Abstract:
Disclosed herein are acid-neutralizing polymerizable and/or non-polymerizable resins, methods of making such resins, and dental compositions having such resins.

Description:
TECHNICAL FIELD 
       [0001]    Disclosed herein are a class of acid-neutralizing resins and hardenable or curable compositions containing such resins. 
       BACKGROUND 
       [0002]    Chemical polymerization of vinyl or acrylate based resins via a free radical polymerization mechanism at ambient temperature is traditionally achieved using a binary, redox curing system consisting of a peroxide and an aromatic tertiary amine. On the other hand, light-activated polymerization proceeds via the generation of free radicals from the activation of a photoinitiator, usually an α-diketone, to its excited triplet state. This is followed by the reduction of the activated photoinitiator by an amine accelerator to form an intermediate excited complex (exciplex), which releases the free radicals on dissociation. There was evidence to suggest that bond strengths of resin composites to dentin were influenced by the compatibility of the polymerization modes between adhesive systems and resin composites (Swift E J, May K N, Wilder A D.  Journal of Prosthodontics,  7: 256-60, 1998). A report further revealed that common light-cured, self-etching adhesive systems were incompatible with chemical-cured composites (Miller M B et al.  Realty  13(1), 182-7, 1999), to the extent that no effective bonding was achieved for some systems. However, the systems that bonded poorly to the chemically cured composites exhibited high shear bond strengths with the use of light-cured resin composites. Generally, the nature of incompatibility of self-etching adhesives with chemical-cured resins is attributed to the in situ reaction between the basic component (amine coinitiatior) of the dual-cure restorative and the acid components of the adhesive system. More specifically, these acid components of the bonding agent are able to readily protonate the tertiary aromatic amine, which could be found in the self-curing resin composite as part of the organic redox catalyst. The protonated amine (quaternary aromatic amine) became inactive and/or not reactive towards the peroxide. Consequently, initiating radicals were able to be generated under ambient conditions. Overall, such a catalyst pair would have a loss in efficiency, and the rate and degree of functional group conversion are significantly diminished compromising the performance of the dental adhesive. In order to avoid such an unwanted amine protonation reaction, the dental restoratives to be used in combination have to be limited to those of the photo-curable type only. 
         [0003]    Although light-cured resin composites have largely superseded the use of chemical-cured composites in esthetic dental applications, chemically activated composites still have important applications in contemporary restorative dentistry. The longer working time of chemically cured composites has been adopted in the ‘directed shrinkage technique’ for posterior resin composite restorations. In this technique, a slow setting, chemically cured composite was used either in bulk or as a basal layer to relieve the stress developed in a restoration by the flow of the partially polymerized material. Chemically cured resins are frequently used as restorative materials in areas that are not easily penetrable by light, and as auto- or dual-curing resin cements for luting of crown and bridges, inlays and onlays along with endodontic posts. In order to facilitate the use of light curing self-etching bonding agents with dual curing or chemically curing composites, a self-curing activator is required to overcome the incompatibility of the acid containing adhesive with the amine in the redox catalyst of the chemically cured system. In the Prime&amp;Bond NT® Dual-Cure bonding system available from DENTSPLY International, Inc., the regular light-cure bonding agent, Prime&amp;Bond NT® is mixed with Self-Cure Activator prior to use. The Prime&amp;Bond NT® Dual-Cure exhibits excellent bond strength when bonding a dual-cure cement, e.g. Calibra® available from DENTSPLY International, Inc., in chemical-cure mode. 
         [0004]    The Self-Cure Activator developed specifically for Prime&amp;Bond NT® does not necessarily work as well with other simplified adhesives. More importantly, Self-Cure Activator has to be mixed with a simplified adhesive prior to use, which is an extra step for clinicians. There is a real need to simplify the system. It was thought that cement incorporating a base could neutralize acids in a simplified adhesive to mitigate or eliminate the issue of deactivation of amine in the cement. As a result, the incompatibility of a simplified adhesive and resin cement in self-cure mode may be reduced or eliminated. 
         [0005]    Osada et al ( Dental materials Journal,  21(11): 1044-50, 2005) reported that addition of an anion exchange resin to the amine component of self-cured resin was an effective means of enhancing the bond strength on dentin and to prevent amine neutralization through the acid groups of self-etching primer adhesives. The drawback with this approach is that flexural modulus of cement with anion exchange resin drops off. More critically, anion exchange resin is polymerized beads with diameter 1-2 mm, which would result in cement with film thickness too large for any clinical usage. 
       SUMMARY 
       [0006]    Disclosed herein is a method of making an acid-neutralizing resins, a resin composition having an acid-neutralizing capability and polymerizable or hardenable dental compositions for application in dental restorations. More specifically this disclosure is related to a method to prepare such reactive resins containing proper moieties that are capable effectively neutralizing stronger acids to prevent the amine co-initiator existing in any formulated dental restoratives from similar neutralizing reaction. Furthermore such acid-neutralizing resins can be either polymerizable or nonpolymerizable, and it can be further formulated in a variety of hardenable dental compositions, including but not limited to dental adhesives, dual-cure dental cements and dental composites. Thus in this disclosure is a method of effectively neutralizing any residual acid either from cured dental primer or from dental adhesives by dental compositions containing acid-neutralizing polymerizable resin, and consequently sound bonding of dental restoratives to tooth substitutes is readily achieved. 
         [0007]    Representative formulas of such base resins may be as follows: 
         [0000]    
       
                 
         
             
             
         
       
     
       R′: H or Me; 
     X: O, S, NH, NR1 (R1=CH3, C2H5) 
       [0008]    R and Y: independently of each other, have C1-C24, linear and/or branched alkylene residue, or aromatic/substituted residue;
 
M: alpha-substituted tertiary amine, pyridine or substituted pyridine, imidazole and/or substituted imidazole, pyrrole and/or substituted parrole, piperidine and/or substituted piperidine, pyrazole and/or substituted pyrazole, oxazole and/or substituted oxazole, thiazole and/or substituted thiozole, isoxazole and/or substituted isoxazole, isothiazole and/or substituted isoxazole, thiadizole indole and/or substituted thiadizole indole, indolizine and/or substituted indolizine, triazole and/or substituted triazole, tetrazole and/or substituted tetrazole, pentazole and/or substituted pentazole, quinoline and/or substituted quinoline, isoquinoline and/or substituted isoquinoline isoquinoline, pyridazine and/or substituted pyridazine, pyrimidine and/or substituted, pyzazine and/or substituted pyzazine, cinnoline and/or substituted cinnoline, phthalzine pyrimidine and/or substituted phthalzine, quinazoline and/or substituted quinazoline, quinoxaline and/or substituted quinoxaline, phenazine and/or substituted triazines, triazines and/or substituted triazines or any combination of these
 
n=1-10 and m=1-10
 
         [0009]    This disclosure relates to resin compositions of acid-neutralizing resins and further hardenable or curable compositions containing the said resins. The hardenable or curable compositions are preferably dental compositions, included but not limited to adhesives, cements and composites. This disclosure relates particularly to a method of effectively neutralizing the excess acids in any cured primers, self-etching adhesives or any other adhesive systems so as to allow subsequently adequate curing for good bonding between such adhesive systems and the dual-cure restoratives. Disclosed herein are compositions of such acid-neutralizing resins and the method to utilize such acid-neutralizing resins in formulated compositions that become capable of effectively neutralizing any residual acid and at the same time effectively preventing the similar neutralizing reaction from the amine coinitiators that existed in standard dual-cure restoratives. Thus a significant enhancement in term of hardening or curing process, especially at the interface between the acidic surface and restorative materials should be readily achieved, which consequently results in improved compatibility and more specifically improved bonding strength. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0010]      FIG. 1  depicts examples of acid neutralizing polymerizable resins. 
           [0011]      FIG. 2  depicts more examples of acid neutralizing polymerizable resins. 
           [0012]      FIG. 3  depicts yet more examples of acid neutralizing polymerizable resins. 
           [0013]      FIG. 4  is a FTIR spectra of a complex of PENTA/bisimidazole dimethacrylate. 
           [0014]      FIG. 5  is a FTIR spectra of a complex of polyacrylic acid/bisimidazole dimethacrylate. 
           [0015]      FIG. 6  demonstrates one preparation of isosorbide passed polymerizable imidazole resin. 
           [0016]      FIG. 7  demonstrates one preparation of AMAHP-based polymerizable imidazole resin via CDI process. 
           [0017]      FIG. 8  depicts a TCDC-based bisimidazole dimethacrylate resin. 
           [0018]      FIG. 9  depicts a HEMA based dimethacrylate imidazole resin. 
           [0019]      FIG. 10  demonstrates one preparation of AMAHP based polymerizable imidazole resins via an imidazole process. 
           [0020]      FIG. 11  demonstrates one preparation of an IEM based dimethacrylate imidazole resin. 
           [0021]      FIG. 12  depicts imidazole acrylate resins. 
           [0022]      FIG. 13  depicts further examples of imidazole acrylate resins. 
           [0023]      FIG. 14  depicts a complex of methacrylic acid and bisimidazole dimethacrylate resin. 
           [0024]      FIG. 15  depicts two typical nonpolymerizable triimidazole resin and tetraimidazole resin. 
           [0025]      FIG. 16  depicts further nonpolymerizable bisimidazole resins. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    In this disclosure, identified are a class of novel additive, acid-neutralizing resins, which could be readily formulated in conventional restoratives and make them capable of neutralizing the acidic component from adhesive and consequently lead to pronounced enhancement in bonding strength due to improved polymerization of the restorative. In addition, as a natural extension of this disclosure, a self-neutralizable adhesive composition should be also formulated by incorporating such polymerizable base resins, which will work similarly towards self-etching primer and any other conventional, dual-cure, self-cure and/or light-cure restoratives. Pronounced improvement in bonding strength was true benefit from such simplified procedures due to incorporation of such polymerizable base resins. 
         [0027]    The following formula illustrates the representative structure of such acid-neutralizing resins. It is expected further alteration from such formulate is possible based on basic knowledge in organic chemistry, which should fall in the scope of this disclosure. 
         [0000]    
       
                 
         
             
             
         
       
     
       R′: H or Me; 
     X: O, S, NH, NR1 (R1=CH3, C2H5) 
       [0028]    R and Y: independently of each other, have C1-C24, linear and/or branched alkylene residue, or aromatic/substituted residue;
 
M: alpha-substituted tertiary amine, pyridine or substituted pyridine, imidazole and/or substituted imidazole, pyrrole and/or substituted parrole, piperidine and/or substituted piperidine, pyrazole and/or substituted pyrazole, oxazole and/or substituted oxazole, thiazole and/or substituted thiozole, isoxazole and/or substituted isoxazole, isothiazole and/or substituted isoxazole, thiadizole indole and/or substituted thiadizole indole, indolizine and/or substituted indolizine, triazole and/or substituted triazole, tetrazole and/or substituted tetrazole, pentazole and/or substituted pentazole, quinoline and/or substituted quinoline, isoquinoline and/or substituted isoquinoline isoquinoline, pyridazine and/or substituted pyridazine, pyrimidine and/or substituted, pyzazine and/or substituted pyzazine, cinnoline and/or substituted cinnoline, phthalzine pyrimidine and/or substituted phthalzine, quinazoline and/or substituted quinazoline, quinoxaline and/or substituted quinoxaline, phenazine and/or substituted triazines, triazines and/or substituted triazines or any combination of these residues;
 
n=1-10 and m=1-10.
 
         [0029]    In the following chart, the typical M is illustrated: 
         [0000]    
       
                 
         
             
             
         
       
     
       EXAMPLES 
     Example 1 
       [0030]    Isosorbide-based bisimidazoledimethacrylate Resin ( FIG. 6 ) was prepared via a two-step process as described in the following: to a 1000 ml 3-nech round flask, 98.88 g of 1,1-carbonydiimidazole (CDI), 550 g of methylene dichloride and 43.9 g of isosorbide were charged and soon the system turns clear at room temperature. Then the crystal was developed as resulted of imidazole formation. After 2 hrs reaction at RT, 131.1 g of 3-(acryloyloxy)-2-hydroxypropyl methacrylate (AMAHP), 40.0 g of potassium carbonate and 4.0 g of terabutylamoniumbromide were added. Keep the reaction proceeding at room temperature for additional 10-12 hrs prior to 200 ml of water was added to stop the reaction. The resulting solution was extraction several times with water to remove all of imidazole and catalysts. Then it was dried over magnesium sulfate overnight at RT prior to it was filtrated. Solvent was removed via Rotovapor at 35-40° C. under vacuum. 240 g of liquid resin was collected with yield of 89%. 
       Example 2 
       [0031]    TCDC-based bisimidazole-dimethacrylate Resins ( FIG. 8 ) was prepared via a two-step process as described in the following: to a 1000 ml 3-nech round flask, 74.45 g of CDI, 400 ml of methylene dichloride and 98.36 g of AMAHP were charged and soon the system turns clear at room temperature. After 6 hrs reaction at RT, a bisimidazole precursor was formed as shown in  FIG. 7 , then 45.0 g of 4,8-bis(hydroxymethyl)-tricyclo[5,2,1,0 2.5 ](TCDC) and 40.0 g of potassium carbonate and 3.8 g of terabutylamoniumbromide were added. Keep the reaction proceeding at room temperature for additional 10-12 hrs prior to 250 ml of DI water was added to stop the reaction. The resulting solution was extraction several times with water to remove all of imidazole and catalysts. Then it was dried over magnesium sulfate overnight at RT prior to it was filtrated. Solvent was removed via Rotovapor at 35-40° C. under vacuum. 
       Example 3 
       [0032]    HEMA-based Monoimidazole-dimethacrylate Resins ( FIG. 9 ) was also prepared via a two-step process as described in the following: to a 1000 ml 3-nech round flask, 81.8 g of CDI, 450 ml of methylene dichloride and 107.5 g of AMAHP were charged and soon the system turns clear at room temperature. After 6 hrs reaction at RT, 66.5 g of HEMA, 40.0 g of potassium carbonate and 4.0 g of terabutylamoniumbromide were added. Keep the reaction proceeding at room temperature for additional 10-12 hrs prior to 200 ml of water was added to stop the reaction. The resulting solution was extraction several times with DI water to remove all of imidazole and catalysts. Then it was dried over magnesium sulfate overnight at RT prior to it was filtrated. Solvent was removed via Rotovapor at 35-40° C. under vacuum. 
       Example 4 
       [0033]    AMAHP-based monoimidazole-monomethacrylate Resins ( FIG. 10 ) was also prepared via a one-step process as described in the following: to a 1000 ml 3-nech round flask, 102 grams of imidazole, 700 ml of methylene dichloride and 161 grams of AMAHP were charged and soon the system turns clear at room temperature. After reaction over night at RT, the resulting solution was extracted several times by using aqueous solution of potassium carbonate. Then it was dried over night with magnesium sulphate prior to remove the solvent via Rotovapor at 35-40° C. under vacuum. Liquid resin was collected. 
       Example 5 
       [0034]    IEM-based monoimidazole-monomethacrylate Resins ( FIG. 11 ) was prepared via a two-step process as described in the following: to a 500 ml 3-nech round flask, 237 grams of AMAHP and 146.2 grams of 2-isocynate ethoxylmethacrylate (IEM), and 0.53 gam of DBTOL were charged at 35° C. Keep reaction for 6 hrs. 339 grams liquid resin was collected. Then 185.1 grams of the precursor resin and 800 ml of methylene dichloride were charged into a 1000 ml three neck round flask at room temperature. Then slowly it was added of 55.5 grams of imidazole crystalline powder. Keep reaction for overnight. The resulting solution was extracted several times by using aqueous solution of potassium carbonate. Then it was dried over night with magnesium sulphate prior to remove the solvent via Rotovapor at 35-40° C. under vacuum. 214 grams of liquid resin was collected. 
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Compositions for Various Bisimidazole Dimethacrylate Resins 
               
             
          
           
               
                   
                 Example 3 
                 Example 1 
                 Example 2 
               
               
                   
                   
               
             
          
           
               
                 Resin Composition 
                 AMAHP/HEMA 
                 Isosorbide/AMAHP/ 
                 TCDC/AMAHP/ 
               
               
                   
                   
                 TEGDMA 
                 TEGDMA 
               
               
                 IMMA Resin, 
                 100  
                 90 
                 90 
               
               
                 TEGDMA, 
                 0 
                 10 
                 10 
               
               
                 (wt/wt, %) 
               
               
                 Resin Form 
                 Liquid 
                 Liquid 
                 liquid 
               
               
                 Viscosity @ 20° C. 
                 3 
                 690  
                 40 
               
               
                 Pa · s 
               
               
                 Solubility @ 37° C. 
                 partially soluble 
                 partially soluble 
                 partially soluble 
               
               
                 in water 
               
               
                 Solubility @ 37° C. 
                 soluble 
                 soluble 
                 soluble 
               
               
                 in water/ethanol(50:50, w/w %) 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 Physical Property for Various Imidazole-based Resin Complexes 
               
             
          
           
               
                   
                 Example 1 
                 Example 1 
                 Example 1 
               
               
                   
                 Complex A 
                 Complex B 
                 Complex C 
               
               
                   
                 50% 
                 50% 
                 33% 
               
               
                   
                 Example 1/TEGDMA(80/20) 
                 Example 1/TEGDMA(80/20) 
                 Example 1 
               
               
                   
                 50% 
                 50% 
                 67% 
               
               
                   
                 OEMA/TEGDMA(75/25) 
                 PENTA/TEGDMA(75/25) 
                 PAA(50K, 25% in Water) 
               
               
                   
                   
               
             
          
           
               
                 As-aged 2 d RT 
                 23 
                 85 
                 N/A 
               
               
                 Viscosity@20° C. 
               
               
                 Pa · s 
               
               
                 As-aged 2 wks RT 
                 20 
                 1610 
                 elastic gel 
               
               
                 Viscosity@20° C. 
               
               
                 Pa · s 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 Physical Property for Various Formulated Imidazole Resins 
               
             
          
           
               
                   
                 Formulated Imidazole 
                   
                   
               
               
                   
                 Resin 1 
                 Formulated Imidazole 
                 Formulated Imidazole 
               
               
                   
                 80% Example 1 
                 Resin 2 
                 Resin 3 
               
               
                   
                 20% TEG DM A 
                 100% Example 3 
                 100% BIDMA Resin 3 
               
               
                   
                 0.165% CQ 
                 0.165% CQ 
                 0.165% CQ 
               
               
                   
                 0.30% EDAB 
                 0.30% EDAB 
                 0.30% EDAB 
               
               
                   
                 0.015% BHT 
                 0.015% BHT 
                 0.015% BHT 
               
               
                   
                   
               
             
          
           
               
                 Viscosity@20° C. 
                 12 
                 10 
                 60 
               
               
                 Pa · s 
               
               
                 Shrinkage @ 
                 NA 
                 NA 
                 NA 
               
               
                 24 hrs % 
               
               
                 Stress @ 60 min 
                 1.10 
                 2.30 
                 0.45/0.30 
               
               
                 MPa 
               
               
                 ΔH 1  in N 2  @ 
                 119 
                 107 
                 83 
               
               
                 UV-Vis J/g 
               
               
                 t o   
                 14 
                 17 
                 28 
               
               
                 seconds 
               
               
                 t max   
                 42 
                 40 
                 58 
               
               
                 seconds 
               
               
                 ΔH 1  in N 2  @ Vis 
                 121 
                 103 
                 83 
               
               
                 J/g 
               
               
                 t o   
                 15 
                 16 
                 30 
               
               
                 seconds 
               
               
                 t max   
                 45 
                 38 
                 77 
               
               
                 seconds 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 4 
               
             
             
               
                   
               
               
                 Physical Property for Various Formulated Imidazole Resins 
               
             
          
           
               
                   
                   
                   
                   
                 Formulated 
               
               
                   
                 Formulated 
                 Formulated 
                 Formulated 
                 Imidazole Resin 7 
               
               
                   
                 Imidazole Resin 4 
                 Imidazole Resin 5 
                 Imidazole Resin 6 
                 67% Example 1 
               
               
                   
                 80% Example 1 
                 80% Example 1 
                 80% Example 1 
                 13% MA Acid 
               
               
                   
                 20% TEGDMA 
                 20% BIDMA Resin 4 
                 20% HEMASA 
                 20% TEGDMA 
               
               
                   
                 0.165% CQ 
                 0.165% CQ 
                 0.165% CQ 
                 0.13% CQ 
               
               
                   
                 0.30% EDAB 
                 0.30% EDAB 
                 0.30% EDAB 
                 0.012% BHT 
               
               
                   
                 0.015% BHT 
                 0.015% BHT 
                 0.015% BHT 
                 0.32% LTPO 
               
               
                   
                   
               
             
          
           
               
                 Viscosity@20° C. 
                 15 
                 160 
                 280 
                 12 
               
               
                 Pa · s 
               
               
                 Shrinkage @ 24 hrs % 
                 NA 
                 NA 
                 NA 
                 NA 
               
               
                 Stress @ 60 min 
                 1.70/1.00 
                 1.15/0.50 
                 0.45/0.32 
                 3.50/2.40 
               
               
                 MPa 
               
               
                 ΔH 1  in N 2  @ UV-Vis 
                 108 
                 86 
                 89 
                 136 
               
               
                 J/g 
               
               
                 t o   
                 20 
                 23 
                 22 
                 9 
               
               
                 seconds 
               
               
                 t max   
                 48 
                 47 
                 50 
                 28 
               
               
                 seconds 
               
               
                 ΔH 1  in N 2  @ Vis 
                 101 
                 81 
                 79 
                 131 
               
               
                 J/g 
               
               
                 t o   
                 21 
                 24 
                 25 
                 8 
               
               
                 seconds 
               
               
                 t max   
                 53 
                 48 
                 66 
                 29 
               
               
                 seconds 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
               
             
           
               
                 TABLE 5 
               
             
             
               
                   
               
               
                 Physical Property for Various Formulated Imidazole Composites 
               
             
          
           
               
                   
                 Composite 1 
                 Composite 2 
                 Composite 3 
                 Composite 4 
               
               
                   
               
               
                 Resins 
                 19.42% 
                 21.05% 
                 20% 
                 20% 
               
               
                   
                 IMMA Resin 
                 IMMA Resin 
                 Conventional 
                 Conventional 
               
               
                   
                 67% Example 1 
                 80% Example 1 
                 100% 
                 100% 
               
               
                   
                 13% MA Acid 
                 20% TEGDMA 
                 EsthetXflow 
                 EsthetXflow 
               
               
                   
                 20% TEGDMA 
                 0.165% CQ 
                 Resin 
                 Resin 
               
               
                   
                 0.13% CQ 
                 0.30% EDAB 
                 0.10% CQ 
                 0.10% CQ 
               
               
                   
                 0.012% BHT 
                 0.015% BHT 
                 1.30% EDAB 
                 1.30% EDAB 
               
               
                   
                 0.32% LTPO 
                   
                 0.005% BHT 
                 0.005% BHT 
               
               
                   
                   
                   
                   
                 1.2% Uvinol M-40 
               
               
                   
                   
                   
                   
                 0.196% Flublau 
               
               
                   
                   
                   
                   
                 conc. 
               
               
                 Fillers 
                 80.58% 
                 78.95% 
                 (80.0%) 
                 80.0% 
               
               
                 (wt/wt) 
               
               
                 Stickiness@37° C. 
                 NA 
                 NA 
                 0.60 
                 1.30 
               
               
                 mm 
               
               
                 Stress @ 60 min 
                   
                 2.30/1.92 
                 1.81/2.58 
               
               
                 MPa 
               
               
                 ΔH 1  in N 2  @ UV-Vis 
                 29 
                 25 
                 25 
               
               
                 J/g 
               
               
                 t o   
                 2 
                 9 
                 36 
               
               
                 seconds 
               
               
                 t max   
                 23 
                 46 
                 117 
               
               
                 seconds 
               
               
                 ΔH 1  in N 2  @ Vis 
                 26 
                 24 
                 22 
               
               
                 J/g 
               
               
                 t o   
                 4 
                 14 
                 21 
               
               
                 seconds 
               
               
                 t max   
                 28 
                 47 
                 107 
               
               
                 seconds 
               
               
                   
               
             
          
         
       
     
         [0035]    One of typical acid-neutralizing polymerizable resins is polymerizable imidazole resin (Example 3) as shown in  FIG. 9 , which structurally is a dimethacrylate resin containing imidazole moiety. Imidazole is well known for its rather basic property; in fact it is appoxmately sixty times more basic than pyridine. Thus it should indicate that imidazole intrinsically capable to neutralize readily most of acidic compounds. In addition, unlike other organic basic compounds, such as tertiary amine, imidazole is stable towards oxidants and would not involve in any redox/H-abstraction reactions that occurred in self-cure and/or light-cure process. 
         [0036]    There has been a compatibility issue between a simplified adhesive and a typical BPO/amine based resin cement in self-cure mode. It is believed that acid-base reaction between acid monomer in a simplified adhesive and amine in cement causes deactivation of amine as co-initiator. It was thought that a cement incorporating Resin Example 3 could neutralize acids in a simplified adhesive to mitigate or eliminate the issue of deactivation of amine in the cement. As a result, the incompatibility of a simplified adhesive and resin cement in self-cure mode may be reduced or eliminated. 
         [0000]    
       
         
               
             
               
               
             
               
               
               
             
           
               
                 TABLE 6 
               
             
             
               
                   
               
               
                 Base Resin Blend-1 with Imidazole-based Monomer 
               
             
          
           
               
                   
                 % By Wt. 
               
               
                   
                   
               
             
          
           
               
                   
                 Nupol 
                 20.000 
               
               
                   
                 Example 3 
                 65.980 
               
               
                   
                 TEGDMA 
                 10.000 
               
               
                   
                 Camphorquinone (CQ) 
                 0.150 
               
               
                   
                 EDAB 
                 0.160 
               
               
                   
                 DHEPT 
                 1.700 
               
               
                   
                 Uvinul M40 
                 2.000 
               
               
                   
                 BHT 
                 0.010 
               
               
                   
                 Total 
                 100.000 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
             
               
               
               
             
           
               
                 TABLE 7 
               
             
             
               
                   
               
               
                 Catalyst Resin Blend-2 with Imidazole-based Monomer 
               
             
          
           
               
                   
                 % By Wt. 
               
               
                   
                   
               
             
          
           
               
                   
                 Nupol 
                 20.000 
               
               
                   
                 Example 3 
                 67.700 
               
               
                   
                 TEGDMA 
                 10.000 
               
               
                   
                 Benzoyl Peroxide (BPO) 
                 2.200 
               
               
                   
                 BHT 
                 0.100 
               
               
                   
                 Total 
                 100.000 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
             
               
               
               
             
           
               
                 TABLE 8 
               
             
             
               
                   
               
               
                 Base Paste-1 with Imidazole-based Monomer 
               
             
          
           
               
                   
                 % By Wt. 
               
               
                   
                   
               
             
          
           
               
                   
                 Blend-1 
                 32.600 
               
               
                   
                 Filler 
                 67.400 
               
               
                   
                 Total (paste) 
                 100.000 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
             
               
               
               
             
           
               
                 TABLE 9 
               
             
             
               
                   
               
               
                 Catalyst Paste-2 with Imidazole-based Monomer 
               
             
          
           
               
                   
                 % By Wt. 
               
               
                   
                   
               
             
          
           
               
                   
                 Blend-2 
                 38.000 
               
               
                   
                 Filler 
                 62.000 
               
               
                   
                 Total 
                 100.000 
               
               
                   
                   
               
             
          
         
       
     
         [0037]    When the catalyst Paste-2 was stored at RT for 72 hrs, a chuck of solid mass was seen on the bottom, most possibly due to some premature polymerization. It is assumed that some impurities in Resin Example 3 may act as self-cure co-initiators. 
         [0038]    Comparative data results of the experimental cement and the control of Calibra are presented on Table 5 and 6. In summary, the experimental cement is compatible with Prime&amp;Bond NT without the use of Self-cure Activator (SCA). The bond strength on dentin for Prime&amp;Bond NT to bond the experimental cement in self-cure on dentin is similar to Prime&amp;Bond NT in combination with a Self-cure Activator, whereas without a self-cure activator, Prime&amp;Bond NT essentially does not bond Calibre in self-cure on dentin. The overall mechanical performance of experimental cement is similar to that of Calibra, except for somewhat lower flexural modulus. 
         [0000]    
       
         
               
             
               
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 10 
               
             
             
               
                   
               
               
                 24 hr SBS of Prime&amp;Bond NT to Bond cements in Self-cure on Dentin 
               
             
          
           
               
                   
                 Bonding Agent 
               
             
          
           
               
                   
                 Prime&amp;Bond 
                 Prime&amp;Bond 
                 Prime&amp;Bond 
                 Prime&amp;Bond 
               
               
                   
                 NT 
                 NT/SCA (1:1) 
                 NT 
                 NT 
               
               
                   
                   
               
             
          
           
               
                 Cement 
                 Calibra base/ 
                 Calibra 
                 Paste-1/ 
                 Paste-1/ 
               
               
                   
                 catalyst (1:1) 
                 base/catalyst 
                 Paste-2 (1:1) 
                 Calibra 
               
               
                   
                   
                 (1:1) 
                   
                 catalyst (1:1) 
               
               
                 SBS (MPa) 
                 1.9 (2.2) 
                 14.1 (2.7) 
                 12.0 (2.5) 
                 16.2 (3.4) 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 11 
               
             
             
               
                   
               
               
                 Mechanical Properties 
               
               
                 Paste-1/Calibra Catalyst vs. Calibra base/catalyst in SC 
               
             
          
           
               
                   
                 Paste-1/Calibra catalyst 
                 Calibra base/catalyst 
               
               
                   
                   
               
             
          
           
               
                   
                 CS (MPa) 
                 274 (11) 
                 278 (8)  
               
               
                   
                 FS (MPa) 
                 98 (9) 
                 103 (14) 
               
               
                   
                 FM (MPa) 
                 6173 (643) 
                 7086 (297) 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
             
               
               
               
             
           
               
                 TABLE 12 
               
             
             
               
                   
               
               
                 Base Resin Blend-3 Containing DMEMA 
               
             
          
           
               
                   
                 % By Wt. 
               
               
                   
                   
               
             
          
           
               
                   
                 Nupol 
                 62.330 
               
               
                   
                 DMEMA 
                 23.650 
               
               
                   
                 TEGDMA 
                 10.000 
               
               
                   
                 Camphorquinone (CQ) 
                 0.150 
               
               
                   
                 EDAB 
                 0.160 
               
               
                   
                 DHEPT 
                 1.700 
               
               
                   
                 Uvinul M40 
                 2.000 
               
               
                   
                 BHT 
                 0.010 
               
               
                   
                 Total 
                 100.000 
               
               
                   
                   
               
               
                   
                 *DMEMA = 2-(Dimethylamino)ethyl methacrylate 
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 13 
               
             
             
               
                   
               
               
                 Base Paste Paste-3 with DMEMA 
               
             
          
           
               
                   
                   
                 % By Wt. 
               
               
                   
                   
               
             
          
           
               
                   
                 Blend-3 
                 32.600 
               
               
                   
                 Filler 
                 67.400 
               
               
                   
                 Total (paste) 
                 100.000 
               
               
                   
                   
               
             
          
         
       
     
         [0039]    When Paste-3 was mixed with Calibra catalyst paste (1:1), no curing into solid was observed even after 3 hrs. 
         [0000]    
       
         
               
             
               
               
             
               
               
               
             
           
               
                 TABLE 14 
               
             
             
               
                   
               
               
                 Base Resin Blend-4 with 4-VPy 
               
             
          
           
               
                   
                 % By Wt. 
               
               
                   
                   
               
             
          
           
               
                   
                 Nupol 
                 69.080 
               
               
                   
                 4-Vpy 
                 15.820 
               
               
                   
                 TEGDMA 
                 11.080 
               
               
                   
                 Camphorquinone (CQ) 
                 0.150 
               
               
                   
                 EDAB 
                 0.160 
               
               
                   
                 DHEPT 
                 1.700 
               
               
                   
                 Uvinul M40 
                 2.000 
               
               
                   
                 BHT 
                 0.010 
               
               
                   
                 Total 
                 100.000 
               
               
                   
                   
               
               
                   
                 *4-Vpy = 4-Vinylpyridine 
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
             
               
               
               
             
           
               
                 TABLE 15 
               
             
             
               
                   
               
               
                 Base Paste-4 with 4-VPy 
               
             
          
           
               
                   
                 % By Wt. 
               
               
                   
                   
               
             
          
           
               
                   
                 Blend-4 
                 32.600 
               
               
                   
                 Filler 
                 67.400 
               
               
                   
                 Total (paste) 
                 100.000 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 16 
               
             
             
               
                   
               
               
                 Base Resin Blend-5 with MEMA 
               
             
          
           
               
                   
                   
                 % By Wt. 
               
               
                   
                   
               
             
          
           
               
                   
                 Nupol 
                 56.880 
               
               
                   
                 MEMA 
                 29.980 
               
               
                   
                 TEGDMA 
                 9.120 
               
               
                   
                 Camphorquinone 
                 0.150 
               
               
                   
                 (CQ) 
               
               
                   
                 EDAB 
                 0.160 
               
               
                   
                 DHEPT 
                 1.700 
               
               
                   
                 Uvinul M40 
                 2.000 
               
               
                   
                 BHT 
                 0.010 
               
               
                   
                 Total 
                 100.000 
               
               
                   
                   
               
               
                   
                 *MEMA = 2-N-Morpholinoethyl methacrylate 
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
             
               
               
               
             
           
               
                 TABLE 17 
               
             
             
               
                   
               
               
                 Base Paste Paste-5 with MEMA 
               
             
          
           
               
                   
                 % By Wt. 
               
               
                   
                   
               
             
          
           
               
                   
                 Blend-5 
                 32.600 
               
               
                   
                 Filler 
                 67.400 
               
               
                   
                 Total (paste) 
                 100.000 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 18 
               
             
             
               
                   
               
               
                 24 hr SBS of Prime&amp;Bond NT to Bond Cements in Self-cure on Dentin 
               
             
          
           
               
                   
                 Bonding Agent 
               
             
          
           
               
                   
                 Prime&amp;Bond 
                 Prime&amp;Bond 
                 Prime&amp;Bond 
                 Prime&amp;Bond 
               
               
                   
                 NT 
                 NT/ SCA (1:1) 
                 NT 
                 NT 
               
               
                   
                   
               
             
          
           
               
                 Cement 
                 Calibra base/ 
                 Calibra base/ 
                 Paste-4/ 
                 Paste-5/ 
               
               
                   
                 catalyst (1:1) 
                 catalyst (1:1) 
                 Calibra 
                 Calibra 
               
               
                   
                   
                   
                 Catalyst 
                 Catalyst 
               
               
                   
                   
                   
                 (1:1) 
                 (1:1) 
               
               
                 SBS (MPa) 
                 1.9 (2.2) 
                 14.1 (2.7) 
                 10.8 (3.4) 
                 6.1 (2.2)