the handpiece is designed per ISO <NUM>. When the motor is turned on, the handpiece is activated thus causing the irrigation needle to rotate at a certain speed. These figures also show how the irrigant is disbursed when the irrigation needle is rotating at different RPM's (<FIG> 500RPM, and <FIG> 1000RPM). The irrigant is delivered at a relatively low pressure from within the luer lock connector of the outer housing to the inner housing of the connector. The inner housing (<FIG>) further includes a fluid chamber (<NUM>, shown as the volume of space between the smaller O'rings and the hollow needle and the larger O'rings and the inner housing) configured to deliver relatively higher pressurized fluid through the number of openings within the irrigation needle. The faster the rotation speed, the increase in dispersion of the irrigant radially from the axis of rotation of the irrigation needle. It is contemplated that the higher the rotation speed, the higher the velocity of the fluid being expressed for the same flow rate of irrigant.

<FIG> show examples of the irrigation needle with modular fluid delivery connector connected to a sonic agitator (14b) with irrigant being delivered from the irrigation needle. This also shows how the irrigant is disbursed when the irrigation needle is oscillating at a frequency of about <NUM> (<FIG>). It is further contemplated that the higher the frequency of the oscillation, the higher the velocity of the fluid being expressed for the same flow rate of irrigant.

<FIG> compare the rotating irrigation needle at different conditions (rotation and irrigation (<FIG>), rotation only (<FIG>), and irrigation only (<FIG>) in a simulated canal filled with silicone gel to simulate debris. For example, in <FIG>, the irrigation needle is rotating at <NUM> RPM and irrigant flow rate of <NUM>/min for <NUM> in simulated canal filled with silicone gel. <FIG> depicts rotating irrigation needle with continuous irrigation at <NUM>/min and no rotation for <NUM> minute in simulated canal (irrigant applied at the beginning, after <NUM> seconds, and after <NUM> minute to remove debris). <FIG> illustrates that the irrigation needle is not rotating with continuous irrigation at <NUM>/min only for one minute in a simulated canal. The results in comparing these three scenarios show visually that combining irrigation with rotation is most optimal in cleaning the canal as compared to rotation only or irrigation only.

<FIG> compare the oscillating irrigation needle at different conditions (oscillation and irrigation (<FIG>) and oscillation only (<FIG>) in a simulated canal filled with silicone gel to simulate debris. <FIG> depicts sonic activated needle at <NUM> and irrigant flow rate of <NUM>/min for <NUM> minute in simulated canal. <FIG> depicts sonic activated irrigation needle at <NUM> and no continuous irrigation for <NUM> minute in simulated canal (irrigant applied at the beginning, after <NUM> seconds, and after <NUM> minute to remove debris). The results in comparing these two scenarios shows visually that combining irrigation and oscillation is most optimal in cleaning the canal as compared to oscillation only.

<FIG> shows the results for the standard EndoActivator with Medium Tip at <NUM> and no continuous irrigation for <NUM> minute in simulated canal (irrigant applied at the beginning, after <NUM> seconds, and after <NUM> minute to remove debris). The results show that this is visually not as good as compared to <FIG> where oscillation and irrigation combined provided for a better cleaning.

In an alternate embodiment of the present disclosure, which does not form part of the claimed invention. when the irrigation needle is an oscillating needle, the connector is modular fluid delivery connector wherein there is no outer housing and bearings as shown in <FIG>.

In one embodiment of the present disclosure, which does not form part of the claimed invention, when the irrigation needle is an oscillating needle, the connector is a barbed connector (<NUM>) that is integrated with the irrigation needle (shown in <FIG>).

Claim 1:
A dental device for delivering fluid continuously while activated in an endodontic application comprising:
a hollow needle (<NUM>) and a handle (<NUM>); wherein the hollow needle includes a distal end portion (<NUM>), an intermediate portion (<NUM>), and a connector portion (<NUM>); the intermediate portion and the distal end portion together form a working portion (<NUM>); the working portion terminates in a tip and is configured to act on a root canal; wherein the handle at one end is configured to be affixed to the connector portion of the hollow needle; wherein the handle at opposite end is capable of being attached to an endodontic handpiece (14a) or a sonic agitator (14b) for the activation,
wherein the hollow needle includes a plurality of openings on the connector portion and at least one opening on the distal end (<NUM>) to allow fluid to be delivered through the hollow needle,
wherein a removable modular fluid delivery connector (<NUM>) is coupled to the hollow needle, wherein the connector includes fluid delivery conduits (<NUM>) for communicating the fluid to at least one opening of the plurality of openings of the hollow needle,
wherein the removable modular fluid delivery connector is assembled to the device by at least partially enveloping the connector portion of the needle to allow fluid communication from the removable modular fluid delivery connector to the hollow needle.