DE19757277A1 - Polymerisation initiator system for dental resins - Google Patents

Abstract

Polymerisation initiator system for initiating the autopolymerisation of a 2-part dental resin comprises (a) a copper salt of formula CuXn, (b) a sulphinic acid compound of formula R1-SO-OR2, and (c) a (thio)amide compound of formula R3-CY-NR4R5. X = inorganic or organic anion; n = relevant stoichiometric number; R1 = alkyl, aryl or acyl; R2 = H, metal, alkyl, aryl or acyl; Y = O or S; R3 = alkyl, aryl, acyl or NR6R7; and R4-R7 = H, alkyl, aryl or acyl.

Description

Dental restorative plastics are usually synthetic plastics, which as polycondensates according to the underlying reaction type, Polyadducts or polymers are referred to. The polymers of acrylic, Methacrylic acid and its derivatives form the basis of modern composite Plastics. Generally, the term composite is used to refer to the Anglo-American Be drawing "composite resin material" traced back and denotes substances belonging to in addition to the macromolecular organic polymers, further components, in usually inorganic particles, as fillers. Dental resin systems Acrylate or methacrylate bases are for most dental applications the material of choice. This is due to the practical properties this substance class. In addition to the required strength, abrasion resistance, Dimensional stability, biocompatibility and aesthetics count above all the users easy-to-use production and processing of the essential material benefit.

The polymerization initiator system has a decisive influence on the Quality of the dental resin material. For redox polymerization and / or radical-initiated polymerization, catalysts (initiators) are used which expediently in two separate masses, Powder / liquid or base / catalyst paste. Shortly before use the two masses are mixed. It is their mixing and most importantly Curing time an essential consideration when assessing an efficient, cost-saving and user-friendly processing. Furthermore In addition to these autopolymerization catalysts, catalysts can also be used (Initiators) are used, which can be activated by radiation.

It is known that the polymerization of acrylate or methacrylate monomers and / or their derivatives can be initiated by a radical mechanism. For the polymerization and curing of dental resin systems, be known connections used. This is how peroxides are used for hot polymerization  such as dibenzoyl peroxide, dilauryl peroxide or tert-butyl perbenzoate and others, for example, compounds described in EP-OS 0410199 set. For the so-called redox polymerization, a system is usually made up of one peroxidic compound and a reducing agent, for example based tertiary aromatic amines, common. As initiators for cold polymerization are radical-delivering redox systems such. B. benzoyl or lauroyl peroxide, together with amines, such as N, N-dimethyl-p-toluidine or other structure related amines. A disadvantage of the compositions mentioned is their lack of ability acidic resin systems, such as HEMA Cure phosphate.

In the document DE-OS 42 19 700 u. a. an initiator system made from thiobarbitur acid derivative, copper salt and chloride ions for curing 2-hydroxyethyl methacrylate (HEMA). Such initiators can also be used with a Peroxide and / or a sulfinic acid salt can be used.

In EP-PS 0480785 thiobarbituric or barbituric acid compounds in Combination with copper or iron halides, primarily chloride ions, as Polymerization initiators for the radical polymerization of dental ad adhesive claims. The disadvantage of these compositions is the front presence of halide ions, primarily chloride ions, which is an increasing Solubility of the hardened mass and the color stability be negative influence.

EP-PS 0408357 describes a multi-component system for the production of a polymerizable composition, which contains an aromatic Sulfinate compound, a polymerizable monomer and an organic peroxide comprising, the sulfinate compound and the peroxide in separate packages stored and mixed together to effect the polymerization.

The coating compositions and adhesives claimed in EP-OS 0751124 be contain sulfonium salts that are both photoinitiated and heated (i.e. cured at approx. 150 ° C).  

EP-OS 0340637 describes transition metal catalysts in combination with an organic compound with a Si-H, Ge-H or Sn-H function for the Polymerization of ethylenically unsaturated compounds described. In this To The polymerization of butadiene and / or styrene is also related Acetylacetonate complexes of cobalt, nickel, vanadium and / or copper mentioned. However, even a relatively long reaction time results in only a small Um sentence.

In US-PS 4237242 and US-PS 4131715 for the polymerization of Acrylic compounds, polyepoxide compounds and metal acetylacetonates as catalyzes sensors used. In these cases it is necessary for the polymer layer to be one Heat treatment of approximately 100 ° C must be subjected to an effective off to ensure curing. As redox initiator systems for polymer products for the Dentistry are described in EP-OS 0678533 azobisisobutyronitrile, dibenzoyl peroxide / amine compounds, copper acetylacetonate / lithium sulfinates, trialkylboranes or called photoinitiators.

The following deficiencies are summarized in these known polymerization systems and processes:

• - insufficient binding strength between the polymerizing material and the tooth structure
• - Solubility of the hardened material, especially in the oral environment
• - discoloration and lack of color stability
• - long curing times
• - high curing temperatures.

The invention is based on the object of an initiator system at the outset to find characterized type from which to produce polymerization products leave that do not have the disadvantages listed.

The object of the invention is achieved by a polymerization initiator system according to the Claims 1 to 13 solved. The invention includes a polymerization initiator composition and its use in polymerizable compositions, ins  especially in free-radically polymerizing, cold-curing dental materials. The Polymerization initiator system according to the invention leads to a rapid and thus user-friendly curing time and a patient-friendly finish curing temperature of maximum 40 ° C. It also shows up in surprising Way that with the polymerization initiator according to the invention composition of acidic dental resin systems and thus the hardening binding of the polymerizing mass to the tooth structure is improved. In addition, the solubility properties of the resin system in this regard significantly improved that, for example, a dental resin in the oral environment of a Patient has a higher resistance to dissolution. The invention Polymerization initiator system can be used to manufacture and use dental Fastening compounds, adhesion-promoting substances and tooth filling materials with variable Filler content can be used.

The invention is illustrated by the examples below.

For the production of chemically curing dental composites and subsequent Material testing, the following powder / liquid systems are mixed:

A powder components I.

80% by weight silanized glass ceramic
15% by weight Aerosil (microfine filler on SiO ₂

-Base)
3% by weight of thiobarbituric acid
2% by weight sodium toluenesulfinate

II

80% by weight silanized glass ceramic
18% by weight Aerosil (microfine filler on SiO ₂

-Base)
1.5% by weight of thiobarbituric acid
0.5% by weight sodium toluenesulfinate

B liquid components I.

30.0% by weight of 2-hydroxyethyl methacrylate phosphate (HEMA phosphate)
40.0% by weight of 2,2-bis-4 (2-hydroxy-3-methacryloxypropyloxy) phenyl propane (bis-GMA)
29.8% by weight of triethylene glycol dimethacrylate (TEDMA)
0.2% by weight copper acetylacetonate

II

25.0% by weight of 2-hydroxyethyl methacrylate phosphate (HEMA phosphate)
40.0% by weight of 2,2-bis-4 (2-hydroxy-3-methacryloxypropyloxy) phenyl propane (bis-GMA)
34.8% by weight of triethylene glycol dimethacrylate (TEDMA)
0.2% by weight copper acetylacetonate

III

30.0% by weight of 2-hydroxyethyl methacrylate phosphate (HEMA phosphate)
40.0% by weight of 2,2-bis-4 (2-hydroxy-3-methacryloxypropyloxy) phenyl propane (bis-GMA)
29.5% by weight of triethylene glycol dimethacrylate (TEDMA)
0.5% by weight copper acetylacetonate

The powder / liquid systems (AI, AII) and (BI, BII, BIII) are each in Ratio 3 to 2 mixed and the setting time, setting temperature and the dentin adhesion measured by known methods. The results achieved are in the shown in the table below.

The results demonstrate, for example, the good properties of the invention modern polymerization initiator systems and their effects on dental Resin systems.

Claims (13)

1. Polymerization initiator system for initiating the autopolymerization of a dental restoration plastic, which is composed of a two-component mixture (A / B), consisting of

• a) a copper salt of the general formula CuX _n , where X is an inorganic and / or organic anion and n is the respective stoichiometric number, and
• b) a sulfinic acid compound of the general formula
  R ₁ -SOO-R ₂ ,
  wherein R _{1 is} an alkyl, aryl or acyl radical and R _{2 is} H, metal or an alkyl, aryl or acyl radical, and
• c) a urethane derivative of the general formula
  R ₃ -C (Y) -N (R ₄ ) R ₅
  where Y is an oxygen or sulfur atom, R _{3 is} an alkyl, aryl, acyl radical or a radical of the general formula
  -N (R ₆ ) R ₇
  and R ₄ , R ₅ , R ₆ and R _{7 are} independently H, alkyl, aryl or acyl.

2. Polymerization initiator system according to claim 1, characterized in that component a) is copper acetylacetonate or copper diacetate. 3. Polymerization initiator system according to one of claims 1 or 2, characterized characterized in that component b) sodium toluenesulfinate or sodium is benzenesulfinate. 4. Polymerization initiator system according to one of claims 1, 2 or 3, characterized characterized in that component c) thiobarbituric acid or 1,3,5-triethyl Is thiobarbituric acid.   5. Polymerization initiator system according to one of claims 1, 2, 3 or 4, characterized characterized in that component a) in the range of 0.01 to 10 wt .-% based on component B of the dental restorative chooses. 6. polymerization initiator system according to one of claims 1, 2, 3, 4 or 5, characterized in that components b) and c) in the range of 0.01 up to 10% by weight based on component A of the dental restoration plastic are selected. 7. Use of a polymerization initiator system for the production and application of an autopolymerizing dental restoration plastic, which is composed of a 2-component mixture (A / B), consisting of

• a) a copper salt of the general formula CuX _n , where X is an inorganic and / or organic anion and n is the respective stoichiometric number, and
• b) a sulfinic acid compound of the general formula
  R ₁ -SOO-R ₂ ,
  wherein R _{1 is} an alkyl, aryl or acyl radical and R _{2 is} H, metal or an alkyl, aryl or acyl radical, and
• c) a urethane derivative of the general formula
  R ₃ -C (Y) -N (R ₄ ) R ₅
  where Y is an oxygen or sulfur atom, R _{3 is} an alkyl, aryl, acyl radical or a radical of the general formula
  -N (R ₆ ) R ₇
  and R ₄ , R ₅ , R ₆ and R _{7 are} independently H, alkyl, aryl or acyl.

8. Use of a polymerization initiator system according to claim 7, characterized characterized in that component a) copper acetylacetonate or copper is diacetate.   9. Use of a polymerization initiator system according to one of claims 7 or 8, characterized in that component b) sodium toluenesulfinate or sodium benzenesulfinate. 10. Use of a polymerization initiator system according to one of the claims 7, 8 or 9, characterized in that component c) thiobarbituric acid or 1,3,5-triethyl-thiobarbituric acid. 11. Use of a polymerization initiator system according to one of the claims 7, 8, 9 or 10, characterized in that component a) in the range from 0.01 to 10 wt .-% based on component B of the dental Re restoration plastic is selected. 12. Use of a polymerization initiator system according to one of the claims 7, 8, 9, 10 or 11, characterized in that components b) and c) in the range of 0.01 to 10 wt .-% based on component A of the dental Restoration plastic are selected. 13. Use of a polymerization initiator system according to one of the claims 7, 8, 9, 10, 11 or 12 for the production and application of dental Be strengthening compounds, adhesion-promoting substances and tooth filling materials variable filler content.