Guided Dental Preparation Planning for Precise Fixed Prostheses

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Solution Overview

Problem

Current dental preparation techniques face issues such as excessive or insufficient tooth substance removal, irregular preparations, difficulty fitting prostheses, and long operating times, particularly in the context of fixed prosthetics like crowns and bridges.

Innovation Solution

A system for diagnosing, planning, and guiding dental preparations using objective parameters, incorporating a computer system with hardware and software, and employing either physical guides with dedicated drills or optical control via stereophotogrammetry to ensure precise tooth preparation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If empirical tooth preparation is performed manually, then the dentist has flexibility in technique, but excessive or insufficient tooth substance removal occurs leading to invasiveness or fragility

Engineering Contradiction:
Improvetooth preparation precisionVSAvoidexcessive tooth substance removal
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary digital planning and simulation of tooth preparation before actual execution. The 3D model allows virtual trial of different preparation designs to determine the optimal approach that removes exactly the right amount of tooth substance, avoiding both excessive removal and insufficient preparation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces manual empirical mechanical preparation with computer-guided mechanical preparation. The drilling and filing operations are guided by pre-planned digital paths, substituting the dentist's manual judgment and hand-eye coordination with automated computer-controlled guidance to achieve precise tooth substance removal.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If manual tooth preparation is performed, then adaptability to individual cases is possible, but irregular tooth preparations occur due to undercuts and lack of parallelism

Engineering Contradiction:
Improvepreparation adaptabilityVSAvoidpreparation regularity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system performs preliminary digital planning where the ideal preparation geometry is designed in advance with perfect parallelism and no undercuts. This pre-planned virtual model serves as a guide for the actual preparation, ensuring regular geometry while adapting to the specific patient's anatomy through customized digital planning.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If static guided surgery with physical templates is used, then drilling precision is improved, but device complexity and ease of operation are compromised

Engineering Contradiction:
Improvedrilling precisionVSAvoidguide system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces the complex mechanical static guide system with a dynamic computer-vision-based guidance system. Instead of physical templates with bushings and locked drills, the system uses cameras to track the drill in real-time and provides visual feedback, eliminating the need for bulky physical guides while maintaining drilling precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Ease of operation

If manual tooth preparation and temporary prosthesis fitting are performed, then clinical flexibility is maintained, but operating time is excessively long

Engineering Contradiction:
Improveclinical flexibilityVSAvoidoperating time
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The system performs preliminary digital planning and prepares the treatment plan before the patient visits. The digital model allows all preparation parameters to be determined in advance, so that during the actual clinical procedure, the dentist simply needs to follow the pre-planned guidance, dramatically reducing operating time while maintaining clinical flexibility through customized digital planning.

Inventive Principle:
Principle #10Preliminary action

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 system simplifies the transfer of implant positions, reduces operating time, and ensures accurate drilling by providing real-time guidance and feedback, resulting in improved fit and mechanical stability of prostheses.

Implementation Method 1

optical control via stereophotogrammetry that, by matching a real patient with a virtual patient

Methodology Applied
Scientific EffectStereophotogrammetry: Photogrammetry

Data Source

PatentEP4710892A1System for diagnosis, planning and guided execution of dental preparations in fixed prostheses
Publication Date: 2026.03.18 ARCURI LORENZO
  • EP4710892A1 patent drawingFigure 1a~12
  • EP4710892A1 patent drawingFigure 13~20b
  • EP4710892A1 patent drawingFigure 21~25b

AI summary

System for diagnosis, planning and guided execution of dental preparations in fixed prostheses, comprising a computer system, with respective hardware and software components, as well as further dedicated peripherals, which implements a process characterized by the following steps: A) preliminary diagnosis of the elements to be submitted to a prosthetic process: A.1) evaluate the dental element(s) and related prosthetic process, A.2) evaluate the bone support, including ratio of intraosseous and extraosseous dental portion, and distance and divergence between teeth to be connected, and A.3) evaluate the internal structure, e.g. enamel, dentin, pulp, cement, material for reconstruction; B) planning of ideal dental preparation(s): B.1) superimpose an ideal prosthetic project to an initial anatomical dental situation; B.2) define a final subgingival/juxtagingival/supragingival preparation; and B.3) starting from an ideal tooth volume, reduce the volume so as to simulate the ideal dental preparation, taking into due consideration: B.3.1) the extent of the reduction depending on the material that will be used to construct the crown, e.g. metal-ceramic, zirconia, zirconia-ceramic, composite, disilicate lithium, ceramic, B.3.2) insertion axis of the prosthesis, where multiple dental elements should be parallelized in order to have a common insertion axis, and B.3.3) inclination of the prosthesis walls, which could be more or less retentive from a mechanical point of view; C) diagnosis of the ideal dental preparation(s) generated: C.1) evaluate the proximity to the pulp in the dental vital elements, including the need of root canal therapy related to vital dental elements, C.2) evaluate the structural surface composition of an ideal abutment, including percentage of enamel/dentin/reconstruction material, in order to assess retention adhesive of the substrate, C.3) evaluate, starting from the final preparation, the quantity of healthy dental tissue in terms of height - splint/cerclage effect, in order to define the mechanical stability of the preparation; D) transfer the ideal dental preparation into the oral cavity of a real patient according to two possible options: a) develop a tooth-supported transfer mask with guide tracks for dedicated drills with axial and depth stops, but capable of sliding along these tracks; b) develop real-time control means using stereophotogrammetry; said control will allow the operator to use a drill in order to file the tooth freehand within a volume of free movement.