Abstract:
A lightweight, small footprint, composite extraction pen, for the delivery of dental filling composite from commercially available composite filled carpules. An electric linear actuator is housed in a slender, pen-like housing configured to accept, constrain and allow the rotational positioning of commercially available composite filled carpules. The carpules are contained within an adaptor that connects to the body of the pen. The linear actuator extends and retracts a piston through a bore in the carpule so as to exert pressure on the composite contained therein. The pen provides precise composite delivery while maintaining a highly visible dental environment.

Description:
COPYRIGHT STATEMENT 
       [0001]    A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
       FIELD 
       [0002]    The present disclosure relates, in general, to dental devices, and more particularly to composite cavity filling technology. 
       BACKGROUND 
       [0003]    In dentistry, once a decayed tooth has been drilled, it must be filled with a composite material. This historically comes is pre-filled carpules. These are bent, hollow polymer containers open on each end that that house the composite material. On the proximal end there is a cup frictionally sealed about its perimeter to the walls of the circular cross sectional carpule, and on the distal end there is a removable cap. Between the cap and the cup resides the composite. It is applied into the cavity by a pressure that is exerted on the cup such that the cup axially slides along the inside of the carpule and forces the composite out the distal end. The current applicators are large cumberson hand actuated pistons or air actuated cylinders. Besides each being large enough to obscure the dentist&#39;s view, each has its own drawbacks. 
         [0004]    The precision of the hand actuated pistons are limited by the stability of the dentist&#39;s hands. This is difficult because of the force needed to drive the cylinder causes the dentist&#39;s hand to shake, and because of its physical size, the dentist cannot brace and fulcrum his hand against the patient&#39;s jaw/chin. The air actuated pistons need a source of compressed air to operate. This adds another cumbersome hose to complicate matters. The size of the current devices prevent a full view of the oral cavity, and their lack of stability results in many a “blind” filling. 
         [0005]    The carpules have to commonly be replaced or swapped out when blending colors and materials. The dental assistant generally does this process, necessitating the transfer of the device and its hoses (in the case of the air actuated cylinder) around the patient. To complicate matters, the application of the composite is a time sensitive maneuver. 
         [0006]    Thus, a smaller, more controllable, cordless device for the application of dental composite from conventional, commercially available carpules, would be a welcome improvement in the dental industry. It would allow a much better delivery of the dental filling composite. Such a solution is provided by the embodiments set forth below. 
       BRIEF SUMMARY 
       [0007]    In accordance with various embodiments, a portable apparatus for the application of dental composite into a tooth to be filled is provided. 
         [0008]    In one aspect, a composite extraction pen, configured to accept and allow the rotational positioning of commercially available composite filled carpules is provided. It is cordless and powered by a rechargeable battery, preferably inductively charged. 
         [0009]    In another aspect, a linear actuator composite extraction device having a small footprint, a pen shaped housing and various engageable composite feed speeds is provided. 
         [0010]    In yet a further aspect, an electronic linear actuator composite extraction device having ample power to extract the stiffest of dental filling composites and with an electronically adjustable delivery speed to address differing flowability composites. 
         [0011]    In yet another aspect, a low profile composite extraction pen is provided capable of precise composite delivery while maintaining a highly visible environment for the dentist. 
         [0012]    In yet another aspect, a lightweight composite extraction pen is provided that is capable of a stable composite delivery, directionally and delivery controlled with a minimal of lateral movement, adapted to accept different manufacture&#39;s carpules. 
         [0013]    Various modifications and additions can be made to the embodiments discussed without departing from the scope of the invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combination of features and embodiments that do not include all of the above described features. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    A further understanding of the nature and advantages of particular embodiments may be realized by reference to the remaining portions of the specification and the drawings, in which like reference numerals are used to refer to similar components. 
           [0015]      FIG. 1  is a top view of the composite extraction pen/ram retracted; 
           [0016]      FIG. 2  is a bottom view of the composite extraction pen/ram retracted; 
           [0017]      FIG. 3  is a right side view of the composite extraction pen/ram retracted; 
           [0018]      FIG. 4  is a left side view of the composite extraction pen/ram retracted; 
           [0019]      FIG. 5  is a front end view of the composite extraction pen; 
           [0020]      FIG. 6  is a back end view of the composite extraction pen; 
           [0021]      FIG. 7  is a right side view of the composite extraction pen/ram extended; 
           [0022]      FIG. 8  is a top view of the composite extraction pen/ram extended; 
           [0023]      FIG. 9  is a top view of the composite extraction pen with a carpule; 
           [0024]      FIG. 10  is a side view of the composite extraction pen with a carpule; 
           [0025]      FIG. 11  is a bottom view of the composite extraction pen with a carpule; and 
           [0026]      FIG. 12  is a side cross sectional view taken through section line BB of  FIG. 9 . 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    While various aspects and features of certain embodiments have been summarized above, the following detailed description illustrates a few exemplary embodiments in further detail to enable one skilled in the art to practice such embodiments. The described examples are provided for illustrative purposes and are not intended to limit the scope of the invention. 
         [0028]    In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the described embodiments. It will be apparent to one skilled in the art, however, that other embodiments of the present invention may be practiced without some of these specific details. While various features are ascribed to different embodiments, it should be appreciated that the features described with respect to one embodiment may be incorporated with other embodiments as well. By the same token, however, no single feature or features of any described embodiment should be considered essential to every embodiment of the invention, as other embodiments of the invention may omit such features. 
         [0029]    Unless otherwise indicated, all numbers herein used to express quantities, dimensions, and so forth, should be understood as being modified in all instances by the term “about.” In this application, the use of the singular includes the plural unless specifically stated otherwise, and use of the terms “and” and “or” means “and/or” unless otherwise indicated. Moreover, the use of the term “including,” as well as other forms, such as “includes” and “included,” should be considered non-exclusive. Also, terms such as “element” or “component” encompass both elements and components comprising one unit and elements and components that comprise more than one unit, unless specifically stated otherwise. 
         [0030]    The term “carpule” as used herein, refers to a sealed container filled with a flowable material that may be extracted from one end or an opening in the container by the application of force to or within the container. 
         [0031]    The present invention relates to a novel design for an improved dental filling composite delivery device. Its predominant features are that it has a very small footprint, is cordless, lightweight, offers accurate delivery amounts at variable speeds, operates with minimal lateral movement, accommodates any configuration of composite carpules, allows for directional composite feed and it can be braced off the patient&#39;s jaw. 
         [0032]    The prior art devices are cumbersome and bulky which is of major concern. The visibility into the patient&#39;s mouth is severely limited as is and any additional equipment just worsens the situation. The dentist works through a set of magnifying glasses and must readjust these every time he has to relocate the device in the patient&#39;s mouth or when he loses perspective of the device with respect to the cavity. 
         [0033]    Large devices do not lend themselves to bracing against the patient&#39;s jaw for composite delivery. Corded and manual pressure actuated devices lack stability and tend to move during delivery. The carpules have to be changed frequently as the contents are often blended for color and transparency effects. This necessitates transfer of the device from the dentist to the dental assistant, across the intervening patient. Complicating this, the composite dries quickly and is light sensitive, so it must be applied correctly and quickly the first time. 
         [0034]    Looking at  FIGS. 1-6  the bare dental composite extraction pen  2  with its extraction ram in a retracted configuration, can be seen from all angles. The pen  2  has a ergonomically comfortable, generally cylindrical, polymer housing. The housing has a cylindrical, proximal grip section  4  having a diameter larger than the diameter of the cylindrical, distal feed section  6 . Between these sections is a transitional region  8  that is tapered from the top and side faces of the grip section  4  toward the feed section  6 . The two sections share a common horizontal, bottom axis  10  ( FIGS. 3 and 4 ). The pen  2  is made in approximate half sections for assembly and disassembly. The mating seam  32  can be seen in  FIGS. 32 and 6 . 
         [0035]    The feed section  6  also has a dual concentric cylinder design, (where they share a common axis) however, the transitional section  14  tapers uniformly 360 degrees between the cylinders such that their common axis lies along the cross sectional midpoint of the feed section  6 . Engaged to the proximal end of the feed section  6  is the interchangeable carpule tip  16 . This carpule tip  16  is a hollow cylinder that has a section beginning at its proximal end, that has half (180 degrees) of its sidewall  18  partially removed along its length. ( FIGS. 1 and 2 ). It is sized for specific carpules  20 . ( FIG. 9 ) The inner bore of the carpule tip  16  is stepped ( FIG. 12 ) such that it can retain a carpule in a linear aligned fashion, locating it based on the carpule&#39;s rear flange  22 . ( FIG. 9 ) 
         [0036]    Located centrally along the transition region  8  is the tactile feed button  12  ( FIGS. 3 and 5 ) that initiates the ram actuation. Along the right side of the pen  2  toward the rear of the grip section  4  is the visual ram speed indicator  24 . ( FIG. 1 ) It is ergonomically located so as to visible at all times of operation. In the preferred embodiment this is a linear array of LED lights that increase with the ram speed. On the left side of the pen  2  at the rear of the grip section  4  is the data port  26 . ( FIG. 4 ) At the proximal end of the grip section  4  is the rear plate  34 . ( FIG. 6 ) From the rear plate  34  extends the ram speed and retraction button  28 . The charging port  30  is also located on the rear plate  34 . 
         [0037]      FIGS. 7 and 8  illustrate the ram  40  in its fully extended state without a carpule  20  in the carpule tip  16 . The stepped configuration of the carpule tip  16  showing the inner bore  42  and outer bore diameters  44  can best be seen in  FIG. 8 . 
         [0038]      FIGS. 9, 10 and 11  illustrate the pen  2  with the carpule  20  installed into the carpule tip  16 . Here one can see a conventional, commercially available dental filling composite carpule  20 . It is a hollow polymer shell with a linear bore, openable at both ends and bent at an acute angle along its length towards the distal tip  36 . The proximal end has a raised peripheral rear flange  22  about its largest diameter opening  8 . The ram is sized for sliding engagement within this linear bore. The carpule is aligned within the carpule tip  16  such that its longitudinal axis is common with the longitudinal axis of the ram. The distal end  10  has a smaller diameter opening (not illustrated) and a frictionally engageable cap (not illustrated). Between the openings, within the bore is a volume of dental composite, sealed from the atmosphere and light at the distal end by the cap and at the proximal end, by a delivery cup (not illustrated) that is frictionally inserted within the bore of the carpule, abutting the composite. When the cap is removed and a pressure is exerted onto the delivery cup, the delivery cup slides within the bore and composite is forced out of the smaller diameter opening at the distal end. It is this distal end opening that directs the composite into the patient&#39;s cavity. The carpule  20  may be rotated 360 degrees within the carpule tip  16 . This allows the distal end opening to swing about an arc with respect to the linear axis of the carpule tip. This allows the dentist great flexibility in the location of the pen  2  while he is filling cavities. The pen need not be inverted to fill upper teeth. The composite material may any one of the commercially available, proprietary formulations. As such, the consistency and flowabilty varies. For this reason, a high torque linear motor mated to a high power battery is utilized. 
         [0039]    Looking at  FIG. 12 , the internal components of the pen  2  can be seen. In this illustration a carpule  20  has been installed and the ram  40  has been extended so as to contact the cup in the end of the carpule  20  and advance it along the linear bore so as to force the composite out of the distal end of the carpule  20  and advance it along the linear axis of the carpule  40 . For visual clarity any hard wiring has been eliminated from this view. 
         [0040]    In the back of the grip section  4  is the rechargeable battery  54 . In the preferred embodiment this is a 3.7 V LiMn 700 mAh high current battery with a18350 form factor (or larger power battery) that is affixed by soldering in place. This is operably connected to power all functions of the pen  2 . Above the battery  54  is the microprocessor  56 . Ahead of the distal end of the battery  54  is an electric, variable speed, high torque motor  50  which is connected to the linear actuator  52 . (Together these form the linear actuator assembly.) In the preferred embodiment the peak motor draw is nominally 2.5A. At the distal end of the linear actuator  52  there is an aluminum ram  40  which threads into the linear actuator  52 . The linear actuator  52  is aligned within the pen  2  so as to have the centerline of so as to ram  20  common with the centerline of the carpule tip  16 . 
         [0041]    The ram  40  has a threaded section  60 , a base  62 , and in the preferred embodiment, a length of approximately 22 mm of which 20 mm may be extended into a carpule  20 . The preferred embodiment ram has an approximately 2 mm thick retainer  64  that accounts for the remainder of the 22 mm. The full length of ram&#39;s extension is just over 20 mm, to ensure that when it protrudes from the end of the linear actuator  52  it is capable of extending 20 mm from into the bore of the carpule  20  and that when fully retracted, the ram is less than 0 mm into the carpule  20 . (In this way the carpule can be completely evacuated by the ram  20 .) 
         [0042]    The ram speed and retraction button  28 , the ram feed button  12 , the battery  54 , battery power indication lights, the motor  50 , the visual ram speed indicator circuit, the battery charging port  30  and the data port  26  are all operably connected to the microprocessor  56  for the directional and speed control of the ram  40 , the visual ram speed LED illumination, and the battery power LED illumination as would be known by a person of ordinary skill in the art. The speed and ram retraction switch directs the microprocessor to adjust the ram extension speed of the linear actuator, and the microprocessor processes and sends the LED illumination signals to the ram speed indicator circuit. (In the prototype pens, the microprocessor also has a data logging circuit with a real time clock that captures number of uses per set cycle, the battery state, the ram speed and length of ram extension per use. This data is stored in the transient memory of the microprocessor and is accessible via the data port  26 . The microprocessor&#39;s ram speed circuit uses an accelerometer for the ram speed feedback) 
         [0043]    The composite extraction pen  2  is housed within a slender, ergonomic linear member similar in shape to a pen. It&#39;s microprocessor  56  variably controls the speed of the motor  54  (and thus the speed of the ram extension) via actuation of the ram speed and retraction button  28 . In the preferred embodiment, the peak speed of ram  20  (motor under load at maximum drive) is 2.43 mm/sec and the slowest speed of the ram  20  (motor under load at minimum drive) is 0.39 mm/sec. In the preferred embodiment, the microprocessor is a Cypress PSoC4 BLE, with a 32-bit ARM Cortex-M0 core capable of running up to 48 MHz. The SoC portion (configurable hardware similar to FPGA) handles some motor PWM timing requirements. 
         [0044]    This button also controls the direction of the motor&#39;s rotation (and thus whether the ram extends or retracts). This button is located at the proximal end of the pen  2  specifically so that there could be no inadvertent alterations to the composite extraction feed speed. (Carpules are expensive.) It is to be noted that the advancement (extension) of the ram  20  is accomplished as long as the feed button  12  is depressed, (continual tactile manipulation) thereby allowing the dentist to extract any quantity of composite desired and to accomplish this in as small increments as they want. On the other hand the reversal (retraction) of the ram  20  is done at the highest rate of speed and in one continual motion by a single actuation of the ram speed and direction button. 
         [0045]    The microprocessor  56  illuminates a series of LEDs in the visual ram speed indicator  24  that increase with increasing speed. The microprocessor also dictates the color of an imbedded power indication LED in the in the button  28 . The length of the extension of the ram  20  is controlled by the length of time that the feed button  12  is depressed. The amount of ram extension (forward) travel is limited manually such that it will dispense the complete volume of the composite material through the smaller diameter opening of the carpule  20 . The amount of travel required to empty a conventional carpule is 15-20 mm. 
         [0046]    In the event of a weakened battery, a DC electric charging cable may be connected to the pen  2  via the charging port and the dentist may continue to use the device, albeit in a corded function. In alternate embodiments an inductive charging circuit may be utilized. 
         [0047]    The carpule tip  16  has a cutaway portion along its length. This cutout allows the removal/insertion of a carpule and it also allows the carpule  20  to be rotated to different angles for disbursement as the dentist prefers. The adaptor is available in various different sizes to accommodate different manufacturer&#39;s carpules  20 . 
         [0048]    In operation, the dentist presses either button once (ram speed and retraction button  28  or the ram feed button  12 ) to electrically awake the pen  2  as the device&#39;s software on the microprocessor shuts down the pen  2  after a preset number of seconds of inactivity. (In alternate embodiments, the microprocessor&#39;s accelerometer may be used to power up and shut down the pen.) The ram speed and retraction button  28  is depressed for a preset number of seconds (Preferably 3 seconds) which will retract the ram  12  at full speed until it is fully retracted. The old carpule  20  can be removed and a new one inserted into the carpule tip  16  via the cutout. (At this time if a different manufacturer&#39;s carpule is to be used, an interchangeable carpule tip  16  may be substituted, and the carpule  20  may be oriented to the desired fill angle.) The carpule  20  is located such that its raised peripheral rear flange  22  abuts the inner stepped bore of the carpule tip  16 . The ram feed button  12  is depressed momentarily so as to advance the ram  20  into the proximal end of the carpule up to the cup. The speed and retraction button is pressed numerous times to incrementally increase the speed of the ram and illuminate more LEDS in the visual ram speed indictor  24 . (It is important that the speed of the ram corresponds to the flow speed of that specific composite.) Pressing the ram feed button  12  drives the motor  50  at the desired speed which causes the mechanically coupled linear actuator  52  to drive the ram  20  forward. The ram, in contact with the cup, forces composite to extrude from the distal end of the carpule. When a new carpule is required, the process is repeated. The power LED light will be red when the battery is critically low, yellow when the battery is low and green as long as there is 50% of the battery&#39;s capacity remaining. 
         [0049]    It is important to note that many of the composites are extremely stiff (little flowability) and require heating if they are to be extracted via a manual device. Otherwise the force required to extract the composite makes the dentist&#39;s hand move to much for accurate application into a cavity (force tremor). However with this pen  2 , utilizing a high torque motor eliminates both the need to heat the composite and the force tremor. 
         [0050]    While certain features and aspects have been described with respect to exemplary embodiments, one skilled in the art will recognize that numerous modifications are possible. Similarly, while certain functionality is ascribed to certain system components, unless the context dictates otherwise, this functionality can be distributed among various other system components in accordance with the several embodiments. 
         [0051]    System components described according to a particular structural architecture may be organized in alternative structural architectures. Hence, while various embodiments are described with—or without—certain features for ease of description and to illustrate exemplary aspects of those embodiments, the various components and/or features described herein with respect to a particular embodiment can be substituted, added, and/or subtracted from among other described embodiments, unless the context dictates otherwise. Consequently, although several exemplary embodiments are described above, it will be appreciated that the invention is intended to cover all modifications and equivalents within the scope of the following claims.