U.S. patent application number 12/587438 was filed with the patent office on 2011-04-07 for method for finishing and fitting dental restorations and an abrasive material for doing same.
Invention is credited to Anthony David Pollasky.
Application Number | 20110081830 12/587438 |
Document ID | / |
Family ID | 43823534 |
Filed Date | 2011-04-07 |
United States Patent
Application |
20110081830 |
Kind Code |
A1 |
Pollasky; Anthony David |
April 7, 2011 |
Method for finishing and fitting dental restorations and an
abrasive material for doing same
Abstract
A method for finishing and fitting dental restorations is
provided. The method comprises the steps of contacting the
restoration surface with a stainless steel abrasive material and
working the stainless steel abrasive material against the
restoration surface to shape and smooth the restoration surface.
The stainless steel abrasive material comprises a base having a
plurality of pyramidal shapes protruding therefrom, a portion of
the protrusions having a substantially polygonal base and
triangular sides which meet at an apex which substantially forms a
point, hereinafter pyramidal protrusions, and a portion of the
protrusions having a substantially polygonal base and substantially
trapezoidal sides with the portion thereof distant from the base
surface forming a plateau such that the protrusions are
substantially butte-like in shape, hereinafter termed butte
protrusions, the protrusions providing intermixing cutting and
planing edges, the ratio of the pyramidal protrusions to the butte
protrusions ranging from 100:0 to 0:100. Also provided is the
stainless steel abrasive material used to carry out the method.
Inventors: |
Pollasky; Anthony David;
(Rochester, MN) |
Family ID: |
43823534 |
Appl. No.: |
12/587438 |
Filed: |
October 7, 2009 |
Current U.S.
Class: |
451/28 |
Current CPC
Class: |
B24D 99/00 20130101;
B24D 2203/00 20130101; A61C 3/06 20130101 |
Class at
Publication: |
451/28 |
International
Class: |
B24B 1/00 20060101
B24B001/00 |
Claims
1. A method for finishing and fitting dental restorations
comprising the steps of 1) contacting the restoration surface with
a stainless steel abrasive material and 2) working the stainless
steel abrasive material against the restoration surface to shape
and smooth the restoration surface, wherein the stainless steel
abrasive material comprises a base having a plurality of pyramidal
shapes protruding therefrom, a portion of the protrusions having a
substantially polygonal base and triangular sides which meet at an
apex which substantially forms a point, hereinafter pyramidal
protrusions, and a portion of the protrusions having a
substantially polygonal base and substantially trapezoidal sides
with the portion thereof distant from the base surface forming a
plateau such that the protrusions are substantially butte-like in
shape, hereinafter termed butte protrusions, the protrusions
providing intermixing cutting and planing edges, the ratio of the
pyramidal protrusions to the butte protrusions ranging from 100:0
to 0:100.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method for finishing and
fitting dental restorations such as, for example, dentures,
bridges, crowns, onlays and inlays and smoothing fillings. The
present invention also relates to an abrasive dental strip for
finishing and fitting dentures, bridges, crowns, onlays and inlays
and smoothing fillings.
BACKGROUND OF THE INVENTION
[0002] Typically dental restorations such as dentures, bridges,
crowns, inlays and onlays are formed in molds which may leave
irregular surfaces on the restorations. Also, when dentists use
dental restorations such as fitting bridges and crowns or applying
onlays or inlays, or fillings, irregular surfaces initially result.
It is particularly important with bridges, crowns, onlays, inlays
and fillings that proper contouring of the material occur so that
the margins and contouring between the bridge, crown, onlay, inlay
or filling and the natural tooth material remaining be precise to
prevent decay at the margins and provide good gingival health.
SUMMARY OF THE INVENTION
[0003] The present invention, in one aspect, provides a method for
finishing and fitting dental restorations comprising the steps of
[0004] 1) contacting the restoration surface with a stainless steel
abrasive material and [0005] 2) working the stainless steel
abrasive material against the restoration surface to shape and
smooth the restoration surface, wherein the stainless steel
abrasive material comprises a base having a plurality of pyramidal
shapes protruding therefrom, a portion of the protrusions having a
substantially polygonal base and triangular sides which meet at an
apex which substantially forms a point, hereinafter pyramidal
protrusions, and a portion of the protrusions having a
substantially polygonal base and substantially trapezoidal sides
with the portion thereof distant from the base surface forming a
plateau such that the protrusions are substantially butte-like in
shape, hereinafter termed butte protrusions, the protrusions
providing intermixing cutting and planing edges, the ratio of the
pyramidal protrusions to the butte protrusions ranging from 100:0
to 0:100.
[0006] The abrasive protrusions, unitary with the base, may be
arranged in rows, spiral, helix, or lattice fashion, or may be
randomly spaced. The arrangement, height, and shape or the abrasive
protrusions helps to define the rate of dental restoration surface
removal and degree of polishing desired.
[0007] The protrusions of the abrasive material useful in the
invention may be the same or different in shape. For example,
various protrusions may have different bases configurations, i.e.,
different numbers of sides, and/or different degrees of slope with
some bases approaching a circular shape. Generally, a triangular
base is preferred. The triangular sides of the pyramidal
protrusions and the trapezoidal sides of the butte protrusions may
have an inward arcuate slope.
[0008] The abrasive material useful in the invention may be
subjected to high and/or low temperature treatment. Optional
performance enhancing surface treatments may be applied to the
protrusions and the base surface to improve abrasive performance,
increase abrasive endurance, aid in non-loading characteristics due
to the lubricity of certain coatings, and reduce surface
porosity.
[0009] The method of the present invention can be used, for
example, on dental restorations such as dentures, bridges, crowns,
inlays and onlays during fabrication thereof, hereinafter generally
termed "dental fabrication". The method is also useful, for
example, in fitting and finishing bridges, crowns, onlays, inlays
and fillings in dental offices, hereinafter generally termed
"dental office applications".
[0010] The abrasive material may be in the form of a flexible strip
having a width preferably in the range of about 0.0625 inch to
about 0.5 inch, more preferably about 0.0625 inch to about 0.25
inch. Narrower strips are generally more useful for dental office
applications while wider strips are generally more useful for
dental fabrication. The abrasive material may also be in the form
of a disk preferably having a diameter of from about 0.5 inch to
about 1.5 inches, more preferably from about 0.75 inch to 1 inch
for use with a hand held high-speed rotary tool for use in both
dental office applications and dental fabrication. The abrasive
material in the form of still larger disks having diameters, for
example, of up to 12 inches and larger are useful in dental
fabrication.
[0011] The method of the present invention is particularly
effective in finishing and fitting dental restorations. A strip or
disk useful in the method of the present invention can provide both
rapid removal of dental restoration material as well as providing
the necessary finishing and smoothing whether the dental
restoration material is metal such as gold, gold alloy, titanium, a
cobalt-chromium alloy or nickel-chrome alloy; porcelain or
porcelain fused to metal; or a composite resin.
[0012] The method of the present invention is also especially
useful with dental composite resins such as, for example, a
resin-based matrix of a bisphenol A-glycidyl methacrylate (BISMA),
resin-like urethane dimethacrylate (UDMA), and an inorganic filler
such as silicon dioxide silica with chemical initiators and
catalysts. Engineered filler glasses and glass ceramics are used to
provide such composites with wear resistance and translucency, the
presence of which can make finishing and smoothing difficult.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIGS. 1A, 1B, and 1C are perspective views of pyramidal
protrusions suitable for the abrasive material useful in the method
of the present invention.
[0014] FIG. 2A is a cross-sectional view of an abrasive material
having pyramidal protrusions on both surfaces thereof useful in the
present invention.
[0015] FIG. 2B is a cross-sectional view of an abrasive material
invention having pyramidal protrusions of varying heights on the
surface thereof useful in the present.
[0016] FIG. 3 is cross-sectional view of a pyramidal protrusion
having a performance enhancing coating thereon useful in the
present invention.
[0017] FIG. 4A is a perspective view of a pyramidal protrusion
having triangular sides with a slope of about 30.degree. which meet
at an apex which substantially forms a point useful in the present
invention.
[0018] FIG. 4B is a perspective view of a pyramidal protrusion
having triangular sides with a slope of about 20.degree. which meet
at an apex which substantially forms a point useful in the present
invention.
[0019] FIG. 4C is a perspective view of a preferred pyramidal
protrusion useful in the present invention having triangular sides
with a slope of about 40.degree. which meet at an apex which
substantially forms a point.
[0020] FIG. 5A is a cross-sectional view of a butte protrusion
having a slope of about 45.degree. and a plateau distant from the
base surface an amount equivalent to 90% of a pyramidal protrusion
having about a 45.degree. slope.
[0021] FIG. 5B is a cross-sectional view of a butte protrusion
having a slope of about 45.degree. and a plateau distant from the
base surface an amount equivalent to 80% of a pyramidal protrusion
having about a 45.degree. slope.
[0022] FIG. 5C is a cross-sectional view of a butte protrusion
having inward arcuate sides and a plateau distant from the base
surface an amount equivalent to 70% of a pyramidal protrusion with
about a 45.degree. slope.
[0023] FIG. 6A is a top view of an abrasive strip with a portion
enlarged about 400.times..
[0024] FIG. 6B is a top view of an abrasive strip having saw-like
teeth on one edge thereof with a portion enlarged about
400.times..
[0025] FIG. 6C is a top view of an abrasive strip having grip
portions on the ends thereof with a portion enlarged about
400.times..
[0026] FIG. 6D is a side view of an implement in which an abrasive
strip useful in the present invention is held.
[0027] FIG. 6E is a side view of an abrasive strip for use in the
implement shown in FIG. 6D with a portion enlarged about
400.times..
[0028] FIG. 6F is a side view of an abrasive strip for use in the
implement shown in FIG. 6D with a portion enlarged about
400.times..
[0029] FIG. 7A is a top view of an abrasive disk enlarged about
400.times. useful in the present invention.
[0030] FIG. 7B is a top view of an abrasive disk having observation
ports therein enlarged about 400.times. useful in the present
invention.
[0031] FIG. 8A is a fragmented top view of a portion of a mask
suitable for use in producing an abrasive material suitable for use
in the present invention.
[0032] FIG. 8B is a fragmented top view of the mask shown in FIG.
8A enlarged about 400.times..
[0033] FIG. 8C is a fragmented top view of an abrasive material
enlarged about 400.times. having pyramidal protrusions which can be
produced using the mask shown in FIGS. 8A and 8B.
[0034] FIG. 8D is a fragmented top view of an abrasive material
enlarged about 400.times. having butte protrusions with plateaus
distant from the base surface an amount equivalent to about 80% of
the height of a pyramidal protrusion having a similar slope which
butte protrusions can be produced using the mask shown in FIGS. 8A
and 8B.
[0035] FIG. 9A is a fragmented top view of a portion of an abrasive
material useful in the present invention.
[0036] FIG. 9B is a fragmented top view of a mask enlarged about
400.times. useful for producing the abrasive shown in FIG. 9A.
[0037] FIG. 10A is a fragmented top view of a portion of an
abrasive material useful in the present invention.
[0038] FIG. 10B is a fragmented top view a mask enlarged about
400.times. useful for producing the abrasive material shown in FIG.
10A.
DETAILED DESCRIPTION OF THE INVENTION
[0039] In the method for finishing and fitting dental restorations
of the present invention, the abrasive material is formed from
stainless steel. Stainless steel is a particularly preferred base
material in the present invention due to the intrinsic resistance
of the material to corrosion, the ability to be sterilized, for
example, by autoclave, a sterilizing liquid such as peracetic acid
or gaseous sterilization with ethylene oxide, and the general
aesthetic appeal. Stainless steel can also be readily reproducibly
etched to form the abrasive material useful in the invention.
[0040] The method of the present invention is distinctly
advantageous in that the abrasive used is formed by etching a
pattern of protrusions from the material which forms the base, i.e.
the abrasive substrate. Known abrasive materials, e.g., sandpaper
and sanding disks have particulate such as, for example, garnet,
aluminum oxide, silicon oxide, and other hard abrasive particles,
adhered to a backing by a binder system. With such known abrasive
materials, the particulate is dislodged from the surface of the
abrasive to form dust during dental fabrication or deposit in a
patient's mouth during dental office procedures. The abrasive
material useful in the present invention is of a unitary structure
and does not present such problems.
[0041] The etching process can be carried out using well-known
resist and etching materials and processes. Prior to application of
the photoresist to the base material, cleaning of the base material
is preferably carried out. The resist coating can be applied using,
for example, hot roll lamination, screen printing, gravure
printing, dip coating and the like.
[0042] The mask which is used to provide the desired abrasive
pattern surface is then placed on the resist covered base material.
Good, i.e., intimate, contact between the resist coating and the
mask is needed to achieve the desired pattern on the base material
where the photoresist not covered by the mask is cured. Curing, or
imaging, is achieved by exposure to light sufficient to cure, i.e.,
cross-link, the polymeric resist. The mask is then removed from the
base material/photoresist/mask composite and the uncured
photoresist is removed from the base material using a developing
solution, or developer. If desired, the photoresist then remaining
on the base material may be imaged again prior to etching to
further ensure good adhesion of the photoresist to the base
material during etching.
[0043] Etching is then performed on those portions of the base
material not protected by the photoresist. The degree of etching
can be adjusted by altering the concentration and temperature of
the etchant solution and the method of application as is known to
those skilled in the art. As etchant removes the base material, a
certain portion of the base material under the mask also is
exposed.
[0044] The rate of etching and the extent to which this is allowed
to continue determines the shape of the protrusions. To achieve the
pyramidal protrusions requires etching to a greater extent than
etching to achieve the butte protrusions. To achieve mixed
pyramidal protrusions and butte protrusions, having mask portions
of differing surface areas can be used with larger mask areas
producing butte protrusions and smaller mask areas producing
pyramidal protrusion.
[0045] The rate of etching also determines the extent to which an
inward arctuate slope is formed. Generally, a faster rate of
etching results in a greater inward arc.
[0046] On thinner base materials where only one side of a substrate
carries the abrasive pattern, both side of the base material may be
etched to equalize metal stresses and reduce curling.
[0047] After etching, any remaining photoresist may be removed by
techniques well known to those skilled in the art.
[0048] The thickness of the abrasive material is not particularly
limited, but after etching should be suitably flexible where it
will be used in strip form, for example, to smooth medial or distal
portions of dental restorations or suitably stiff when used as a
flat abrasive. Of course, stiffness can be provided, if necessary,
by attachment to a stiff substrate such as, for example, a metal
plate or synthetic resin plate having suitable stiffness.
[0049] In the method of the present invention the surface of the
abrasive material can be heat treated, cryogenically treated or
heat treated and cryogenically treated or metallurically altered,
e.g., case hardening, for example, to form a thin harder layer on
the surface of the base surface and protrusions to improve hardness
as is well known to those skilled in the art.
[0050] Performance enhancing coatings may optionally be applied to
the surface of the abrasive useful in the present invention.
Preferred coatings include, for example, titanium nitride, chromium
nitride, boron nitride and diamond or diamond-like coatings. Such
coatings may be applied, for example, by chemical vapor deposition,
plasma-assisted chemical vapor deposition, hypersonic plasma
particle deposition, or physical vapor deposition, as appropriate
for material being deposited as is well known in the art.
Performance enhancing coatings such as, for example, nickel or
chrome plating or plating in combination with diamond dust may also
be applied to the abrasive material for use in the invention.
[0051] With respect to the drawings, like references number will
generally be used with reference to like parts.
[0052] FIGS. 1A, 1B, and 1C depict various possible embodiments of
the pyramidal protrusions of the abrasive material useful in the
invention with the bases of the pyramidal protrusions being
triangular, square and pentagonal, respectively. Of course, other
polygonal shapes can be used. In FIG. 1A, protrusion 11a is shown
having triangular base 12a, triangular side 14a, and apex 16a. In
FIG. 1B, protrusion 11b is shown having square base 12b, triangular
side 14b and apex 16b. In FIG. 1C, protrusion 11c is shown having
polygonal base 12c, triangular side 14c and apex 16c.
[0053] FIG. 2A depicts abrasive material 20a useful in the
invention having pyramidal protrusions 21a on both sides of base
23a with sides 24a and apexes 26a extending from base 23a. In FIG.
2B, abrasive material 20b has pyramidal protrusions 21b' and 21b''
each having different elevations from base 23a and having sides
24b' and 24b'' and apexes 26b' and 26b'', respectively. Of course,
butte protrusions or mixed pyramidal protrusions and butte
protrusions may be formed of varying heights on a substrate
surface.
[0054] FIG. 3 shows abrasive material 30 having pyramidal
protrusion 32 with height H and base width W on base 33 having a
thickness B. On the surface 34 of protrusion 32 and exposed base 33
is performance enhancing coating 38. In some cases, the etching
process can leave the stainless steel surface with a somewhat
pitted appearance under high magnification. In such cases, treating
the surface can provide a hardened, smooth surface layer on the
stainless steel. When depositing a coating on the surface, the
coating penetrates the surface imperfections on the surface of the
stainless steel for greater adhesion to the stainless steel.
[0055] Preferably, the slope of the sides of the pyramidal
protrusions or the butte protrusions can vary from slight, e.g.,
about 20.degree. or less to about 45.degree. or more, more
preferably from about 25.degree. to about 40.degree., most
preferably from about 30.degree. to 35.degree.. In FIGS. 4A, 4B,
and 4C, the slopes of the sides 44a, 44b, and 44c of the pyramidal
protrusions 41a, 41b and 41c are 30.degree., 20.degree. and
40.degree., respectively. The slope of the sides of the protrusions
can be controlled by the adjusting the etchant conditions. For
example, when etching the stainless steel sheet with a ferric
chloride solution, a protrusion having a lesser slope can be formed
by adjusting the ferric chloride to etch more slowly or extending
the etching time.
[0056] FIGS. 5A, 5B, and 5C depict various types of butte
protrusions of the abrasive material useful in the method of the
present invention having varying amounts of height compared to
comparable pyramidal protrusions. In FIG. 5A, butte protrusion 55a
is shown having side 54a with a slope of about 30.degree. on base
material 53a with flat top portion 57a and height about 90% of that
of a pyramid with comparable slope. In FIG. 5B, butte protrusion
55b is shown having side 54b with a slope of about 30.degree. on
base material 53b with flat top portion 57b and height about 80% of
that of a pyramid with comparable slope. In FIG. 5C, butte
protrusion 55c is shown having an inward arctuate slope 59c on base
material 53a with flat top portion 57a and height about 70% of that
of a pyramid with comparable slope as measured on butte protrusion
55c with the inward arcuate portion ignored.
[0057] FIGS. 6A, 6B and 6C show various abrasive strip
configurations useful in the method of the present invention. FIG.
6A shows abrasive dental strip 60a with pyramidal protrusions 61a
and optional non-abrasive etched base portion 63a. Non-abrasive
base portion 63a is useful during insertion of the abrasive strip
60a between teeth prior to shaping and/or finishing with abrasive
portions having pyramidal protrusions 61a during dental fabrication
or dental office applications.
[0058] FIG. 6B shows abrasive dental strip 60b with pyramidal
protrusions 61b and optional non-abrasive base portion 63b, similar
to that shown in FIG. 6A. Abrasive dental strip 60b further has a
cutting edge 68b with teeth 69b for shaping, for example, at tooth
margins. Although the pyramidal protrusions 61b on abrasive
material 60b may appear to have directionality, abrasive material
60b typically abrades independent of direction of use due to the
movements of the hands of the user.
[0059] FIG. 6C shows abrasive dental strip 60c with pyramidal
protrusions 61c and optional non-abrasive base portion 63c, similar
to that shown in FIG. 6A. Abrasive dental strip 60c further has
grips 68c at each end to aid in the user gripping dental strip 60c.
The grips may be formed of any sterilizable material. Preferably,
polymeric material such as, for example, silicone, can be used to
provide stable, comfortable grips for the user.
[0060] The optional non-abrasive portion is generally formed by
omission of any photoresist material during the etching of the
stainless steel. The strips are preferably formed by laser cutting
the strips from sheets of etched stainless steel. However, high
definition plasma arc cutting and abrasive water jet cutting may be
used.
[0061] FIGS. 6D, 6E and 6F show an implement for use in the present
invention, particularly in dental office applications, and abrasive
materials for use therein. Abrasive strip 60d is held in implement
160d at attachment points 162d in holder portion 164d in FIG. 6D.
Handle portion 166d is provided on implement 160d for holding the
implement by a user, for example, in dental office applications.
Abrasive strip 60e, shown in FIG. 6E, has pyramidal protrusions 61e
on base material 63e to form an abrasive surface and openings 69e
in non-abrasive base portion 63e for attachment to implement 160d
shown in FIG. 6D. Abrasive dental strip 60e further has a cutting
edge 68e for shaping, for example, at tooth margins. Abrasive strip
60f, shown in FIG. 6F, has protrusions 61f on base material 63f to
form an abrasive surface and openings 69f in non-abrasive base 63f
for attachment to implement 160d at attachment points 162d as shown
in FIG. 6D.
[0062] FIGS. 7A and 7B depict abrasive disks shown about 400.times.
which are preferably for use with hand held high-speed rotary tools
for use in dental fabrication or dental office applications.
Abrasive disk 70a in FIG. 7A has pyramidal protrusions 71a and
aperture 171a for affixing abrasive disk 70a to a hand held
high-speed rotary tool. Abrasive disk 70b in FIG. 7B has aperture
171b and pyramidal protrusions 71b similar to those in abrasive
disk 70a. Abrasive disk 70b further has viewing slots 79b such that
when the disk is rotating at as much as, for example, 30,000 rpm or
more, the user, for example, the dentist, can watch as the bridge,
crown, onlay, inlay or filling is shaped and smoothed the desired
amount.
[0063] FIG. 8A shows a portion of a mask pattern which can be used
to provide abrasive materials for use in the present invention. The
mask material of FIG. 8A is shown at about 400.times. in FIG.
8B.
[0064] In FIG. 8B, enlarged mask 80b has clear portions 81b' which
allow the light to pass through to cure the photoresist.
Surrounding the clear portions are the opaque portions 83b' which
prevent curing of the photoresist. In FIG. 9B, enlarged mask 90b
has clear portions 91b' which allow the light to pass through to
cure the photoresist. Surrounding the clear portions are the opaque
portions 93b' which prevent curing of the photoresist.
[0065] After curing of the photoresist and removal of the mask, the
uncured photoresist is removed by rinsing with a solution
appropriate for the photoresist used. The substrate etches such
that pyramidal protrusions or butte protrusions are formed under
the areas of the cured photoresist with the base surface being
formed in the areas having no photoresist. In some cases where
pyramidal protrusions are being formed, the photoresist may be
removed during the etching process.
[0066] In FIG. 8C, an abrasive material useful in the present
invention is shown enlarged 400.times.. Abrasive material 80c,
which can be produced using a mask as shown in FIGS. 8A and 8B, has
pyramidal protrusions 81c extending from base 83c. In FIG. 8D,
another abrasive material useful in the present invention is shown
enlarged 400.times.. Abrasive material 80d, which can be produced
using a mask as shown in FIGS. 8A and 8B, has butte protrusions 85d
extending from base 83d. Protrusions 85d are similar in shape to
protrusion 50b shown in FIG. 5B.
[0067] In FIG. 9A, a portion of an abrasive material useful in the
present invention is shown. The mask portion shown enlarged
400.times. in FIG. 9B is suitable for use in making the abrasive
material shown in FIG. 9A. In FIG. 9B, enlarged mask 90b has clear
portions 91b' which allow the light to pass through to cure the
photoresist. Surrounding the clear portions are the opaque portions
93b' which prevent curing of the photoresist. After etching,
protrusions are formed in the areas of cured photoresist, with base
material remaining in the etched areas having no photoresist.
[0068] In FIG. 10A, a portion of abrasive material 100a is shown
having protrusions 101a on base 103a. A portion of a mask useful in
producing an abrasive material shown in FIG. 10A is shown in FIG.
10B enlarged 400.times.. Mask 100b has clear portions 101b' with
opaque areas 103b'.
EXAMPLES
Example 1
[0069] A sheet of 420 spring tempered stainless steel having a
thickness of about 0.032 inch was cleaned and passivated. A
photoresist solution was coated onto the passivated stainless steel
and dried. A mask having pattern as shown in FIG. 9B was applied
over the photoresist.
[0070] The stainless steel/photoresist/mask composite was exposed
to 60 millijoules of light to effect imaging of the photoresist.
The unexposed, uncrosslinked photoresist was then removed by
rinsing with a developer solution. The stainless steel having the
photoresist pattern thereon was re-exposed to 100 millijoules light
to ensure adherence of the photo resist to the stainless steel
during etching.
[0071] The stainless steel was etched to a depth of about 0.012
inch using 36 Baume ferric chloride solution at a temperature of
145.degree. F. The resulting etched sheet was rinsed with water and
the remaining photoresist was removed using an aqueous potassium
hydroxide stripping solution.
[0072] The etched stainless steel was coated with titanium chromium
nitride at a temperature of about 500.degree. F. and subsequently
cryogenically cooled at -300.degree. F.
[0073] The resulting abrasive material had pyramidal protrusions
with triangular bases. The height of the apexes of the protrusions
from the base material was about 0.002 inch and a slope of about
30.degree.. The resulting abrasive material was a coarse dental
abrasive.
[0074] The material was satisfactory for cutting into strips or
disks and exhibited excellent performance for dental fabrication
and was suitable for use in dental office procedures.
Example 2
[0075] A sheet of spring tempered stainless steel having a
thickness of about 0.032 inch was cleaned and passivated. A
photoresist solution was coated onto the passivated stainless steel
and dried. A mask having pattern like that of FIG. 8B was applied
over the photoresist.
[0076] The stainless steel/photoresist/mask composite was exposed
to 60 millijoules of light to effect imaging of the photoresist.
The unexposed, uncrosslinked photoresist was then removed by
rinsing with a developer solution. The stainless steel having the
photoresist pattern thereon was re-exposed to 100 millijoules light
to ensure adherence of the photo resist to the stainless steel
during etching.
[0077] The stainless steel was etched to a depth of about 0.009
inch using 36 Baume ferric chloride solution at a temperature of
145.degree. F. The resulting etched sheet was rinsed with water and
the remaining photoresist was removed using an aqueous potassium
hydroxide stripping solution.
[0078] The etched stainless steel was coated with titanium chromium
nitride at a temperature of about 500.degree. F. and subsequently
cryogenically cooled at -300.degree. F.
[0079] The resulting abrasive material had pyramidal protrusions
with triangular bases. The height of the apexes of the protrusions
from the base material was about 0.008 inch and the slope of the
protrusions was about 30.degree.. The resulting abrasive material
was a medium dental abrasive.
[0080] The material was satisfactory for cutting into strips or
disks and exhibited excellent performance for dental fabrication
and was suitable for use in dental office procedures.
Example 3
[0081] A sheet of 420 spring tempered stainless steel having a
thickness of about 0.020 inch was cleaned and passivated. A
photoresist solution was coated onto the passivated stainless steel
and dried. A mask having pattern like that of FIG. 10B was applied
over the photoresist.
[0082] The stainless steel/photoresist/mask composite was exposed
to 60 millijoules of light to effect imaging of the photoresist.
The unexposed, uncrosslinked photoresist was then removed by
rinsing with a developer solution. The stainless steel having the
photoresist pattern thereon was re-exposed to 100 millijoules light
to ensure adherence of the photo resist to the stainless steel
during etching.
[0083] The stainless steel was etched to a depth of about 0.003
inch using 36 Baume ferric chloride solution at a temperature of
145.degree. F. The resulting etched sheet was rinsed with water and
the remaining photoresist was removed using an aqueous potassium
hydroxide stripping solution.
[0084] The etched stainless steel was coated with titanium chromium
nitride at a temperature of about 500.degree. F. and subsequently
cryogenically cooled at -300.degree. F.
[0085] The resulting abrasive material had pyramidal protrusions
with triangular bases. The height of the apexes of the protrusions
from the base material was about 0.002 inch and the slope of the
sides of the protrusions was about 30.degree.. The resulting
abrasive material was a fine dental abrasive.
[0086] The material was satisfactory for cutting into strips or
disks and exhibited excellent performance for dental fabrication
and was suitable for use in dental office procedures.
[0087] Although the present invention has been described with
reference to preferred embodiments, it will be understood that
various modifications may be made without departing from the spirit
and scope of the invention.
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