Lithium Silicate Deep Quartz Glass Ceramic for Machinable Dental Restorations

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing lithium silicate glass ceramics used in dental restorations are difficult to machine and require further heat treatment to achieve desired mechanical properties, complicating the production process and tool wear.

Innovation Solution

A lithium silicate deep quartz glass ceramic with lithium silicate as the main crystal phase and deep quartz as an additional phase, which can be easily machined and does not require subsequent heat treatment for strength, combining high mechanical and optical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional lithium disilicate glass ceramic is used, then high mechanical strength is achieved, but machining difficulty increases and tool wear increases

Engineering Contradiction:
Improvemechanical strengthVSAvoidmachining ease
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent changes the chemical composition parameters of the glass ceramic by incorporating specific amounts of Al2O3 (1-6 wt%), TiO2 (0.5-3 wt%), and other oxides in controlled ratios, which modifies the material properties to achieve both high strength and improved machinability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite glass ceramic system combining lithium disilicate base glass with multiple crystalline phases (anorthite, gehlenite, perovskite) formed through controlled heat treatment, achieving synergistic effects that simultaneously provide strength and processability

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If lithium metasilicate glass ceramic is used as precursor, then machining ease improves, but additional heat treatment is required

Engineering Contradiction:
Improvemachining easeVSAvoidprocess complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent performs preliminary crystallization during the initial heat treatment stage, forming the desired anorthite-gehlenite-perovskite phase assemblage before machining, so that the final product achieves both ease of machining and high mechanical strength without requiring subsequent heat treatment

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention merges the crystallization process and strength development into a single heat treatment step performed before machining, combining multiple functions (crystallization, phase formation, strength acquisition) into one operation to eliminate the need for additional heat treatment after machining

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If secondary crystal phases are added to lithium silicate glass ceramic, then mechanical properties improve, but optical properties deteriorate

Engineering Contradiction:
Improvemechanical strengthVSAvoidtranslucency
Core Design Contradiction:
StrengthVSIllumination intensity

Solution Approach 1:

The patent creates local quality differentiation by forming specific crystalline phases (anorthite, gehlenite, perovskite) with controlled size distributions and spatial arrangements within the glass matrix, where the crystal size is optimized to be small enough to maintain translucency but sufficient to provide mechanical reinforcement

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the physical parameters of the crystal phases, particularly controlling crystal size, shape, and distribution through precise heat treatment parameters (temperature, time, cooling rate), achieving optimal balance between strength enhancement and optical transparency

Inventive Principle:
Principle #35Parameter changes

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 glass ceramic achieves high strength and ease of machining, allowing for efficient production of dental restorations with excellent mechanical and optical properties, mimicking natural tooth color without additional heat treatment.

Implementation Method 1

The lithium silicate deep quartz glass ceramic according to the invention contains lithium silicate as the main crystal phase and deep quartz as the further crystal phase

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Data Source

PatentEP4273107B1Lithium silicate glass ceramic with alpha quartz
Publication Date: 2025.08.27 IVOCLAR VIVADENT AG

AI summary

Lithium silicate deep quartz glass ceramics are described, which are characterized by a combination of very good mechanical and optical properties and can therefore be used particularly as restorative material in dentistry.