Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2000-05-31
2003-01-28
Pezzuto, Helen L. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S274000, C526S286000, C526S287000, C526S318200, C526S318300
Reexamination Certificate
active
06512068
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an adhesive composition for hard tissue, which exhibits good adhesiveness to hard tissue such as bones, nails, teeth and others, of humans and animals. More precisely, it relates to an adhesive composition for dental use, which is for bonding restorative dental materials, especially dental resin materials such as dental bonding materials, dental cement materials, composite resins for dental restoration, compomers for dental restoration and the like, to teeth in dental treatment.
2. Description of the Related Art
For restoration of teeth damaged by caries or the like, generally used are restorative dental materials such as restorative composite resins, restorative compomers, etc. However, such restorative dental materials are not adhesive by themselves. In general, therefore, ordinary dental restoration comprises pre-treating the surface of a tooth with a strong acid etchant such as phosphoric acid or the like, then applying a bonding material to the etched surface of the tooth, and bonding a restorative material to the tooth via the bonding material. However, the method using such an acid etchant requires washing the etched tooth with water to completely remove the strong acid from the tooth followed by drying the tooth. This method is defective because the post-etching treatment is complicated. Further the dental bonding system using the acid etchant could ensure good adhesiveness to tooth enamel but could not to dentin.
To solve the problems, a dental bonding system using a self-etching primer has been proposed in Japanese Patent Laid-Open No. 223289/1987, in which, briefly, a tooth is pre-treated with a self-etching primer that comprises an acid (including acid monomers) and a hydrophilic monomer and not with an acid etchant, and a bonding material is directly applied to the pre-treated tooth not washed with water. In the system, the adhesiveness of the bonding material to dentin could be improved in some degree. However, since the primer contains a hydrophilic monomer in large quantities, the monomer penetrates into a tooth and the resin layer formed through polymerization and curing of the primer on the tooth could not be sufficiently waterproof. As a result, the resin layer or hybrid layer could not be sufficiently adhesive to the tooth for a long period of time. In the above reference 223289/1987, disclosed is a bonding durability test of testing bonded tooth pieces for their bonding durability by immersing them in water at 45° C. for 5 days. The test results indicate bonding durability in some degree of the tooth pieces bonded with a primer that contains a hydrophilic monomer such as 2-hydroxyethyl methacrylate (HEMA) and the like in large quantities. However, even the primer that could ensure the bonding strength in the bonding durability test is still problematic in actual dental use, since its cured layer is of ten degraded while in the mouth for a long period of time. As a result, the restorative material bonded to a tooth via the hybrid layer will peel off since water will leak in the bonded interface. In that situation, it is further desired a technique of further improving the bonding durability of restorative materials to teeth.
In Japanese Patent Laid-Open No. 113057/1989, proposed is a primer comprising water, a water-soluble polymerizable monomer and a salt of an acid. The laid-open specification says that the primer containing a salt of an acid and not an acid itself could exhibit improved adhesiveness to dentin. However, there is no description in the above reference relating to the bonding strength of a self-etching primer to enamel, which is the most important parameter of that primer. In this connection, it has been found that the bonding strength to enamel of the primer described in the Examples of the laid-open specification of the above reference is extremely low. Accordingly, from the primer proposed in 113057/1989, a self-etching primer with strong adhesiveness to both the two types of hard tissue, enamel and dentin, is not completed. In addition, as so mentioned hereinabove with respect to Japanese Patent Laid-Open No. 223289/1987, the primer disclosed in the laid-open specification does not solve the essential problem with it in that its bonding durability is poor since it contains a hydrophilic monomer such as HEMA in large quantities.
In Japanese Patent Laid-Open No. 251115/1998, a primer is disclosed comprising a specific phosphoric acid monomer, a polycarboxylic acid monomer and water. Though not containing a hydrophilic monomer such as HEMA or the like, the primer disclosed could exhibit good adhesiveness to teeth. However, the primer necessarily contains a water-soluble organic solvent so as to uniformly dissolve the constituent ingredients therein, in which, the water-soluble organic solvent is indispensable. If the primer containing a water-insoluble acid monomer dissolved in such a water-soluble organic solvent is intended to penetrate into a tooth, especially into dentin having a large water content, the acid monomer therein will be insolubilized with the tissue fluid in the tooth and therefore could not fully penetrate or diffuse in the tooth. Therefore, the primer is defective in that its bonding strength greatly fluctuates depending on the constituent ingredients. In addition, the organic solvent for the primer includes HEMA, and it is clear that 251115/1998 does not relate to improving the bonding durability of the primer. The primer disclosed was actually tested for its bonding durability. In the test, the bonding strength of the primer samples tested was not uniform and was poor.
Japanese Patent Laid-Open No. 93211/1994, discloses a primer containing a specific phosphate and/or its salt, and water. The laid-open specification of the above reference discloses that the primer composition has good adhesiveness to metals especially to stainless, well bonding thereto. However, in a bonding test with teeth, the primer samples described in the Examples of 93211/1994 did not exhibit high adhesiveness to teeth. In particular, in a bonding durability test with teeth such as thermocycle tests, the bonding strength of the primer samples are noticeably lowered. Accordingly, the primer disclosed in 93211/1994 is not suitable for dental treatment.
SUMMARY OF THE INVENTION
The subject matter of the present invention is to provide an adhesive composition for hard tissue which is effective for improving the adhesiveness between hard tissue, especially teeth (enamel, dentin, cementum) and dental resin materials, for example, dental bonding materials, dental resin cements, dental glass ionomer cements, restorative dental composite resins, restorative dental compomers and the like, especially for improving the bonding durability of such dental resin materials to teeth in water.
The adhesive composition of the present invention must satisfy the following requirements (1) to (5):
(1) The adhesive composition must be able to decalcify the smeared layer that may be formed in cutting teeth with a cutting tool such as a cutting turbine, a cutting laser or the like, in order that it can satisfactorily exhibit its good adhesiveness to a tooth.
(2) The adhesive composition must contain a substantially water-insoluble, acid group-containing polymerizable monomer with good waterproofness, as an indispensable ingredient, in order that it can ensure good adhesiveness to a tooth and good tooth-bonding durability, where the phrase “substantially water insoluble” is used in the present application to mean a water solubility of at most 5% by weight at 25° C.
(3) The substantially water-insoluble, acid group-containing polymerizable monomer in the adhesive composition must be solubilized in water, and the adhesive composition must contain water as another indispensable ingredient, in order that the monomer can easily penetrate into a tooth that contains water.
(4) The solubilized, acid group-containing polymerizable monomer must be adhesive to a tooth.
(5) The solubilized, acid grou
Kuraray Co. Ltd.
Pezzuto Helen L.
LandOfFree
Adhesive composition and method for producing it does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Adhesive composition and method for producing it, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adhesive composition and method for producing it will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3029318