U.S. patent number 3,808,689 [Application Number 05/311,104] was granted by the patent office on 1974-05-07 for dental articulator trays.
Invention is credited to S. Charles Spinella.
United States Patent |
3,808,689 |
Spinella |
May 7, 1974 |
DENTAL ARTICULATOR TRAYS
Abstract
Improved dental articulators of either the pivotal or stem type
are provided with a tray permanently attached to each of the two
articulator platforms, and each tray has a keyway slot of dovetail
cross section extending longitudinally along its inner or operating
face as a coupling means for engaging a mounting base bearing a
dental cast on one side and a corresponding dovetail key on the
other side for engaging said slot. The key and keyway taper to a
substantial extent in the horizontal plane as they approach a pivot
or stem at the back of the articulator, and they taper at least
slightly in the vertical plane in the same direction to provide a
coupling system that can be easily and rapidly engaged or
disengaged and yet locate the mounting base in any similarly
equipped articulator with great precision. Also, a novel method of
constructing this articulator involves assembling preformed trays
with their keyways engaging keys of two opposite faces of a
mounting jig to maintain exact alignment of the trays and their
keyways while the other sides of the trays are being permanently
cemented to the platforms of the articulator.
Inventors: |
Spinella; S. Charles (Fort
Lauderdale, FL) |
Family
ID: |
23205422 |
Appl.
No.: |
05/311,104 |
Filed: |
December 1, 1972 |
Current U.S.
Class: |
433/60 |
Current CPC
Class: |
A61C
11/02 (20130101); A61C 9/002 (20130101); A61C
11/08 (20130101) |
Current International
Class: |
A61C
9/00 (20060101); A61C 11/00 (20060101); A61C
11/02 (20060101); A61C 11/08 (20060101); A61c
011/00 () |
Field of
Search: |
;32/32 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Mancene; Louis G.
Assistant Examiner: Lever; J. Q.
Attorney, Agent or Firm: Morgan, Finnegan, Durham &
Pine
Claims
I claim:
1. In a dental articulator including a pair of opposed articulator
platform members mounted to a frame structure in spaced
relationship to one another, at least one of said platform members
mounted for adjustable pivotal movement with respect to the other
of said platform members, the improvement therein which
comprises:
a tray member rigidly attached to each of said articulator platform
members;
each of said tray members being provided with slidably engageable
coupling means adapted to releasably lockably engage an article
having a complementary shaped coupling means; said tray member
coupling means having tapering dimensions in two different planes,
said dimensions tapering in each plane in the direction of movement
for coupling engagement between said tray member and said
article.
2. An articulator as claimed in claim 1, wherein each of said
tapering dimensions of said tray member coupling means tapers in a
direction approaching the axis about which said articulator
platforms are pivoted with respect to each other.
3. An articulator as claimed in claim 1, wherein each of said tray
member coupling means comprises a longitudinally extending keyway
slot having undercut side walls tapering toward each other in a
direction approaching the pivotal axis of said articulator platform
members, said undercut side walls of said keyway slot also tapering
from top to bottom in said direction approaching said pivotal axis
of said articulator platform members.
4. An articulator as claimed in claim 3, wherein said keyway slot
has a substantially dovetail cross-section.
5. An articulator as claimed in claim 3, wherein the taper of said
undercut side walls of said keyway slot toward each other is
substantially greater than the taper from the top to the bottom of
the slot.
6. An articulator as claimed in claim 5, wherein said undercut side
walls of said keyway slot taper toward each other approximately
from 8.degree.-60.degree., and taper from top to bottom
approximately at least 2.degree..
7. An articulator as claimed in claim 6, wherein said undercut side
walls of said keyway slot taper toward each other approximately
30.degree..
8. In a combination of a dental articulator including a pair of
opposed articulator platform members mounted to a frame structure
in spaced relationship to one another, at least one of said
platform members mounted for adjustable pivotal movement with
respect to the other of said platform members, and a mounting base
bearing a dental cast on one side thereof secured to each of said
articulator platform members, the improvement therein which
comprises:
a tray member rigidly attached to each of said articulator platform
members;
each of said tray members provided with slidably engageable
coupling means adapted to releasably lockably engage complementary
shaped coupling means provided on the underside of each of said
dental cast mounting bases;
said tray member and dental cast mounting base coupling means
having tapering dimensions in two different planes, said dimensions
tapering in each plane in the direction of movement for coupling
engagement between said tray members and said mounting bases,
whereby said dental cast mounting bases are rapidly slid into
precise locking engagement with said tray members on said
articulator platform members.
9. The combination as claimed in claim 8, wherein
each of said tray member coupling means comprises a longitudinally
extending keyway slot having undercut side walls tapering toward
each other in a direction approaching the pivotal axis of said
articulator platform members, said undercut side walls of said
keyway slot also tapering from top to bottom in said direction
approaching said pivotal axis of said articulator platform members;
and
each of said dental cast mounting base coupling means comprises a
longitudinally extending key member having a shape complementary to
that of said keyway slot.
10. The combination as claimed in claim 9, wherein said key member
and said keyway slot each have a substantially dovetail
cross-section.
11. A mounting jig for accurately aligning a pair of tray members
in opposed registry and subsequent mounting to an associated pair
of opposed platform members secured to a dental articulator frame
structure, comprising
a block member having top and bottom faces spaced apart a distance
corresponding to the distance of the opening between the
articulator platform members; and
each of said top and bottom faces of the jig block having a
longitudinally extending key member projecting outwardly
therefrom,
the longitudinally extending side edges of each of said key members
being undercut and tapering both toward each other and from top to
bottom from one end of said key member to the opposite end
thereof.
12. A mounting jig as claimed in claim 11, wherein said top and
bottom faces are spaced apart a distance of approximately 3.75-4.0
inches.
13. A mounting jig as claimed in claim 11, wherein said undercut
side edges of each of said projecting keys taper toward each other
approximately from 8.degree.-60.degree. and taper from top to
bottom approximately at least 2.degree..
14. A mounting jig as claimed in claim 13, wherein said undercut
side edges of each of said projecting keys taper toward each other
approximately 30.degree..
15. A method for positioning mounting bases bearing dental casts
with repetitive accuracy on opposed platform members secured to a
dental articulator frame structure, comprising the steps of:
forming a mounting jig having top and bottom faces spaced apart a
distance corresponding to the distance of the opening between the
opposed articulator platform members,
providing a longitudinally extending key member projection on each
of said top and bottom faces of said jig block, and
undercutting the longitudinally extending side edges of each of
said key members and tapering said side edges both toward each
other and from top to bottom from one end of said key member to the
opposite end thereof;
forming the underside of said mounting bases bearing dental casts
with a key member identical to the shape of the key members formed
on said mounting jig;
sliding a tray member provided on one side with a keyway slot
having a shape complementary to that of said key members formed on
said jig block into releasable locking engagement with each of said
key members on said top and bottom faces of said jig block;
placing said mounting jig with said tray members releasably
lockably engaged therewith between said opposed platform members of
said dental articulator;
securing said tray members to said opposed platform members;
and
thereafter slidably removing said mounting jig from said tray
members secured to said opposed platform members of said dental
articulator,
whereby said mounting bases bearing dental casts may be accurately
repetitively positioned on said dental articulator by slidably
engaging said tray members affixed to said opposed articulator
platform members.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is concerned with improved dental articulators and
their manufacture whereby they are equipped with a permanently
attached tray of particular configuration on each platform. These
trays are provided with coupling means for interlocking engagement
with complementary coupling means on the mounting bases of dental
casts for removably mounting the dental cast in the articulator
with precision.
2. Prior Art
In conventional practice for dental restorations, the dentist takes
a wax bite of the patient's teeth after suitable preparation and
then makes plaster casts which are sent along with the wax bite or
impression to the dental laboratory. The laboratory assembles the
two casts and the wax bite together within the articulator frame to
determine the height setting; then the whole articulator body is
tilted back 90.degree. without opening it, and a suitable cement
(i.e. plaster of paris or dental stone, hereinafter termed
"plaster") is cast around each frame or platform of the articulator
after said assembly has been properly aligned visually with the
articulator axis. Meanwhile, the wax bite maintains the proper
alignment between the casts of the upper and lower jaws of the
patient. This casting operation cements the upper jaw cast to the
upper frame of the articulator by means of the plaster which embeds
the upper frame or platform of the articulator; and the lower jaw
cast and lower frame are similarly bonded. After the plaster has
hardened, the excess plaster is trimmed away, and the laboratory
technician then opens the articulator and removes the wax bite
before building the desired kind of dental restoration in
conventional manner.
This mounting of the dental casts in an articulator is of an
irremovable type, because those casts can only be removed from the
articulator by breaking their mounting bases to free the framework
of the articulator platform. Such removal is deferred until the
dentist and patient accept the finished dental restoration.
Meanwhile, the denture is delivered to the dentist by mail or
otherwise while mounted on the articulator in order that the
dentist may check the fit of the dental restoration and ascertain
what if any corrections must be made in order to provide well
fitting and serviceable dentures for the patient. If any
alterations are required, the denture is mounted back on the dental
cast in the articulator, and the entire articulator is returned to
the laboratory for further work. Thus, a separate articulator is
required for each patient, and that articulator must be reserved
exclusively for that patient until the dental restoration has been
completed which may require several corrections or alterations.
This can prevent the use of the articulator by any other patient
for a period of weeks or even months in addition to sometimes
involving substantial delivery charges for sending the fairly heavy
articulator back and forth between dentist and laboratory.
Various types of articulators equipped with removable mounting
bases for the casts have been proposed or disclosed. For example,
Bragg U.S. Pat. No. 565,326 and Shmukler et al. U.S. Pat. No.
2,423,522 disclose adjustable articulators provided with ball
joints and set screws, and these have removable mounting bases for
the dental casts; but it appears that the casts must be
rearticulated or properly aligned whenever they are reinstalled, if
that articulator has been employed in the interim for any other
patient. Also, these articulators are relatively complex, and one
of them requires casting special metal plates in the mounting base
to provide a demountable unit.
Neer U.S. Pat. No. 2,611,961 describes a device designed for the
exact repositioning of dental casts wherein the lower jaw cast is
mounted on a base and positioned thereon by a series of
intersecting V grooves oriented in three different directions. Only
the bottom mounting base is capable of quick registry when it is
being remounted in that articulator; and even then the lower base
is not locked in by the grooves but merely rests thereon, and it
may be subject to misalignment by having its ribs ride somewhat
upward along the sides of the grooves in the bottom platform. The
upper jaw cast is mounted in conventional manner with an
articulator platform embedded therein, and it differs from common
constructions only in having an arm that is removable by detaching
two machine screws.
Benfield et al. U.S. Pat. No. 2,911,722 is concerned with dental
trays of rather complicated special designs equipped with internal
serrations and special gates or latches. These devices permit the
dental casts mounted on plaster bases to be removed for work
outside of the dental tray and then reinstalled in the locking tray
of the articulator in proper registration with its former
position.
Windish U.S. Pat. No. 3,059,336 discloses a stem articulator that
is particularly designed to enable dental restorations to be
provided without requiring the dentist to adjust the surfaces
thereof in the patient's mouth. In one embodiment, transverse or
lateral undercut grooves of apparently constant size are provided
so that the mounted casts may slide laterally and be removed.
Alternatively, in a different embodiment, pins are employed to
secure the mounted casts against movement.
The present invention is directed at improved dental articulators
which permit dental casts to be rapidly and easily removed and
reinstalled on the trays of the dental articulator without loss of
proper alignment of the upper and lower dental casts. It provides
important economies in respect of the technician's time as well as
in materials and equipment.
SUMMARY OF THE INVENTION
The present invention relates to an improved dental articulator in
which the improvement comprises trays that are rigidly attached to
the articulator platforms and each tray being provided with an
undercut coupling means which has tapering dimensions in two
different planes with said dimensions tapering in the direction of
coupling engagement whereby said trays are capable of rapid and
precise engagement with a complementary undercut coupling
means.
Other aspects of the invention include one or more of such features
as both of the dimensions tapering in the longitudinal direction
when approaching the axis or stem of an articulator, the provision
of a keyway in the trays, especially a keyway of substantially
dovetail cross section, a mounting base bearing the patient's cast
on one side while the other side thereof has a complementary
undercut coupling means which is capable of a close sliding
engagement with the tray coupling means.
Another aspect of the invention involves the method of making these
articulators including one or more of such features as uniting
preformed trays with the structural members of an articulator while
the trays are facing one another in predetermined parallel space
relationship with their tapering, undercut coupling means disposed
in mirror image alignment opposite one another. Preferably, this is
accomplished by means of a mounting jig on which said articulator
trays are assembled. Subsequently mounting bases may be cast for
the dental casts while at the same time forming complementary
coupling means on the other side of said mounting base by means of
the coupling means on the dental trays serving as molds for the
complementary coupling means that are being formed on the mounting
bases. Various other objects, advantages and benefits of the
invention will be apparent to those skilled in the art upon
consideration of the detailed disclosure hereinafter.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view illustrating the important
parts and manner of construction of one embodiment of an
articulator according to the present invention.
FIG. 2 is a front elevation of the completed articulator with a
lower jaw cast mounted therein.
DESCRIPTION OF SPECIFIC EMBODIMENTS
In FIG. 1 is shown in schematic fashion an articulator frame 10 of
a conventional nonadjustable type that is commonly used in fixedly
mounting dental casts by cementing them to the open frame structure
of the articulator with plaster which embeds the upper and lower
metal platforms 12 and 14, respectively. In the present embodiment,
this articulator chassis is employed to carry the novel trays
described in detail hereinafter. These trays allow the dental casts
and their mounting bases to be readily mounted on and disengaged
from the articulator. The other basic members of this simple hinged
articulator consist of the rear frame members 16 connected to the
lower platform 14 and projecting upwardly at the rear to provide
journals 18 for the pivot pin 20 and the rear support arms 22 which
connect the upper platform 12 to the pivot pin 20. An adjustable
stop means (not shown) is usually provided to restrict the extent
of the swing of the upper platform 12 towards the lower platform 14
in order to avoid any damage to dental casts or a dental
restoration resulting from an accidental rapid downward swing of
the upper platform 12.
In the center of FIG. 1 are illustrated a lower dental tray 24 and
an inverted upper tray 26 of the same construction which are ready
to be aligned and permanently fastened to the articulator chassis
10 as described hereinafter. The tray 24 has an upwardly extending
lip 28 at its rear edge, and a substantial area of its upper or
operating face 30 is preferably flat and relatively smooth except
for the coupling slot or keyway 32. As may be readily seen in FIG.
2, this slot 32 is of the undercut type, preferably of dovetail
cross section, in order to provide an interlocking engagement with
a mounting base as described hereinafter.
As will be evident to those skilled in the art, many other
articulator frames, including those of the stem type as well as
adjustable and nonadjustable pivoting types, may also be employed
as the chassis members of the present articulators. However, little
is gained in certain instances by using an adjustable articulator
frame inasmuch as some of these employ complex construction
features or involved procedures for realigning mounted casts after
they have been removed from an articulator, consequently
reinstallation is often relatively slow. In contrast, the new
articulators are self-aligning and permit rapid engagement and
release of mounted dental casts.
It will be observed that the keyway 32 is relatively wide at its
open end 34 and that it tapers in width as it extends
longitudinally toward the articulator axis or pivot pin 20 at the
rear. Thus, the rear or inner end 36 of the slot, which is
preferably but not necessarily closed, is distinctly narrower than
its open end 34. The angle of taper between the two edges of the
slot may vary widely and still provide a good coupling fit.
Excellent results are obtainable with taper angles of about 8 to 20
degrees, but somewhat smaller angles and larger angles of
60.degree. or even more are also contemplated.
The depth of the slot 32 should also diminish and become shallower
at its inner end 36 than at its outer end 34, but this draft or
angle of taper may be much smaller and still provide free but
precise coupling engagement. For example, the angle of taper
relative to the horizontal may be as little as about 1.degree., but
a slope of about 2.degree. or more is generally preferable.
However, it is only necessary to provide enough taper or draft in
the tapering dimensions for easy separation of the interlocked
members. The tapering dimensions of the undercut coupling members
of this invention provide important advantages in several respects.
They avoid the sloppy fit that one is likely to encounter with a
reasonably freely sliding fit between members having parallel
sides; and they render engagement and disengagement of the mounting
bases very easy while providing a high degree of precision.
The outer or nonoperating face 38 is optionally provided with one
or more grooves 40 of rectangular cross section for the purpose of
enlarging the surface area of that face in contact with the
adhesive described hereinafter.
The trays 24 and 26 may be made from a wide variety of construction
materials, in fact from almost any solid material which may be
shaped to intricate contours and which has no detrimental effects
on the casting and setting of plaster compositions. Many different
metals may be employed including aluminum, zinc, copper, nickel,
brass, bronze, steel and stainless alloys thereof. In general, any
metal that can be shaped or formed by either casting or machining
is suitable.
Plastic trays are usually preferred for economy and easy
fabrication. The resins employed may be of any type that can be
molded or machined to form trays of the configuration described
herein. The resin compositions may include any suitable
conventional reinforcing agents, additives, extenders or fillers,
as exemplified by clays, sawdust and textile, wood or glass fibers.
Thermosetting resins in general are suitable as may be illustrated
by phenolformaldehyde, aminoplasts such as urea-formaldehyde and
melamine-formaldehyde resins; styrenated unsaturated polyesters,
epoxy resins, etc. Excellent results have been obtained with the
epoxy resins and high impact polystyrene compositions. In many
instances thermoplastic resins are preferred as they can be molded
rapidly at low cost with good precision by injection molding
techniques. This is generally preferable to shaping thermosetting
resins by compression molding or casting a tray from molten metal
or machining it from a metal bar.
Among the many suitable thermoplastic resins are the polyolefins,
such as polyethylene and polypropylene, acrylic polymers as
exemplified by polymethylmethacrylate, nylons, formaldehyde
polymers as illustrated by DELRIN, polyphenyloxide, polycarbonates
like LEXAN, acrylonitrile-butadiene-styrene (ABS) resins, acetal
copolymer resins, such as CELCON, polyethylene terephthalate,
polystyrene, vinyl resins as illustrated by the polymers of vinyl
chloride and its copolymers with vinyl acetate, ABS resins, etc. In
general a dimensionally stable and tough resin of high impact
characteristics is preferred for providing a long service life for
the trays.
FIG. 1 also depicts a mounting jig 42 as a rectangular block
bearing a male coupling member in the form of an undercut key 44 on
its upper side and a similar key 46 on its lower side. These keys
are of dovetail cross section and they taper from a wide end 48 to
a narrow end 50; they are complementary to the keyways 32 and thus
designed to fit closely into those ksyways in the trays 24 and 26.
This jig is intended to establish the proper alignment of the trays
while the articulators of the present invention are being
constructed.
In assembling the articulators, the tray 24 is placed against the
bottom face of the jig 42 and pushed into place with its dovetail
slot 32 engaging the key 46 until a snug interlocked fit is
obtained; and the upper tray 26 is similarly fitted onto the
projecting key 44 at the top of the jig block 42. This orients the
two trays in a precise manner with their keyways 32 in mirror image
alignment and the inner or operating faces of the trays 24 and 26
parallel to one another and spaced apart by the depth of the side
walls of jig 42, a spacing that corresponds to the typical 3.75 -
4.0 inches opening of a conventional articulator. A liquid or paste
resin adhesive is spread onto the outer faces 38 and grooves 40 of
trays 24 and 26, then the assembly on the jig is inserted between
the two metal frame platforms 12 and 14 and more of the adhesive is
disposed in and around those frame members 12 and 14 to completely
cover them. Next the adhesive is allowed to set and permanently
bond the tray 26 to the platform 12 and the tray 24 to the platform
14. Other means of fixedly mounting these trays, including screws
and bolts, are contemplated but are usually less desirable as such
construction may be less rigid and/or more expensive.
Suitable resins for this luting or cementing operation are known
liquid or a semisolid resin compositions which bond firmly to both
the resin or metal of which the trays are constructed as well as
the metal articulator frame. Among the many suitable bonding resins
for this purpose are epoxy resins compositions containing amine,
polyamide or other suitable hardeners; polymethylmethacrylic resin
adhesives have provided good results. After the bonding resin has
hardened, the jig 42 is removed and any flash is trimmed away; then
the articulator is ready for use.
The completed articulator is illustrated in FIG. 2 with the
conventional stop for restricting the closure of the device again
omitted. The lower tray 24 is fastened to the articulator by the
bonding resin layer 52 in which the lower platform 14 (see FIG. 1)
is embedded and the upper tray 26 is similarly fastened in place by
the resin layer 54 which embeds the upper platform 12. It will be
apparent that the keyways 32 are sharply undercut at their corners
56 in a dovetail-shaped cross section to provide interlocking
engagement with the keys on the mounting bases described
hereinafter. In general, a dovetail configuration is preferred for
simplicity, and the undercut angle relative to the horizontal
surface of the tray is desirably between about 30.degree. and
60.degree., e.g., about 45.degree.. The undercut angle may be
considerably greater or less than this range, but little or no
advantage is gained thereby as extreme angular cuts tend to make
the master mold for the trays more difficult and expensive to
fabricate. Other undercut configurations may also be employed, as
exemplified by a coupling key system of T-shape with square or
rounded ends on the crossbar of the T.
FIG. 2 also illustrates the position in the device of a dental
casting 58 of the lower jaw. The upper jaw casting is usually
articulated at the same time but has been omitted here in order to
illustrate the tapered keyway in the upper tray. The lower cast 58
is mounted on the plaster base 60 which has a projecting key 62
engaging the keyway 32 of the lower tray 24. The key 62 is tapered
both in width and depth in the same way as the keyway slot 32;
hence this key is complementary and forms a close interlocking fit
with the keyway 32.
The trays 24 and 26 with their keyways 32 serve as molds for
shaping the keys 62; and this casting operation is usually
performed by the dental technician rather than the dentist. The
dentist forwards the dental casting 58 along with the upper jaw
casting and wax bite or impression (not shown). After assembling
the two casts with the wax bite therebetween, the technician
articulates this assembly visually in the articulator with the
articulator turned onto its back so that its pivot pin 20 is now at
the bottom; then he pours the plaster in the form of a paste or
slurry to cover the faces of the trays including the keyways 32 as
well as the rough bases of the casts. Usually, the trays and
keyways have previously been coated with a parting agent as
described hereinafter. There is no embedding of the metal frame of
the articulator as that member has already been permanently covered
by the tray 24 and the bonding layer 52. Masking tape may be placed
across the rear lips 28 of the trays to shield the back of the
articulator pivot and chassis from unwanted plaster in this
operation. When the plaster slurry has hardened and the flash has
been trimmed, the cast 58 is united with the mounting base 60 which
has a coupling key 62 projecting from its other side; and the upper
jaw cast is similarly mounted on a plaster base (not shown) that is
detachably coupled by means of a projecting key to the upper tray
26.
Although plaster does not adhere to some resinous materials, such
as polyethylene, it is usually preferred to employ a parting agent
before casting or molding coupling keys onto mounting bases for the
dental casts in order to insure easy separation of the undercut
coupling keys and keyways. The parting agent is applied to the
trays and their keyway slots but not to any part of the dental
casts as the plaster should form firm bonds with those casts. Good
results have been obtained with liquid silicone compositions,
glycerine and hydrocarbon materials such as paraffin waxes, mineral
oil and petroleum jelly.
These mounted casts are locked in place against any lateral (i.e.,
transverse) or vertical motion, but they can be simply and swiftly
disengaged from the articulator by merely withdrawing them in a
longitudinal direction, i.e., along the Freenum line. This prevents
any breakage of casts resulting from turning the articulator on its
side or top to examine the casts. Also, it is a simple matter to
prevent accidental dislodgement in the longitudinal direction, as
by merely fastening a piece of pressure-sensitive adhesive tape
across the openings 34 at the front ends of slots 32.
Although the keys and keyways may be aligned in a lateral
direction, there appears to be little or no advantage obtainable
with such orientation; and there is probably greater likelihood of
a cast accidentally slipping out of the articulator and being
broken when the dental casts are inspected at various angles.
While the aforesaid coupling members may be reversed in position so
that the keyways are located in the mounting base 58, and also in
the jig 42, while keys project from the operating faces of trays 24
and 26, little or no improvement appears to result from this
configuration.
The present invention provides a number of significant advantages
which result in substantial economies in both time and materials.
For example, a dental technician can work more conveniently and
rapidly on a dental restoration on a mounting base that has been
removed from the articulator, as he is now able to work at any
angle and from any side. In doing this, it is important that the
technician is able to substantial instantaneously remove and
replace the base without requiring rearticulation or realignment in
the articulator in order to obtain that convenience in working. In
the new system, the mounting bases align and lock in one motion as
there is only one possible position of reengagement.
Less plaster is required because there is no need to embed the
platform frame members therein. Also it is only necessary for the
dental technician and the dentist to each have a single articulator
of the improved model and this moderately heavy device does not
have to be shipped back and forth, only the dental cast mounting
bases must be sent. Moreover, the dentist and technician can employ
entirely different types of articulator frames, even stem and pivot
types, for work on the same dental restoration as long as the trays
were fastened in place on the different articulators by using
mounting jigs of the same dimensions. Also, the new articulator
trays do not require the destruction of the casts in order to free
them from the articulator frame. Accordingly, a patient's casts can
be kept indefinitely on the mounting bases along without the
necessity of reserving an articulator exclusively for that
particular patient.
In addition, it was noted with considerable surprise that several
badly chipped mounting base keys 62 provided precise alignment when
the mounting bases were reinstalled in the articulator despite the
badly battered condition of those coupling keys.
While the present invention has been described herein in respect to
a limited number of embodiments for the purposes of a full
disclosure, it will be readily apparent to those skilled in the art
that many other modifications and variations are within the scope
of this invention. Accordingly the present invention should not be
considered as limited in any particulars except as may be recited
in the appended claims or required by the prior art.
* * * * *