Photoinitiator modified polyacidic polymer

Abstract

The present invention relates to an initiator modified polyacidic polymer having a covalently bonded initiator compound, and to a dental resin-modified glass ionomer composition comprising this polyacidic polymer. Furthermore, the present invention relates to a use of the initiator modified polyacidic polymer for the preparation of a dental composition. The covalently bonded initiator compound of the initiator modified polyacidic polymer may be any compound of a redox initiator system, a photoinitiator system, for example a Norrish type I or II photoinitiator, an electron donor component, a sensitizer component or a coinitiator component.

Claims

1. A dental resin-modified glass ionomer composition comprising (a) a reactive particulate filler, and (b) a polyacidic polymer which is reactive with the reactive particulate filler in a cement reaction, wherein the composition further comprises an initiator system consisting of one or more initiator compounds generating alone or in combination free radicals, wherein at least one of the one or more initiator compounds is linked to the polyacidic polymer (b) by a covalent bond forming an initiator modified polyacidic polymer having a covalently bonded initiator compound, wherein the initiator modified polyacidic polymer is a compound having repeating units of a following formula (I): ##STR00031## wherein X, which may be a same or different, and independently represent OH, O—L—Z, or NH—L—Z, wherein L is a single bond or a divalent linker group, and Z is a covalently bonded initiator compound; Y is a hydrogen atom, COOH or a covalently bonded initiator compound; wherein the covalently bonded initiator compound is selected from the group of benzophenone, 1,2-diketones, 1,3 diketones, aromatic amines, and phosphines; k, l, m, n, o and p are independently integers of at least 0, k+l+m+n+o+p is at least 1; and at least one Xis present which is not OH when Y is a hydrogen atom or COOH; wherein the polyacidic polymer has a weight average molecular weight of 1 to 300 kDa; wherein the initiator modified polyacidic polymer contains 0.01 to 20 mole % covalently bonded initiator compound per 100 mole % of acidic groups of the polyacidic polymer.

2. The dental resin-modified glass ionomer composition according to claim 1, wherein the initiator system is a photoinitiator system consisting of one or more initiator compounds generating alone or in combination free radicals when irradiated with light having a wavelength in a range of from 400 to 800 nm.

3. The dental resin-modified glass ionomer composition according to claim 1, wherein the polyacidic polymer (b) is a polyacrylic acid or a copolymer of acrylic acid and itaconic acid.

4. The dental resin-modified glass ionomer composition according to claim 2, wherein the one or more initiator compounded is at least a Norrish type II photoinitiator comprising a sensitizer component and an electron donor component.

5. The dental resin-modified glass ionomer composition according to claim 1, wherein the covalently bonded initiator compound Y and Z are independent from each other and represent moieties of a following formula (II): ##STR00032## wherein R.sup.1 and R.sup.2 which may be a same or different, and independently represent a C.sub.1-6 straight chain alkyl group, C.sub.3-6 branched alkyl group or cyclic alkyl group.

6. The dental resin-modified glass ionomer composition according to claim 1, wherein a temporary or final restoration of a hard dental tissue is comprised of the dental resin-modified glass ionomer composition.

7. The dental resin-modified glass ionomer composition according to claim 1, which further comprises (c) a water-soluble, hydrolysis-stable monomer having a single polymerizable double bond and optionally a carboxylic acid group or hydroxyl group; and/or (d) a water-soluble, hydrolysis-stable polymerizable crosslinker having at least two polymerizable carbon-carbon double bonds.

8. The dental resin-modified glass ionomer composition according to claim 1, wherein the initiator modified polyacidic polymer contains 0.05 to 10 mole % covalently bonded initiator compound per 100 mole % of acidic groups of the initiator modified polyacidic polymer.

9. An initiator modified polyacidic polymer having a covalently bonded initiator compound, wherein the initiator modified polyacidic polymer contains 0.01 to 20 mole% covalently bonded initiator compound per 100 mole % of acidic groups of the initiator modified polyacidic polymer, wherein the initiator modified polyacidic polymer is a compound having repeating units of a following formula (I): ##STR00033## wherein X, which may be a same or different, and independently represent OH, O—L—Z, or NH—L—Z, wherein L is a single bond or a divalent linker group, and Z is a covalently bonded initiator compound; Y is a hydrogen atom, COOH or a covalently bonded initiator compound; wherein the covalently bonded initiator compound is selected from the group of benzophenone, 1,2-diketones, 1,3 diketones, aromatic amines, and phosphines; k, l, m, n, o and p are independently integers of at least 0, k+l+m+n+o+p is at least 1; and at least one X is present which is not OH when Y is a hydrogen atom or COOH; wherein the polyacidic polymer has a weight average molecular weight of 1 to 300 kDa.

10. An initiator modified polyacidic polymer according to claim 9, wherein the covalently bonded initiator compound Y and Z are independent from each other,and represent moieties of a following formula (II): ##STR00034## wherein R.sup.1 and R.sup.2 which may be a same or different, and independently represent a C.sub.1-6 straight chain alkyl group, C.sub.3-6 branched alkyl group or cyclic alkyl group.

11. A method of forming a dental composition; said method comprising: mixing a composition comprising an initiator modified polyacidic polymer having a covalently bonded initiator compound with a reactive particulate filler to form the dental composition; wherein the initiator modified polyacidic polymer is a compound having repeating units of a following formula (I): ##STR00035## wherein X, which may be a same or different, and independently represent OH, O—L—Z, or NH—L—Z, wherein L is a single bond or a divalent linker group, and Z is a covalently bonded initiator compound; Y is a hydrogen atom, COOH or a covalently bonded initiator compound; wherein the covalently bonded initiator compound is selected from the group of benzophenone, 1,2-diketones, 1,3 diketones, aromatic amines, and phosphines; k, l, m, n, o and p are independently integers of at least 0, k+l+m+n+o+p is at least 1; and at least one X is present which is not OH when Y is a hydrogen atom or COOH; wherein the polyacidic polymer has a weight average molecular weight of 1 to 300 kDa; wherein the initiator modified polyacidic polymer contains 0.01 to 20 mole % covalently bonded initiator compound per 100 mole % of acidic groups of the polyacidic polymer.

12. The method according to claim 11, wherein the covalently bonded initiator compound Y and Z are independent from each other, and represent moieties of a following formula (II): ##STR00036## wherein R.sup.1 and R.sup.2 which may be a same or different, and independently represent a C.sub.1-6 straight chain alkyl group, C.sub.3-6 branched alkyl group or cyclic alkyl group.

13. The dental resin-modified glass ionomer composition according to claim 1, wherein a luting cement for crown and bridge cementation is comprised of the dental resin-modified glass ionomer composition.

Description

EXAMPLES

Example 1

(1) Synthesis of Poly[(N-(4-(Dimethylamino Phenyl)Acrylamide)-Co-(Acrylic Acid)]

(2) To a solution of 5 g polyacrylic acid (Mw 136.00 g/mol) in 15 ml dioxane at 40° C. were added 563 mg (69 mmol) 4-dimethylamino phenylisocyanat dissolved in 5 ml dioxane within 5 min. The solution was stirred overnight at 40° C. The reaction mixture cooled to room temperature was dropped into 200 ml acetonitrile. Then, the precipitated modified polymer was separated by decanting the overlaying solution, and dissolved in 100 ml water. The acetonitrile was removed by distillation at 100 mbar and 40° C. Then, the remaining solution was dialysed (MWCO=1000 Da), and the water was removed by freeze-drying.

(3) Yield: 1.89 (36%)

(4) Polymer modification (.sup.1H NMR): appr. 2.5%

(5) .sup.1H NMR (DMSO-d.sub.6): δ (ppm)=12.23 (s, COOH), 7.27-6.67 (m, Ar), 2.84-2.82 (d, CHCH.sub.2CH), 2.11 (s, CH), 1.51-1.33 (m, CH.sub.2CH.sub.2CH),

(6) ##STR00030##

Application Examples 1 and 2 and Comparative Example 1

(7) Aqueous dental glass ionomer compositions of Application Example 1 according to the invention and of the Comparative Example 1 have been prepared by forming a liquid and a powder composition of the ingredients listed in Table 1 below, which respectively add up to 100 wt %, and admixing both parts in the shown powder/liquid (P/L) ratio.

(8) [Curing Time]

(9) Working time: Period of time, measured from the start of mixing the powder and glass in the shown P/L ratio, during which it is possible to manipulate the material without an adverse effect on the properties.

(10) Setting time: Point of time at which the mixture stopped being deformed even under pressing.

(11) [Flexural Strength]

(12) The obtained dental glass ionomer compositions of Example 1 and Comparative Example 1 were filled in a stainless steel mould having the size (25±2) mm×(2.0±0.1) mm×(2.0±0.1) mm, for the preparation of test specimens. The thus obtained dental glass ionomer compositions were cured with a dental curing light (light-cured, LC) as well as without external power source (self-cured, SC). For the resulting cured dental glass ionomer composition, the flexural strength has been determined according to ISO 4049.

(13) TABLE-US-00001 TABLE 1 Composition and properties of Application example 1 and Comparative example 1 Application Comparative Example 1 Example 1 SAH 1-173-03A/ SAH 1-176-01A/ SAH 1-173-03B SKA 17-072-01 B Liquid Water 33.8 33.8 Cross-linker 15.0 15.0 Acrylic acid 25.0 25.0 Modified polyacid 20.0 25.0 Amine modified Polyacid of 5.5 — synthesis example 1 Camphorquinone + Inhibitor 0.7 0.7 DMABN — 0.5 Σ 100 100 Powder Reactive glass mixture 99.34 99.34 KPS 0.22 0.22 NapTS 0.44 0.44 Σ 100 100 P/L ratio 3.0 3.0 (SC) 3.2 (LC) Curing time Working time (seconds) 140 145 Setting time (seconds) 277 285 Flexural strength (SC) [MPa]  95 ± 17  84 ± 7 E-Modulus (SC) [MPa] 12060 ± 910 10520 ± 340 Flexural strength (LC) [MPa] 115 ± 5  117 ± 14 E-Modulus (LC) [MPa] 12090 ± 410 12650 ± 370 Example 2 (Amine Modified PAA Charge JBR 03-129-01) Liquid FSZ 01-145-01 Powder FSZ 01-143-01 Liquid Water 33.85 Cross-linker 15.0 Modified polyacid 20.0 Amine Modified polyacid 5.5 Acrylic acid 25.0 DMAPAA 0 CQ 0.62 Inhibtitor 0.03 Σ 100 Powder Reactive glass mixture 99.54 NapTS 0.58 KPS 0.88 Σ 100 P/L ratio 3.0 Curing time Working time (seconds) 140 SKA 17-121-01 A Setting time (seconds) 200 SKA 17-121-01 B Flexural strength (SC) [MPa]  85 ± 12 SKA 17-119-01 B Flexural strength (LC) [MPa]  98 ± 3 SKA 17-119-01 A E-Modulus (SC) [MPa] 11000 ± 460 SKA 17-119-01 B E-Modulus (LC) [MPa] 12000 ± 500 SKA 17-119-01 A