Stem-Aware Sintered Dental Preforms for Faster Chairside Restorations
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Solution Overview
Problem
The existing methods for creating dental restorations from ceramic materials require separate steps of milling and sintering, which are time-consuming and prevent chair-side applications, leading to longer wait times for patients.
Innovation Solution
A method and apparatus for making custom dental restorations using a sintered preform with a stem, which can be directly shaped into final form without additional sintering, utilizing unique nesting methods, machining strategies, and tool paths to reduce material removal and processing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If separate steps of milling porous ceramic and sintering the milled shape are used, then manufacturing precision and material strength are improved, but manufacturing time and process complexity increase
Solution Approach 1:
The patent applies preliminary action by pre-sintering the ceramic material into a dense preform before the chair-side milling process. This eliminates the need for post-milling sintering, as the material is already in its final dense state. The preform is prepared in advance with the stem and basic geometry, allowing the dentist to complete the restoration shaping immediately without waiting for a separate sintering cycle.
2Strength
If separate steps of milling and sintering are used, then material strength is improved, but device complexity and process steps increase
Solution Approach 1:
The patent merges the sintering and milling operations into a single integrated process flow. By pre-sintering the ceramic material into a dense preform that can be directly milled, the invention combines what were previously separate manufacturing steps (sintering then milling) into one continuous chair-side operation. This eliminates the need for separate sintering equipment and processes at the dental office, simplifying the overall device and process complexity.
3Ease of manufacture
If traditional mill blanks with single size and shape are used, then ease of manufacture is improved, but material waste increases
Solution Approach 1:
The patent applies local quality by providing a library of preforms with different sizes, shapes, and stem configurations tailored to specific restoration requirements. Each preform is optimized for its intended application, allowing the dentist to select the most appropriate preform that closely matches the restoration geometry. This reduces material waste compared to using universal mill blanks that require extensive removal regardless of the specific tooth preparation needs.
4Manufacturing precision
If porous ceramic material is milled and then sintered, then manufacturing precision is improved, but productivity decreases
Solution Approach 1:
The patent applies preliminary action by pre-sintering the ceramic material into a dense preform before the chair-side milling process. This eliminates the need for post-milling sintering, as the material is already in its final dense state. The preform is prepared in advance with the stem and basic geometry, allowing the dentist to complete the restoration shaping immediately without waiting for a separate sintering cycle.
Data Source
AI summary
A method is provided for shaping a custom dental restoration from a preform, wherein the preform comprises a preform body and a preform stem. A method is further disclosed for generating one or more nesting positions for the restoration design within the geometry of the preform body relative to the position of the preform stem. A method is further disclosed for generating machining instructions based on the selected nesting position to optimize machining for chair-side applications.