U.S. patent number 3,882,638 [Application Number 05/403,436] was granted by the patent office on 1975-05-13 for air-abrasive prophylaxis equipment.
Invention is credited to Robert B. Black.
United States Patent |
3,882,638 |
Black |
May 13, 1975 |
Air-abrasive prophylaxis equipment
Abstract
Air-abrasive equipment is provided for prophylaxis or tooth
cleaning purposes. Provision is made for directing not only the
air-abrasive stream or jet but also for directing a stream of
warmed water, preferably in the form of a curtain surrounding the
air-abrasive stream and serving to enhance the cleaning action and
also to entrain the abrasive particles so that they may readily be
withdrawn or removed through a liquid suction system.
Inventors: |
Black; Robert B. (Corpus
Christi, TX) |
Family
ID: |
23595762 |
Appl.
No.: |
05/403,436 |
Filed: |
October 4, 1973 |
Current U.S.
Class: |
451/91; 451/101;
451/102 |
Current CPC
Class: |
B24C
7/0046 (20130101); A61C 3/025 (20130101); B24C
5/02 (20130101); B24C 7/0084 (20130101) |
Current International
Class: |
B24C
7/00 (20060101); B24C 5/02 (20060101); B24C
5/00 (20060101); A61C 3/025 (20060101); A61C
3/02 (20060101); B24c 007/00 () |
Field of
Search: |
;51/8R,12,11 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kelly; Donald G.
Attorney, Agent or Firm: Synnestvedt & Lechner
Claims
I claim:
1. A system for handling and feeding abrasive particles comprising
means for mixing abrasive particles with a gaseous stream, first
nozzle means for delivering the abrasive laden stream to a point of
use, controllable supply means for starting and stopping the
abrasive laden stream, second nozzle means in predetermined
relation to the first nozzle means for delivering a stream of
liquid adjacent said point of use, controllable supply means for
starting and stopping the stream of liquid and control means for
the supply means including means providing for substantially
concurrently starting and stopping of the discharge of the gaseous
and liquid streams from the nozzle means.
2. A system as defined in claim 1 in which the first and second
nozzle means are integrated in a common handpiece.
3. A system for handling and feeding abrasive particles comprising
means for mixing abrasive particles with a gaseous stream, first
nozzle means for delivering the abrasive laden stream to a point of
use, a first shut-off valve between the mixing means and the first
nozzle means, a water feed line, a water heater in said line,
second nozzle means for receiving heated water from the water
heater and for delivering a stream of heated water substantially to
said point of use, a second shut-off valve between the water heater
and the second nozzle means, and control means including means
interrelating the opening of both of the shut-off valves, and means
providing for opening of the second shut-off valve without opening
the first shut-off valve.
4. A system for entraining abrasive particles in a gas stream
comprising a receptacle having walls defining a reservoir for
abrasive particles, a wall structure within the reservoir defining
a chamber separate from the abrasive reservoir and having a gas
inlet, an abrasive pick up tube extended through said chamber and
having its inlet end projecting from said chamber downwardly into
the abrasive supply in a lower region of the abrasive reservoir, a
port through the chamber wall for delivering gas from the chamber
into the supply of abrasive in the region of the inlet end of said
tube, a delivery connection extended from the pick up tube at a
point remote from the inlet end of the tube, and a gas supply line
connected with said tube near the delivery connection.
5. A system as defined in claim 4 and further including an
adjustable valve in said gas supply line.
6. A system as defined in claim 5 and further including a
controllable shut-off valve in said delivery connection.
Description
This invention relates to air-abrasive equipment and is
particularly concerned with equipment of this type especially
adapted for use in the cleaning of teeth, especially the removal of
foreign material from the exposed surfaces of the teeth, such as
those materials which are broadly classified as stain and
calculus.
As is known, stain may originate from various sources or causes
including smoking, tobacco chewing, excessive drinking of tea or
from vegetable origin. Calculus is of several different types,
especially serumal and salivary, and calculus deposits ordinarily
accumulate in pockets between the teeth and the surrounding soft
tissues, the serumal calculus originating from blood in this area
and the salivary calculus originating from the saliva. These
constituents precipitate and bond themselves to the exposed tooth
surfaces.
Various techniques and equipment are already known and used in the
cleaning of teeth, including hand instruments, rotary rubber cups
carrying an abrasive paste of pumice or silex, all of which
techniques may be used effectively in the removal of calculus, but
none of which techniques are satisfactory in effecting the removal
of various types of stain, especially the removal of stain from
broad areas of the teeth.
The equipment and the technique of the present invention are not
only usable in the removal of calculus, but are also particularly
advantageous in the removal of stain which frequently occurs in
relatively broad areas mixed with a thin coating of salivary
calculus.
Air-abrasive equipment has been known and extensively used in
dental work, but in general such air-abrasive equipment has been
employed primarily in the cutting of the tooth structure in
preparation for the filling of cavities. In contrast, the equipment
of the present invention is especially adapted to the cleaning of
teeth, particularly to the removal of stain, whether or not mixed
with a coating of calculus.
In air-abrasive equipment used for dental purposes, the delivery
and dispersal of abrasive particles in air suspension in the mouth
in objectionable and in some prior equipment employed for tooth
cutting, vacuum means such as an exhaust blower has been employed.
This, however, it bulky and cumbersome. In some prior systems it
has also been contemplated to wash the teeth with water following
the abrasive treatment, but such subsequent washing does not
overcome the objectionable initial distribution of the abrasive
particles on the soft tissues and other parts of the mouth.
It is an object of the present invention to overcome the various
difficulties and disadvantages above referred to and to provide an
airbrasive prophylaxis equipment adapted to the convenient and
effective removal of stain and or calculus in a manner which is
simple and which produces minimum discomfort to the patient.
According to the invention the equipment includes a hand piece
having a nozzle with an air-abrasive discharge passage and further
having a series of water discharge passages in an array surrounding
the air-abrasive passage, together with control means by which
warmed water is delivered for discharge through the array of water
passages and by means of which the control of the air-abrasive and
water streams is coordinated in a manner assuring the delivery of
water at all times when the air-abrasive stream is being
delivered.
In the hand piece provided according to the present invention the
water discharge passages are arranged to impinge upon the surface
of the tooth being cleaned in an area immediately adjacent to the
area of impingement of the air-abrasive stream. Preferably a
plurality of water streams are provided arranged in the manner of a
curtain surrounding the air-abrasive stream. By positioning the
water streams to impinge upon the tooth surface adjacent to but not
coincident with the target area of impingement of the air-abrasive
stream, the full effectiveness of the air-abrasive stream for its
intended prophylaxis purpose is assued, while, at the same time,
the water is present in the immediate vicinity of the target area
of the abrasive stream, so that the abrasive particles are
immediately taken up in suspension in the water and will flow with
the ater away from the tooth surface being cleaned for removal from
the mouth by the commonly used suction tube.
How the foregoing and other objects and advantages are attained
will appear more fully from the following description referring to
the accompanying drawings in which:
FIG. 1 is a schematic diagram of equipment according to the present
invention including a hand piece having an air-abrasive discharge
passage and also water discharge passages, together with supply and
control mechanism for the abrasive and water;
FIG. 2 is an enlarged sectional view of a device for mixing
abrasive particles with an air stream to be delivered to the hand
piece;
FIG. 3 is a view of the hand piece, with the parts in section so as
to illustrate the interior construction, especially of the head of
the hand piece; and
FIG. 4 is a detailed view showing the arrangement of the
air-abrasive nozzle and of the surrounding array of water discharge
passages.
Referring first to FIGS. 3 and 4, the hand piece comprises a tube 5
by which the instrument is to be held when in use in the mouth. The
head of the hand piece is generally indicated by the reference
numeral 6, and it will be seen that the head is supported at one
end of the tube 5 by means of the block 7 and the connected tubes 8
and 9. Tube 8 connects with the central passage 10 in the head
which in turn connects with the abrasive nozzle 11 having a
discharge passage extended at right angles to the axis of the
handle 5.
Tube 9 connects with the annular chamber 12 surrounding the passage
10 and the air-abrasive nozzle, the chamber 12 serving as a supply
chamber for the series of water discharge passages 13.
As will be seen from FIGS. 3 and 4 the water discharge passages 13
are arranged in an array surrounding the air-abrasive nozzle 11 and
the water passages are preferably inclined somewhat toward the
air-abrasive stream, but this inclination is relatively slight and
should not be so great as to intersect or join the air-abrasive
stream at a point in advance of the impingement of the air-abrasive
stream against the tooth surface being cleaned.
It will be seen that the air-abrasive and water nozzle arrangement
provides a curtain or envelope of water surrounding but spaced from
the air-abrasive stream in the target area of the air-abrasive
stream, so that the action of the abrasive particles is not
impaired at the target area. At the same time the envelope or
curtain of water will merge with the air-abrasive stream at least
beyond the normal air-abrasive target distance from the head of the
hand piece, and this is of importance because the abrasive
particles will be taken into suspension in the water, without
danger of direct impingement upon soft tissues or other parts of
the mouth.
The block 7 at the end of the handle 5 is provided with passages
which interconnect the tubes 8 and 9 with tubes 14 and 15 adapted
to cooperate with the flexible supply tubes 16 and 17 for the
air-abrasive and water, these flexible tubes 16 and 17 desirably
being combined in a common sheath indicated at 18. The flexible
tubes 16 and 17 are of course extended to the supply and control
equipment which is illustrated in FIGS. 1 and 2.
In considering FIGS. 1 and 2 it is first noted that although
various gases may be employed as carrier for the abrasive
particles, for instance carbon dioxide, air is suitable and for
many purposes is preferred. A line 19 from a source of pressurized
air, for instance at from 40 to 80 psi is connected through the
filter 20 and the normally closed solenoid shut-off valve 21, with
the branch lines 22 and 23. Line 22 is provided with a pressure
regulated device 24 which delivers the air through connections 25
and 26 to the abrasive mixing device indicated generally at 27. A
pressure gauge 28 indicates the pressure following the reduction of
the device 24. The connection 25 is provided with a check valve 29
and the connection 26 with a check valve 30.
As best seen in FIG. 2, the device 27 includes an outer casing 31
having a rounded bottom 32, and with a removable closure 33 at the
top, the casing 31 serving as a reservoir for abrasive particles as
indicated at 34.
Positioned centrally within the casing 31 is a receptacle or
chamber 35 connected with the closure member 33 and projecting
downwardly into the casing 31 to provide a central chamber with
which the air connection 26 connects. Centrally disposed within the
container 35 is a tube 36 which extends through the closure member
33 and is provided with openings with one of which the air
connection 25 connects. The lower end of the tube 36 fits in an
aperture in the bottom of the container 35 and projects downwardly
below the bottom of the container 35 where the tube is provided
with ports 37 for receiving abrasive. Additional ports 38 in the
bottom of the container 35 provide for delivery of air from the
container downwardly into the mass of abrasive, thereby effecting
introduction of the abrasive particles from the bottom region of
the casing 31 into the tube 36. The delivery line for the
abrasive-laden air is indicated at 39 and this line is connected
with the upper end of the tube 36, preferably in line with the air
supply connection 25, the line 39 being extended through a pinch
valve 40 from which the connection 16 delivers the air-abrasive
stream to the hand piece, as above described in relation to FIGS. 3
and 4.
The connection 25 is provided with an adjustable needle valve 41
for controlling the amount of air flowing directly to the upper end
of the tube 36 of the abrasive mixer. This valve provides for
adjustment of the quantity of abrasive picked up by the air stream.
When the valve 41 is wide open, a minimum of abrasive will be
entrained because the air will readily flow through the line 25 and
the connection 39 to the hand piece. As the valve 41 is completely
closed, the arrangement then provides for maximum pickup of
abrasive, because all of the air reaching the delivery line 39 must
pass through the chamber 35 and through the ports 38 and 37,
thereby entraining a maximum of the abrasive. If desired a valve 41
a may also be provided in branch 26.
Turning now to the water supply system, as shown in FIG. 1 an
appropriate pressurized water supply line is indicated at 42, this
line delivering water through the filter 43 and through a water
pressure regulator 44 to a water heater 45. This water heater is
adapted to elevate the temperature of the water, for instance to
about 100.degree.F, and thereby provide appropriate temperature for
use in the mouth. Desirably the water heater 45 has some storage
capacity, so that a supply of the warmed water will always be
available for use. The warmed water flows through the line 17 to
the hand piece as shown in FIGS. 3 and 4, a shut-off valve 46 being
provided so that the water flow may be started and stopped at will
by the operator.
While reference has been made to the use of a spray of water, it is
to be understood that certain other liquids may be used, for
instance liquids having medicaments in solution.
Turning now to the control system for starting and stopping the
abrasive stream and the water flow, it is first pointed out that
the valve 40, which may desirably be of the "pinch" valve type is
provided with a pneumatic actuating device of known type indicated
at 47, this device 47 being supplied with actuating air from the
branch 23a of the connection 23 above mentioned. The device 47 is
under the control of a solenoid operated by the circuit
diagrammatically indicated at 48, which circuit is associated with
a contact 49 of a switch device mentioned just below.
The water shut-off valve 46 is solenoid operated and the control
circuit for that valve is diagrammatically indicated at 50, being
associated with the contact 51 of the main control switch. This
main control switch desirably comprises a switch arm 52 connected
with a current source 53, the switch arm having a contactor adapted
to engage either the contact 51 or both of the contacts 51 and 49.
Switches of this type are well known and for dental purposes are
commonly arranged for foot actuation.
With the arrangement just described, the operator in using the
equipment will operate the switch arm 52 and this will initially
engage the contact 51, thereby opening the water supply valve 46.
By further movement of the arm 52 the contact 49 is engaged, and by
opening the valve 40 in order to deliver the air-abrasive stream to
the hand piece. It is advantageous that the switch arm 52 may be
operated to substantially concurrently initiate flow of both the
water and the air-abrasive stream, but it is preferred to employ an
arrangement such as shown, so that water alone may be delivered and
also so that whenever abrasive is delivered there is assurance that
water will also be delivered.
The upper portion of the casing 31 of the abrasive mixer (see FIGS.
1 and 2) is provided with an exhaust port 54 which is connected to
atmosphere by the line 55 through a bleed valve 56 and through an
abrasive powder trap 57. This valve 56 is normally open and may be
of the pinch valve type such as described above with reference to
valve 40, the valve 56 being supplied with actuating air pressure
through the branch 23b of the line 23, and being under the control
of a circuit indicated at 58 which is connected with the contact 59
of a master on-off switch 60. This switch 60 is associated with a
power source diagrammatically indicated at 61 and serves not only
to operate the valve 56 but further to operate the valve 21 by
virtue of the connection 62.
When the equipment is to be used, the switch 60 is closed, thereby
opening the normally closed solenoid valve 21 and thereby also
closing the normally open valve 56. The flow of the air-abrasive
and of the water is then manually controlled by the foot switch 52
in the manner described above. When the equipment is no longer
needed for operation, the master shut-off switch 60 may then be
opened and the normally closed solenoid valve shuts off the air
supply, and in addition the valve 56 opens and provides for
bleed-off of the pressure in the system including the abrasive
mixing device, discharge of abrasive particles being prevented by
the powder trap 57. This automatic bleed-off of pressure is
important particularly for the purpose of providing for refilling
the abrasive casing 31. If the pressure has been exhausted from the
system, the removable closure 33 may be separated in order to
permit introduction of a new charge of abrasive.
A valve 63 may be provided in order to adjust the pressure of the
air supplied through the connection 23 to the pinch valves 40 and
56.
For prophylaxis purposes it is preferred to employ abrasive
particles of very small particle size and of uniformity of particle
size, for instance particles of the order of 20-70 microns. It is
preferred according to the invention to provide such particles
formed of pure Iceland spar. As an alternative, fine microbeads of
glass may be used, either one of these abrasives being capable of
removing stain from the teeth without, however, any appreciable
etching effect on the tooth enamel, and thus without any of the
possibly detrimental effects which could flow from certain other
abrasives, such as free silicates or dolomite.
In addition to various of the advantages mentioned above, the
equipment of the present invention is also advantageous in that it
eliminates the necessity for drying the teeth prior to cleaning.
Bulky suction or vacuum equipment is not needed and since the
abrasive is readily removed by means of the customary saliva
ejector, separate disposal of the abrasive is not required.
* * * * *