WO2007014571A1 - Glass-crystalline compound for the treatment of surfaces - Google Patents

Abstract

The invention relates to a compound comprising the following components (%): SiO2 30-50, Al2O3 5-15, K2O 5-8, Na2O 5-10, CaO 5-25, B2O3 2-20, Li2O 0-5, MgO 0-5, P2O5 2-20, Sb2O3 0-1, SnO2 0-3, TiO2 0-5, ZnO 0-5, ZrO2 5-10.

Description

Internal character: BIO.205.01 WHERE

BioCerma, Inc. c / o Harvard Business Service, Inc. 25 Greystone Manor, Lewes, Delaware 19958-9776, USA

Glassy crystalline mass for quenching surfaces

Description

Included patents:

EP 1167311 Low-sintering apatite glass ceramics EP 1329430 Alkali zinc glass-ceramic and glass EP 1170261 Potassium-zinc-silicate glass sintering at low temperature US Pat. No. 5,617,623 Lithium disilicate glass ceramics EP 0847375 A silicate glass composition and method for modifying ceramic materials DE 19816865 Implant, especially dental implant, with coating of bioactive silicate glass US 4708652 Apatite composite ceramics

description

Glassy crystalline mass for quenching surfaces

The invention relates to a composition which is particularly suitable for restorative dentistry and in particular for improving surfaces of dental ceramic veneers.

Natural teeth are characterized by tooth enamel on the surface. This enamel is mechanically special. However, chemical attack can destroy the enamel. Enamel is predominantly composed of hydroxyapatite. This hydroxyapatite gives the tooth its typical appearance.

Artificial teeth for crowns and bridges, for example, can be made to resemble natural teeth, which are fired in several layers by dental ceramic masses. This is state of the art (e.g., DE-OS-38 09 019).

Stratification with different masses can lead to thermal stresses, which can be triggers for cracks or cracks, for example. These can occur immediately during manufacture or afterwards as so-called late jumps. A composition which can reduce such stresses is described in EP 0847375. Also admixture with the finished mass of hydroxyapatite as fine-grained particles is e-benso, as provided in US 4708652, provided (no ingredient in contrast to the composition of the invention). The starting material contains no phosphate component (ie no calcium phosphate) and significantly less zirconium dioxide than the composition according to the invention. When manufacturing artificial teeth with conventional masses, either the work can be polished to a high gloss at the end or sealed with a glass frit.

Both methods are used equally. When polishing, it is often possible for small cracks to remain on the surface, which allow uncontrolled penetration of substances in the patient's mouth. Glaze masses, on the other hand, are quick to apply, but are especially controversial in the case of allergic persons because of the release of interfering elements. In addition, many glaze masses are loosened or bitten away after a longer wearing time.

There is no generally accepted solution to this problem.

Most manufacturers offer veneered ceramic ranges whose masses are more or less coordinated. Not every veneer can be covered with any type of glaze. Mostly there is a close dependence on the used veneer assortment.

While conventional glazings are pure glasses or leucite glass-ceramics, the composition of the invention can be adjusted by modifiers aesthetically or mechanically or in other properties of the particular situation. In addition, it has a calcium and phosphate content, which makes it similar to the natural enamel.

The object according to the invention is achieved by the glass ceramic, which by means of calcium phosphate comes much closer to the natural tooth in terms of its properties and at the same time can be used on several veneering ceramics due to the nature and composition.

Due to the glass phase and composition, for example, the high solubility of hydroxyapatite, which may be present in the composition of the invention, be lowered compared to the natural tooth. The existing crystal phase can be out Hydroxylapatite or else consist of other calcium compounds. Danben may have leucite as another crystal phase. The manufacturing process determines the nature and formation of the crystal phase.

Hydroxylapatite is widely used as a bioactive material, e.g. in the context of implants - EP 19816865. For the application according to the invention, however, it is crucial that hydroxlapatite can be present, but, as with natural tooth enamel, it is present as more or less bioinert material (gingiva is well accepted, but growth - eg of bone substance or damaging Bacterial colonies - not significantly promoted).

Blending dental materials (not specifically glaziers) are described in EP 1167311, EP 1170261 or EP 1329430, but these compositions all contain more than 50% SiO 2. Such compositions, especially with lithium disilicate, are often used as pressable masses for frameworks, e.g. US 6517623.

By contrast, the composition according to the invention contains no appreciable proportions of lithium disilicate. However, it is conceivable that in addition to conventional application methods, the composition can also be overpressed by a veneer (not primarily a framework).

At the same time, EP 1167311 requires a high ZnO content of 9-16%. This lowers the firing temperature. The composition of the invention is to be fired at temperatures below 850 ⁰ C, despite a significant ZrO 2 content, which increases the surface stability in order to ensure a broad application. In

EP 1167311 are expected to provide smaller ZrO 2 contents. Zirconium oxide has in the meantime proven itself particularly with dental framework materials and, due to its mechanical properties, in particular with stabilizers, has characterized the metal-free market (all-ceramic frameworks for long-span bridges). The composition of the invention is characterized by:

A low firing temperature below 850 ^° C. and a composition of the components (in percent by weight):

SiO2 30-50

AI2O3 5-15

K2O 5-8

Na2O 5-10

CaO 5-25

B2O3 2-20

Li2O 0-5

MgO 0-5

P2O5 2-20

Sb2O3 0-1

SnO2 0-3

TiO2 0-5

ZnO 0-5

ZrO 2 5-10 (with or without stabilizers, such as Y 2 O 3, CeO 2, or MgO)

Excipients (e.g., pigments, property modifiers) 0.5-15

Compared to similar patents, this compound is compatible with many dental ceramic materials and can therefore be applied to many artificially produced ceramic teeth. Lithium disilicate scaffolds as described in EP 1167311 are not a mandatory basis. According to the invention, the composition should not have any appreciable proportions of lithium disilicate and should normally not be applied directly to substrates but as a last layer on veneers, in order to make them match the natural tooth enamel without, however, having the same life-time-degrading chemical solubility. However, if the last layer is to be applied directly to the dental framework for clinical or dental considerations, this is also possible.

Due to the special design of the mass, it can be fired on a wide variety of masses. This includes in particular certain metal ceramic compositions and all-ceramic compositions with different thermal expansion coefficients and firing temperatures.

Claims

claims 1. Mass with the following components (%): SiO2 30-50 AI2O3 5-15 K2O 5-8 Na2O 5-10 CaO 5-25 B2O3 2-20 Li2O 0-5 MgO 0-5 P2O5 2-20 Sb2O3 0-1 SnO2 0-3 TiO2 0-5 ZnO 0-5 ZrO2 5-10 2. Mass according to claim 1, wherein it is a dental composition. 3. A composition according to claim 1 or 2, with adjuvants, such as pigments and / or property modifiers, in a proportion between 0.5 and 15%. 4. A composition according to claim 1, 2 or 3, with at least one stabilizer, such as Y2O3, CeO2, or MgO. 5. Use of a composition according to any one of the preceding claims at a firing temperature of below 850 ⁰ C. 6. Use of a composition according to one of the preceding claims for tempering a surface. 7. Use according to claim 6, wherein the surface is a surface of an implant.