HIGHLY EFFECTIVE, SILICA-FREE, STORAGE STABLE DENTAL ETCHING GEL

Abstract

The present invention relates to a dental etching composition comprising phosphoric acid, water and urethane-urea compound(s), to the use of said dental etching composition for etching the hard substance of the tooth, to a dental etching composition for use in a therapeutic method of etching the hard substance of the tooth in the course of filling treatment, and to a kit comprising a dental etching composition.

Claims

1. A dental etching composition comprising A) an acid selected from the group consisting of phosphoric acid, hydrochloric acid, hydrofluoric acid, maleic acid and citric acid, B) water, and C) one or more urethane-urea compounds.

2. The dental etching composition of claim 1, wherein the acid (A) is phosphoric acid or hydrochloric acid.

3. The dental etching composition of claim 1, wherein the urethane-urea compounds (C) have the formula
R.sup.1—O—C(═O)—NH—R.sup.2—NH—C(═O)[—NH—R.sup.3—NH—C(═O)—NH—R.sup.2—NH—C(═O)].sub.x—OR.sup.1 wherein R.sup.1 is an n-alkyl radical having 4 to 22 carbon atoms, a branched alkyl radical having 4 to 22 carbon atoms, an alkenyl radical having 3 to 18 carbon atoms, a cycloalkyl radical having 3 to 20 carbon atoms, an aryl radical having 6 to 12 carbon atoms, an arylalkyl radical having 7 to 12 carbon atoms, a radical of the formula C.sub.mH.sub.2m+1(O—C.sub.nH.sub.2n).sub.p—, C.sub.mH.sub.2m+1(OOC—CH.sub.2v).sub.p—, or R.sup.5—C.sub.6H.sub.4(O—C.sub.nH.sub.2n).sub.p—, wherein m=1 to 22, n=2 to 4, p=1 to 15, v=4 or 5, and R.sup.5 is an alkyl radical having 1 to 12 carbon atoms, wherein different R.sup.1 radicals may be the same or different, R.sup.2 is a branched or unbranched alkylene radical having 4 to 22 carbon atoms, alkenylene radical having 3 to 18 carbon atoms, alkynylene radical having 2 to 20 carbon atoms, cycloalkylene radical having 3 to 20 carbon atoms, cycloalkenylene radical having 3 to 20 carbon atoms, arylene radical having 6 to 12 carbon atoms, or arylalkylene radical having 7 to 14 carbon atoms, wherein different R.sup.2 radicals may be the same or different, R.sup.3 is ##STR00005## with wherein R.sup.4=CH.sub.3 or H, and wherein different R.sup.3 radicals may be the same or different, and x is an integer from 1 to 100.

4. The dental etching composition of claim 1, wherein the urethane-urea compounds (C) have the formula
R.sup.1—O—C(═O)—NH—R.sup.2—NH—C(═O)[—NH—R.sup.3—NH—C(═O)—NH—R.sup.2—NH—C(═O)].sub.x—OR.sup.1 wherein R.sup.1 is an n-alkyl radical having 4 to 10 carbon atoms, a branched alkyl radical having 4 to 10 carbon atoms, an alkenyl radical having 3 to 10 carbon atoms, a cycloalkyl radical having 3 to 10 carbon atoms, an aryl radical having 6 to 12 carbon atoms, an arylalkyl radical having 7 to 12 carbon atoms, a radical of the formula C.sub.mH.sub.2m+1(O—C.sub.nH.sub.2n).sub.p—, C.sub.mH.sub.2m+1(OOC—C.sub.vH.sub.2v).sub.p— or R.sup.5—C.sub.6H.sub.4(O—C.sub.nH.sub.2n).sub.p—, wherein m=1 to 10, n=2 to 4, p=1 to 15, v=4 or 5, and R.sup.5 is an alkyl radical having 1 to 12 carbon atoms, a branched alkyl radical having 4 to 10 carbon atoms, a radical of the formula C.sub.mH.sub.2m+1(O—C.sub.nH.sub.2n).sub.p-s or C.sub.mH.sub.2m+1(OOC—CH.sub.2v).sub.p—, wherein m=1 to 10, n=2 to 4, p=1 to 15 and v=4 or 5, and wherein different R.sup.1 radicals may be the same or different, R.sup.2 is ##STR00006##  or —(CH.sub.2).sub.w—, wherein w=2 to 10, wherein different R.sup.2 radicals may the same or different, R.sup.3 is ##STR00007##  wherein different R.sup.3 radicals may be the same or different, and x is an integer from 1 to 20.

5. The dental etching composition of claim 1, additionally comprising D) one or more water-miscible solvents.

6. The dental etching composition of claim 5, wherein the water-miscible solvents (D) are selected from the group consisting of ethanol, propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, 2-methylpropan-1-ol, 2-methylpropan-2-ol, glycerol, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, 2-butoxyethan-1-ol, DMSO and acetone, preferably selected from the group consisting of ethanol, propan-1-ol, propan-2-ol, glycerol, polyethylene glycol, polypropylene glycol and DMSO.

7. The dental etching composition of claim 1, additionally comprising E) colorants.

8. The dental etching composition of claim 7, wherein the colorants (E) are selected from the group consisting of dyes, organic color pigments and inorganic color pigments, and/or wherein the colorants (E) are blue, green or red colorants.

9. The dental etching composition of claim 1, comprising A) the acid in an amount of 10% to 45% by weight, B) water in an amount of 30% to 60% by weight, C) the urethane-urea compounds in an amount of 5% to 20% by weight, D) a water-miscible solvent in an amount of 0% to 20% by weight, and E) a colorant in an amount of 0% to 5% by weight, based in each case on the overall composition.

10. The dental etching composition of claim 1, wherein the composition is essentially free of fumed silica, and/or wherein the composition does not contain any further constituents apart from (A) the acid, (B) water, (C) the urethane-urea compounds, (D) a water-miscible solvent, and (E) a colorant.

11. The dental etching composition of claim 1, wherein the composition has a loss factor tan δ of less than 1 and/or a viscosity in the range from 0.1 to 200 Pa*s.

12. A method for etching of the hard substance of a tooth, the method comprising etching the hard substance of the tooth with the dental etching composition of claim 1.

13. The method of claim 12, comprising the steps of i) optionally desiccating the tooth to be treated, ii) applying the dental etching composition of claim 1 to the hard substance of the tooth to be treated, iii) allowing a contact time of the dental etching composition to achieve an etching effect on the hard substance of the tooth, iv) rinsing off the dental etching composition, v) applying a dental primer composition and/or adhesive composition to the etched hard substance of the tooth, vi) optionally polymerizing the dental primer composition and/or adhesive composition, vii) applying a dental restoration composition and viii) polymerizing the dental restoration composition.

14. The method of claim 13, wherein the hard substance of the tooth is etched in the course of filling treatment.

15. A kit comprising: the dental etching composition of claim 1, a dental primer composition and/or adhesive composition, and optionally a dental restoration composition.

16. The dental etching composition of claim 4, wherein: R.sup.1 is an n-alkyl radical having 4 to 10 carbon atoms; R.sup.2 is ##STR00008##  and x is an integer from 1 to 10.

17. The dental etching composition of claim 9, comprising: A) the acid in an amount of 30% to 42% by weight, B) water in an amount of 40% to 60% by weight, C) the urethane-urea compounds in an amount of 5% to 15% by weight, D) the water-miscible solvent in an amount of 1% to 15% by weight, and E) the colorant in an amount of 0.0001% to 1% by weight, based in each case on the overall composition.

18. The dental etching composition of claim 10, wherein the composition is essentially free of silica particles and inorganic solids.

19. The dental etching composition of claim 11, wherein the composition has a viscosity in the range from 1 to 50 Pa*s.

20. The dental etching composition of claim 11, wherein after storage at 23° C. for 6 months, the composition has a loss factor tan δ of less than 1 and/or a viscosity in the range from 0.1 to 200 Pa*s.

Description

DETAILED DESCRIPTION OF THE DISCLOSURE

[0082] The present invention relates to a dental etching composition comprising phosphoric acid, water and urethane-urea compound(s), to the use of said dental etching composition for etching the hard substance of the tooth, to a dental etching composition for use in a therapeutic method of etching the hard substance of the tooth in the course of filling treatment, and to a kit comprising a dental etching composition.

[0083] It has been found in accordance with the invention that, surprisingly, it is possible to obtain storage-stable, silica-free, highly effective etching gels when these include particular types of urethane-urea compounds as thickeners.

[0084] More particularly, the object is achieved by a dental etching composition comprising [0085] A) an acid selected from the group consisting of phosphoric acid, hydrochloric acid, hydrofluoric acid, maleic acid and citric acid, [0086] B) water, and [0087] C) one or more urethane-urea compounds.

[0088] The acid (A) is preferably phosphoric acid or hydrochloric acid, more preferably phosphoric acid.

[0089] Suitable urethane-urea compounds (C) and the syntheses thereof are described in patent specifications EP 0 006 252 B1, EP 1 048 681 B1, EP 1 188 779 B1, EP 1 396 510 B1, EP 2 370 489 B1, EP 2 475 699 B1 and EP 3 328 909 B1, which are herein incorporated by reference.

[0090] In a preferred embodiment, the urethane-urea compounds (C) conform to the formula

R.sup.1—O—C(═O)—NH—R.sup.2—NH—C(═O)[—NH—R.sup.3—NH—C(═O)—NH—R.sup.2—NH—C(═O)].sub.x—OR.sup.1

in which [0091] R.sup.1 is an n-alkyl radical having 4 to 22 carbon atoms, a branched alkyl radical having 4 to 22 carbon atoms, an alkenyl radical having 3 to 18 carbon atoms, a cycloalkyl radical having 3 to 20 carbon atoms, an aryl radical having 6 to 12 carbon atoms, an arylalkyl radical having 7 to 12 carbon atoms, a radical of the formula C.sub.mH.sub.2m+1(O—C.sub.nH.sub.2n).sub.p—, C.sub.mH.sub.2m+1(OOC—C.sub.2H.sub.2v).sub.p—, or R.sup.5—C.sub.6H.sub.4(O—C.sub.nH.sub.2n).sub.p—, wherein m=1 to 22, n=2 to 4, p=1 to 15, v=4 or 5, and R.sup.5 is an alkyl radical having 1 to 12 carbon atoms, and where different R.sup.1 radicals may be the same or different, [0092] R.sup.2 is a branched or unbranched alkylene radical having 4 to 22 carbon atoms, alkenylene radical having 3 to 18 carbon atoms, alkynylene radical having 2 to 20 carbon atoms, cycloalkylene radical having 3 to 20 carbon atoms, cycloalkenylene radical having 3 to 20 carbon atoms, arylene radical having 6 to 12 carbon atoms, or arylalkylene radical having 7 to 14 carbon atoms, where different R.sup.2 radicals may be the same or different, [0093] R.sup.3 is

##STR00001## [0094] with R.sup.4=CH.sub.3 or H, where different R.sup.3 radicals may be the same or different, and [0095] x is an integer from 1 to 100.

[0096] In a particularly preferred embodiment, [0097] R.sup.1 is an n-alkyl radical having 4 to 10 carbon atoms, a branched alkyl radical having 4 to 10 carbon atoms, an alkenyl radical having 3 to 10 carbon atoms, a cycloalkyl radical having 3 to 10 carbon atoms, an aryl radical having 6 to 12 carbon atoms, an arylalkyl radical having 7 to 12 carbon atoms, a radical of the formula C.sub.mH.sub.2m+1(O—C.sub.nH.sub.2n).sub.p—, C.sub.mH.sub.2m+1(OOC—C.sub.vH.sub.2v).sub.p— or R.sup.5—C.sub.6H.sub.4(O—C.sub.nH.sub.2n).sub.p—, wherein m=1 to 10, n=2 to 4, p=1 to 15, v=4 or 5, and R.sup.5 is an alkyl radical having 1 to 12 carbon atoms, preferably an n-alkyl radical having 4 to 10 carbon atoms, a branched alkyl radical having 4 to 10 carbon atoms, a radical of the formula C.sub.mH.sub.2m+1(O—C.sub.nH.sub.2n).sub.p— or C.sub.mH.sub.2m+1(OOC—C.sub.vH.sub.2v).sub.p—, wherein m=1 to 10, n=2 to 4, p=1 to 15 and v=4 or 5, where different R.sup.1 radicals may be the same or different, [0098] R.sup.2 is

##STR00002##  or —(CH.sub.2).sub.w—, wherein w=2 to 10, preferably

##STR00003##  where different R.sup.2 radicals may the same or different, [0099] R.sup.3 is

##STR00004##  where different R.sup.3 radicals may the same or different, and [0100] x is an integer from 1 to 20, preferably 1 to 10.

[0101] In the synthesis of the urethane-urea compounds (C), an alcohol is advantageously first reacted with a diisocyanate to give a monoadduct.

R.sup.1—OH+OCN—R.sup.2—NCO.fwdarw.R.sup.1—O—C(═O)—NH—R.sup.2—NCO

[0102] The reaction is preferably effected in the absence of solvents. In order to arrive at the monoisocyanate adduct to a maximum degree, it is advantageous to work with a 1.5- to 5-fold excess of diisocyanate, which can be distilled off again on completion of reaction.

[0103] The monoadduct is then reacted with a diamine to give urethane-urea compounds (C).

2R.sup.1—O—C(═O)—NH—R.sup.2—NCO+H.sub.2N—R.sup.3—NH.sub.2.fwdarw.

R.sup.1—O—C(═O)—NH—R.sup.2—NH—C(═O)—NH—R.sup.3—NH—C(═O)—NH—R.sup.2—NH—C(═O)—OR.sup.1

[0104] If excess diisocyanate is still present, what are obtained are urethane-urea compounds of higher molecular weight.

2R.sup.1—O—C(═O)—NH—R.sup.2—NCO+(x−1)OCN—R.sup.2—NCO+xH.sub.2N—R.sup.3—NH.sub.2.fwdarw.

R.sup.1—O—C(═O)—NH—R.sup.2—NH—C(═O)[—NH—R.sup.3—NH—C(═O)—NH—R.sup.2—NH—C(═O)].sub.x—OR.sup.1

[0105] This reaction is preferably effected in aprotic solvents, preferably in DMSO, and can advantageously be conducted in the presence of lithium salts, preferably lithium chloride. The proportion of the urethane-urea compounds in the solution is preferably 10% to 75% by weight, preferably 40% to 60% by weight.

[0106] In a preferred embodiment, the dental etching composition additionally comprises one or more water-miscible solvents (D).

[0107] The water-miscible solvents (D) are preferably selected from the group consisting of ethanol, propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, 2-methylpropan-1-ol, 2-methylpropan-2-ol, glycerol, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, 2-butoxyethan-1-ol, DMSO and acetone, and preferably selected from the group consisting of ethanol, propan-1-ol, propan-2-ol, glycerol, polyethylene glycol, polypropylene glycol and DMSO.

[0108] In a preferred embodiment, the dental etching composition additionally comprises colorants (E).

[0109] The colorants (E) are preferably selected from the group consisting of dyes, organic color pigments and inorganic color pigments, preferably from dyes, more preferably from phenothiazine dyes,

and/or
the colorants (E) are blue, green or red, preferably blue, colorants.

[0110] In a preferred embodiment, the dental etching composition comprises [0111] A) the acid in an amount of 10% to 45% by weight, preferably of 30% to 42% by weight, [0112] B) water in an amount of 30% to 60% by weight, preferably of 40% to 60% by weight, [0113] C) the one or more urethane-urea compounds in an amount of 5% to 20% by weight, preferably of 5% to 15% by weight, [0114] D) water miscible solvent(s) in an amount of 0% to 20% by weight, preferably of 1% to 15% by weight, and [0115] E) colorants in an amount of 0% to 5% by weight, preferably of 0.0001% to 1% by weight, [0116] based in each case on the overall composition.

[0117] Since the presence of inorganic solids, especially silica as in the prior art, has the disadvantages described above, the dental etching composition in a particular embodiment is essentially free of fumed silica, preferably essentially free of silica particles, more preferably essentially free of inorganic solids.

[0118] What is meant by essentially free is that, within the scope of the industrial preparation options, the content of fumed silica, silica particles or inorganic solids is so low that the adverse effects described do not occur. What is preferably meant by essentially free is therefore a content of fumed silica, silica particles or inorganic solids of less than 1% by weight, preferably less than 0.5% by weight, more preferably less than 0.1% by weight, based in each case on the overall composition. Very particular preference is given to compositions containing no fumed silica, silica particles or inorganic solids at all. Inorganic solids are not considered to include dissolved inorganic substances, especially the lithium salts used in the synthesis of the urethane-urea compounds.

[0119] In a preferred embodiment, the dental etching composition does not contain any further constituents apart from constituents (A), (B), (C), (D) and (E).

[0120] The dental etching compositions according to the invention are notable for their gel character and for their optimal viscosity for application. More particularly, the dental etching compositions have a loss factor tan δ of less than 1 and/or a viscosity in the range from 0.1 to 200 Pa*s, preferably from 0.5 to 150 Pa*s, more preferably from 1 to 100 Pa*s, most preferably from 1 to 50 Pa*s.

[0121] The values of tan δ and viscosity are based on the test method detailed in the description further down and are applicable both to the evaluation point at the end of phase I and to the evaluation point at the end of phase IV.

[0122] The dental etching compositions of the invention are additionally also notable for their good storage stability. Thus, the gel character and the optimal viscosity for application are largely maintained even during storage. More particularly, the dental etching compositions preferably, even after storage at 23° C. for 6 months, have a loss factor tan δ of less than 1 and/or a viscosity in the range of 0.1 to 200 Pa*s, preferably of 0.5 to 150 Pa*s, more preferably of 1 to 100 Pa*s, most preferably of 1 to 50 Pa*s.

[0123] More preferably, the dental etching compositions, even after storage at 23° C. for 12 months, preferably at 23° C. to 18 months, more preferably at 23° C. for 24 months, have a loss factor tan δ of less than 1 and/or a viscosity in the range of 0.1 to 200 Pa*s, preferably of 0.5 to 150 Pa*s, more preferably of 1 to 100 Pa*s, most preferably of 1 to 50 Pa*s,

and/or
after storage at 37° C. for 6 months, preferably at 37° C. for 12 months, have a loss factor tan δ of less than 1 and/or a viscosity in the range of 0.1 to 200 Pa*s, preferably of 0.5 to 150 Pa*s, more preferably of 1 to 100 Pa*s, most preferably of 1 to 50 Pa*s,
and/or
after storage at 23° C. for 12 months, preferably at 23° C. for 18 months, more preferably at 23° C. for 24 months, have a viscosity that varies from the viscosity prior to storage by not more than ±50%, preferably by not more than ±35%, more preferably by not more than ±20%.

[0124] A further aspect of the present invention is the use of a dental etching composition as described above for etching of the hard substance of the tooth.

[0125] In a preferred embodiment, this use comprises the steps of [0126] i) optionally desiccating the teeth (or tooth) to be treated, preferably with a dental dam, [0127] ii) applying the dental etching composition to the hard substance of the tooth to be treated, [0128] iii) allowing a contact time of the dental etching composition to achieve an etching effect on the hard substance of the tooth, [0129] iv) rinsing off the dental etching composition, [0130] v) applying a dental primer composition and/or adhesive composition to the etched hard substance of the tooth, [0131] vi) optionally polymerizing the dental primer composition and/or adhesive composition, [0132] vii) applying a dental restoration composition and [0133] viii) polymerizing the dental restoration composition.

[0134] The above elucidations relating to the preferred dental etching compositions are likewise applicable to the use thereof.

[0135] A further aspect of the present invention is a dental etching composition as described above for use in a therapeutic method of etching the hard substance of the tooth in the course of filling treatment.

[0136] In a preferred embodiment, this is a dental etching composition as described above for use in a therapeutic method comprising the steps of [0137] i) optionally desiccating the teeth (or tooth) to be treated, preferably with a dental dam, [0138] ii) applying a dental etching composition as described herein to the hard substance of the tooth to be treated, [0139] iii) allowing a contact time of the dental etching composition to achieve an etching effect on the hard substance of the tooth, [0140] iv) rinsing off the dental etching composition, [0141] v) applying a dental primer composition and/or adhesive composition to the etched hard substance of the tooth, [0142] vi) optionally polymerizing the dental primer composition and/or adhesive composition, [0143] vii) applying a dental restoration composition and [0144] viii) polymerizing the dental restoration composition.

[0145] The above elucidations relating to the preferred dental etching compositions are likewise applicable to use thereof in a therapeutic method.

[0146] A further aspect of the present invention is a kit comprising

[0147] a dental etching composition as described above,

[0148] a dental primer composition and/or adhesive composition and

[0149] optionally a dental restoration composition.

[0150] The above elucidations relating to the preferred dental etching compositions are likewise applicable to a kit comprising said etching composition.

[0151] Where particular configurations are described as preferred for any aspect of the invention (composition; use; use in a therapeutic method or kit), the corresponding details are respectively also applicable to the other aspects of the present invention, mutatis mutandis. Preferred individual features of aspects of the invention (as defined in the claims and/or disclosed in the description) are combinable with one another and are preferably combined with one another unless the opposite is apparent to the person skilled in the art from the present text in the individual case.

EXAMPLES

Example 1A

[0152] To 1.5 mol (261.3 g) of tolylene 2,4-diisocyanate was slowly added dropwise, over the course of 2 hours, 0.5 mol (37.1 g) of 1-butanol. During this addition, the temperature was kept between 50 and 55° C. After the addition had ended, stirring was continued at 50 to 55° C. for a further 3 hours until the theoretical NCO content of 35.2% had been attained. The excess of the diisocyanate was distilled off under reduced pressure (0.1 mbar) at 150 to 170° C. The NCO content was 16.9%, the free TDI content <0.5%.

Example 1B

[0153] To 1.5 mol (261.3 g) of tolylene 2,4-diisocyanate was slowly added dropwise, over the course of 2 hours, 0.5 mol (103.1 g) of triethylene glycol mono-n-butyl ether. During this addition, the temperature was kept between 50 and 55° C. After the addition had ended, stirring was continued at 50 to 55° C. for a further 3 hours until the theoretical NCO content of 28.8% had been attained. The excess of the diisocyanate was distilled off under reduced pressure (0.1 mbar) at 150 to 170° C. The NCO content was 11.0%, the free TDI content <0.5%.

Example 1C

[0154] To 1.5 mol (261.3 g) of tolylene 2,4-diisocyanate was slowly added dropwise, over the course of 2 hours, 0.5 mol (175.0 g) of methoxy polyethylene glycol (MW 350). During this addition, the temperature was kept between 50 and 55° C. After the addition had ended, stirring was continued at 50 to 55° C. for a further 3 hours until the theoretical NCO content of 24.1% had been attained. The excess of the diisocyanate was distilled off under reduced pressure (0.1 mbar) at 150 to 170° C. The NCO content was 8.0%, the free TDI content <0.5%.

Example 1D

[0155] To 1.5 mol (261.3 g) of tolylene 2,4-diisocyanate was slowly added dropwise, over the course of 2 hours, 0.5 mol (275.0 g) of methoxy polyethylene glycol (MW 550). During this addition, the temperature was kept between 50 and 55° C. After the addition had ended, stirring was continued at 50 to 55° C. for a further 3 hours until the theoretical NCO content of 19.6% had been attained. The excess of the diisocyanate was distilled off under reduced pressure (0.1 mbar) at 150 to 170° C. The NCO content was 5.8%, the free TDI content <0.5%.

Example 1E

[0156] To 2.0 mol (348.1 g) of tolylene 2,4-diisocyanate was slowly added dropwise, over the course of 2 hours, 0.5 mol (175.0 g) of methoxy polyethylene glycol (MW 350). During this addition, the temperature was kept between 50 and 55° C. After the addition had ended, stirring was continued at 50 to 55° C. for a further 3 hours until the theoretical NCO content of 28.1% had been attained. The excess of the diisocyanate was distilled off under reduced pressure (0.1 mbar) at 150 to 170° C. The NCO content was 8.0%, the free TDI content <0.5%.

Example 1F

[0157] To 1.0 mol (174.2 g) of tolylene 2,4-diisocyanate was slowly added dropwise, over the course of 2 hours, 0.5 mol (175.0 g) of methoxy polyethylene glycol (MW 350). During this addition, the temperature was kept between 50 and 55° C. After the addition had ended, stirring was continued at 50 to 55° C. for a further 3 hours until the theoretical NCO content of 18.0% had been attained. The excess of the diisocyanate was distilled off under reduced pressure (0.1 mbar) at 150 to 170° C. The NCO content was 8.0%, the free TDI content <0.5%.

Example 1G

[0158] To 1.5 mol (375.4 g) of diphenylmethane 4,4′-diisocyanate was slowly added dropwise, over the course of 2 hours, 0.5 mol (37.1 g) of 1-butanol. During this addition, the temperature was kept between 50 and 55° C. After the addition had ended, stirring was continued at 50 to 55° C. for a further 3 hours until the theoretical NCO content of 25.5% had been attained. The excess of the diisocyanate was distilled off under reduced pressure (0.1 mbar) at 150 to 170° C.

[0159] The NCO content was 13.0%, the free MDI content <0.5%.

Example 1H

[0160] To 1.5 mol (252.3 g) of hexamethylene 1,6-diisocyanate was slowly added dropwise, over the course of 2 hours, 0.5 mol (37.1 g) of 1-butanol. During this addition, the temperature was kept between 50 and 55° C. After the addition had ended, stirring was continued at 50 to 55° C. for a further 3 hours until the theoretical NCO content of 36.3% had been attained. The excess of the diisocyanate was distilled off under reduced pressure (0.1 mbar) at 150 to 170° C. The NCO content was 17.3%, the free HMDI content <0.5%.

TABLE-US-00001 TABLE 1A Examples 1A to 1D Example 1A 1B 1C 1D Diisocyanate Tolylene Tolylene Tolylene Tolylene 2,4- 2,4- 2,4- 2,4- diisocyanate diisocyanate diisocyanate diisocyanate Alcohol 1-Butanol Triethylene Methoxy Methoxy glycol mono- polyethylene polyethylene butyl ether glycol 350 glycol 550 Diisocyanate/ 3:1 3:1 3:1 3:1 alcohol ratio NCO content 16.9% 11.0% 8.0% 5.8%

TABLE-US-00002 TABLE 1B Examples 1E to 1H Example 1E 1F 1G 1H Diisocyanate Tolylene Tolylene Diphenyl- Hexa- 2,4- 2,4- methane methylene diisocyanate diisocyanate 4,4′- 1,6- diisocyanate diisocyanate Alcohol Methoxy Methoxy 1-Butanol 1-Butanol polyethylene polyethylene glycol 350 glycol 350 Diisocyanate/ 4:1 2:1 3:1 3:1 alcohol ratio NCO content 8.0% 8.0% 13.0% 17.3%

Example 2A

[0161] 17.0 g (0.4 mol) of lithium chloride and 34.1 g (0.25 mol) of xylylene-1,3-diamine were dissolved in 175 g of DMSO at 80° C. Subsequently, over the course of one hour, 124.2 g of example 1A was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 50%.

Example 2B

[0162] 17.0 g (0.4 mol) of lithium chloride and 34.1 g (0.25 mol) of xylylene-1,3-diamine were dissolved in 224 g of DMSO at 80° C. Subsequently, over the course of one hour, 190.2 g of example 1B was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 50%.

Example 2C

[0163] 17.0 g (0.4 mol) of lithium chloride and 34.1 g (0.25 mol) of xylylene-1,3-diamine were dissolved in 313 g of DMSO at 80° C. Subsequently, over the course of one hour, 262.1 g of example 1C was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 50%.

Example 2D

[0164] 17.0 g (0.4 mol) of lithium chloride and 34.1 g (0.25 mol) of xylylene-1,3-diamine were dissolved in 413 g of DMSO at 80° C. Subsequently, over the course of one hour, 362.1 g of example 1D was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 50%.

Example 2E

[0165] 17.0 g (0.4 mol) of lithium chloride and 34.1 g (0.25 mol) of xylylene-1,3-diamine were dissolved in 313 g of DMSO at 80° C. Subsequently, over the course of one hour, 262.1 g of example 1E was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 50%.

Example 2F

[0166] 17.0 g (0.4 mol) of lithium chloride and 34.1 g (0.25 mol) of xylylene-1,3-diamine were dissolved in 313 g of DMSO at 80° C. Subsequently, over the course of one hour, 262.1 g of example 1F was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 50%.

Example 2G

[0167] 17.0 g (0.4 mol) of lithium chloride and 34.1 g (0.25 mol) of xylylene-1,3-diamine were dissolved in 213 g of DMSO at 80° C. Subsequently, over the course of one hour, 162.2 g of example 1G was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 50%.

Example 2H

[0168] 17.0 g (0.4 mol) of lithium chloride and 34.1 g (0.25 mol) of xylylene-1,3-diamine were dissolved in 172 g of DMSO at 80° C. Subsequently, over the course of one hour, 121.2 g of example 1H was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 50%.

Example 2I

[0169] 17.0 g (0.4 mol) of lithium chloride and 34.1 g (0.25 mol) of xylylene-1,2-diamine were dissolved in 313 g of DMSO at 80° C. Subsequently, over the course of one hour, 262.1 g of example 1C was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 50%.

Example 2J

[0170] 17.0 g (0.4 mol) of lithium chloride and 34.1 g (0.25 mol) of xylylene-1,4-diamine were dissolved in 313 g of DMSO at 80° C. Subsequently, over the course of one hour, 262.1 g of example 1C was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 50%.

Example 2K

[0171] 17.0 g (0.4 mol) of lithium chloride and 35.6 g (0.25 mol) of 1,3-bis(aminomethyl)cyclohexane were dissolved in 315 g of DMSO at 80° C. Subsequently, over the course of one hour, 262.1 g of example 1C was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 50%.

Example 2L

[0172] 27.6 g (0.4 mol) of lithium nitrate and 34.1 g (0.25 mol) of xylylene-1,3-diamine were dissolved in 324 g of DMSO at 80° C. Subsequently, over the course of one hour, 262.1 g of example 1C was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 50%.

Example 2M

[0173] 17.0 g (0.4 mol) of lithium chloride and 34.1 g (0.25 mol) of xylylene-1,3-diamine were dissolved in 209 g of DMSO at 80° C. Subsequently, over the course of one hour, 262.1 g of example 1C was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 40%.

Example 2N

[0174] 17.0 g (0.4 mol) of lithium chloride and 34.1 g (0.25 mol) of xylylene-1,3-diamine were dissolved in 470 g of DMSO at 80° C. Subsequently, over the course of one hour, 262.1 g of example 1C was added. On completion of addition, the mixture was stirred at 80° C. for a further 30 minutes and then cooled down to room temperature. The proportion of dissolved solids in the resultant urethane-urea solution was 60%.

TABLE-US-00003 TABLE 2A Examples 2A to 2D Example 2A 2B 2C 2D Monoadduct 1A 1B 1C 1D Diamine Xylylene- Xylylene- Xylylene- Xylylene- 1,3- 1,3- 1,3- 1,3- diamine diamine diamine diamine Li salt LiCl LiCl LiCl LiCl Solids content 50% 50% 50% 50%

TABLE-US-00004 TABLE 2B Examples 2E to 2H Example 2E 2F 2G 2H Monoadduct 1E 1F 1G 1H Diamine Xylylene- Xylylene- Xylylene- Xylylene- 1,3- 1,3- 1,3- 1,3- diamine diamine diamine diamine Li salt LiCl LiCl LiCl LiCl Solids content 50% 50% 50% 50%

TABLE-US-00005 TABLE 2C Examples 21 to 2L Example 2I 2J 2K 2L Monoadduct 1C 1C 1C 1C Diamine Xylylene- Xylylene- 1,3-Bis(amino- Xylylene- 1,2- 1,4- methyl)cyclo- 1,3- diamin diamin hexane diamine Li salt LiCl LiCl LiCl LiNO.sub.3 Solids content 50% 50% 50% 50%

TABLE-US-00006 TABLE 2D Examples 2M to 2N Example 2M 2N Monoadduct 1C 1C Diamine Xylylene- Xylylene- 1,3- 1,3- diamine diamine Li salt LiCl LiCl Solids content 40% 60%

Example 3A

[0175] In a beaker, 41.2 g of 85% phosphoric acid and 1.0 g of PEG-400 and 0.01 g of methylene blue were dissolved in 39.4 g of demineralized water while stirring. Subsequently, 18.4 g of the DMSO solution from example 2A was added in portions while stirring and the mixture was stirred at room temperature for a further 30 minutes.

Examples 3B to 3N

[0176] Analogously to example 3A, etching gels 3B to 3N were produced using, rather than the DMSO solution from example 2A, the DMSO solutions from examples 2B to 2N.

Example 3O

[0177] In a beaker, 41.2 g of 85% phosphoric acid and 1.0 g of glycerol and 0.01 g of methylene blue were dissolved in 39.4 g of demineralized water while stirring. Subsequently, 18.4 g of the DMSO solution from example 2A was added in portions while stirring and the mixture was stirred at room temperature for a further 30 minutes.

Example 3P

[0178] In a beaker, 41.2 g of 85% phosphoric acid and 2.0 g of ethanol and 0.01 g of methylene blue were dissolved in 38.4 g of demineralized water while stirring. Subsequently, 18.4 g of the DMSO solution from example 2A was added in portions while stirring and the mixture was stirred at room temperature for a further 30 minutes.

Example 3Q

[0179] In a beaker, 41.2 g of 85% phosphoric acid and 0.01 g of methylene blue were dissolved in 40.4 g of demineralized water while stirring. Subsequently, 18.4 g of the DMSO solution from example 2A was added in portions while stirring and the mixture was stirred at room temperature for a further 30 minutes.

Example 3R

[0180] In a beaker, 41.2 g of 85% phosphoric acid, 2.5 g of PEG-400, 4.5 g of glycerol and 0.01 g of methylene blue were dissolved in 39.4 g of demineralized water while stirring. Subsequently, 12.4 g of the DMSO solution from example 2A was added in portions while stirring and the mixture was stirred at room temperature for a further 30 minutes.

Example 3S

[0181] In a beaker, 41.2 g of 85% phosphoric acid, 1.0 g of PEG-400 and 1.5 g of glycerol and 0.01 g of methylene blue were dissolved in 41.3 g of demineralized water while stirring. Subsequently, 15.0 g of the DMSO solution from example 2A was added in portions while stirring and the mixture was stirred at room temperature for a further 30 minutes.

Example 3T

[0182] In a beaker, 41.2 g of 85% phosphoric acid and 1.0 g of glycerol and 0.01 g of methylene blue were dissolved in 36.8 g of demineralized water while stirring. Subsequently, 22.0 g of the DMSO solution from example 2A was added in portions while stirring and the mixture was stirred at room temperature for a further 30 minutes.

Example 3U

[0183] In a beaker, 41.2 g of 85% phosphoric acid and 0.5 g of glycerol and 0.01 g of methylene blue were dissolved in 33.9 g of demineralized water while stirring. Subsequently, 24.4 g of the DMSO solution from example 2A was added in portions while stirring and the mixture was stirred at room temperature for a further 30 minutes.

TABLE-US-00007 TABLE 3A Examples 3A to 3Q 3A to 3N 3O 3P 3Q (A)*.sup.1 H.sub.3PO.sub.4*.sup.1 35.02 35.02 35.02 35.02 (B)*.sup.2 Water*.sup.2 45.57 45.57 44.57 46.57 (C)*.sup.3 Urethane-urea 9.20 9.20 9.20 9.20 compound*.sup.3 (D)*.sup.4 PEG-400 1.00 Glycerol 1.00 Ethanol 2.00 DMSO*.sup.4 9.20 9.20 9.20 9.20 (E) Methylene blue 0.01 0.01 0.01 0.01 Total 100.00 100.00 100.00 100.00 *.sup.1Since 85% phosphoric acid was used in the examples, only the actual proportion of phosphoric acid is stated here under (A). *.sup.2As well as the water used, the water content from the phosphoric acid is also stated under (B). *.sup.3Since Examples 2 are a solution of the urethane-urea compound, only the actual proportion of the urethane-urea compound is stated under (C). *.sup.4As well as any further water-miscible solvents, the proportion of the solvent in the solution of the urethane-urea compound is also stated under (D).

TABLE-US-00008 TABLE 3B Examples 3R to 3U 3R 3S 3T 3U (A)*.sup.1 H.sub.3PO.sub.4*.sup.1 35.02 35.02 35.02 35.02 (B)*.sup.2 Water*.sup.2 45.57 47.47 41.97 40.07 (C)*.sup.3 Urethane-urea 6.20 7.50 11.00 12.20 compound*.sup.3 (D)*.sup.4 PEG-400 2.50 1.00 Glycerol 4.50 1.50 1.00 0.50 DM SO*.sup.4 6.20 7.50 11.00 12.20 (E) Methylene blue 0.01 0.01 0.01 0.01 Total 100.00 100.00 100.00 100.00 *.sup.1Since 85% phosphoric acid was used in the examples, only the actual proportion of phosphoric acid is stated here under (A). *.sup.2As well as the water used, the water content from the phosphoric acid is also stated under (B). *.sup.3Since Examples 2 are a solution of the urethane-urea compound, only the actual proportion of the urethane-urea compound is stated under (C). *.sup.4As well as any further water-miscible solvents, the proportion of the solvent in the solution of the urethane-urea compound is also stated under (D).

Comparative Example 4A

[0184] In a beaker, 10.0 g of gum arabic and 0.01 g of methylene blue were dissolved in 48.8 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. No thickening effect occurred. The solution was of low viscosity.

Comparative Example 4B

[0185] In a beaker, 20.0 g of gum arabic and 0.01 g of methylene blue were dissolved in 38.8 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. No thickening effect occurred. The solution was of low viscosity.

Comparative Example 4C

[0186] In a beaker, 2.0 g of xanthan gum and 0.01 g of methylene blue were dissolved in 56.8 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. The viscosity was 3.0 Pa*s. During storage at 23° C., there was a gradual rise in viscosity over the course of 6 months to 4.2 Pa*s. Even after a storage time of one month at 23° C., distinct formation of gas occurred.

Comparative Example 4D

[0187] In a beaker, 5.0 g of xanthan gum and 0.01 g of methylene blue were dissolved in 53.8 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. The viscosity was 6.0 Pa*s. During storage at 23° C., there was a gradual rise in viscosity over the course of 6 months to 8.3 Pa*s. Even after a storage time of one month at 23° C., distinct formation of gas occurred.

Comparative Example 4E

[0188] In a beaker, 10.0 g of polyvinylalcohol and 0.01 g of methylene blue were dissolved in 48.8 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. Barely any thickening effect occurred. The solution was of low viscosity.

Comparative Example 4F

[0189] In a beaker, 20.0 g of polyvinylalcohol and 0.01 g of methylene blue were dissolved in 38.8 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. Barely any thickening effect occurred. The solution was of low viscosity.

Comparative Example 4G

[0190] In a beaker, 30.0 g of polyvinylalcohol and 0.01 g of methylene blue were dissolved in 28.8 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. The viscosity was 10.0 Pa*s. The material did not have good applicability to the prepared tooth surface. It become fluid as a result of the movement on application and flowed off the tooth.

Comparative Example 4H

[0191] In a beaker, 2.5 g of hydroxyethyl cellulose and 0.01 g of methylene blue were dissolved in 56.3 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. Only a minor thickening effect occurred. The solution was of relatively low viscosity.

Comparative Example 4I

[0192] In a beaker, 5.0 g of hydroxyethyl cellulose and 0.01 g of methylene blue were dissolved in 53.8 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. The viscosity was 6.5 Pa*s. During storage at 23° C., the viscosity already decreased to 2.5 Pa*s within one month.

Comparative Example 4J

[0193] In a beaker, 20.0 g of glycerol and 0.01 g of methylene blue were dissolved in 38.8 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. No thickening effect occurred. The solution was of low viscosity.

Comparative Example 4K

[0194] In a beaker, 40.0 g of glycerol and 0.01 g of methylene blue were dissolved in 18.8 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. No thickening effect occurred. The solution was of low viscosity.

Comparative Example 4L

[0195] In a beaker, 0.01 g of methylene blue was dissolved in 58.8 g of glycerol while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. No thickening effect occurred. The solution was of low viscosity.

Comparative Example 4M

[0196] In a beaker, 2.5 g of carboxymethyl cellulose and 0.01 g of methylene blue were dissolved in 56.3 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. The viscosity was 2.5 Pa*s, but decreased noticeably during storage, and the gel become more fluid.

Comparative Example 4N

[0197] In a beaker, 5.0 g of carboxymethyl cellulose and 0.01 g of methylene blue were dissolved in 53.8 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring and the mixture was stirred at room temperature for a further 30 minutes. The viscosity was 8.2 Pa*s, but decreased noticeably during storage, and the gel become more fluid.

Comparative Example 4O

[0198] In a beaker, 0.01 g of methylene blue was dissolved in 58.8 g of demineralized water while stirring. Subsequently, 41.2 g of 85% phosphoric acid was added while stirring. Subsequently, 5.0 g of Aerosil A200 was added and dispersed with an Ultra Turrax for 5 minutes. The viscosity was 10.4 Pa*s, but increased noticeably during storage, and the gel thickened.

Comparative Example 4P

[0199] In a beaker, 0.01 g of methylene blue was dissolved in 8.8 g of demineralized water while stirring. Subsequently, first 50.0 g of Snowtex ST-O (20% colloidal silica in water; particle size 10-20 nm) and then 41.2 g of 85% phosphoric acid were added while stirring and the mixture was stirred at room temperature for a further 30 minutes. The viscosity was 8.8 Pa*s, but increased noticeably during storage, and the gel thickened.

TABLE-US-00009 TABLE 4A Comparative Examples 4A to 4D 4A 4B 4C 4D (A)*.sup.1 H.sub.3PO.sub.4*.sup.1 35.02 35.02 35.02 35.02 (B)*.sup.2 Water*.sup.2 54.97 44.97 62.97 59.97 (X) Gum arabic 10.00 20.00 Xanthan gum 2.00 5.00 (E) Methylene blue 0.01 0.01 0.01 0.01 Total 100.00 100.00 100.00 100.00

TABLE-US-00010 TABLE 4B Comparative Examples 4E to 4H 4E 4F 4G 4H (A)*.sup.1 H.sub.3PO.sub.4*.sup.1 35.02 35.02 35.02 35.02 (B)*.sup.2 Water*.sup.2 54.97 44.97 34.97 62.47 (X) Polyvinylalcohol 10.00 20.00 30.00 Hydroxyethyl 2.50 cellulose (E) Methylene blue 0.01 0.01 0.01 0.01 Total 100.00 100.00 100.00 100.00

TABLE-US-00011 TABLE 4C Comparative Examples 4I to 4L 4I 4J 4K 4L (A)*.sup.1 H.sub.3PO.sub.4*.sup.1 35.02 35.02 35.02 35.02 (B)*.sup.2 Water*.sup.2 59.97 44.97 24.97 6.18 (X) Hydroxyethyl 5.00 cellulose (D) Glycerol 20.00 40.00 58.79 (E) Methylene blue 0.01 0.01 0.01 0.01 Total 100.00 100.00 100.00 100.00

TABLE-US-00012 TABLE 4D Comparative Examples 4M to 4P 4M 4N 4O 4P (A)*.sup.1 H.sub.3PO.sub.4*.sup.1 35.02 35.02 35.02 35.02 (B)*.sup.2, 5 Water*.sup.2, 5 62.47 59.97 59.97 54.97 (X) Carboxymethyl 2.50 5.00 cellulose Fumed silica 5.00 Colloidal silica*.sup.6 10.00 (E) Methylene blue 0.01 0.01 0.01 0.01 Total 100.00 100.00 100.00 100.00
*.sup.1 Since 85% phosphoric acid was used in the examples, only the actual proportion of phosphoric acid is stated here under (A).
*.sup.2 As well as the water used, the water content from the phosphoric acid is also stated under (B).
*.sup.5 When the aqueous dispersion of colloidal silica is used, the water content from the dispersion is also stated under (B).
*.sup.6 For the colloidal silica, only the SiO.sub.2 content is stated under (X).

Shear Bond Strength:

[0200] The tests for shear bond strength were conducted in accordance with ISO 29022:2013. Bovine front teeth were embedded in an epoxy matrix in the form of a cylinder having diameter d=2.5 cm, then the enamel or dentine surface was exposed. The surface of the teeth was standardized by coarse grinding with abrasive paper of P120 grit (125±1 μm) and then fine grinding with abrasive paper of P400 grit (35±1 μm). The tooth surface thus prepared was freed of impurities under flowing deionized water and then freed of excess water by a gentle/briefly applied jet of oil- and water-free compressed air immediately prior to the application of the etchant. The teeth must not be overdried in order to prevent morphological changes in the hard substance of the tooth. The etchant was applied directly from the syringe over the area of the hard substance of the tooth and left at rest for 30 s (enamel) or 15 s (dentine). This was followed by rinsing-off under flowing water for several seconds. The etched tooth obtained was freed of excess water by a gentle/briefly applied jet of oil- and water-free compressed air and processed further while moist. The adhesive (Futurabond U, VOCO GmbH) was applied to the prepared tooth surface and massaged into the surface for 20 s. Solvents present in the adhesive were removed by blowing with a jet of oil- and water-free compressed air for 5 seconds. This was followed by curing with light for 10 s (Celalux 2, VOCO GmbH, 420-490 nm, 1000 W/cm.sup.2). After curing, the embedded tooth specimen was introduced into a bonding clamp including insert form (in accordance with ISO 29022:2013—from Ultradent Products, South Jordan). The insert form was applied to the surface of the tooth, checked for an adequate fit and fixed to the screws of the apparatus. The composite (GrandioSO A1, VOCO GmbH) was applied to the composite face in the recess of the insert form with a filling instrument and then cured by light for 10 seconds (Celalux 2, VOCO GmbH, 420-490 nm, 1000 W/cm.sup.2). The composite specimen was removed from the bonding clamp and stored in water at (37±2) ° C. for (24±2) h. Removal from the water was followed immediately by determination of shear bond strength. For this purpose, the composite test specimens were subjected to stress in a shear test using a universal tester (ZwickRoell GmbH & Co. KG, Ulm) at a crosshead speed of (1.0±0.1) mm/min and an initial force of 1 N until fracture. Shear strength in MPa is found as the quotient of breaking force in N and bonded area in mm.sup.2.

Viscosity:

[0201] Viscosity was determined with a Physica MCR 301 rheometer (Anton Paar) in an oscillation test (plate/plate) at 23° C. The plate diameter was 50 mm and the plate distance 1 mm. The method of measuring the viscosities comprises four successive phases.

[0202] In phase I of the measurement, measurement was effected at a deformation of 0.1% and an oscillation frequency of 10 Hz for five minutes (measurement point duration 5 s). The last point of phase I was used here for evaluation.

[0203] In phase II of the measurement, measurement was effected at an oscillation frequency of 10 Hz for 60 s (measurement point duration 1 s), with increasing deformation by 5 percentage points per second from 0.1% to 300%.

[0204] In phase III of the measurement, measurement was again effected at a deformation of 0.1% and an oscillation frequency of 10 Hz for 60 s (measurement point duration 1).

[0205] In phase IV of the measurement, measurement was continued at a deformation of 0.1% and an oscillation frequency of 10 Hz, but with a greater measurement point duration, for 4 minutes (measurement point duration 4 s). The last point of phase IV was used here for evaluation.

[0206] The evaluation point of phase I here describes the viscosity at the state of rest, and the evaluation point of phase IV the viscosity on completion of shear stress (i.e., after application to the surface of the tooth).

TABLE-US-00013 TABLE 5A Examples 3A-3G Example 3A 3B 3C 3D 3E 3F 3G Adhesion (dentine) 33.2 31.8 32.2 31.7 32.5 32.3 33.3 [MPa] Adhesion (enamel) 35.2 34.5 34.7 34.7 35.0 35.1 35.1 [MPa] Viscosity (I) [Pa*s] 2.5 2.5 2.6 2.4 2.7 2.3 2.3 Viscosity (IV) [Pa*s] 2.5 2.5 2.6 2.4 2.7 2.2 2.3 tan δ (I) 0.89 0.83 0.85 0.82 0.90 0.90 0.83 tan δ (IV) 0.89 0.84 0.85 0.83 0.91 0.91 0.84 Viscosity (I) (6 2.5 2.5 2.5 2.4 2.7 2.2 2.2 months, 23° C.) [Pa*s] Viscosity (IV) (6 2.4 2.5 2.5 2.3 2.6 2.1 2.2 months, 23° C.) [Pa*s] tan δ (I) (6 months, 0.90 0.89 0.86 0.87 0.85 0.93 0.90 23° C.) tan δ (IV) (6 months, 0.90 0.90 0.88 0.90 0.87 0.96 0.90 23° C.)

TABLE-US-00014 TABLE 5B Examples 3H-3N Example 3H 3I 3J 3K 3L 3M 3N Adhesion (dentine) 32.3 31.1 30.7 33.6 31.2 33.1 32.1 [MPa] Adhesion (enamel) 35.2 35.5 34.6 34.8 35.5 34.5 34.9 [MPa] Viscosity (I) [Pa*s] 2.4 2.1 2.4 2.3 2.6 2.8 2.9 Viscosity (IV) [Pa*s] 2.4 2.0 2.3 2.3 2.5 2.7 2.8 tan δ (I) 0.88 0.89 0.87 0.87 0.81 0.79 0.88 tan δ (IV) 0.90 0.90 0.89 0.88 0.83 0.81 0.90 Viscosity (I) (6 2.4 2.0 2.3 2.3 2.6 2.7 2.8 months, 23° C.) [Pa*s] Viscosity (IV) (6 2.3 2.0 2.3 2.2 2.5 2.6 2.7 months, 23° C.) [Pa*s] tan δ (I) (6 months, 0.88 0.90 0.89 0.88 0.82 0.80 0.88 23° C.) tan δ (IV) (6 months, 0.89 0.91 0.91 0.89 0.85 0.81 0.89 23° C.)

TABLE-US-00015 TABLE 5C Examples 3O-3U Example 3O 3P 3Q 3R 3S 3T 3U Adhesion (dentine) 31.3 31.6 32.7 30.1 32.4 32.1 30.0 [MPa] Adhesion (enamel) 34.9 35.3 35.4 33.9 33.8 34.1 33.1 [MPa] Viscosity (I) [Pa*s] 1.8 1.3 1.1 1.9 2.1 3.5 4.6 Viscosity (IV) [Pa*s] 1.7 1.3 1.1 1.8 2.0 3.2 4.3 tan δ (I) 0.91 0.97 0.99 0.90 0.87 0.75 0.91 tan δ (IV) 0.92 0.98 0.99 0.92 0.89 0.78 0.92 Viscosity (I) (6 1.7 1.4 1.2 1.8 2.0 3.4 4.4 months, 23° C.) [Pa*s] Viscosity (IV) (6 1.7 1.4 1.2 1.1 1.9 3.2 4.1 months, 23° C.) [Pa*s] tan δ (I) (6 months, 0.91 0.95 0.96 0.90 0.86 0.79 0.91 23° C.) tan δ (IV) (6 months, 0.92 0.96 0.98 0.91 0.88 0.83 0.92 23° C.)

TABLE-US-00016 TABLE 6A Comparative Examples 4A-4G Comparative Example 4A 4B 4C 4D 4E 4F 4G Adhesion (dentine) 14.2 15.1 17.3 16.8 15.3 12.8 11.5 [MPa] Adhesion (enamel) 16.3 18.4 20.4 19.1 17.7 14.3 12.3 [MPa] Viscosity (I) [Pa*s] 0.2 0.3 3.0 6.0 0.6 0.8 10.0 Viscosity (IV) [Pa*s] 0.2 0.3 2.9 5.8 0.6 0.8 1.1 tan δ (I) 1.50 1.39 0.88 0.82 1.28 1.22 1.50 tan δ (IV) 1.50 1.39 0.90 0.85 1.29 1.23 1.50 Viscosity (I) (6 n.d. n.d. 4.2 8.3 n.d. n.d. n.d. months, 23° C.) [Pa*s] Viscosity (IV) (6 n.d. n.d. 4.1 8.0 n.d. n.d. n.d. months, 23° C.) [Pa*s] tan δ (I) (6 months, n.d. n.d. 0.81 0.75 n.d. n.d. n.d. 23° C.) tan δ (IV) (6 months, n.d. n.d. 0.84 0.79 n.d. n.d. n.d. 23° C.)

TABLE-US-00017 TABLE 6B Comparative Examples 4H-4N Comparative Example 4H 4I 4J 4K 4L 4M 4N Adhesion (dentine) 20.4 20.8 n.d. n.d. n.d. 18.4 19.7 [MPa] Adhesion (enamel) 22.3 22.5 n.d. n.d. n.d. 19.8 20.5 [MPa] Viscosity (I) [Pa*s] 1.2 6.5 0.2 0.2 0.3 2.5 8.2 Viscosity (IV) [Pa*s] 1.1 6.2 0.2 0.2 0.3 2.3 7.9 tan δ (I) 1.12 0.91 1.51 1.48 1.41 0.97 1.12 tan δ (IV) 1.14 0.94 1.51 1.48 1.41 0.99 1.14 Viscosity (I) (6 0.9 1.8 n.d. n.d. n.d. 1.1 1.8 months, 23° C.) [Pa*s] Viscosity (IV) (6 0.9 1.4 n.d. n.d. n.d. 1.0 1.6 months, 23° C.) [Pa*s] tan δ (I) (6 months, 1.18 1.02 n.d. n.d. n.d. 1.13 1.03 23° C.) tan δ (IV) (6 months, 1.19 1.05 n.d. n.d. n.d. 1.14 1.05 23° C.)

TABLE-US-00018 TABLE 6C Comparative Examples 4O-4P Comparative Example 4O 4P Adhesion (dentine) 28.9 25.3 [MPa] Adhesion (enamel) 30.7 28.4 [MPa] Viscosity (I) [Pa*s] 60.4 58.8 Viscosity (IV) [Pa*s] 58.9 58.4 tan δ (I) 0.65 0.78 tan δ (IV) 0.88 0.83 Viscosity (I) (6 22.4 15.7 months, 23° C.) [Pa*s] Viscosity (IV) (6 20.1 15.3 months, 23° C.) [Pa*s] tan δ (I) (6 months, 0.54 0.69 23° C.) tan δ (IV) (6 months, 0.68 0.75 23° C.)