Laser-Induced Phase Conversion in Glass-Ceramic Dental Restorations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current glass-ceramic materials for dental restorations lack the ability to precisely adjust mechanical and optical properties across different regions, failing to mimic the structure and aesthetics of natural teeth, with existing methods causing tool wear and insufficient edge strength, and exhibiting homogeneous crystalline growth without spatial order.
Innovation Solution
A process involving laser irradiation with a wavelength of at least 500 nm is used to induce phase conversion in confined regions of a glass-ceramic body, allowing for precise adjustment of crystalline phases and properties, mimicking the structure of natural teeth by creating regions with different crystalline phases that change gradually.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If lithium disilicate glass-ceramic is used to achieve high strength and toughness, then mechanical properties are improved, but tool wear increases and edge strength becomes insufficient
Solution Approach 1:
The patent applies local quality by creating distinct regions within the glass-ceramic body: a first region with lithium disilicate crystals for high strength and toughness, and a second region with different crystalline phases optimized for machining. This spatial differentiation allows the restoration to have both high mechanical performance in critical areas and ease of manufacture in other areas, resolving the contradiction between strength and tool wear.
Solution Approach 2:
The glass-ceramic body is segmented into multiple regions with different crystalline phase compositions. The first region contains lithium disilicate for structural integrity, while the second region contains phases like cristobalite or tridymite that are easier to machine. This segmentation allows each region to fulfill its specific function, addressing both the strength requirement and the manufacturability concern.
2Device complexity
If homogeneous crystalline growth is achieved throughout the whole volume, then material constitution is simplified, but aesthetic appearance and mechanical stability fail to mimic natural teeth
Solution Approach 1:
The patent implements local quality by creating spatially differentiated crystalline phases that mimic the natural tooth structure. The first region with lithium disilicate provides the enamel-like properties, while the second region with different crystalline phases provides the dentin-like properties. This local differentiation enables the restoration to accurately replicate both the aesthetic appearance and mechanical stability of natural teeth.
Solution Approach 2:
The glass-ceramic body functions as a composite material system with multiple crystalline phases distributed in specific regions. By combining lithium disilicate with other phases like cristobalite or tridymite in a controlled spatial arrangement, the material achieves properties that neither phase could provide alone, successfully mimicking the complex structure of natural teeth.
3Length of moving object
If thickness is reduced to a few hundreds of micrometers for aesthetic reasons, then appearance is improved, but edge strength becomes insufficient
Solution Approach 1:
The patent addresses this contradiction by concentrating lithium disilicate crystals in the first region, particularly at edges and thin sections, to provide localized high strength where needed. This allows the overall restoration to maintain reduced thickness for aesthetics while the critical edge areas retain sufficient strength through the enhanced crystalline phase distribution.
Solution Approach 2:
The patent employs preliminary action by pre-distributing lithium disilicate crystals to specific regions before the final restoration is completed. This pre-positioning of high-strength phases in critical areas ensures that even when the overall thickness is reduced, the edge strength remains sufficient to withstand functional loads.
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
This process achieves a glass-ceramic body with high flexural strength and aesthetic appeal, capable of mimicking the inhomogeneous structure of natural teeth, reducing tool wear and enhancing mechanical stability, while allowing for precise control over crystalline phase distribution and machining.
Implementation Method 1
transferring energy to the basic body by laser irradiating said region with a laser beam having a wavelength of at least 500 nm
Implementation Method 2
conversion of a starting phase of the material of the basic body into at least one crystalline phase is induced in a confined region
Implementation Method 3
conversion of a starting phase of the material of the basic body into at least one crystalline phase
Data Source
AI summary
The present invention relates to a process for preparing a prosthetic element comprising a glass-ceramic body. The process comprises the steps of a) providing a basic body comprising an amorphous glass phase and containing the components of the glass-ceramic body to be prepared, and b) transferring energy to the basic body to induce conversion of a starting phase of the material of the basic body into at least one crystalline phase in a confined region. According to the invention, energy is transferred to the confined region of the basic body by laser irradiating said region with a laser beam having a wavelength of at least 500 nm.