DD295758A5 - DENTAL ADHESIVE - Google Patents

Abstract

The invention relates to a dental adhesive, with the help of which it is possible to firmly and moisture-resistant to connect metals in the stomatological laboratory and clinical field. The object was achieved by using a mixture of 85 mol% dipropylenetriamine and 15 mol% * as epoxide addition component (bisphenol A diglycidyl ether). The adhesive mixture is also added an inorganic filler. You get an adhesive that resists the damp environment and the changing thermal and mechanical stresses of the oral cavity well {dental adhesive; Networking; Bisphenol A diglycidyl ether; Dipropylene triamine, *}

Description

dental adhesive

The invention relates to adhesives that are to be used in the field of prosthetic dentistry for connecting bridge parts of the same or different metals to bridge bodies.

Clinical connection procedures for uniting bridge parts include soldering in dental laboratory technology. Although soldering is a long-established practice relevant to practice, it has some disadvantages, so that the solder joint is always a weak point (H. Landt, P. Lockowandt, Zahn-Mund-Kieferheilkd.

71 [19831,609; P. Thomsen, dental laboratory 32 Ц984] 893; Th. Wendler, Quintess. Dental Technology 11 [1985] 725).

An alternative to soldering is the bonding technology already proven in many areas of technology. In prosthetic stomatology adhesives have been used, such as epoxy resins, cyanoacrylates, polyurethanes and methacrylates. The adhesive strength is usually good in the dry environment, but after wet stress and Wechselbadbeanspruchung there is a strong decrease in the adhesive strength. This is especially true for epoxy resins, which have high adhesive strengths in the dry state, but decrease significantly in the adhesive strength by water influence (R. Schwindling,

P. Reichert, Dt. Zahnärztl. Z. 19 [1964] 333; H.Schwickerath, Dt. Zahnärztl. Z. 24 [1969] 858; W.Vogel, Stomatol. DDR 24 [1974] 624). It is therefore desirable to have available adhesives which do not have the disadvantages mentioned.

The aim of the invention is to develop an adhesive with which metals in the stomatological laboratory and clinical area can be firmly and permanently connected.

The adhesive must be able to withstand the moist environment of the oral cavity, the different composition of the food and changing dynamic and static stresses.

The object of the invention is to supplement the soldering method previously used in the field of stomatological-laboratory technology for the joining of metals by a Kiebetechnikzu.

Surprisingly and unpredictably, it has been found that the combination of the pentafunctional hardener dipropylenetriamine with the difunctional amine N, N'-dibenzyl-3,6-dioxaoctanediamine-1,8 in a certain ratio gives a dental adhesive which is compatible with the complex stresses of the oral cavity resists.

This effect is particularly surprising in that epoxy-amine adhesives are considered to be particularly sensitive to moisture.

Further systematic investigations showed that only the mixture according to the invention meets the requirements of the oral cavity milieu. Even adhesive compositions close to the invention are unable to meet the broad range of prosthetic adhesive requirements. Adhesive compositions which have a high compressive shear strength are not moisture-resistant or show only a relatively small number of load cycles in the fatigue test (see Table 1).

Tab.1 Properties of selected adhesive compositions *

composition Compressive shear Compressive shear Lastwec ^ sel d. hardener strength strength mol% N-mm " ² N · mm " ² (7.7 N r-rrr ² dry / NB 1115 wet storage / Burden) NB1115 20 days A 90 mol% A1 29.76 low - 10 mol% A 2 B 70 mol% A1 34.87 16.51 Break at 30 mol% A 2 692 220th C 50mol% A1 23,10 low - 50 mol% A 2 D 85 mol% A1 38.96 44,21 2 219700 15 mol% A 2 without breakage

A1: dipropylenetriamine

 A2: N, N'-dibenzyl-e-dioxaoctanediamine-i.e

 * Epoxy: Bisphenol A diglycidyl ether

 Filler: 35Ma .-% DK11.

According to the invention the object of creating a dental adhesive is achieved in that a mixture of 85 mol% dipropylenetriamine and 15 mol% of N, N'-dibenzyl-3,6-dioxaoctandiamin-1,8 is used as the addition component for epoxides and that inorganic Fillers are contained in a proportion of 20-40 wt .-% based on the total adhesive mixture. The epoxide used is preferably bisphenol A diglycidyl ether or a low molecular weight, containing at least two epoxide groups per molecule epoxy resin, wherein epoxy and NH functions are used in the equivalent ratio.

As inorganic fillers which are expediently silanized according to known regulations, it is advantageous to use spherical silica particles having a narrow particle size distribution, in particular 0.9 × particle diameter, as obtained, for example, by ultrasonic atomization of silica sols in accordance with DO 247884. But also the use of wet-filled silica z. B. Mikronisil (grain diameter 20 цт, manufacturer Chemische Fabrik Fehrbrücke) leads to dental adhesives with very good properties. For a high quality of the bond, it is also advantageous to start from metal surfaces which are coated with an SiO "-C layer (R.Musil, H.-J.Tiller, The Kulzer Silicoater method wiss. Documentation of Fa Kulzer, Wehrheim 1984)

 The adhesive according to the invention exhibits in particular the following advantages or valuable properties:

- easy accessibility of the adhesive components

- very good adhesion

- Low stress curing due to low volume shrinkage

- moisture resistant

- excellent behavior under thermal cycling

- long-term stable in the Dauerschwellversuch

- no edge gap.

The invention will be explained in more detail in the examples below.

Examples example 1

1.751 g of bisphenol A diglycidyl ether (F _P 42-43 "C) are melted and, after cooling, 0.256 g of dipropylenetriamine and 0.113 g of N, N'-dibenzyl-3,6-dioxaoctanediamine-1,8 are added The adhesive mixture is thoroughly mixed at room temperature for a few minutes, 1.15 g of silanized disperse silica (spherical particles having a mean grain diameter of 0.9 × t) are added and mixed again, after which the adhesive batch is ready for bonding bridge components.

The surfaces of the specimens to be bonded (Gisadent-NCA, manufacturer VEB Feingußwerk Lobenstein) are blasted with 400 t of corundum for 30 seconds each at a pressure of 5 bar and then cleaned by panning in ethanol. After air drying, the flame-pyrolytic coating of the metal surface is carried out with a SiOx-C layer. After cooling, the adhesive surfaces are coated with a 1% ethanolic solution of NB1115 (manufacturer VEB Chemiewerk Nünchritz) and then applied the adhesive. The specimens are fixed under pressure and 2h. cured at 80 ⁰ C. The shear strength values were determined after 24 hours of dry storage and after 10,20,30,85,175,260 days of alternating bath stress. The conditions of Wechselbadbeanspruchung consist of a permanent water storage (distilled water) at 37 ⁰ C and a temperature shock at a regular interval of 8 hours, the sample each 5 minutes at 5 ° C, 37 ° C and 60 ⁰ C was tempered.

Pressure shear values N · mm "

dry 38.96

wet

10 days 40.79 20 days 41.21 30 days 44.88 85 days 42,70 175 days 40,00 260 days 39.18

Permanent swelling test (7.7N · mm ² load): 2219700 Load change without breakage.

Example 2

1.781 g of bisphenol A diglycidyl ether (F _p 42-43 ⁰ C) are melted. After cooling, 0.256 g of dipropylenetriamine and 0.113 g of N, N'-dibenzyl-3,6-dioxaoctanediamine-1,8 are added. In the course of 10 minutes, the adhesive mixture is mixed well at room temperature, 0.538 g of micronisil (wet-precipitated silica, grain diameter 20pm, manufacturer Chemische Werke Fehrbrücke) added and the mixture thoroughly mixed again. Thereafter, the approach as described in Example 1 for the bonding of bridge parts can be used

Pressure shear values (N · mm ^"2) wet 39.82 7 days

14 days 36.63

Claims (2)

1. Dental adhesive for bonding metallic dental moldings based on bisphenol A diglycidyl ether or low molecular weight, containing at least two epoxy groups per molecule epoxy resins, characterized in that the addition component for epoxides, a mixture of 85Mol-% dipropylenetriamine and 15Mol-% N ^ ' Dibenzyl-S ^ -Dioxaoctandiamin-1,8 is used and that inorganic fillers in a proportion of 20-40 wt .-% based on the total adhesive mixture are included. 2. An adhesive according to claim 1, characterized in that the inorganic fillers obtained by ultrasonic atomization of silica sols obtained spherical silica particles, wet-filled silica and aerosils are used.