Pneumatic remover for use in removing dental prosthetics

A pneumatic remover assembly having a central housing with a reciprocating internal mass and spring, a first end unit having a spool-type valve for activating the remover, a second end unit having various conduits disposed therein for introducing and exhausting compressed air in and out of the remover, and a unique adjustment ring which is capable of adjusting the flow rate of the compressed air which is introduced to the remover, thereby regulating the striking intensity of the remover. The adjustment ring comprises an airflow groove disposed within the interior surface of the adjustment ring which is in contact with the second end unit of the remover assembly. This airflow groove has a gradually increasing depth along its length and is in continuous communication with the compressed air injection conduit disposed in the second end unit.

The present invention generally relates to an adjustable pneumatic remover 
and in particular to a device used to remove fabricated crowns and bridges 
from teeth restored in such a manner. 
BACKGROUND OF THE INVENTION 
The fabricated dental prosthetic, usually formed from precious metals, 
porcelain, composite materials, or a combination, has proven to be a very 
functional and durable dental restoration, and is intended to be 
permanently affixed to the underlying tooth. On many occasions, however, 
it is necessary for the dentist to remove the dental prosthetic to provide 
further or more comprehensive treatment, to treat conditions that may 
arise, or for a variety of other medical reasons. More often than not, it 
is desirable to remove the crown or bridge in such a way that the 
underlying tooth and its supporting mechanism will remain intact, and will 
not be harmed or compromised in any way. 
The removal of dental prosthetics, such as crowns, bridges and the like, 
has remained substantially a manual procedure wherein the dentist uses a 
forceps, hook, or pliers to extract the prosthetic from the tooth. 
Prosthetics which are affixed via a strong adhesive are extremely 
difficult to remove and often require painful and time consuming surgery 
to aid in the extraction. 
The most widely accepted dental prosthetic remover is in the form of a 
pliers. However, pliers require the exertion of substantial force by the 
dentist which causes pain to the patient and often results in the damaging 
of the prosthetic device making it unusable for future restorations. Due 
to the high cost of replacing dental prosthetics, the effort exerted by 
the dentist and the pain inflicted upon the patient, it has been most 
desirable within the dental profession to develop a device which rapidly 
and painlessly removes prosthetics, while substantially lessening the 
number of prosthetics which are damaged during the removal process. 
Recent advances in the development of pneumatic extractor devices has 
provided simple and quick extraction of dental prosthetics with minimal 
physical exertion by the dentist and pain to the patient. One such device 
is described in French Patent No. 2204966. The extractor, according to 
French Patent No. 2204966, utilizes compressed air which is introduced 
into a central portion of the extractor to actuate a hammer disposed about 
the central portion. This extractor is operated by a ball and pin control 
valve. A hook extractor appliance is affixed to the end of the extractor 
which is opposite to that end wherein compressed air is introduced into 
the central portion. The hook extractor appliance moves in the same 
direction of the hammer movement during the course of operation. 
The extractor device according to French Patent No. 2204966 has a number of 
disadvantages. Firstly, the amount or flow of compressed air or strike 
intensity cannot be controlled via the device itself. That is, the air 
flow into the central portion of the extractor will be the same as the air 
flowing from the compressed air supply tank. It would be most desirable to 
be able to control the amount of compressed air that enters the extractor 
so as to provide for varied amounts of force (i.e., strike intensity) 
generated by the extractor during operation. Secondly, the use of a moving 
part such as a marble or ball in the air control valve can cause system 
failure due to misalignment or blockage of the air conduits. Finally, it 
would be desirable to have an extractor device which is capable of being 
connected directly to the multipurpose utility dental chair hoses which 
are readily available in most dental examining rooms. French Patent No. 
2204966 requires the use of a separate and distinct compressed air hose 
which will require substantial installation costs associated with the use 
of this extractor design. 
The present invention overcomes the inherent disadvantages of French Patent 
No. 2204966 by providing a remover device having a gentle, fingertip, 
push-button operation which is capable of providing the required striking 
intensity for crown or bridge removal. This steady strike action reduces 
slippage once the dental appliance is properly positioned about the 
prosthetic. Its minimal recoil action provides increased patient comfort, 
while sure and steady strikes reduce replacement costs. The present 
invention also provides a means for controlling the compressed air flow 
into the remover device which allows for preset, controlled uniformity of 
strike intensity which reduces damage to reusable crowns and bridges. The 
ability to control the air flowing into the remover also allows for its 
use in the removal of prosthetics with either temporary or permanent 
adhesives which necessitate different amounts of air flow or striking 
intensity to perform the function of removing the prosthesis from the 
tooth or gum. Moreover, the present invention is readily connected to 
virtually any conventional two, three or four hole dental chair utility 
hose (compressed air port, vacuum port, water port and light port). Thus, 
avoiding the high cost of retro-fitting each dental examining room with a 
separate compressed air line or hose. 
The present invention also provides many additional advantages which shall 
become apparent as described below. 
SUMMARY OF THE INVENTION 
A pneumatic remover assembly which comprises: a housing unit which 
comprises an outer housing, a work chamber disposed within the outer 
housing, a shaft member centrally disposed within the work chamber, an 
internal mass reciprocally disposed about the shaft member, and a spring 
means disposed between the internal mass and a rear end of the housing 
unit, the shaft member having a first conduit means disposed along its 
entire length which allows for passage of a compressed air or gas 
therethrough; a first end unit disposed at an end of the housing unit such 
that the internal mass is disposed between the spring means and the first 
end unit, the first end unit comprising a valve mean, a means for securing 
a dental appliance to the first end unit, a second conduit means for 
introducing the compressed air or gas from the first conduit means to the 
valve means, a third conduit means disposed within the valve means which 
is capable of passing the compressed air or gas from the second conduit 
means through the valve means, and a fourth conduit means for removing the 
compressed air or gas from the valve means and introducing the compressed 
air or gas into the work chamber where it is capable of acting on the 
internal mass by moving it away from the first end unit; a second end unit 
disposed at the opposite end of the housing unit from the first end unit 
such that the spring means is disposed between the second end unit and the 
internal mass, the second end unit comprising a fifth conduit means which 
is capable of introducing the compressed air or gas into the first conduit 
means of the shaft member, at least one sixth conduit means capable of 
removing the compressed air or gas from the center chamber and out of the 
assembly; and a means for adjusting the flow rate of the compressed air or 
gas which is introduced to the pneumatic remover assembly via the fifth 
conduit means. 
The means for adjusting the flow rate of the compressed air or gas is an 
adjustment ring and a seventh conduit means disposed between the 
adjustment ring and the fifth conduit means. The adjustment ring comprises 
an airflow groove disposed about the surface of the adjustment ring which 
is in contact with the second end unit, the airflow groove has a gradually 
increasing depth along its length and is in communication with the seventh 
conduit means. 
A dental appliance for use in removing dental crowns and bridge from 
outside of the gum or palate which comprises an elongated stem portion and 
a means for gripping a dental prosthetic being disposed at about a 
90.degree. angle from the elongated stem portion. 
A dental appliance for use in removing dental crowns and bridge from inside 
of the gum or palate which comprises an elongated stem portion, a second 
stem portion disposed at an angle of about 17 degrees 30 minutes from the 
elongated stem portion, a third stem portion disposed at an angle of about 
38 degrees from the elongated stem portion, and a means for gripping a 
dental prosthetic disposed at an angle of about 90 degrees from the third 
stem portion. 
A dental appliance for use in removing dental crowns and bridge located in 
the front of the mouth which comprises an elongated stem portion and a 
second stem portion disposed at an angle of about 16 degrees from the 
elongated stem portion. 
Other and further objects, advantages and features of the present invention 
will be understood by reference to the following specification in 
conjunction with the annexed drawings, wherein like parts have been given 
like numbers.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A pneumatic remover assembly having a central housing with a reciprocating 
internal mass or hammer and spring, a first end unit having a spool-type 
valve for activating the remover, a second end unit having various 
conduits disposed therein for introducing and exhausting compressed air in 
and out of the remover, and a unique adjustment ring which is capable of 
adjusting the flow rate of the compressed air which is introduced to the 
remover and, thus, controlling the striking intensity of the remover. The 
adjustment ring comprises an airflow groove disposed about the surface of 
the adjustment ring which is in contact with the second end unit of the 
remover assembly. This airflow groove has a gradually increasing depth 
along its length and is in continuous communication with the compressed 
air injection conduit disposed in the second end unit. 
The present invention can best be described by referring to the 
accompanying drawings wherein FIG. 1 is a schematic representation of the 
pneumatic remover assembly according to the present invention. FIG. 1 is 
in cross-section to permit clear description of the remover assembly 1. 
Pneumatic remover assembly 1 has a housing unit 3 which comprises an outer 
housing 5, a work chamber 7 disposed within outer housing 5, shaft member 
9 centrally disposed within work chamber 7, an internal mass 11 
reciprocally disposed about shaft member 9, and a spring means 13 disposed 
between internal mass 11 and a rear end of housing unit 3. Shaft member 9 
includes a first conduit means 15 centrally disposed along its entire 
length which allows for passage of a compressed air or gas therethrough. 
Pneumatic remover assembly 1 also includes a first end unit 17 disposed at 
an end of housing unit 3 such that internal mass 11 is disposed between 
spring means 13 and first end unit 17. First end unit 17 comprising a 
valve means 19, a means for securing 21 a dental appliance to first end 
unit 17, a second conduit means 23 for introducing the compressed air or 
gas from first conduit means 15 to valve means 19, a third conduit means 
25 disposed within valve means 19 which is capable of passing the 
compressed air or gas from second conduit means 23 through valve means 19, 
and a fourth conduit means 27 for removing the compressed air or gas from 
valve means 19 and introducing the compressed air or gas into work chamber 
7 where it is capable of acting on internal mass 11 by moving it away from 
first end unit 17. 
A second end unit 29 is disposed at the opposite end of housing unit 3 from 
first end unit 17 such that spring means 13 is disposed between second end 
unit 29 and internal mass 11. Second end unit 29 comprising a fifth 
conduit means 31 which is capable of introducing the compressed air or gas 
into first conduit means 15 of shaft member 9, at least one sixth conduit 
means 33 capable of removing the compressed air or gas from work chamber 7 
and out of assembly 1. 
Assembly 1 also include a means for adjusting the flow rate of the 
compressed air or gas which is introduced to pneumatic remover assembly 1 
via fifth conduit means 31. Adjusting of the flow rate has a direct impact 
on the striking intensity applied to the respective dental prosthetic. The 
means for adjusting the flow rate of the compressed air or gas is an 
adjustment ring 35 and a seventh conduit means 37 disposed between 
adjustment ring 35 and fifth conduit means 31. 
As shown in FIGS. 9, 10a, 10b and 10c, adjustment ring 35 comprises an 
airflow groove 51 disposed about interior surface 53 of adjustment ring 35 
which is in contact with second end unit 29. Airflow groove 51 has a 
gradually increasing depth along its length and is in communication with 
seventh conduit means 37. Airflow groove 51 has an exhaust notch or exit 
port 55 which is disposed near rear surface 57 of adjustment ring 35 which 
permits the compressed air to exit from assembly 1. As shown in FIGS. 1 
and 6, adjustment ring 35 is secured about second end unit 29 by means of 
a spring 90 and pin 92 disposed within seat 94 of second end unit 29 and 
hole 52 disposed in adjustment ring 35. The rotational movement of 
adjustment ring 35 is controlled by means of a guide pin 56 disposed 
between a channel 58 of adjustment ring 35 and second end unit 29. It is 
the length of channel 58 which restricts the rotational movement of 
adjustment ring 35. 
As shown in FIGS. 1, 11 and 12 valve means 19 comprises a valve housing 61, 
a valve stem or spool 63, and a spring 65, whereby third conduit means 25 
which is disposed within valve means 19 is in the open position when valve 
stem 63 is depressed and in the closed position when valve stem 63 is 
returned to its normal position. Spring 65 and valve housing 61 are 
initially disposed within valve seat 24 shown in FIG. 2, followed by the 
placement of valve stem 63 inside of valve housing 61. 
Sixth conduit means 33 which is capable of removing the compressed air or 
gas from the center chamber is preferably a groove with a concave shape. 
Groove 33 is typically disposed along exterior surface 34 of second end 
unit 29 such that it is formed between exterior surface 34 and the 
interior surface of outer housing 5. 
FIGS. 13-15 depict various unique dental appliances which are useful with 
remover assembly 1 according to the present invention. Each dental 
appliance is replaceably affixed to first end unit 17 by threaded means 21 
for securing the dental appliance thereto. The dental appliance preferably 
has a threaded portion at one end thereof which is screwed into threaded 
means 21 for securing it to first end unit 17 of remover assembly 1. 
FIG. 13 depicts a dental appliance 71 for use in removing dental crowns and 
bridge from outside of the gum or palate. This dental appliance 71 
comprises an elongated stem portion 73 and a means 75 for gripping a 
dental prosthetic being disposed at about a 90.degree. angle from 
elongated stem portion 73. 
FIG. 14 is a dental appliance 77 for use in removing dental crowns and 
bridge from inside of the gum or palate. This dental appliance 77 
comprises an elongated stem portion 79, a second stem portion 81 disposed 
at an angle of about 17 degrees 30 minutes from elongated stem portion 79, 
a third stem portion 83 disposed at an angle of about 38 degrees from 
elongated stem portion 79, and a means 85 for gripping a dental prosthetic 
disposed at an angle of about 90 degrees from second stem portion 81. 
FIG. 15 is a dental appliance 87 for use in removing dental crowns and 
bridge located in the front of the mouth. This dental appliance 87 
comprises an elongated stem portion 89 and a second stem portion 91 
disposed at an angle of about 16 degrees from elongated stem portion 89. 
During use, pneumatic remover assembly 1 is connected to a conventional 
dental chair utility hose comprising 2, 3 or 4 basic dental utilities, 
i.e., compressed air, vacuum, water, or light. For demonstration purposes 
only, FIGS. 1 and 7 depict a remover assembly 1 which is suitable for 
connection with a two utility dental hose (i.e., water and compressed 
air). The compressed air male injection port (not shown) is inserted into 
female port 32 such that the compressed air is capable of unrestrictedly 
entering conduit 31 of second end unit 29. The water male injection port 
(not shown) is inserted into dead-end female port 36 such that the water 
is incapable of entering conduit 31 or any interior portion of remover 
assembly 1. One of dental appliances (71, 77, 87) is selected depending 
upon the intended application and secured to first end unit 17 by screwing 
into threaded means 21. The desired striking intensity and operating air 
pressure is determined using the conventional foot regulator. The basic 
strike intensity is controlled with foot pedal pressure, while finer 
modification is regulated by rotation of adjustment ring 35 about second 
end unit 29 wherein reduced striking intensity is obtained by allowing 
more compressed air to pass through conduit 37, airflow groove 51 and 
notch 55. That is, the larger the depth of airflow groove 51 at the 
intersection with conduit 37, the more compressed air can exit via conduit 
37. Increased striking intensity is therefore obtained by reducing the 
amount of compressed air which exits assembly 1 via conduit 37. In that 
instance, it would be desirable to have less depth in airflow groove 51 at 
the intersection with conduit 37. Conversely, if less striking intensity 
is desired, then a greater depth in airflow groove 51 at the intersection 
with conduit 37 would be required. 
For removal of a crown, the dental appliance (71, 77, 87) is positioned at 
the least sensitive point of the crown margin. The strike is delivered by 
depressing valve stem 63 such that compressed air from the dental chair 
utility hose enters conduit 31, a predetermined amount compressed air is 
diverted via conduit 37 and removed from assembly 1 via adjustment ring 35 
to establish the desired striking intensity, and passes through conduit 15 
of shaft means 9 where it enters conduit 23. When valve stem 63 is 
depressed conduit 25 is opened such that compressed air passes 
therethrough into conduit 27. The compressed air is carried along conduit 
27 into work chamber 7 where it causes internal mass or hammer 11 to move 
toward second end unit 29, while spring 13 is compressed. It is the 
movement of internal mass or hammer 11 which provides the force required 
to remove the dental prosthetic in the same direction without any 
substantial physical exertion by the dentist. After the strike is 
delivered valve 63 returns to its normal position by releasing valve stem 
63, thereby closing conduit 25 which prevents any additional compressed 
air from entering work chamber 7. Any residual compressed air left in work 
chamber 7 from the previous strike is exhausted from remover assembly via 
conduit 33. Conduit 33 is preferably a plurality of grooves disposed about 
the exterior surface 34 of second end unit 29. 
It is preferable that all pans of extract assembly 1 be fabricated from 
either aluminum or stainless steel in order to permit sterilization 
thereof so as to avoid the transmission of infectious disease from patient 
to patient. 
While we have shown and described several embodiments in accordance with 
our invention, it is to be clearly understood that the same are 
susceptible to numerous changes apparent to one skilled in the art. 
Therefore, we do not wish to be limited to the details shown and described 
but intend to show all changes and modifications which come within the 
scope of the appended claims.