TCD-Urethane Acrylate Monomers for Low-Shrinkage Dental Composites

Solution Overview

Problem

Dental composites using acrylate monomers exhibit higher reactivity and irritant effects on biological tissues, making them unsuitable for widespread use despite their potential benefits due to their increased reactivity with other monomers, while methacrylate-based composites are preferred for their lower cytotoxicity.

Innovation Solution

A dental composite composition utilizing more than 50% acrylate monomers with a TCD-urethane structure, specifically an acrylic acid ester of tricyclo[5.2.1.0.2.6]decane, as the crosslinker, which demonstrates low cytotoxicity and high biological compatibility, allowing for low-shrinkage polymerization and improved mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If acrylate monomers are used as crosslinkers in dental composites, then reactivity and conversion levels increase, but irritant effect and cytotoxicity increase

Engineering Contradiction:

ImprovereactivityVSAvoidirritant effect

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the chemical structure of acrylate monomers by introducing a TCD-urethane framework, which changes the physical and chemical parameters of the monomer. This structural modification maintains high reactivity while reducing cytotoxicity, as evidenced by the favorable toxicological test results despite acrylate content >5%.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite monomer system combining the TCD framework with urethane groups and acrylate functionality. This composite structure integrates the rigidity and low-shrinkage properties of TCD with the reactivity of acrylates, while the urethane groups contribute to reduced cytotoxicity.

Inventive Principle:

Principle #40Composite materials

2Productivity

If acrylate monomers are used as crosslinkers in dental composites, then conversion levels increase, but cytotoxicity increases

Engineering Contradiction:

Improveconversion levelVSAvoidcytotoxicity

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the chemical structure of acrylate monomers by introducing a TCD-urethane framework, which changes the physical and chemical parameters of the monomer. This structural modification maintains high reactivity while reducing cytotoxicity, as evidenced by the favorable toxicological test results despite acrylate content >5%.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the typically harmful high reactivity of acrylates (which causes cytotoxicity) into a beneficial property by combining it with the TCD-urethane structure. The high conversion level achieved is beneficial for mechanical properties, while the specific molecular structure mitigates the cytotoxicity that would normally accompany high acrylate content.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Speed

If TCD-urethane acrylate monomers are used, then reactivity increases, but traditionally acrylates have higher irritant effects

Engineering Contradiction:

ImprovereactivityVSAvoidirritant effect

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the chemical structure of acrylate monomers by introducing a TCD-urethane framework, which changes the physical and chemical parameters of the monomer. This structural modification maintains high reactivity while reducing cytotoxicity, as evidenced by the favorable toxicological test results despite acrylate content >5%.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite monomer system combining the TCD framework with urethane groups and acrylate functionality. This composite structure integrates the rigidity and low-shrinkage properties of TCD with the reactivity of acrylates, while the urethane groups contribute to reduced cytotoxicity.

Inventive Principle:

Principle #40Composite materials

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 use of TCD-urethane acrylate monomers in dental composites achieves high conversion levels with low volume shrinkage and favorable biocompatibility, reducing cytotoxicity and enhancing mechanical properties, making them suitable for both direct and indirect dentistry applications.

Implementation Method 1

The so-called siloranes represent a combination of epoxy functionalities on siloxane units and can be polymerized with low shrinkage via a cationic crosslinking mechanism by ring-opening polymerization

Methodology Applied

Scientific EffectRing-opening polymerization:

Implementation Method 2

can be polymerized with low shrinkage via a cationic crosslinking mechanism by ring-opening polymerization

Methodology Applied

Scientific EffectCationic crosslinking:

Data Source

PatentEP1935393B1Dental composites with Tricyclo[5.2.1.02.6]decane derivatives

Publication Date: 2015.02.25 HERAEUS KULZER GMBH

AI summary

Dental composite compositions containing monomers, crosslinkers, fillers, initiators, wherein A is the crosslinker component of more than 50%, of acrylate monomers with a TCD urethane structure of the general formula wherein A, X, Z, R1 R2 R3 and r have the meanings specified in claim 1, yield polymers with particularly low cytotoxicity in accordance with the standards of ISO 10993-5 and DIN EN ISO 7405.