WO1997041798A1

WO1997041798A1 - Improved dental implant process and treated prosthetic

Info

Publication number: WO1997041798A1
Application number: PCT/US1996/006411
Authority: WO
Inventors: Robert L. Ibsen; William R. Glace; Donald R. Pacropsis
Original assignee: Den-Mat Corporation
Priority date: 1996-05-07
Filing date: 1996-05-07
Publication date: 1997-11-13
Also published as: AU5729896A

Abstract

This invention is a process of implanting a metal dental prosthesis into or on the alveolar bone, to provide anchorage or stabilization either to a tooth or to another prosthesis, which involves surgical exposure of the alveolar bone, providing means for (a) fixing a metal implant (1) in the alveolar bone (15), and (b) fixing the metal implant (1) to either a tooth or to the other prosthesis, and closing the exposure of the alveolar bone (15). The improvement which comprises the step of applying to one or more portions of the implant (1) or to the locus of the implant in the alveolar bone (15), a primary coating comprising a cross-linked resin that (a) optionally contains leachable fluoride, and (b) is biocompatible with osseous and non-osseous tissue to effect direct bonding of the implant to the tooth or to the prosthesis, or to bone or to non-osseous tissue or a combination of them. A treated prosthetic is also described.

Description

Improved Dental Implant Process And Treated Prosthetic

Brie f Description Of The Invention

A process of treating a metal dental implant inserted into or placed on the alveolar bone, in order to provide anchorage or stabilization ei¬ ther to teeth or to a prosthesis, which involves the improvement of ap- plying to one or more portions of the implant or to the locus of the im¬ plant in the alveolar bone, a special biocompatible crosslinked resin that optionally contains leachable fluoride, to effect direct bonding of the implant to teeth or to a prosthesis, or to bone or to non-osseous tis¬ sue or a combination of them. The invention relates as well to the treated prosthetic.

Background To The Invention Geristore™ and Tenure™, sold by Den-Mat Corporation, Santa Maria, CA, are promoted for certain uses in dentistry. U.S. Patents Nos. 4,738,722, 5,334,625 and 5,151,453, incorporated herein by reference, describe Geristore™. Geristore™ is a small particle composite that con¬ tains fluoride, is radiopaque and hydrophilic. It has low-cure shrink¬ age, low coefficient of thermal expansion and high strength. It aggres¬ sively bonds by chemical coupling to dentin, enamel, composites used in dentistry, porcelain and metal, such as stainless steel. It is a paste/paste formulation that is easy to mix. It is capable of rapid cure by exposure to room temperature and for more rapid cure, by exposure to light. In addition, though it contains a fluoride, which could be toxic when ingested in large dosages, it is biocompatible and safe to use within a human or other animal when applied topically. Tenure™ is a solvent based crosslinkable acrylic resin, provided as a solution/solution formulation. Its composition is described in U.S. Patent No. 4,964,911, patented October 27, 1990, and more effectively disclosed in allowed copending application Serial No. 965, 102, filed Oc- tober 22, 1992, to issue as U.S. Patent Re , the disclosure of which is incorporated by reference. It is not an ionomer and does not release fluoride ion. It is less hydrophilic than Geristore™. It too is a crosslinkable resin. It contains a volatile solvent (typically acetone), which readily evaporates. After evaporation, a film of the resin rapidly cures in situ. Tenure™ bonds by chemical coupling to dentin, enamel, porcelain, metal and the composites typically used in dentistry. It has been recommended for use with Geristore™ in chemically bonding Geristore™ to dentin or enamel.

Dental implantation, i.e., oral implantation, involves the insertion a prosthesis in bone or the fixing of a prosthesis to bone. The implant is typically a metal pin, blade or casting inserted into or placed on the al¬ veolar bone in order to provide anchorage or stabilization either to teeth or to a prosthesis. Anchorage of the prosthesis in bone is dependent on bone growth around and through the prosthesis, and/or the presence of threading in the prosthesis that forms a complementary threading in the bone. Many prosethesis used in dental implantation are screwed into the bone. A prosthesis, in the context of dental implants, includes the device that anchors or stabilizes (e.g., metal pin, blade or casting) and the device that is so anchored or stabilized. The latter device can be an acrylic resin or composite material (e.g., a filled resin) crafted (by molding, shaping, etc.) into the shape of a tooth or a set of teeth. An endodontic implant comprises a metal pin or post extending through the root canal into the periapical bone to lengthen and strengthen a pulp- less tooth. An Endosteal (endosseous) [i.e., the thin layer of cells lining the medullary cavity of a bone] implant is an implant, usually of metal, introduced into the maxilla or mandible so that part of it protrudes into the mouth. The implant consists of three parts: a.) the body which is placed in the bone, b.) the abutment, which is visible in the mouth and supports and/or retains the prosthesis (or superstructure) and c.) the superstructure to which other components are attached. An implanta¬ tion denture employs a prosthesis which obtains its stabihty and reten¬ tion from a substructure lying under the soft tissues of the denture- bearing area, and which projects through the gingival tissues, e.g., sub- periosteal, blade, or pin. A subpeήosteal implant is an implant that conforms to the bone surface of the jaw, and is covered with mucope- riosteum, having abutments exposed in the mouth on which bridges, dentures, etc. may be fixed. An implantation denture substructure is a metal framework lying in contact with, or embedded in, bone. Projec¬ tions from it pass through the mucoperiosteum to support an implant denture. The Osseointergraded implant is an implant in which there exists a direct connection between its surface and the host bone. A dio- dontic implant is a sterile metal rod placed in a root canal and extend¬ ing through the root apex with the intention of stabilizing a tooth, espe¬ cially one with a short root. It is often referred to an endodontic im- plant. Mandibular staple implant is a modified endosseous implant in which the metal appliance passes through the entire height of the man¬ dible in the anterior region where posts pierce the oral mucosa in order to give fixation points to a suitable superstructure.

Cements have been employed in this procedure, but they are not fa- vored for one reason or another.

Great stresses are put upon such protheses that are employed in implant procedures. Many of the prosthesis implanted into the alveolar bone are mechanically bonded to the bone. A metal (e.g., steel, tita¬ nium, and their alloys) pin that is threaded into the alvaleor bone de- pends on bone growth to and about the pin in order to fix (stabilize) it to the bone. It would be desirable to employ an adhesive to facilitate ad¬ hesion of the pin to bone. One reason for the inadequacies of some ad¬ hesives has been their inability to provide a strong enough bond be¬ tween bone and the prosthesis. Another reason is that an effective bonding cement is often bioincompatible to the bone and any soft tissue associated with the implantation procedure. As a result, adhesives can generate an adverse reaction, possibly to the extent that bone growth is inhibited and the growth about the prothesis is inhibit, thereby im¬ pairing the strength of the implant. Though the occurrence of an adverse tissue response to an implant is low, there are times when an implant can induce such a response For example, metals or other foreign materials used in implants may in¬ duce, e.g, tissue infection, fibrous tissue bonding to the implant, an epithelial inversion around the neck of implant resulting in tissue in- flammation, and the like. Frequently, such adverse tissue response is a result of overheated bone, or a lack of compatibility of the patient's bone or blood to the implant material. Even the most biocompatible metal, titanium, employed as an implant, can, under certain circumstance, cause an adverse tissue response. It would be desirable to treat such implants so that they are totally biocompatible with any tissue surface that they contact, thereby eliminating even the potential for such ad¬ verse tissue response.

The Invention This invention relates to dental implantation as described above. More particularly, the invention relates to an improvement in the proc¬ ess of treating a metal dental implant inserted into or placed on the al¬ veolar bone, to provide anchorage or stabilization either to teeth or to a prosthesis. The process includes in the traditional steps of dental im¬ plantation, the application to one or more portions of the implant or to the locus of the implant in the alveolar bone, of a special biocompatible crosslinked resin that optionally contains leachable fluoride, to effect direct bonding of the implant to teeth or to a prosthesis, or to bone or to non-osseous tissue or a combination of them.

More specifically, the invention includes in the process of implant- ing a metal dental prosthesis into or on the alveolar bone, to provide anchorage or stabilization either to a tooth or to another prosthesis, which involves surgical exposure of the alveolar bone, providing means for (a) fixing a metal implant in the alveolar bone, and (b) fixing the metal implant to either a tooth or to the other prosthesis, and closing the exposure of the alveolar bone to effect normal healing of the surgi¬ cally affected site, the improvement which comprises including in re¬ spect to such means the step of applying to one or more portions of the implant or to the locus of the implant in the alveolar bone, a crosslinked resin that (i) optionally contains leachable fluoride and (ii) is biocom- patible with osseous and non-osseous tissue, to effect direct bonding of the implant to the tooth or to the prosthesis, or to bone or to non- osseous tissue or a combination of them.

This invention relates to the improvement in the process of im¬ planting a dental prothetic into or on bone by using a certain biocom- patible adhesive to materially improves the bonding strength of the prothetic to bone. It has been found that a particular adhesive can be applied to a prosthetic device that is inserted into or placed on the al¬ veolar bone, to provide maximum biocompatibility and superior adhe¬ sion of the prosthetic device to bone and surrounding tissue. The invention relates to an improved implantation process that is distinctive because it involves the step of coating at least one of (a) a dental prosthetic to be implanted in or on the alveolar bone and (b) the locus in the alveolar bone where the prosthetic is to be implanted, with a) a tenaciously-bonded hydrophilic water insoluble crosslinked resin coating (hereinafter called "the primary coating"), b) that optionally contains a measurable amount of a wa- ter/fluid leachable fluoride capable of (a) being leached from the coating in a metered amount, and (b) transport¬ ing a small amount of leached fluoride from the coating into the bone and associated soft tissue (hereinafter called "the primary coating with fluoride"). In one aspect, the invention encompasses a process that enhances normal alveolar bone growth impacted by the insertion of a metal pros¬ thetic device in the bone during dental implantation of the prosthetic . In addition, because of the biocompatibility and adhesive qualities of the treatment, a prosthetic device (typically made of metal, ceramic or plastic) is more stably bonded to the alveolar bone and to associated soft tissue which the prosthetic comes into contact.

The invention relates to a metal dental implant prosthesic as de¬ scribed herein that contains, on at least a portion of thereof, a layer of the primary coating with or without fluoride whereby the implant is biocompatible to tissue that it might contact in or during implantation.

In the preferred embodiment, the primary coating on the prosthetic con¬ tains fluoride.

The amount of fluoride provided in the primary coating is insuffi¬ cient to cause fluorosis or any other toxic reaction, and, by processes unknown, except possibly antimicrobial processes, the fluoride assists the normal processes of bone and tissue growth.

The invention also encompasses in these dental implantation proc¬ esses, the use of a composite layering of a strongly adhesively-bonded crosslinkable acrylic resin, possessing less hydrophilicity than the pri- mary coating with or without fluoride, that rapidly in situ cures on an application surface, the bone and/or prosthetic surface, to function as a primer (hereinafter called the "primer coating") for the primary coating with or without fluoride that is applied to the same surface(s). The bio¬ compatibility of the primary coating on the surface, bone and/or pros- thetic device over the primer coating enhances healing, the adhesion of the bone to bone and bone to softer tissue, and prosthetic device to bone or softer tissue, and precludes or minimizes bone or softer tissue rejec¬ tion to the surgical implantation procedure.

The primary coating comprises a resin based on an ethylenically unsaturated-functional monomer that contains a hygroscopic group.

The ethylenically-unsaturated-functional monomer contains hygro¬ scopic groups and exhibits hydrophilicity. Typical of such groups are hydroxyl, amide, amine, aliphatic ether, amine, hydroxyalkyl amine, hydroxyalkyl amide, pyrrolidone, ureyl, and the like. Another ingredient of the primary coating composition is a polycar¬ boxylic acid, i.e., a polymer that contains pendant carboxyl groups. The polycarboxylic acid is thought to enhance bonding of the primary coat¬ ing resins to metallic and other substrates, particularly to organic and inorganic salt forming materials that are present in the substrate to which the primary coating is applied. In addition, the polycarboxylic acid enhances the bonding of the resin components of the primary coating composition to any inorganic fillers provided in the coating for¬ mulation. In a number of contemplated uses for the primary coating, in accordance with this invention, the polycarboxylic acid may be excluded from the primary coating formulation. In addition, one may employ the alkali metal salt ofthe polycarboxylic acid.

In addition, the primary coating contains a variety of crosslinking agents. One type of crosslinking agent is "hard crosslinker" and an¬ other is a "soft crosslinker." Both hard and soft crosslinker are poly- functional molecules in which the functionality is complementary to the ethylenic unsaturation of the ethylenically-unsaturated-functional monomer. In the case of the hard crosslinker, the functional groups are bonded via an ahphatic group of up to 10 carbon atoms, to a central moiety that is aromatic in nature, that is, comprises a group that has the rigidity characteristics of a benzene ring. Illustrative of such rigid groups are aromatic rings such as benzene, biphenyl, anthracyl, benzo¬ phenone, norbornyl, and the like. Such hard crosslinkers raise the T_g of the cured coating,

The soft crosslinker contains the functional groups bonded to a cen- tral moiety that is ahphatic in nature, that is, comprises a group that has the flexibility of an alkane or an alkyl benzene containing . Illus¬ trative of such flexible groups are the residues of ethylene glycol, dieth¬ ylene glycol, 2,2-bis(4-hydroxyphenyl)propane, 2,2,-bis(4- hydroxyphenyl)fluorinated alkanes, and the like. Such soft crosslinkers toughen the cured coating and can raise the T_g of the cured coating, but not as high as the typical hard crosslinker,

Another feature of the primary coating is that it tenaciously bonds to surfaces onto which it is coated as well as securely tie up any inor¬ ganic filler that is included in the primary coating formulation. In or- der to achieve this, the coating contains a coupling agent as part of its formulation. These coupling agents provide chemical bonding to the surface to which the coating is applied. Chemical bonding means strong and weak bonding forces. Strong bonding forces, as used herein, refers to covalent, ionic, hydrogen bonding and complexation, and weak bonding forces, encompasses the other forms of bonding. Where weak bonding forces are employed, the extent of such bonding is such that the adhesion to the surface is of the nature of a stronger bonding force. For example, van der Waal forces are weak bonding forces. In the case of the invention, the amount of such forces existing between the coating and the surface will be sufficient to give the performance of a stronger bonding force.

A desirable coupling agent is a material, such as a molecule, that is functionally complementary to the ethylenically-unsaturated-functional monomer. Desirably, the coupling agent contains a functional group that is reactable with the ethylenic unsaturation. Preferably, the func¬ tional group is an acrylic-type ethylenic unsaturation. At another part of the coupling agent molecule is a surface bonding group that can im¬ part one or more properties to the primary coating: 1) chemical bonding capabilities to the substrate surface to which the primary coating is applied; and/or 2) wetting agent properties in that it reduces the surface tension of the coating, causing the coating to spread across or penetrate more easily the surface of the substrate onto which the primary coating is applied.

The utilization the primary coating with fluoride is a special and significant embodiment of the invention. The fluoride component op¬ tionally provided in the primary coating is desirably present in the coating such that it is leachable from the coating over an extended pe- riod of time.

In order to cure the primary coating, the primary coating formula¬ tion is provided with a conventional free-radical catalytic curing agent and/or a free-radical photoinitiator. When both are provided, the coat¬ ing can be cured by each of the system, preferably by both to insure that volatile monomeric components are left as residual components in the coating. This avoids the possibility of toxic reaction to the presence of such volatile monomeric components.

In respect to the above processes, the invention relates to the im¬ provement where the primary coating comprises a two component sys- tem of: (a) a first component comprising:

(1) the fluoride source, such as a particulate siliceous fluoride con¬ taining filler in which the fluoride is water leachable;

(2) a coupling agent, such as one or more of (i) N-phenylglycine, the alkali metal salt thereof, or the mixture of the foregoing two com¬ pounds, (ii) the adduct of N-(p-tolyl)glycine and glycidyl methacry¬ late, the alkah metal salt thereof, or the mixture of the foregoing two compounds, and (iii) the adduct of N-phenylglycine and glycidyl methacrylate, the alkali metal salt thereof, or the mixture of the foregoing two compounds;

(3) a photoinitiator; if desired, a radiopaquing agent; and, if desired, a buffering agent; and

(b) a second component comprising:

(1) the ethylenically-unsaturated-functional monomer; (2) a soft crosslinker such as 2,2-bis(4-methacryloxy 2- ethoxyphenyl) propane, diethylene glycol bismethacrylate, and the like;

(3) a hard crosslinker such as one or more of (i) the adduct of pyro- mellitic acid dianhydride and 2-hydroxyethyl methacrylate, (ii) the adduct of 3,3',4,4'-benzophenonetetracarboxylic dianhydride and 2- hydroxyethyl- methacrylate, (iii) 4-methacryloxyethyltrimellitic an¬ hydride, and (iv) other compounds containing at least one group or moiety capable of free radical polymerization and at least one aro¬ matic ring or moiety containing electron-withdrawing substituents that do not interfere with free radical polymerization;

(4) a photoinitiator;

(5) a polymerized carboxylic acid;

(6) a free-radical scavenger; and

(7) a curing catalyst. In another embodiment of the primary coating, it may be a light- curable adhesive composition of the following two-component system:

(a) a first component comprising:

(1) a fluoride source such as a particulate siliceous fluoride con- taining filler in which the fluoride is water leachable;

(2) a soft crosslinker;

(3) an ethylenically-unsaturated-functional monomer;

(4) a photoinitiator;

(5) a free-radical scavenger; (6) a thermal initiator;

7) a polymerized carboxylic acid;

(8) a hard crosslinker such as one or more of (i) the adduct of py- romellitic acid dianhydride and 2-hydroxyethyl methacrylate; (ii) the adduct of 3,3',4,4'-benzophenonetetracarboxylic dianhydride and 2-hydroxyethyl- methacrylate, (iii) 4- methacryloxyethyltrimellitic anhydride, and (iv) other compounds containing at least one group or moiety capable of free radical po¬ lymerization and at least one aromatic ring or moiety containing electron-withdrawing substituents that do not interfere with free radical polymerization, and

(b) a second component comprising:

(1) a fluoride source such as a particulate siliceous fluoride con¬ taining filler in which the fluoride is water leachable;

(2) a soft crosslinker; (3) an ethylenically-unsaturated-functional monomer;

(4) a coupling agent such as one or more of (i) N-phenylglycine, the alkali metal salt thereof, or the mixture of the foregoing two com¬ pounds, (ii) the adduct of N-(p-tolyl)glycine and glycidyl methacry¬ late, the alkali metal salt thereof, or the mixture of the foregoing two compounds, and (iii) the adduct of N-phenylglycine and glycidyl methacrylate, the alkali metal salt thereof, or the mixture of the foregoing two compounds;

(5) a photoinitiator; if desired, a radiopaquing agent; and, if desired, a buffering agent. A more specific embodiment of the primary coating composition is the following composition:

1. A particulate glass having the composition set forth in Table 1 below;

2. A coupling agent: The alkali metal salt of the adduct of N-(p -tolyl) glycine and gly¬ cidyl methacrylate; e.g.,

1. A hard crosslinker: The adduct of pyromellitic acid dianhydride and 2-hydroxyethyl methacrylate;

2. A photoinitiator: Ethyl 4— dimethylamino benzoate and campho- quinone (i.e., 2,3-bornanedione);

3. A soft crosslinker: Ethoxylated bisphenol A dimethacrylate and the adduct of gly cidylmethacry late and bisphenol A, 4. An ethylenically-unsaturated-functional monomer: 2- hydroxyethyl methacrylate;

5. Butylated hydroxytoluene free radical scavenger.

6. A polycarboxylic acid;

7. Benzoyl peroxide or other peroxides that cause free radical addi- tion at about 55°C. or at a lower temperature.

The primer coating involves a two part (package) composition, com¬ prising (a) a compound selected from the group consisting of (1) N- phenylglycine, (2) the adduct of N-(p-tolyl) glycine and glycidyl methacrylate, (3) the addition reaction product of N-phenylglycine and glycidyl methacrylate, (4) N(p-tolyl) glycine, N-phenylalanine, sarkosine, N-lauroylsarkosine, glycine, N,N-dimethyl-glycine, 3-

(N-phenyl) amino propionic acid, 3-(N-p-tolyl) amino propionic acid, omega-amino fatty acids, N-substituted-omega-amino fatty acids, and the other amino acids; in which each member of the group of (1), (2), (3) and (4) that is present in the solution is an alkali metal salt form of that member, and

Ob) a composition comprising at least one monomer selected from the group consisting of (1) the addition reaction product of py- romellitic acid dianhydride and 2-hydroxyethyl methacrylate, (2) the addition reaction product of 3,3', 4,4'- benzophenonetetracarboxylic dianhydr- ide and 2-hydroxyethyl methacrylate, (3) 4-methacryloxyethyltrimel- litic anhydride, and (4) other compounds containing at least one group or moiety capable of free radical polymerization and at least one aromatic ring or moiety containing electron-withdrawing substituents that do not interfere with free radical polymerization.

The use ofthe primer coating composition involves, in one preferred embodiment the steps of —

(a) first contacting the surface with an aqueous solution com¬ prising at least one strong acid or acidic salt in order to con- dition the surface,

(b) then contacting the surface with a solution comprising a solvent and at least one compound selected from the group consisting of (1) N-phenylglycine, (2) the adduct of N-(p- tolyl)glycine and glycidyl methacrylate, (3) the addition re- action product of N-phenylglycine and glycidyl methacry- late, and (4) other amino acids, in which each member of the group of (1), (2), (3) and (4) that is present in the solu¬ tion is an alkali metal salt form of that member, heat the surface to remove the solvent or maintain the surface at ambient temperature until the solvent is evaporated, and

(c) then contacting the surface with a solution comprising at least one monomer selected from the group consisting of (1) the addition reaction product of pyromellitic acid dianhy¬ dride and 2-hydroxyethyl methacrylate, (2) the addition re- action product of 3,3', 4,4'-benzophenone tetracarboxylic di¬ anhydride and 2-hydroxyethyl methacrylate, (3) 4- methacryloxyethyltrimellitic-anhydride, and (4) other com¬ pounds containing at least one group or moiety capable of free radical polymerization and at least one aromatic ring or moiety containing electron-withdrawing substituents that do not interfere with free radical polymerization

(d) heat the surface to remove residual solvent or maintain the surface at ambient temperature until the solvent is evapo¬ rated from the primer coating and the coating is fully re- acted.

Brief Description Of The Drawings Figure 1 is a graph showing the uniform, long term leaching of fluo¬ ride from a fluoride source used in making a primary coating.

Figure 2 is an area plot of concentration of a siliceous fluoride source from which one may obtain long term and uniform leaching of fluoride.

Figure 3 is side view with partial cross sections of a blade prosthetic implant.

Figure 4 is a partial cross sectional side view of a mandible in which a blade prosthetic implant is imbedded in the body of the mandible. Figure 5 is a partial cross sectional front view of a mandible con¬ taining a sub-periosteal implant.

Figure 6 is a partial cross sectional front view of a mandible con¬ taining a trans mandibular implant. Figure 7 illustrates a cross sectional side view of a two stage endos¬ seous implant located in alveolar bone.

Detail Description Of The Invention This invention relates to a process for orally implanting a prosthetic that serves to support and reinforce either another prosthetic or teeth. The invention is directed to the surgical dental implant process within the alveolar bone where the improvement involves implanting a metal prothesis that has an outer coat of the primary coating. The invention includes all of the steps conventionally practiced in dental implantation plus the step or steps of coating one or more of the prosthesis used in such implantation with the primary coating. In addition, the invention also relates to the steps in which a prosthesis is imbedded in the alveo¬ lar bone, and the bone contiguous to the prosthesis is infused by appli¬ cation of the primary coating. In addition, the invention further relates to the steps in which a second prosthesis is bonded to the prosthesis imbedded in bone, in which the interface between the two prosthesis contains a layer of the primary coating serving to interbond the two prosthesis. The Primary Coating

The primary coating is typically a crosslinked heat and/or light set resin that contains hygroscopic groups that attract water to the coat¬ ing. When the crosslinking is not too extensive, the primary coating can absorb enough water that it can swell. The amount of water that the primary coating can absorb can be as high as 37 weight percent. However, the degree of crosslinking of the primary coating is typically high enough that water absorption will not exceed about weight percent. The backbone of the polymer providing the hygroscopic groups of the resin phase of the primary coating is typically ahphatic and may contain groups therein that enhance the hydrophilicity of the resin phase. Though the primary coating's resin can be made by a condensa- tion reaction, such as by low temperature resin formation by the reac¬ tion of a blocked poly isocyanate with a polyol, the resin is typically the in situ reaction product of one or more of a polymerizable ethylenically unsaturated organic monomer containing groups that are attractive to water. Thus the components of the primary coating may be — (a) an ethylenically unsaturated-functional monomer that contains a hygroscopic group. Typical of such groups are hydroxyl, amide, amine, aliphatic ether, amine, hydroxyalkyl amine, hydroxyalkyl amide, pyr¬ rolidone, ureyl, and the like. Illustrative of such monomers are the following:

A particularly desirable ethylenically unsaturated-functional monomer is an acrylic-type monomer having the following structure:

wherein R' and R", individually, are hydrogen, alkyl of 1 to about 4 car- bon atoms, monocyclic aryl, such as phenyl, alkyl phenyl where the al¬ kyl is 1 to about 3 carbon atoms, cyclohexyl, and the like; R² is hydro¬ gen, alkyl of 1 to about 3 carbon atoms, and the like; X is O, S and N-R³, where R³ is hydrogen, alkyl of 1 to about 4 carbon atoms, -R^Y, and the like; R¹ is a divalent radical connecting Y to X, and may be one of the following:

-CH₂-

-CH₂CHR⁴-

-CH₂CH₂CH₂-

OH -CH₂CHCH₂-

-CH₂CHR⁴OCH₂CHR⁴- wherein each R⁴ is hydrogen or alkyl of 1 to about 3 carbon atoms; and Y is OH, NR⁵, SH, OR⁶, where R⁵ is hydrogen, methylol, methylol methyl ether, R⁶ is alkyl of 1 to about 3 carbon atoms provided that R¹ is -CH2-, and the like; q is 0 or 1 and p is 0 or 1, and p is 0 when q is 1 and 1 when q is 0; Z is hydrogen.

A particularly desirable thermosetting coating is based on 2- hydroxyethyl methylmethacrylate ("HEMA"), 2-hydroxyethyl acrylate,

2,3-dihydroxypropyl methacrylate, acrylamide, methacrylamide, hy¬ droxyalkyl acrylamide, hydroxyalkyl methacrylamide, and the like ma¬ terials, (b) A linear polycarboxylic acid or acid salt that contains a plurality of pendant carboxyl or carboxylic acid salt groups such as one having the formula:

R° is hydrogen or alkali metal, such as Li, Na, K, Ru and Cs to form a salt, and preferably hydrogen, sodium or potassium, R⁷ and R⁸ are hy- drogen or alkyl containing from 1 to about 3 carbon atoms, R⁹ is hydro¬ gen, alkyl of 1 to about 3 carbon atoms, or COOR°, provided that R⁹ is not alkyl when R⁷ is alkyl, R¹⁰ is a valence bond when the formula is for a homopolymer or a divalent organic moiety of a polymerized ethyleni- cally unsaturated monomer, p is a number representing at least 40 mole percent of the units of the polymer, and m is a number providing for a molecular weight of from about 2,000 to about 500,000. Particu¬ larly preferred polycarboxylic acids are polyacrylic acid, polymaleic acid, polyitaconic acid, or a copolymer of acrylic acid, maleic acid, fu¬ maric acid or itaconic acid with other ethylenically unsaturated mono¬ mers such as methyl acrylate, ethylacrylate, methylmethacrylate, vinyl acetate, vinylmethylether, styrene, α-methylstyrene, vinylcvclohexane, dimethy lfumarate, ethylene, and the like. Preferably, these polymers have molecular weights M_w of about 3000-250,000. In one embodiment, the polycarboxylic acid or the salt form may contain about 1-5 weight % of d-tartaric acids.]

(c) A desirable coupling agent is an acrylic-type monomer that pos¬ sesses acrylic-type unsaturation and contains a surface bonding group possessing one or more of the following groups: i) an alkylene polyether; vi) tertiary amine ii) hydroxyl vii) phosphoryl iii) carboxyl viii) phosphinyl iv) carboxylic acid salt ix) stannoyl v) quaternary ammonium x) amide xi) alkylene amine A preferred couphng agent is a simple aromatic substituted amino acid or its alkali metal salt such as the free acid or alkali metal salt of (i) N-phenylglycine, (ii) the adduct of N-(p -tolyl) glycine and glycidyl methacrylate, which are illustrated by the structures:

where Y is one of the alkali metals, i.e., lithium, sodium, potassium, ru¬ bidium and cesium, preferably sodium or potassium, and (iii) the adduct of N-phenylglycine and glycidyl methacrylate, the alkali metal salt thereof, or the mixture of the foregoing two compounds, which com¬ pounds are illustrated by the structures, and (iii) the adduct of N- phenylglycine and glycidyl methacrylate, which are illustrated by the structures:

where Y is described above; or the mixture of the foregoing two com- pounds, alone or in combination with a compound containing at least one group or moiety capable of free radical polymerization and at least one aromatic ring or moiety containing one or more electron- withdrawing substituent that does not interfere with free radical po¬ lymerization. The purpose of the coupling agent is to interreact with the polymeri¬ zation of the aforementioned ethylenically unsaturated-functional monomer that contains a hygroscopic group and enhance wetting by the resulting resin of proteinaceous surfaces by the surfaces interaction with the carboxylic acid or carboxylic acid salt group in the bonding agent.

(d) A number of acrylic coating resins rely on polyacrylyl substituted monomers to crosslink and chain extend the polymer that comes into existence on polymerization in the presence of an polymerization initia¬ tor. For example, the pure forms of HEMA typically contain small amounts of ethylene glycol dimethacrylate which will crosslink a poly¬ mer based on HEMA. The degree of crosslink may be so minuscule as to have little effect on the ultimate properties of the polymer. Crosslinking agents are frequently added to HEMA based resins to im¬ part a particular quality of crosslinking and toughness to the cured resin. For example, diethylene glycol dimethacrylate can otherwise lower the crosslink density of the resin which may impart toughness to the resulting cured polymer. Those types of crosslinkers would be con¬ sidered a soft crosshnker, as defined above. However, in the practice of this invention, it is desired to use dual crosslinkers, one that is hard and one that is soft. In this respect, one may include the above crosslinker, in its normal impurity concentrations, as part of the soft crosslinker, but in the preferred embodiment, it is desirable to employ hard and soft crosslinkers that contain at least two acrylyl groups bonded to aromatic containing moiety(ies). A desirable hard crosslinker is characterized by the following formulae:

<B"

wherein n is 0 or 1. The preferred hard crosslinking agent is one of (i) the esters or imides of pyromellitic acid dianhydride and 2-hydroxyethyl methacrylate or 2-aminoethyl methacrylate, or the corresponding acry¬ lates, as illustrated in group B above, (ii) the ester or imides of 3,3',4,4^/- benzophenonetetracarboxylic dianhydride and 2- hydroxyethylmethacrylate or 2-aminoethyl methacrylate, or the corre¬ sponding acrylates, as illustrated in group A above, (iii) the esters and imide/amides of 4-trimelhtic acid anhydride and 2- hydroxyethylmethacrylate or 2-aminoethyl methacrylate, or the corre¬ sponding acrylates, as illustrated in group C above, (iv) the ester or imides of 2,2-bis(3,4,-dianhydridophenyl)- 1,1, 1,3,3, 3-hexafluoropropane and 2-hydroxyethyl methacrylate or 2-aminoethyl methacrylate, or the corresponding acrylates, as illustrated in group D above, and (iv) other compounds containing at least one group or moiety capable of free radi¬ cal polymerization and at least one aromatic ring or moiety containing electron-withdrawing substituents that do not interfere with free radi¬ cal polymerization. The soft crosslinker is typically an diacrylic or di- methacrylic ester or ether of bisphenol A, but also include as soft crosslinkers are the other glycol dimethacrylates and diacrylates men¬ tioned herein. Preferred soft crosslinkers are ethoxylated bisphenol A dimethacrylate and the adduct of glycidylmethacrylate and bisphenol A, (e) The fluoride component is present in the primary coating as a com¬ ponent of a non-resinous component of the formulation. The fluoride component may be, but need not be soluble in the resin component of the primary coating. In the preferred practice of the invention, the fluoride component in the primary coating will dissolve in water and to the extent the water is removed from the fluoride source, fluoride is car¬ ried with it. As noted above, the particularly desirable form of the fluoride component, is an inorganic fluoride in which the fluoride is pre¬ sent, e.g., in the form of an fluorosilicate structure or an alumina fluo¬ ride structure. The fluoride source of the patent is a glass composition in which the fluoride content is derived from an alkaline earth metal fluoride such as calcium fluoride, barium fluoride and strontium fluo- ride. A most preferred fluoride source is described in U.S. Patent No. 5,360,770 which is incorporated herein by reference, particularly the examples and illustration of the patent that show how to make the fluo¬ ride source. As noted above, the primary coating is optionally provided with a leachable fluoride component. The fluoride is leachable from the coating over a three to four month period. This means that after many days and even months, the coating should be able to release small measured amounts of fluoride into the wound area. The longevity of the fluoride in the coating and the ability to meter it from the coating are dependent on a number of factors, such as: • the concentration of fluoride in the coating;

• the nature of the chemical bond of the fluoride within the coat¬ ing composition;

• the level of hygroscopicity of the coating;

• if the fluoride is part of a solid, the degree of particulateness of the solid, coupled with the rate at which fluoride can be leached from the sohd;

• if the fluoride is part of a liquid molecule, the rate at which the fluoride is cleaved from the molecule to form a leachable fluo¬ ride; and • if the fluoride is part of a polymer, the rate at which fluoride in the polymer can be solubilized and leached from the polymer. A particularly desirable form of the fluoride component, is an inor¬ ganic fluoride in which the fluoride is present, e.g., in the form of an fluorosilicate structure or an alumina fluoride structure. Illustrative of such fluoride structures are fluorite (or fluorspar), CaF₂, BaF_2, SrF₂, cryolite, Na3AlF_6> and fluorapatite, 3Ca3(PO₄)2Ca(F,Cl)₂. A preferred fluoride source is described in U.S. Patent No. 5,360,770. The fluoride source of the patent is a glass composition in which the fluoride content is derived from an alkahne earth metal fluoride such as calcium fluo- ride, barium fluoride and strontium fluoride. A particularly preferred glass composition that provides fluoride is the following:

Table 1

in which M is an alkaline earth metal and MO is barium oxide and barium oxide binary and ternary mixtures with other alkaline earth metal oxides, such as BaO, BaO-CaO, BaO-SrO and CaO-BaO-SrO. Such preferred source of fluoride not only provides long term fluoride release from the primary coating but it also provides an essentially uni¬ form release of fluoride over that period of time. Figures 1 and 2 illus- trate the long term fluoride leachability of this fluoride source. Figure

1 illustrates the release of fluoride by placing the aforementioned bar¬ ium oxide based glass in water and determining the release of fluoride over an extended period of time. As can be seen, the fluoride release follows a straight line showing uniform release over 550 days, about VΛ years. Figure 2 shows area plots of ingredients in order to optimize the glass formulation for maximizing the fluoride release over an extended period, e.g., VΛ years.

(f) Also included in the formulation, as an optional ingredient, is a pho¬ toinitiator. According to one aspect this invention, the light-initiated curing of a polymerizable matrix material involves photosensitization of light-sensitive compounds by ultraviolet or visible light, which, in turn, initiates polymerization of the matrix material. The photoinitiator to be used in this invention comprises a combination of a photosensitive ketone and a tertiary amine. Typical photosensitive ketones include benzophenone, acetophenone, thioxanthen-9-one, 9-fluorenone, an- thraquinone, 4'-methoxyacetophenone, diethoxyacetophenone, biacetyl, 2,3-pentadione, benzyl, 4,4'-methoxybenzil, 4,4'-oxidibenzil, and 2,3- bornadione (dl camphroquinone). Typical tertiary amines include ethyl- 4-dimethyl amino benzoate, ethyl- 2 -dimethyl amino benzoate, 4,4'- bis(dimethylamino) benzophenone, N-methyldiethanolamine, and di- methylaminobenzaldehyde. A preferred combination of the photoini- tiators is 2,3-bornanedione with ethyl-4-dimethyl amino benzoate.

Other suitable initiator are illustrated in U.S. Pat. No. 4,674,980 to Ib¬ sen, et al., the disclosure of which is incorporated by reference. Alter¬ natively, any known photosensitizing system which can function effec¬ tively in a paste/paste composition when exposed to light may substi- tute for the above-named compounds or combinations. The amount of the photoinitiator should be sufficient to initiate polymerization in a selected resin and complete it in depth within about half a minute when the filler-resin composition is exposed to a visible-light output of at least 5,000 foot candles. In addition, any known free-radical scavenger (anti-oxidants) such as butylated hydroxytoluene can be used to scav¬ enge small amounts of free radicals generated during extended shelf storage.

(g) The polymerization system of the primary coating composition may depend on effecting cure with either the photoinitiator or by use of a thermal initiator, which is a typical thermal curing agent known in the art. Illustrative of these are benzoyl peroxide, dicumyl peroxide, diter- tiary butyl peroxide, tertiary butyl hydroperoxide, cumyl hydroperoxide, or other suitable peroxides may initiate polymerization of the polym¬ erizable ethylenically unsaturated components of the primary coating. Addition of such thermal initiators is desirable to insure complete po¬ lymerization. Even when light alone does not cure the matrix material, the peroxide initiates curing of the uncured material thermally upon standing. Benzoyl peroxide may be used together with 2-hydroxyethyl- p -toluidine. The primary coating may contain pigments such as iron oxide or ti¬ tanium oxide and a color stabilizing agent such as 2,2-hydroxy-5-tert. octyl pheny lbenzotriazole.

In formulating the primary coating, the selection of the ingredients in formulating the coating is narrowly critical. Illustrative of such a formulation is the paste/paste primary coating composition as set forth in Table 2.

Table 2 Paste A

Paste B

The two pastes, Paste A and Paste B, are preferably mixed well in equal amounts. The pastes may be mixed with a spatula or put onto a blade mixer prior to apphcation to a surface. For example, the physi¬ cian or technician may use the system by combining the pastes in the ratios desired, and then mixing them. The resulting paste is then ap¬ plied to the surface as needed. The coating will self-cure in about 20-30 minutes, but cures instantly on exposure to light. Light having a wave length of about 480 77M at an intensity of about 5000 foot-candles is pre¬ ferred. An exposure of about 30 second is sufficient to cure the cement in most applications.

As noted above, a primer coating may be applied to the treated sur¬ face before coating on the primary coating. This may be effected by the following procedure:

(1) First contacting the surface with an aqueous solution comprising at least one strong acid or acidic salt with a dispensable brush or a skube (a preformed Styrofoam™ sponge) in order to condition the surface, Leave for 15 seconds and blot dry with a skube. Note: if hemorrhage is in the area, use a hemostatic solution or the aqueous solution with a hemostatic solution to control seepage and keep the bonding surface dry.

(2) Immediately mix with stirring with a dispensable brush a solu¬ tion comprising a solvent and at least one compound selected from the group consisting of (1) N-phenylglycine, (2) the adduct of N-(p- tolyl)glycine and glycidyl methacrylate, (3) the addition reaction product of N-phenylglycine and glycidyl methacrylate, and (4) other amino acids, in which each member of the group of (1), (2), (3) and (4) that is present in the solution is an alkali metal salt form of that member, and a solution comprising at least one monomer selected from the group consisting of (1) the addition reaction product of py- romellitic acid dianhydride and 2-hydroxyethyl methacrylate, (2) the addition reaction product of 3,3', 4,4'-benzophenone tetracar- boxylic dianhydride and 2-hydroxyethyl methacrylate, (3) 4- methacryloxyethyltrimellitic-anhydride, and (4) other compounds containing at least one group or moiety capable of free radical po- lymerization and at least one aromatic ring or moiety containing electron-withdrawing substituents that do not interfere with free radical polymerization. Apply 3-5 coats of the mixture onto the pre¬ pared bonding surface with the dispensable brush used for mixing. Allow to dry for 15 seconds. (3) Mix Paste A and B together and load into a syringe. Immedi¬ ately inject the paste mixture onto the prepared bonding surface and light-activate for 30 seconds. This will effect cure. The above procedure can be effected without using the primer coating. In such an embodiment, it is important to clean the surface to which the primary coating is being applied. Water washing the surface if an acid wash is not recommended or needed will prepare the surface pro¬ vided the surface is thoroughly dry before applying the primary coating. As noted above, the invention can involve forming a cured patch of the primary coating on glass >r Teflon® with a knife coater. The coat- ing should be as thin as workable, such as from about 1 to about 100 mils. The patch may have a thickness of about 0.75 mil to about 95 mils, preferably from abou'. 2 to about 50 mils. Its length and width is dependent upon where tba patch is to be employed. For example, the patch can be inserted ir co the bone cavity, typically at the floor of the cavity, that is created for the implant and with paste of the primary coating applied to it, ne patch can be adhesively bonded to the bone or prosthesis dependir ^ on where the paste is applied. Because the patch is biocompatible, it is not rejected and, as such, will aid the natural growth of new υone without infection. This is particularly the case where the p if jh contains fluoride. The primer coating may contain solvent solutions of the free acid or alkali metal salt of (i) N-phenylglycine, (ii) the adduct of N-(p- tolyl)glycine and glycidyl methacrylate, which are illustrated by the structures:

where Y is one of the alkali metals, i.e., lithium, sodium, potassium, ru¬ bidium and cesium, preferably sodium or potassium, and (iii) the adduct of N-phenylglycine and glycidyl methacrylate, the alkali metal salt thereof, or the mixture of the foregoing two compounds, which com- pounds are illustrated by the structures, and (iii) the adduct of N- phenylglycine and glycidyl methacrylate, which are illustrated by the structures:

where Y is described above; and the solvent solution of PMDM (see the isomeric mixture of "B" above that describes the adduct of pyromellitic acid dianhydride and 2-hydroxyethyl methacrylate). The preferred sol¬ vent is a mixture of water and a polar solvent such as acetone.

When applying the primer coating, the surface may be prepared with an acid wash as disclosed in the aforementioned reissue applica- tion. The first stage of the primer coating may be a solvent solution of the NTG-GMA adduct, typically dried before the second solution is ap¬ plied to it. The second stage is a solution of, e.g., PMDM that is coated over the first stage. That coating is also dried before applying the pri¬ mary coating. On drying, the primer coating is cured. Drying may be effected at ambient conditions, or accelerated by the addition of heat to the undried coating.

In those cases, the primary coating may be brushed or injected with a conventional hypodermic needle from a conventional hypodermic sy- ringe onto and within the cavity formed by drilling into the alveolar bone. The prosthesis can then be inserted into the cavity by screwing or tapping it in, or if the cavity is oversized for the prosthesis, then the adhesive, with or without a patch, can be used to fill the space between the prosthesis and the bone wall(s) of the cavity. The primary coating can be set by exposing the coating to light or by heating the area to a temperature that causes the initiator to decompose and initiate polym¬ erization, resulting in a cured resin. Bone growth then occurs through and about the cavity to which the primary coating is applied without rejection of the coating. Portions of the prosthesis may not be confined by bone, and may extend through the mucoperiosteum and the gingiva.

Those portions may also be coated with the primary coating with or without fluoride. In those instances where the primary coating, with or without fluoride, is applied to bone, it will be desirable to first coat the bone with the primer coating, drying and curing that coating and then applying the primary coating over the cured primer coat. After the primary coat is applied, the prosthetic device may then be implanted so as to contact the uncured primary coat. At this point, the primary coat may be cured resulting in a strong bond to the prosthetic device and the bone surface. Figure 3 is side view of a blade prosthetic implant 1. In its typical embodiment, it is made wholly of a metal such as stainless steel and its alloys or of titanium and titanium alloys. It comprises blade 3 con¬ taining cavities 5 into which bone growth can occur. Attached to blade 3, as shown, are cylindrical pins 7 to which are affixed tapered cylindri- cal posts or abutment 9. Each post or abutment 9 contains an unta- pered cylindrical hollow interior 6 that contains helical or advancing spiral thread 11. Interior 6 can be entered through opening 13. Figure 4 shows implant 8 comprising mandible 15, teeth 14, blade prosthetic implant 1, prosthetic tooth 10 and locking screw 2. In this embodiment, the mandible is drilled to create cavity 4 into which blade prosthetic implant 1 is fitted. Cavity 4 is then filled by injection with primary coating, in this case functioning as a potting material, and on cure of the primary coating, implant 1 is securely bonded in place. If desired, a patch of primary coating can be placed on the bottom of cavity 4, and af- fixed thereat by the paste of primary coating coating on its surface that directly contacts bone. On the other hand, cavity 4 can be drilled just wide enough to insert blade 3 within cavity 4, and though primary coating may be injected into that space, bone growth can be relied on to fix blade 3 and implant 1 in the bone. Prosthetic tooth 10 is placed over post or abutment 9. The tooth may be made of an acrylic resin or of a conventional composite material. Tooth 10 is screwed to post or abut¬ ment 9 with screw 2 typically containing a hex key head.

Figure 5, a partial cross sectional front view, illustrates subpe- riosteal implant 19 in which the mandible 15 onto which the implant is made, is shown in cross section. In this subperiosteal implant, implant

24 conforms to the bone surface 15, via wire 18 and crossover braces 20 attached to a similarly positioned wire (not shown) on the other side of the mandible. The oppositely positioned wire (not shown) contains in¬ wardly position pins 22 that are positioned in drilled holes 21. Implant 24 is covered with mucoperiosteum 17, and has posts or abutments 9 extending from pins 7 bonded to braces 20, to be exposed in the mouth above gingiva 16. Bridges, dentures, etc. may be fixed to posts or abutments 9, e.g., as shown in Figures 3 and 4.

Figure 6 is a partial cross sectional front view of a mandible con- taining a trans-mandibular implant. In this implant, a base surface 23 is placed on the underside of mandible 15, and held in position by pins 26 imbedded in mandible 15. Posts 25 are screwed through base sur¬ face 23 and mandible 15 to leave exposed pin extending through mu- coperiosteum 17, to be exposed in the mouth above gingival 16. A por- tion of base surface (not shown) wraps around mandible 15, and is con¬ nected to pins 27 inserted into holes drilled in the bone. The

Figure 7 illustrates a cross sectional side view of a two stage endos¬ seous implants located in alveolar bone. In the case of implant 40, it comprising a cylindrical hner containing an exterior thread 34 and a hollow threaded 33 interior into which screw 37 can be placed. Its up¬ per surface 36 lays at the bone 39 surface that interfaces with mucope- riosteum 17. It is provided with a transverse hole into which bone growth will penetrate serving to lock the implant in position. Implant 41 is more elongated and extends through mucoperiosteum 17 and gin- giva 16. It comprises an abutment 29, threaded portion 30 and helical threaded portion 31. It also contains a plurality of transverse holes 32 serving to accept bone growth. It interior is hollow and threaded so that a screw can be inserted to hold another prosthetic device, such as a bridge, acrylic tooth, and the like. The process is practiced by employing conventional surgical implan¬ tation techniques. Incisions in the gingiva are required to expose the bone area and reveal the damaged tooth or teeth. Extraction of the damaged tooth is required where tooth repair is not feasible. Exposure of the bone is required for treating the area for reception of the im- plants. Closure of the gingival flap after installation of the implant is effected by conventional procedures well known in the art.

Test were run to determine bond strengths to substrates involving implants that include bone tissue. Four substrates were tested for bond strengths . They were — • bovine bone tissue, dentin, stainless steel, enamel, porcelain, nonprecious (NP) metals titanium and hydroxyapatite (the principal bone salt, Ca₅(PO₄)₃OH, which pro_¬ vides the compressional strength of vertebrate bone). The metal surfaces were prepared by roughening the surface with a dental burr and then treated with a degreasing agent. The hydroxya¬ patite surface was etched with 37% phosphoric acid. The bone tissue was treated with a dehydrating agent. The bonding tests¹ were con-

¹ Bond Strength Standard Test:

Materials and Equipment

I. Instron Tester

2 Gelatin capsules, #3

3 Five 1/4-ounce polycons

4. Bovine teeth

5. Dental model trimmer

6 King Temporary Crown and Bridge Mateπal or any other cold curing acrylic resin 7. Den-Mat designed laboratory curing light

8 Timer

9 Mixing sticks

10. Light-Cured Marathon™ Resin and Powder (Den-Mat Corporation)

II. Bond strength test fixtures ofr Instron Tester

12. Small disposable beakery

13. Water bath

Method:

I. Select 5 large bovine teeth.

2 Using dental model trimmer, grind each tooth to a flat, dentin surface.

3. After all 5 teeth have been ground, remove lids from 5 Vi-ounce polycons and set aside.

4. Into a small disposable beaker, weigh 5-^l/_s grams of Kind Powder (Den-Mat Corporation) and 6 grams of Kind Liquid (Den-Mat Corporation). Mix well with a plastic mixing stick and pour into previously set aside polycon lids until half full

5. Carefully place tooth into center of polycon lid, taking care not to contaminate flat ground surface. Allow Kind to cure at least to a rubbery consistence.

6. Mix another quantity of Kind and pour into polycon lid until full, taking are again not to contaminate flat ground surface. Allow Kind to cure completely.

7. When all 5 samples have been imbedded and Kind is completely cured, apply material to be tested to ground flat surface, following instructions for that particular product.

8. Fill small diameter half of each of 5 #3 gelatin capsules with Marathon™ mixed to a 3 1 powder/liquid ratio. Apply to prepared tooth surface.

9 Cure each prepared sample in laboratory curing light as follows

10. place sample at a 30" angle to the perpendicular in center of curing chamber.

II. Turn on curing light for one minute suing timer.

12. Rotate sample 90° and expose for an additional minute.

13. Repeat step c. two more times so that entire 360° of circle has been covered ducted by placing the primary coating (or the primer coating where spe¬ cifically indicated) on the treated substrate, and cured by exposure to light. A heavy body composite, Marathon™ (sold by Den-Mat, Inc.) was placed in a 5.3mm diameter gelatin capsule which was then placed on the substrate and cured with light. The samples were placed in 37°C. H2O for 24 hours and debonded using an Instron Universal 1011 testing machine using a cross head speed of lmm/min. The following results show the mean bond strengths and standard deviations in megapascals of at least 10 mpa;

• hydroxyapatite: 20.9 mpa, SD², 3.6 mpa;

• bone tissue: 7.9 mpa, SD, 2.4 mpa.

• titanium: primary coating A = 21.3 mpa, SD, 1.94 primary coating B = 24.1 mpa, SD, 2.39 The following shear tests (psi after 24 hours in water) indicate the su¬ perior bonding of the primary coating to various dental surfaces suitably for prosthetic device construction.

Primary coating B is a lower viscosity version of primary coating A.

Though this invention has been described with respect to a plurahty of details, it is not intended that the invention be limited thereby except to the extent that such limitations appear in the claims. Other em-

14. Mark sample for identification and place in 37° water bath for one hour

15. Make sure that Instron Tester is configured for bond strength of testing.

16. After 1 hour, remove samples from conditioning water. Using special fixture, stress until failure on Instron at a crosshead speed of 0.02 in/mm

Calculations: bond Strength = loadatfailwe (For #3 gelatin capsules, area of sample is 0 0342 mm ) areaofsample Average of three highest values is taken as the bond strength

² Standard deviation bodiments that are obvious variations of the embodiments herein dis¬ closed are intended to be encompassed by this invention.

Claims

CLAIMS:

1. In the process of implanting a metal dental prosthesis into or on the alveolar bone, to provide anchorage or stabilization either to a tooth or to another prosthesis, which involves surgical exposure of the alveo¬ lar bone, providing means for (a) fixing a metal implant in the alveolar bone, and (b) fixing the metal implant to either a tooth or to the other prosthesis, and closing the exposure of the alveolar bone, the improve¬ ment which comprises including in respect to such means the step of applying to one or more portions of the implant or to the locus of the implant in the alveolar bone, a primary coating comprising a crosslinked resin that (i) optionally contains leachable fluoride and (ii) is biocompatible with osseous and non-osseous tissue, to effect direct bonding of the implant to the tooth or to the prosthesis, or to bone or to non-osseous tissue or a combination of them.

2. The process of claim 1 wherein the primary coating contains leachable fluoride.

3. The process of claim 1 wherein the primary coating is free of leachable fluoride.

4. The process of claim 1 wherein closing the exposure of the alveo¬ lar bone is for the purpose of effecting normal healing of the surgically affected site.

5. The process of claim 1 wherein the primary coating comprises a) a tenaciously-bonded hydrophilic water insoluble crosslinked resin coating, b) that optionally contains a measurable amount of a water/fluid leachable fluoride capable of (a) being leached from the coating in a metered amount, and (b) transport¬ ing a small amount of leached fluoride from the coating into the bone and associated soft tissue.

6. The process of claim 5 wherein the resultant implanted prosthe¬ sis is more stably bonded to the alveolar bone and to associated soft tis¬ sue with which the prosthesis comes into contact.

7. The process of claim 6 wherein the prosthesis is made of one or more of metal, ceramic and plastic.

8. The process of claim 1 wherein the improvement includes the use of a primer coating comprising a strongly adhesively-bonded crosslink- able acrylic resin that possesses less hydrophilicity than the primary coating with or without fluoride.

9. The process of claim 8 wherein the primer coating rapidly in situ cures on one or more of an application surface, the bone and prosthetic surface, to function as a primer surface for the primary coating with or without fluoride that is applied to the same surface.

10. The process of claim 1 wherein the primary coating comprises a resin based on an ethylenically unsaturated-functional monomer that contains a hygroscopic group.

11. The process of claim 10 wherein the ethylenically-unsaturated- functional monomer contains hygroscopic groups and exhibits hydro¬ philicity.

12. The process of claim 11 wherein the groups are from the group consisting of hydroxyl, amide, amine, aliphatic ether, amine, hy¬ droxyalkyl amine, hydroxyalkyl amide, pyrrolidone, and ureyl.

13. The process of claim 12 wherein the primary coating contains a polycarboxylic acid.

14. The process of claim 13 wherein the polycarboxylic acid is in the form of its alkah metal salt.

15. The process of claim 13 wherein the primary coating contains a variety of crosslinking agents.

16. The process of claim 15 wherein one crosslinking agent is a hard crosslinker and another is a soft crosslinker.

17. The process of claim 16 wherein each hard and soft crosslinker is a polyfunctional molecule in which the functionality is complementary to the ethylenic unsaturation of the ethylenically-unsaturated- functional monomer.

18. The process of claim 17 wherein in the hard crosslinker, the functional groups are bonded via an aliphatic group of up to 10 carbon atoms, to a central moiety that is aromatic in nature.

19. The process of claim 18 wherein the hard crosslinkers raise the T_g of the cured primary coating,

20. The process of claim 17 wherein the soft crosslinker contains the functional groups bonded to a central moiety that comprises a group that has the flexibility of an alkane or contains alkyl benzene.

21. The process of claim 20 where the flexible groups are the resi¬ dues of ethylene glycol, diethylene glycol, 2,2-bis(4- hydroxyphenyl)propane, or 2,2,-bis(4-hydroxyphenyl)fluorinated al¬ kanes.

22. The process of claim 15 wherein the primary coating contains a coupling agent.

23. The process of claim 22 wherein the coupling agent is function- ally complementary to the ethylenically-unsaturated-functional mono¬ mer.

24. The process of claim 23 wherein the coupling agent contains a functional group that is reactable with the ethylenic unsaturation.

25. The process of claim 24 wherein the functional group is an acrylic-type ethylenic unsaturation.

26. The process of claim 23 wherein at another part of the coupling agent molecule is a surface bonding group that can impart one or more properties to the primary coating: a) chemical bonding capabilities to the substrate surface to which the primary coating is applied; and b) wetting agent properties in that it reduces the surface tension of the coating, causing the coating to spread across or penetrate more easily the surface of the substrate onto which the primary coating is applied.

27. The process of claim 2 wherein the fluoride is present in the primary coating such that it is leachable from the primary coating over an extended period of time.

28. The process of claim 4 wherein the primary coating contains at least one of free-radical catalytic curing agent and a free-radical photo- initiator.

29. The process of claim 28 wherein the primary coating contains a free-radical catalytic curing agent and a free -radical photoinitiator, and the coating can be cured by each of them.

30. The process of claim 4 wherein the primary coating comprises a two component blend in which the a) first component comprising: i) a fluoride source that includes a particulate sili¬ ceous fluoride containing filler in which the fluoride is water leachable; ii) a coupling agent that includes one or more of (i)

N-phenylglycine, the alkah metal salt thereof, or the mixture of the foregoing two compounds, (ii) the adduct of N-(p-tolyl)glycine and glycidyl methacrylate, the al¬ kali metal salt thereof, or the mixture of the foregoing two compounds, and (iii) the adduct of N-phenylglycine and glycidyl methacrylate, the alkali metal salt thereof, or the mixture of the foregoing two compounds; iii) a photoinitiator; optionally, a radiopaquing agent; and, optionally, a buffering agent; and b) second component comprising: AO

i) an ethylenically- unsaturated-functional mono¬ mer; ii) a soft crosslinker that includes one or more of 2,2- bis(4-methacryloxy 2-ethoxyphenyl) propane and dieth- y lene glycol bismethacrylate; iii) a hard crosslinker that includes one or more of (i) the adduct of pyromellitic acid dianhydride and 2- hydroxyethyl- methacrylate, (ii) the adduct of 3,3',4,4'- benzophenonetetracarboxylic dianhydride and 2- hydroxye thy lmethacry late, (iii) 4- methacryloxyethyltrimelli- tic anhydride, and (iv) other compounds containing at least one group or moiety ca¬ pable of free radical polymerization and at least one aromatic ring or moiety containing electron- withdrawing substituents that do not interfere with free radical polymerization; iv) a photoinitiator; v) a polymerized carboxylic acid; vi) a free-radical scavenger; and vii) a curing catalyst.

31. The process of claim 4 wherein the primary coating is a light- curable adhesive composition containing: a) a first component comprising: i) a fluoride source including a particulate siliceous fluoride containing filler in which the fluoride is water leachable; ii) a soft crosshnker; iii) an ethylenically-unsaturated-functional mono¬ mer; iv) a photoinitiator; v) a free-radical scavenger; vi) a thermal initiator; vii) a polymerized carboxylic acid; viii) a hard crosshnker including one or more of (i) the 5 adduct of pyromellitic acid dianhydride and 2- hydroxyethyl- methacrylate; (ii) the adduct of 3,3',4,4'- benzophenonetetracarboxylic dianhydride and 2- hydroxyethylmethacrylate, (iii) 4- methacryloxyethyltrimel litic anhydride, and (iv) other

10 compounds containing at least one group or moiety ca¬ pable of free radical polymerization and at least one aromatic ring or moiety containing electron- withdrawing substituents that do not interfere with free radical polymerization, and

15 b) a second component comprising: i) a fluoride source including a particulate siliceous fluoride containing filler in which the fluoride is water leachable; ii) a soft crosslinker;

20 iii) an ethylenically-unsaturated-functional mono¬ mer; iv) a coupling agent including one or more of (i) N- phenylglycine, the alkali metal salt thereof, or the mix¬ ture of the foregoing two compounds, (ii) the adduct of

25 N-(p-tolyl)glycine and glycidyl methacrylate, the alkali metal salt thereof, or the mixture of the foregoing two compounds, and (iii) the adduct of N-phenylglycine and glycidyl methacrylate, the alkali metal salt thereof, or the mixture of the foregoing two compounds;

30 v) a photoinitiator; vi) a radiopaquing agent; and vii) a buffering agent.

32. The process of claim 4 wherein primary coating composition con¬ tains a) a particulate glass having the composition of —

in which M is an alkaline earth metal and MO is barium oxide and barium oxide binary and ternary mixtures with other alkaline earth metal oxides; b) The alkali metal salt of the adduct of N-(p -tolyl) glycine and glycidyl methacrylate; c) The adduct of pyromellitic acid dianhydride and 2- hydroxyethyl methacrylate; d) Ethyl 4-dimethylamino benzoate and camphoquinone (i.e., 2,3-bornanedione); e) Ethoxylated bisphenol A dimethacrylate and the adduct of glycidylmethacrylate and bisphenol A, f) 2-hydroxyethyl methacrylate; g) Butylated hydroxytoluene free radical scavenger. h) Polyacrylic acid; i) Benzoyl peroxide or other peroxide that cause free radical addition at about 55°C. or at a lower temperature.

33. The process of claim 8 wherein the primer coating involves a two part (package) composition, comprising (a) a compound selected from the group consisting of (1) N- phenylglycine, (2) the adduct of N-(p-tolyl) glycine and glycidyl methacrylate, (3) the addition reaction product of N-phenylglycine and glycidyl methacrylate, (4) N(p-tolyl) glycine, N-phenylalanine, sarkosine, N-lauroylsarkosine, glycine, N,N-dimethyl-glycine, 3- (N-phenyl) amino propionic acid, 3-(N-p-tolyl) amino propionic acid, omega-amino fatty acids, N-substituted-omega-amino fatty acids, and the other amino acids; in which each member of the group of (1), (2), (3) and (4) that is present in the solution is an alkali metal salt form of that member, and

(b) a composition comprising at least one monomer selected from the group consisting of (1) the addition reaction product of pyromellitic acid dianhydride and 2-hydroxyethyl methacrylate,

(2) the addition reaction product of 3,3', 4,4'- benzophenonetetracarboxylic dianhydr- ide and 2-hydroxyethyl methacrylate, (3) 4-methacryloxyethyltrimel- htic anhydride, and (4) other compounds containing at least one group or moiety capable of free radical polymerization and at least one aromatic ring or moiety containing electron-withdrawing substituents that do not interfere with free radical polymerization.

34. The process of claim 33 wherein the primer coating is applied according to the steps of — (a) first contacting the surface with an aqueous solution comprising at least one strong acid or acidic salt in order to condition the surface,

(b) then contacting the surface with a solution comprising a solvent and at least one compound selected from the group consisting of (1) N-phenylglycine, (2) the adduct of N-(p- tolyl)glycine and glycidyl methacrylate, (3) the addition re¬ action product of N-phenylglycine and glycidyl methacry¬ late, and (4) other amino acids, in which each member of the group of (1), (2), (3) and (4) that is present in the solu- tion is an alkali metal salt form of that member, heat the surface to remove the solvent or maintain the surface at ambient temperature until the solvent is evaporated, and

(c) then contacting the surface with a solution comprising at least one monomer selected from the group consisting of (1) the addition reaction product of pyromellitic acid dianhy¬ dride and 2-hydroxyethyl methacrylate, (2) the addition re¬ action product of 3,3', 4,4'-benzophenone tetracarboxylic di¬ anhydride and 2-hydroxyethyl methacrylate, (3) 4- methacryloxyethyltrimellitic-anhydride, and (4) other com- pounds containing at least one group or moiety capable of free radical polymerization and at least one aromatic ring or moiety containing electron-withdrawing substituents that do not interfere with free radical polymerization

(d) heating the surface to remove residual solvent or main- tain the surface at ambient temperature until the solvent is evaporated from the primer coating and the coating is fully reacted.

35. A metal dental implant prosthesic that contains on at least a por¬ tion of thereof, a layer of a primary coating whereby the implant is bio- compatible to tissue that it contacts in or during dental implantation.

36. The metal dental implant prosthetic of claim 35 wherein the pri¬ mary coating contains fluoride.