US-12616560-B2 - Dental machining system for generating process parameters of the machining

US12616560B2US 12616560 B2US12616560 B2US 12616560B2US-12616560-B2

Abstract

A dental machining system for manufacturing a dental restoration, including: a dental tool machine which includes: a dental blank holder for holding one or more dental blanks relatively movable with respect to one or more dental tools; one or more driving units each for movably holding at least one dental tool for machining the dental blanks; a determination unit for determining the type of each dental blank; an adjustment device for allowing the user to adjust the machining time, a level of quality of the dental restoration, and a level of security of the dental restoration and dental tool against machining damage. The system further includes a control unit which executes a trained artificial intelligence algorithm adapted to generate process parameters for the machining.

Inventors

Sebastian Steger
Oliver Nowarra
Daniel Weiss

Assignees

DENTSPLY SIRONA INC.

Dates

Publication Date: 20260505
Application Date: 20210311
Priority Date: 20200320

Claims (15)

1 . A dental machining system for manufacturing a dental restoration/appliance comprising: a dental tool machine which comprises: a dental blank holder configured to hold one or more dental blanks relatively movable with respect to one or more dental tools; one or more driving units each configured to movably hold at least one dental tool for machining the one or more dental blanks; and a storage medium to store instructions, which when executed by the dental machining system, cause the dental machining system to: train an artificial intelligence algorithm to generate process parameters for the machining based on a type of the one or more dental blanks, process parameters used for a previously completed machining, and at least one of a normalized machining time, a level of quality of the dental restoration/appliance, or a level of security of the dental restoration/appliance and the at least one dental tool; receive, from a user, an adjustment of at least one of a machining time, the level of quality of the dental restoration/appliance, or the level of security of the dental restoration/appliance and the at least one dental tool against machining damage; determine a type of each of the one or more dental blanks; execute the trained artificial intelligence algorithm to generate process parameters for the machining based on the type of the one or more dental blanks, and at least one of the machining time, the level of quality of the dental restoration/appliance, or the level of security of the dental restoration/appliance and the at least one dental tool; calculate a temporal trajectory of the at least one dental tool for the machining based on construction data of the dental restoration/appliance and the generated process parameters; and control the dental blank holder and the one or more driving units based on the calculated temporal trajectory.
2 . The dental machining system according to claim 1 , wherein to determine the type of each the one or more dental blanks, the instructions cause the dental machining system to compute the type of the at least one dental tool and a wear condition of the at least one dental tool; and wherein to execute the trained artificial intelligence algorithm to generate process parameters, the instructions cause the dental machining system to use the type of the at least one dental tool and the wear condition of the at least one dental tool to generate process parameters.
3 . The dental machining system according to claim 1 , wherein the instructions cause the dental machining system to sense dynamical quantities relating to the at least one dental tool; and execute the trained artificial intelligence algorithm based on the sensed dynamical quantities, and adaptively control the dental blank holder and the one or more driving units based on the generated process parameters during the machining.
4 . The dental machining system according to claim 1 , wherein the instructions cause the dental machining system to determine a dental tool load along the temporal trajectory of the at least one dental tool, and execute the trained artificial intelligence algorithm based on the temporal trajectory and the determined dental tool load, and adaptively control the dental blank holder and the one or more driving units based on the generated process parameters during the machining.
5 . The dental machining system according to claim 1 , wherein the instructions cause the dental machining system to adjust at least one of the machining time, the level of quality of the dental restoration/appliance, or the level of security of the dental restoration/appliance and at least one dental tool against machining damage in a continuous manner or discrete manner.
6 . The dental machining system according to claim 1 , wherein the instructions cause the dental machining system to train the artificial intelligence algorithm for generating process parameters for the machining further based on the type of the at least one dental tool and a wear conditions of the at least one dental tool before start or after completion of a previously completed machining.
7 . The dental machining system according to claim 1 , wherein the instructions cause the dental machining system to train the artificial intelligence algorithm for generating process parameters for the machining further based on a sensed dynamical quantities relating to the at least one dental tool of a previously completed machining.
8 . The dental machining system according to claim 1 , wherein the instructions cause the dental machining system to train the artificial intelligence algorithm for generating process parameters for the machining further based on the temporal trajectory of the at least one dental tool relative to the one or more dental blanks and a determined dental tool load along the temporal trajectory of a previously completed machining.
9 . The dental machining system according to claim 1 , wherein the instructions cause the dental machining system to train the artificial intelligence algorithm for generating process parameters for the machining of a new type of dental blank further based on the type of the new dental blank, process parameters used for at least one previously completed machining of the new type dental blank, and at least one of the normalized machining time, the level of quality of the dental restoration/appliance, or the level of security of the dental restoration/appliance and the at least one dental tool against machining damage.
10 . The dental machining system according to claim 1 , wherein the instructions cause the dental machining system to train the artificial intelligence algorithm for generating process parameters for the machining with a new type of dental tool machine further based on the type of the new dental tool machine, process parameters used for at least one completed machining with the new type dental tool machine, and at least one of the normalized machining time, the level of quality of the dental restoration/appliance, or the level of security of the dental restoration/appliance and the at least one dental tool against machining damage.
11 . The dental machining system according to claim 1 , wherein the control unit is further configured to train the artificial intelligence algorithm for generating process parameters for the machining with a new trajectory calculation algorithm further based on a change in the trajectory calculation algorithm, process parameters used for at least one completed machining with the new trajectory calculation algorithm, and at least one of the normalized machining time, the level of quality of the dental restoration/appliance, or the level of security of the dental restoration/appliance and the at least one dental tool against machining damage.
12 . The dental machining system according to claim 1 , wherein the machining time is determined based on a measured machining time and the construction data of the dental restoration/appliance.
13 . The dental machining system according to claim 1 , wherein the process parameters comprise at least one of a rotational speed of the at least one dental tool, feed rates of the at least one dental tool into a material, path distance of the at least one dental tool, limit values for machining forces and torques acting on the at least one dental tool, or feed rate of the one or more dental blanks.
14 . The dental machining system according to claim 1 , wherein the level quality of the dental restoration/appliance comprises at least one of a surface smoothness, a degree of chipping, or a precision of the dental restoration/appliance.
15 . The dental machining system according to claim 3 , wherein the dynamical quantity corresponds to at least one of a position, a speed, an acceleration, a vibration of the respective dental tool, a force, a torque acting on the respective dental tool, a supply current to a dental tool motor of the respective dental tool, or a sound generated by the respective dental tool.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This is a National Phase application of International Application No. PCT/EP2021/056134, filed Mar. 11, 2021, which claims the benefit of and priority to European Application Ser. No. 20164430.9, filed on Mar. 20, 2020, which are herein incorporated by reference for all purposes. TECHNICAL FIELD OF THE INVENTION The present invention relates to a dental machining system which has a dental tool machine for manufacturing a dental restoration or a dental appliance from a dental blank by using one or more dental tools. The present invention more particularly relates to a method of generating the process parameters for machining the dental blank. BACKGROUND OF THE INVENTION In general, a dental machining system has a dental tool machine for machining a dental blank. The dental tool machine generally has one or more driving units each movably holding at least one dental tool for machining the dental blank. The dental tools are respectively mounted to the tool motors in the driving units. The dental tools can be exchanged after their service lifes are over. The dental blank is mounted to a dental blank holder which is relatively movable with respect to the dental tools. A control unit controls the operation of the dental machining system. Generally, a CAD/CAM software is executed, for example, on a PC which is connected to the dental tool machine. The CAD/CAM software is generally used to digitally provide construction data of the dental restoration to be manufactured. The CAD/CAM software further generates the temporal trajectory of the dental tool in the dental tool machine based on the construction data and the process parameters of the machining. Thereafter the dental blank holder and the driving units are controlled based on the temporal trajectory of the dental tool. Typically, the user inputs the type of the dental blank via the user interface of the dental tool machine. The user is usually allowed to discretely adjust via a graphical user interface of the CAD/CAM software the machining time (e.g., very fast, fast, normal), a level of quality of the dental restoration (e.g., very high, high, normal), and/or a level of security of the dental restoration and dental tool against machining damage (e.g., very high, high, normal). In complex test series, the process parameters for the dental machine tool such as the feed rate of the dental blank, the path distance of the dental tool, the feed rates of the dental tool into the material, the rotational speed of the dental tool and the like must be defined manually for each type of dental blank and, for instance, each level of quality of the dental restoration, and each level of security desired by the user. So far, empirical values from the previous tests have been used as a basis for defining the process parameters. Based on the empirical values, the process parameters are defined for a basic setup. By means of suitable methods, e.g. statistical design of experiments (DoE), a process parameter space may be configured, which is then examined by means of real elaboration on the dental tool machine. A rough process parameter model can be derived from these results of the examination. Based on this model, process parameter combinations can then be determined which promise an advantageous behavior with regard to the above optimization variables such as the machining time, the level of quality of the dental restoration (e.g., no chipping), the level of security of the dental restoration (e.g., no damage to the dental restoration or the dental tool), the dental tool service life, and the like. The process parameter combinations must be further examined and or refined by further tests on the dental tool machine. A problem with this prior art method is that a complex series of numerous tests must be conducted for different/new type of dental blanks, different/new type of dental tool machines, different/new operating modes of the dental tool machines or different/new type of framework conditions. However, this is very time consuming and labor intensive. The experimental effort is too high when the process parameters depend in continuum on the optimization variables e.g., the dental tool wear condition, dynamics, or load. SUMMARY OF THE INVENTION An objective of the present invention is to overcome the problems of the prior art and to provide a dental machining system which can precisely generate process parameters of the machining for manufacturing a dental restoration/appliance. This objective has been achieved through the dental machining system as defined in claim 1. The subject-matters of the dependent claims relate to further embodiments and developments. DETAILED DESCRIPTION OF THE INVENTION According to an embodiment of the present invention, the dental machining system utilizes artificial intelligence, for instance, a neural network or the like. According to the present invention, the dental machining system has a training mod