(Meth)acrylamide Phosphates for Hydrolysis-Stable Dental Adhesives
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current self-etching dental adhesives face hydrolysis issues due to water exposure, leading to decreased adhesion over time, as the ester bonds in methacrylates are prone to hydrolysis under acidic, aqueous conditions, necessitating separate storage and mixing of components.
Innovation Solution
Development of hydrolysis-stable (meth)acrylamide phosphates with a specific general formula, capable of forming heterocyclic rings and suitable for radical polymerization, which are highly soluble in water and maintain stability under acidic conditions, allowing for a single composition that can etch tooth surfaces without losing functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acid monomers with ester bonds are used in self-etching adhesives, then adhesion function and etching capability are achieved, but hydrolysis occurs under aqueous conditions leading to loss of adhesion over time
Solution Approach 1:
The patent changes the chemical structure of the adhesion monomer by replacing the ester bond with an amide phosphate group. This structural parameter change transforms the molecule from being hydrolyzable to hydrolysis-stable, while maintaining the acid function necessary for etching and adhesion. The amide phosphate group resists hydrolysis under aqueous conditions, solving the contradiction between adhesion function and hydrolysis stability.
Solution Approach 2:
The patent creates a composite functional group (amide phosphate) that combines the beneficial properties of amide bonds (hydrolysis resistance) with phosphate groups (acid function for etching). This composite structure integrates multiple functions into a single stable molecular unit that maintains adhesion capability without undergoing hydrolysis.
2Stability of the object's composition
If acid monomers are stored separately from aqueous components to prevent hydrolysis, then hydrolysis stability is improved, but device complexity and ease of operation deteriorate due to separate storage and mixing requirements
Solution Approach 1:
The patent merges the acid monomer with hydrolysis-resistant properties directly into a single stable molecular structure (amide phosphate). This eliminates the need for separate storage of acid monomers and aqueous components, as the hydrolysis stability is built into the molecule itself. The adhesive can be stored as a single composition without risk of hydrolysis, simplifying both storage and operation.
3Productivity
If ester bonds are used in methacrylates for adhesion, then polymerization activity and reactivity are improved, but hydrolysis resistance deteriorates under acidic aqueous conditions
Solution Approach 1:
The patent changes the bond type parameter from ester to amide phosphate. This chemical parameter change maintains the reactivity needed for polymerization while conferring hydrolysis resistance. The amide phosphate group is chemically stable against hydrolysis under acidic conditions, unlike the ester bond, thus resolving the contradiction between polymerization activity and hydrolysis resistance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The (meth)acrylamide phosphates demonstrate long-term hydrolysis stability, enabling storage-stable dental materials that can effectively etch enamel and dentine, maintaining adhesion properties even in aqueous environments, thus addressing the limitations of existing adhesives.
Implementation Method 1
The object is achieved according to the invention by polymerizable dental materials which contain at least one (meth)acrylamide phosphate of the following general formula (I) or a pyrophosphate thereof
Implementation Method 2
hydrolysis-stable (meth)acrylamide phosphates with a specific general formula, capable of forming heterocyclic rings and suitable for radical polymerization, which are highly soluble in water and maintain stability under acidic conditions
Implementation Method 3
Water is used in most cases as solvent or co-solvent in enamel-dentine adhesives, as it promotes the wetting of the hard tooth substance
Data Source
AI summary
Polymerizable dental material, characterized in that it contains at least one (meth)acrylamide phosphate of the following general formula (I):in which R1 is H or CH3; R2 is H or a C1-C4 alkyl radical or forms together with the nitrogen atom to which it is bonded and one or more atoms which belong to R3 or R3′ a heterocyclic ring; R3, R3′ independently of each other are a linear or branched aliphatic C1-C50 radical with a valency of m+n or p+n, an aromatic C6-C18 radical with a valency of m+n or p+n, or a cycloaliphatic, araliphatic or heterocyclic C3-C18 radical with a valency of m+n or p+n, wherein the carbon chains of the radical or radicals can be interrupted by O, S, CONR4, OCONH, or form together with one or more atoms which belong to R2 and the nitrogen atom, to which the R2 is bonded a heterocyclic ring, R3′ being H if p=0, and R4 being H, C1-C10 alkyl, C6-C12 aryl, C6-10 aralkyl or a bicylic C4-C12 radial; n is 1, 2, 3 or 4 if p=0, and is 1 or 2 if p ≠0; m is 1, 2, 3 or 4; p is 0, 1, 2, 3 or 4; x is 0 or S.