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.

Description

FIELD OF THE INVENTION

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

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

The present invention, in one aspect, provides 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.

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.

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.

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.

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”.

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.

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.

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

FIGS. 1A, 1B, and 1C are perspective views of pyramidal protrusions suitable for the abrasive material useful in the method of the present invention.

FIG. 2A is a cross-sectional view of an abrasive material having pyramidal protrusions on both surfaces thereof useful in the present invention.

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.

FIG. 3 is cross-sectional view of a pyramidal protrusion having a performance enhancing coating thereon useful in the present invention.

FIG. 4A is a perspective view of a pyramidal protrusion having triangular sides with a slope of about 30° which meet at an apex which substantially forms a point useful in the present invention.

FIG. 4B is a perspective view of a pyramidal protrusion having triangular sides with a slope of about 20° which meet at an apex which substantially forms a point useful in the present invention.

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° which meet at an apex which substantially forms a point.

FIG. 5A is a cross-sectional view of a butte protrusion having a slope of about 45° and a plateau distant from the base surface an amount equivalent to 90% of a pyramidal protrusion having about a 45° slope.

FIG. 5B is a cross-sectional view of a butte protrusion having a slope of about 45° and a plateau distant from the base surface an amount equivalent to 80% of a pyramidal protrusion having about a 45° slope.

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° slope.

FIG. 6A is a top view of an abrasive strip with a portion enlarged about 400×.

FIG. 6B is a top view of an abrasive strip having saw-like teeth on one edge thereof with a portion enlarged about 400×.

FIG. 6C is a top view of an abrasive strip having grip portions on the ends thereof with a portion enlarged about 400×.

FIG. 6D is a side view of an implement in which an abrasive strip useful in the present invention is held.

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×.

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×.

FIG. 7A is a top view of an abrasive disk enlarged about 400× useful in the present invention.

FIG. 7B is a top view of an abrasive disk having observation ports therein enlarged about 400× useful in the present invention.

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.

FIG. 8B is a fragmented top view of the mask shown in FIG. 8A enlarged about 400×.

FIG. 8C is a fragmented top view of an abrasive material enlarged about 400× having pyramidal protrusions which can be produced using the mask shown in FIGS. 8A and 8B.

FIG. 8D is a fragmented top view of an abrasive material enlarged about 400× 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.

FIG. 9A is a fragmented top view of a portion of an abrasive material useful in the present invention.

FIG. 9B is a fragmented top view of a mask enlarged about 400× useful for producing the abrasive shown in FIG. 9A.

FIG. 10A is a fragmented top view of a portion of an abrasive material useful in the present invention.

FIG. 10B is a fragmented top view a mask enlarged about 400× useful for producing the abrasive material shown in FIG. 10A.

DETAILED DESCRIPTION OF THE INVENTION

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.

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.

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.

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.

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.

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.

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.

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.

After etching, any remaining photoresist may be removed by techniques well known to those skilled in the art.

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.

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.

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.

With respect to the drawings, like references number will generally be used with reference to like parts.

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.

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.

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.

Preferably, the slope of the sides of the pyramidal protrusions or the butte protrusions can vary from slight, e.g., about 20° or less to about 45° or more, more preferably from about 25° to about 40°, most preferably from about 30° to 35°. 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°, 20° and 40°, 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.

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° 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° 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.

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.

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.

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.

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.

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.

FIGS. 7A and 7B depict abrasive disks shown about 400× 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.

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× in FIG. 8B.

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.

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.

In FIG. 8C, an abrasive material useful in the present invention is shown enlarged 400×. 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×. 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.

In FIG. 9A, a portion of an abrasive material useful in the present invention is shown. The mask portion shown enlarged 400× 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.

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×. Mask 100b has clear portions 101b′ with opaque areas 103b′.

EXAMPLES

Example 1

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.

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.

The stainless steel was etched to a depth of about 0.012 inch using 36 Baume ferric chloride solution at a temperature of 145° F. The resulting etched sheet was rinsed with water and the remaining photoresist was removed using an aqueous potassium hydroxide stripping solution.

The etched stainless steel was coated with titanium chromium nitride at a temperature of about 500° F. and subsequently cryogenically cooled at −300° F.

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°. The resulting abrasive material was a coarse dental abrasive.

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

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.

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.

The stainless steel was etched to a depth of about 0.009 inch using 36 Baume ferric chloride solution at a temperature of 145° F. The resulting etched sheet was rinsed with water and the remaining photoresist was removed using an aqueous potassium hydroxide stripping solution.

The etched stainless steel was coated with titanium chromium nitride at a temperature of about 500° F. and subsequently cryogenically cooled at −300° F.

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°. The resulting abrasive material was a medium dental abrasive.

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

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.

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.

The stainless steel was etched to a depth of about 0.003 inch using 36 Baume ferric chloride solution at a temperature of 145° F. The resulting etched sheet was rinsed with water and the remaining photoresist was removed using an aqueous potassium hydroxide stripping solution.

The etched stainless steel was coated with titanium chromium nitride at a temperature of about 500° F. and subsequently cryogenically cooled at −300° F.

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°. The resulting abrasive material was a fine dental abrasive.

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.

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.

Claims

1. A method for finishing and fitting dental restorations comprising the steps of 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.

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,