CN116416406A

CN116416406A - Design method and preparation method of pseudo-tooth root implant system

Info

Publication number: CN116416406A
Application number: CN202111675364.6A
Authority: CN
Inventors: 常小龙; 卢凌霄; 辛晨; 徐志伟; 刘翔
Original assignee: Shanghai Weiwei Ziya Medical Technology Co ltd
Current assignee: Shanghai Weiwei Ziya Medical Technology Co ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2023-07-11

Abstract

The invention provides a design method and a preparation method of an artificial tooth root implant system. The three-dimensional model of the affected tooth is used as a design basis, is close to the real tooth, and realizes the simulation of the force transmission characteristic of the natural molar and the stress distribution characteristic of the tooth root. When the three-dimensional model does not meet the requirements, the method also carries out flattening treatment and/or parting angle treatment on the tooth root of the three-dimensional model, so that the designed tooth root is easier to locate in the tooth extraction socket, the excessive or insufficient parting angle is avoided, and the implantation difficulty is reduced. In addition, the invention also designs a coating model and a bone grafting bin model. The coating model is in interference connection with the tooth extraction socket, and anti-inflammatory and growth-promoting medicines can be accommodated in the bone grafting bin model, so that the short-term and long-term stability after planting is facilitated. And the coating model and the bone grafting bin model are subjected to porosification treatment, so that the diffusion of the medicine and the growth of bone tissues are facilitated. Therefore, the implant formed according to the present invention can not only improve the implant stability but also reduce the difficulty of implantation.

Description

Design method and preparation method of pseudo-tooth root implant system

Technical Field

The invention relates to the technical field of dental implants, in particular to a design method and a preparation method of a pseudo-tooth root implant system.

Background

Currently, the clinical treatment of dentition deficiency mainly utilizes cylindrical implants, screwed into alveolar bone with surface threads to achieve initial and long-term stability. Because the chewing mechanical mode of the teeth is complex, particularly for the posterior tooth area, the cylindrical implant is not matched with the tooth extraction socket, and a cantilever beam structure is easy to form, so that the failure is caused. In recent years, the research of the pseudo-tooth root implant improves the matching property of the implant and the tooth socket, accords with a physiological structure better, and is beneficial to stress conduction and stability. However, there are problems in that some tooth roots are irregular, and there are inverted concave structures or flared structures, so that implantation is difficult, and inflammatory reactions are liable to occur at the bifurcation of the tooth roots.

Although with the development of clinical knowledge and digitization technology, based on computer aided design and manufacturing technology (computer aided design/CAD/CAM) and computed tomography technology (computed tomography, CT), it is possible to achieve a simulation of the geometric features of natural tooth roots or to make specific modifications for solving the problems brought by conventional cylindrical or tapered screw-like implants. However, for the irregular curved surface of the tooth structure and the situations of large individual and position differences and structural changes, the traditional design and processing mode are difficult to meet the personalized requirements of patients.

Therefore, a new design method and a new preparation method of the pseudo-tooth root implant system are needed to form a new pseudo-tooth root implant system, so that the personalized implant requirements of patients are met, the implant difficulty is reduced, and the initial and long-term stability of the implant is ensured.

Disclosure of Invention

The invention aims to provide a design method and a preparation method of an artificial tooth root implant system, which are used for solving at least one of the problems that the artificial tooth root implant is difficult to implant, the initial and long-term stability after the artificial tooth root implant is poor, and the personalized implant requirements of patients cannot be met.

In order to solve the technical problems, the invention provides a design method of a pseudo-root implant system, wherein the pseudo-root implant system is used for planting a diseased tooth; the design method comprises the following steps:

collecting oral cavity data and obtaining a three-dimensional model of the affected teeth;

judging whether the three-dimensional model meets the set requirements, if so, taking the three-dimensional model as a reference model, if not, carrying out straightening treatment and/or parting angle treatment on the tooth root in the three-dimensional model, and taking the treated three-dimensional model as the reference model;

obtaining a coating model sleeved on the outer surface of the tooth root at least according to the tooth root in the reference model; and obtaining a bone grafting bin model according to part or all of the single tooth root in the reference model or according to a three-dimensional area between more than two tooth roots in the coating model so as to form a pseudo-tooth root implant system with a coating and a bone grafting bin on the pseudo-tooth root.

Optionally, in the method for designing a pseudo-root implant system, the process of collecting oral cavity data and obtaining a three-dimensional model of the affected tooth includes:

adopting CBCT scanning to collect dental data, alveolar bone data and gingival tissue data so as to at least obtain an affected tooth tissue model and an alveolar bone model and a gingival tissue model of an affected tooth;

performing Boolean intersection operation on the affected tooth tissue model and the alveolar bone model to obtain a tooth root in the three-dimensional model of the affected tooth;

performing Boolean cross operation on the suffering tooth tissue model and the gum tissue model to obtain a gum penetrating part in the three-dimensional suffering tooth model;

performing Boolean subtraction operation on the affected tooth tissue model, the gingival tissue model and the alveolar bone model to obtain a dental crown in the three-dimensional model of the affected tooth;

the tooth crown in the three-dimensional model, the gum penetrating part in the three-dimensional model and the tooth root in the three-dimensional model are sequentially connected along the crown root direction to form the three-dimensional model of the suffering tooth.

Optionally, in the design method of the pseudo-root implant system, when the crown of the affected tooth is missing or defective, acquiring the pair of the affected teeth according to the dentition data

A crown of a tooth or a symmetric tooth is used as the crown of the three-dimensional model.

Optionally, in the design method of the pseudo-root implant system, a plurality of cross-sectional images of the affected tooth are obtained through CBCT scanning; and along the coronal direction, each of said cross-sectional images corresponds to a planar image of a corresponding layer in said three-dimensional model;

the process for judging whether the three-dimensional model meets the set requirements comprises the following steps:

according to the three-dimensional model and the cross-sectional images, starting from a layer closest to the dental crown in the dental root, sequentially obtaining projection lines of central connecting lines of every two adjacent layers on a coronal plane and a sagittal plane respectively, and calculating included angles between projection lines of the first two layers on the coronal plane or the sagittal plane and projection lines of the second two layers on the corresponding planes in every three continuous layers;

when the included angle is larger than or equal to 5 degrees, the tooth root does not meet the set requirement;

when all the included angles are smaller than 5 degrees, the tooth root meets the set requirement;

optionally, in the design method of the pseudo-root implant system, the three-dimensional model of the affected tooth includes at least two roots;

the process for judging whether the three-dimensional model meets the set requirement or not further comprises the following steps:

Acquiring projection lines of central axes of each tooth root on a coronal plane and a sagittal plane in the three-dimensional model, and calculating an included angle between projection lines of central axes of each two tooth roots on the coronal plane or the sagittal plane to obtain a bifurcation angle;

when the bifurcation angle is smaller than 5 degrees or larger than 15 degrees, the bifurcation angle does not meet the set requirement;

when the bifurcation angle is larger than or equal to 5 degrees and smaller than or equal to 15 degrees, the bifurcation angle meets the set requirement.

Optionally, in the method for designing a pseudo-root implant system, the method for flattening the root in the three-dimensional model includes:

taking the middle layer of each continuous three layers with the included angle larger than or equal to 5 degrees as an inflection point layer;

extracting the cross-sectional image corresponding to the inflection point layer, and taking the radial profile line of the tooth root in the cross-sectional image as an initial profile line;

according to the initial contour line, taking a central connecting line of the inflection point layer and a layer adjacent to the inflection point layer and close to the direction of the dental crowns as a reference axis, and executing equidistant processing towards the direction pointing to the dental roots so as to obtain at least one equidistant contour line;

and performing a lofting basic operation on the initial contour lines and all the equidistant contour lines to obtain a flattened tooth root.

Optionally, in the method for designing the pseudo-root implant system, during the process of performing equidistant treatment, all equidistant contour lines are sequentially reduced in equidistant manner along the radial direction; wherein each reduction has a size ranging from 0.1 mm to 0.8 mm and the smallest diameter of the last said equidistant profile is greater than or equal to 0.3 mm; the axial distance between the starting contour and the last of the equidistant contours ranges from 0.1 mm to 8 mm.

Optionally, in the method for designing an artificial tooth root implant system, the method further includes:

obtaining a reference axis and a target axis, wherein the reference axis is the central axis of the tooth root meeting the set requirement or the central axis of the tooth root subjected to flattening treatment, and the target axis is the central axis of the target tooth root to be treated;

projecting the reference axis and the target axis onto both coronal and sagittal planes, and forming an intersection between the projection lines of the reference axis and the target axis on either the coronal or sagittal planes;

rotating the projection line of the target axis around the intersection point until the included angle between the projection line of the target axis and the projection line of the reference axis meets the set requirement; and taking the target axis after rotation as the central axis of the tooth root after bifurcation angle treatment.

Optionally, in the method for designing a pseudo-root implant system, the process of forming the bone grafting bin model according to a part of the root in the reference model includes:

selecting a placement area of a bone grafting bin model when the reference model has a single tooth root;

taking the outer surface of the tooth root corresponding to the placement area as a reference surface, and stretching the reference surface along the radial direction of the tooth root and towards one side far away from the tooth root so as to obtain a bone grafting bin solid model;

or intercepting a part of the single tooth root in the reference model, and taking the part of the single tooth root as a bone grafting bin solid model;

performing inward shell extraction on the bone grafting bin solid model to obtain a bone grafting bin shell with set thickness;

and performing porosification treatment on the bone grafting bin shell to obtain the bone grafting bin model arranged on the outer surface of the tooth root or replacing part of the tooth root.

Optionally, in the method for designing an artificial tooth root implant system, the process of obtaining a coating model sleeved on the outer surface of the tooth root at least according to the tooth root in the reference model includes:

intercepting the root in the reference model when the reference model has a single root and the bone grafting bin model is arranged on the outer surface of the root;

Performing Boolean joint operation on the bone grafting bin solid model positioned on the outer surface of the tooth root and the intercepted tooth root to obtain a coating solid model;

performing outward shell drawing on the coating entity model to obtain a coating shell with a set thickness;

and performing a porosification treatment on the coating shell to obtain the coating model.

intercepting the roots in the reference model as a coating solid model when the reference model has a single root and the bone grafting bin model is obtained according to a part of the single root or when the reference model has more than two roots;

Optionally, in the method for designing a pseudo-root implant system, the process of obtaining a bone grafting bin model according to a three-dimensional area between two or more roots in the coating model includes:

Nesting the root of the reference model into the coating model;

converting the reference model and the coating model into a point cloud format, and connecting all points with each other to obtain a minimum envelope surface;

performing Boolean subtraction operation on the minimum envelope surface and the reference model sleeved with the coating model, wherein the rest minimum envelope surface is the bone grafting bin solid model;

and performing porosification treatment on the bone grafting bin shell to obtain the bone grafting bin model.

Optionally, in the method for designing a pseudo-root implant system, the porosification process includes:

selecting a plurality of bracket unit bodies, wherein all the bracket unit bodies are arranged in an array type infinite way in a three-dimensional space; wherein the bracket unit body is of a porous structure;

and carrying out Boolean cross operation on the coating shell or the bone grafting bin shell and the plurality of bracket unit bodies to enable the coating shell or the bone grafting bin shell to form a porous structure.

Optionally, in the design method of the pseudo-root implant system, a plane in which a coronal side of the coating model is located at a side of a plane in which a coronal side of the root in the reference model is located away from the crown, and an axial distance between the plane in which the coronal side of the coating model is located and the plane in which the coronal side of the root in the reference model is located is: 0.1 mm-1 mm.

Optionally, in the design method of the pseudo-root implant system, when the reference model has a single root, an opening is formed on the coating model, and the opening is used for exposing at least part of the bone grafting bin model when the reference model and the bone grafting bin model are nested in the coating model.

Optionally, in the design method of the pseudo-root implant system, the porosity of the coating model ranges from 30% to 80%, and the pore size ranges from 100 micrometers to 1000 micrometers.

Optionally, in the design method of the pseudo-root implant system, the range of the set thickness of the coating shell is: 0.2 mm-2 mm.

Optionally, in the design method of the pseudo-root implant system, the porosity of the bone grafting bin model ranges from 80% to 90%, and the pore diameter ranges from 1000 micrometers to 1400 micrometers.

Optionally, in the design method of the pseudo-root implant system, the set thickness range of the bone grafting bin shell is 0.3 mm-0.7 mm.

Optionally, in the design method of the pseudo root implant system, the design method further includes:

Acquiring a dental crown in the reference model, and taking the dental crown out of the shell inwards to obtain a second dental crown; wherein the coronal surface of the second dental crown is the coronal surface of the abutment;

selecting a plane, wherein the plane is perpendicular to the central axis of the second dental crown;

intersecting the plane with the second dental crown along the direction of the central axis of the second dental crown so as to obtain a minimum intersecting contour line and a maximum intersecting contour line;

stretching towards one side of the tooth root along the central axis by taking the plane of the minimum intersecting contour line as a reference plane until the plane intersects with the crown square surface of the gum penetrating part in the reference model so as to form a base station;

or, taking the minimum intersecting contour line as an initial contour line and the maximum intersecting contour line as a final contour line, and executing the basic lofting operation to form the base station.

Optionally, in the design method of the pseudo-root implant system, the design method further comprises the following steps:

removing crowns in the reference model to form a planting platform from the rest crowns of the reference model;

selecting an area at the central position of the planting platform, and stretching the area towards one side of the dental crown with the area to form a base protruding out of the planting platform;

The side wall shape of the base station is adjusted so that the included angle between the side wall of the base station and the planting platform meets the set requirement;

adjusting the coronal most surface of the abutment so that the coronal most surface of the abutment and the coronal most surface of the dental crown in the reference model have the same surface profile;

wherein the abutment and the remaining reference model form a pseudo-root implant body model.

Optionally, in the design method of the pseudo-root implant system, an axial length of the abutment is smaller than an axial length of the dental crown; the radial length of the abutment is less than the radial length of the crown; the set requirement range of the included angle between the projection line of the side wall of the base station on the coronal plane or the sagittal plane and the cross section is as follows: 90-150 deg..

pulling the crown in the reference model inward; wherein, in executing the shell extraction command, setting and retaining the dental crowns in the reference model to obtain a first porcelain model; setting a crown that does not remain in the reference model to obtain a first basal crown model;

performing Boolean subtraction operation on the first basal crown model and the base station to obtain a second basal crown model;

Taking the bottom surface of the first porcelain model as a reference plane, and cutting off a part of the first porcelain model with a set thickness towards the crown direction to serve as a neck ring model;

performing Boolean subtraction operation on the neck ring model and the first porcelain model to obtain a second porcelain model;

performing Boolean addition operation on the neck ring model and the second basal crown model to obtain a third basal crown model;

the dental crown model comprises a second basal crown model, a second porcelain model and a neck ring model; the second porcelain model and the neck ring model are both sleeved on the outer surface of the second base crown model, and the neck ring model is connected with the bottom surface of the second porcelain model;

alternatively, the crown model includes a third basal crown model and the second porcelain model; the second porcelain decorative model is sleeved on the outer surface of the third basal crown model.

Optionally, in the design method of the pseudo-root implant system, the set thickness range of the neck ring model is: 0.3 mm-3 mm.

Optionally, in the design method of the pseudo root implant system, the design method further includes: and selecting a Maryland bridge model or a clasp model connected with the second decorative porcelain model according to the oral cavity data.

selecting a screw-like model; the rod part of the screw-like model is hollow cylinder;

nesting the roots of the pseudo-root implant body model into the coating model, and placing the bone grafting bin model in the three-dimensional region;

placing the simulated screw model in the simulated root implant body model along the coronal direction, enabling the simulated screw model to coincide with the central axis of the simulated root implant body model, wherein the top end of the simulated screw model is positioned in the base station, and the rod part of the simulated screw model penetrates through the coating model and the bone grafting bin model; or, penetrating the screw-like model through the bone grafting bin model along the cheek-tongue direction;

when the screw-imitating model is arranged along the coronal direction, carrying out Boolean intersection operation on the screw-imitating model, the pseudo-tooth root implant body model, the coating model and the bone grafting bin model, so that a screw channel is formed in the pseudo-tooth root implant body model, a through hole is formed in the coating model, and two guide ring models which are opposite along the coronal direction are formed in the bone grafting bin model;

When the screw-like model is arranged along the cheek-tongue direction, the screw-like model and the bone grafting bin model are subjected to Boolean intersection operation, so that two guide ring models which are opposite along the cheek-tongue direction are formed in the bone grafting bin model.

Optionally, in the design method of the pseudo root implant system, the design method further includes: designing a screw model arranged along the coronal direction and a screw model arranged along the buccal-lingual direction; wherein, the rod part of the screw model is provided with self-tapping threads, and the maximum diameter of the stem of the screw model is equal to the inner diameter of the stem of the simulated screw model;

the screw model arranged along the cheek-tongue direction is also matched with a nut model and a gasket model; the gasket model is sleeved with the rod part of the screw model and connected with the head end of the screw model; one side surface of the gasket model far away from the head end of the screw model and one side surface of the nut model close to the head end of the screw model are formed by fitting part of the side surface of the alveolar bone at the affected tooth.

Based on the same inventive concept, the invention also provides a preparation method of the pseudo-tooth root implant system, and the pseudo-tooth root implant system designed by the design method of the pseudo-tooth root implant system is prepared by adopting a 3D printing technology and/or a CNC technology.

Optionally, in the method for preparing the pseudo-root implant system, the coating and the bone grafting bin are respectively made of titanium alloy materials or shape memory materials independently.

In summary, the invention provides a design method and a preparation method of a pseudo-root implant system. In the design method of the pseudo-tooth root implant system, the three-dimensional model of the affected tooth obtained through scanning is used as a design basis, is closer to the real tooth, realizes the simulation of the force transmission characteristic of natural molar teeth and the stress distribution characteristic of tooth roots, disperses occlusion stress through multi-tooth root arrangement, and therefore has strong anti-rotation performance. And when the three-dimensional model does not meet the set requirement, the method can perform flattening treatment and/or parting angle treatment on the tooth root of the three-dimensional model, so that the designed tooth root is easier to locate in a tooth extraction socket, the excessive or insufficient parting angle is avoided, and the implantation difficulty is reduced. In addition, the invention also designs a coating model and the bone grafting bin model. The coating model is sleeved on the outer surface of the tooth root of the reference model, and can be in interference connection with the tooth extraction socket during planting, so that the short-term and long-term stability after planting is facilitated. The bone grafting bin model is a shell model, and can contain anti-inflammatory and growth-promoting medicines, so that the short-term and long-term stability after planting is facilitated. And the coating model and the bone grafting bin model are subjected to porosification treatment, so that the diffusion of the medicine and the growth of bone tissues are facilitated. Therefore, the artificial tooth root implant system formed by the invention not only can simulate the stress characteristic of natural tooth grinding and disperse the occlusal stress and improve the short-term and long-term stability of the implant, but also reduces implantation difficulty by flattening the tooth root and/or treating the parting angle.

Drawings

FIG. 1 is a flow chart of a method of designing a pseudo-root implant system in an embodiment of the present invention;

FIG. 2 is a schematic view of a model of a tooth tissue in an embodiment of the invention;

FIG. 3 is a schematic illustration of a crown in a three-dimensional model in an embodiment of the present invention;

FIG. 4 is a schematic view of a gum-penetrating portion and root in a three-dimensional model in an embodiment of the present invention;

FIG. 5 is a schematic illustration of a root in a three-dimensional model in an embodiment of the invention;

FIG. 6 is a schematic representation of a three-dimensional model in an embodiment of the invention;

FIG. 7 is a schematic diagram of corner layer locations in an embodiment of the invention;

FIG. 8 is a schematic diagram of a flattening process in an embodiment of the present invention;

FIG. 9 is a schematic diagram of an isometric process in an example embodiment of the invention;

FIG. 10 is a schematic diagram of the loft basic operation in an embodiment of the present invention;

FIG. 11 is a schematic diagram of a reference model in an embodiment of the invention;

FIG. 12 is a schematic view of a bifurcation angle acquisition in a coronal plane view in accordance with an embodiment of the present invention;

FIGS. 13-16 are schematic illustrations of the placement of a bone graft bin model in a reference model with a single root in an embodiment of the invention;

FIG. 17 is a schematic view of a coated shell with a single root in an embodiment of the invention;

FIG. 18 is a schematic view of a coated shell with two roots in an embodiment of the invention;

fig. 19 is a schematic layout view of a supporting unit body in the embodiment of the present invention;

FIG. 20 is a schematic illustration of a coating model in an embodiment of the invention;

FIG. 21 is a schematic view of a coating housing in an embodiment of the invention;

FIG. 22 is a schematic diagram of a coating model and reference model combination in an embodiment of the invention;

FIG. 23 is a schematic illustration of a minimum envelope surface in an embodiment of the invention;

FIG. 24 is a schematic illustration of a bone grafting cartridge solid model in an embodiment of the invention;

FIG. 25 is a cross-sectional view of a bone graft compartment model in an embodiment of the invention;

FIG. 26 is a schematic illustration of a pseudo-root implant body model in an embodiment of the present invention;

FIG. 27 is a schematic view of a basic model after removal of a crown in an embodiment of the present invention;

FIG. 28 is a schematic view of a crown in a basic model in an embodiment of the present invention;

fig. 29 is a schematic view of a second crown in an embodiment of the invention;

FIG. 30 is a schematic illustration of a minimum intersecting contour line and a maximum intersecting contour line in an embodiment of the invention;

FIG. 31 is a schematic illustration of a stretched base station with minimum intersecting contour lines as a reference in an embodiment of the invention;

FIG. 32 is a schematic diagram of a base station in an embodiment of the invention;

FIG. 33 is a schematic view of a pseudo-root implant body model in an embodiment of the present invention;

FIG. 34 is a schematic view of a first basal crown model in an embodiment of the invention;

FIG. 35 is a cross-sectional view of a second crown molding, a second porcelain molding, and a neck ring molding in an embodiment of the invention;

FIG. 36 is a cross-sectional view of a second porcelain model in an embodiment of the invention;

FIG. 37 is a cross-sectional view of a third basal crown model in an embodiment of the invention;

FIG. 38 is a schematic view of a pseudo-root implant system model in an embodiment of the present invention;

FIG. 39 is a schematic illustration of the position of a coronal screw-like model in an embodiment of the invention;

FIG. 40 is a schematic illustration of the position of a buccal lingual screw imitation model in an embodiment of the invention;

FIG. 41 is a schematic view of a coronal set screw-like model in an embodiment of the invention;

FIG. 42 is a schematic view of a coronal screw penetration pseudo-root implant body model in an embodiment of the present invention;

FIG. 43 is a schematic view of a coronal screw penetration pseudo-root implant body model in an embodiment of the present invention;

FIG. 44 is a schematic view of the location of a screw channel in an embodiment of the present invention;

FIG. 45 is a schematic illustration of a simulation screw model of a buccal lingual arrangement in an embodiment of the invention;

FIG. 46 is a schematic view of a buccal lingual screw penetrating a model of an artificial root implant body in an embodiment of the invention;

FIG. 47 is a cross-sectional view of a bone graft compartment model in an embodiment of the invention;

FIG. 48 is a schematic view of a coronal screw model in an embodiment of the invention;

FIG. 49 is a schematic view of a buccal lingual screw model, a nut model, and a washer model in an embodiment of the invention;

wherein, the reference numerals are as follows:

m0-a model M1-a three-dimensional model of the affected tooth tissue; m2-reference model; m3-coating shell; m4-coating model; m5-bone grafting bin solid model; m6-bone grafting bin model; m7-a tooth root planning implant body model; m8-a first basal crown model; m9-neck ring mold; m10-a second porcelain decoration model; m11-a second basal crown model; m12-third basal crown model; m13-guide ring model; m14-coronal screw imitation model; m15-a buccal lingual screw imitation model; m16-coronal screw model; m17-bucoglossal screw model; m18-nut model; m19-shim model;

101-dental crown; 1011-second crown; 102-a gingival penetration portion; 103-root; 104-gingival tissue; 105-alveolar bone; 106-base station;

a-irregularly inclined structures; b-supporting the unit body; c-a minimum envelope surface; d-screw channel; e-a screw-like model position placed along the coronal direction; f-position of the screw-like model placed in the buccal lingual direction.

Detailed Description

The invention will be described in further detail with reference to the drawings and the specific embodiments thereof in order to make the objects, advantages and features of the invention more apparent. It should be noted that the drawings are in a very simplified form and are not drawn to scale, merely for convenience and clarity in aiding in the description of embodiments of the invention. Furthermore, the structures shown in the drawings are often part of actual structures. In particular, the drawings are shown with different emphasis instead being placed upon illustrating the various embodiments. It should be further understood that the terms "first," "second," "third," and the like in this specification are used merely for distinguishing between various components, elements, steps, etc. in the specification and not for indicating a logical or sequential relationship between the various components, elements, steps, etc., unless otherwise indicated. Wherein, the "dental crown" refers to a part above gum tissue in the specification; the "gingival penetration portion" is the portion covered by gingival tissue; "root" is the portion located below the gingival tissue.

The present embodiment provides a design method of an artificial tooth root implant system, please refer to fig. 1, which includes:

Step one S10: collecting oral cavity data and obtaining a three-dimensional model of the affected teeth;

step two S20: judging whether the three-dimensional model meets the set requirements, if so, taking the three-dimensional model as a reference model, if not, carrying out straightening treatment and/or parting angle treatment on the tooth root in the three-dimensional model, and taking the treated three-dimensional model as the reference model;

step three S30: obtaining a coating model sleeved on the outer surface of the tooth root at least according to the tooth root in the reference model; and obtaining a bone grafting bin model according to part or all of the single tooth root in the reference model or according to a three-dimensional area between more than two tooth roots in the coating model so as to form a pseudo-tooth root implant system with a coating and a bone grafting bin on the pseudo-tooth root.

Therefore, the design method of the pseudo-tooth root implant system provided by the embodiment is closer to the real teeth by taking the three-dimensional model of the affected tooth obtained by scanning as a design basis, realizes the simulation of the force transmission characteristic of the natural teeth and the stress distribution characteristic of the tooth roots, and particularly has stronger anti-rotation performance for multi-tooth root molar teeth by simulating multi-tooth root to disperse the occlusion stress. And when the three-dimensional model does not meet the set requirement, the embodiment can perform flattening treatment and/or parting angle treatment on the tooth root of the three-dimensional model, so that the designed tooth root is easier to locate in a tooth extraction socket, the excessive or insufficient parting angle is avoided, and the implantation difficulty is reduced. In addition, the embodiment also designs a coating model and the bone grafting bin model. The coating model is sleeved on the outer surface of the tooth root of the reference model, and can be in interference connection with the tooth extraction socket during planting, so that the short-term and long-term stability after planting is facilitated. The bone grafting bin model is a shell model, and can contain anti-inflammatory and growth-promoting medicines, so that the short-term and long-term stability after planting is facilitated. Wherein, the coating model and the bone grafting bin model are both subjected to porosification treatment, which is beneficial to the diffusion of medicines and the growth of bone tissues. Therefore, the artificial tooth root implant system formed by adopting the design method of the artificial tooth root implant system provided by the embodiment not only can simulate the stress characteristic of natural teeth and disperse the occlusion stress so as to improve the short-term and long-term stability of the implant, but also can reduce implantation difficulty by carrying out flattening treatment on the tooth root and/or carrying out treatment on parting angles.

The method of designing the pseudo-root implant system is described in detail below with reference to fig. 1-49.

Step one S10: referring to fig. 2-6, oral data is collected to obtain a three-dimensional model of the affected teeth.

The conversion of the actual dentition form of the oral cavity into a digital model through optical scanning is the basis for personalized design of the affected teeth. Among the ways in which oral data may be acquired include, but are not limited to, cone-beam computed tomography (Cone beam computed tomograph, CBCT) and three-dimensional oral scanners. The oral cavity of a patient is scanned by adopting cone beam computer tomography (Cone beam computed tomograph, CBCT) to obtain the three-dimensional data of the complete upper and lower jawbones and teeth of the patient, wherein the scanning range is that a scanning marking line is parallel to a mandibular plane, and the scanning range is from the highest point at the top of the condyle of the mandible to the lower edge of the mandible and from top to bottom. Scanning by a three-dimensional oral scanning instrument to obtain three-dimensional data of dentition and soft tissues in the oral cavity. Thus, by intraoral data acquisition, at least dentition data, alveolar bone data, and gingival tissue data are acquired. In order to improve the accuracy of the data, the acquired data may be processed by technical means known to those skilled in the art, for example: filtering noise points, layer thickness setting, image threshold selection, mask processing, morphological processing, smoothing processing, region growing, filling mask, calculating a three-dimensional model and the like are carried out on CBCT data; and performing scanning calibration, scanning precision, noise point deletion, trimming of a mouth scanning model area, surface broken repair, occlusion relation treatment and the like on mouth scanning data.

Referring to fig. 2, at least an affected tooth tissue model M0 and an alveolar bone model and a gingival tissue model at the affected tooth are obtained according to the obtained dental dentition data, the alveolar bone data and the gingival tissue data. Wherein gum tissue 104 covers the gum penetrating portion 102 of the tooth and the alveolar bone 105 surrounds the root 103 of said tooth. The alveolar bone model and gingival tissue model are solid models of the gingival tissue 104 and the alveolar bone 105 at the affected tooth. Then, the affected tissue model M0 is subjected to a boolean subtraction operation with the gum tissue model and the alveolar bone model to obtain a crown 101 in the three-dimensional model of the affected tooth M1 as shown in fig. 3. The diseased tooth tissue model M0 and the gum tissue model are subjected to boolean cross operation to obtain the gingival penetration portion 102 in the three-dimensional model of the diseased tooth M1 as shown in fig. 4. The affected tissue model M0 and the alveolar bone model are subjected to boolean intersection operation to obtain the root 103 in the three-dimensional model M1 of the affected tooth as shown in fig. 5. Finally, as shown in fig. 6, the obtained three-dimensional model M1 of the affected tooth includes a crown 101, a gum penetrating portion 102, and a root 103, which are sequentially connected in the coronal direction.

Further, when the crown 101 of the affected tooth is missing or defective, the pair of the affected teeth is obtained based on the dentition data

A crown 101 of a tooth or a symmetric tooth is used as the crown 101 of the three-dimensional model M1. Wherein, pair->

The teeth are opposite teeth meshed with the affected teeth, and the symmetrical teeth are teeth symmetrical to the affected teeth along the median sagittal plane. When the crown 101 of the affected tooth is missing or defective, the crown 101 of the three-dimensional model M1 is preferably the crown 101 of a symmetric tooth. In addition, in consideration of design effect and later-stage hole preparation and planting, periodontal ligament, adjacent tooth and pair of suffering teeth are also acquired as much as possible when the oral cavity data are acquired>

Teeth, etc., as design references and post-implantation needs.

Step two S20: referring to fig. 6-12, it is determined whether the three-dimensional model M1 meets a set requirement, if so, the three-dimensional model M1 is taken as a reference model M2, if not, the root 103 in the three-dimensional model M1 is subjected to flattening and/or angle division, and the processed three-dimensional model M1 is taken as the reference model M2.

Because of the complex chewing motion of the oral cavity, the tooth body and supporting tissues are subjected to dynamic impact load in the motion process, the deformation and stress distribution state of the tooth body and the supporting tissues are related to the motion process and time, and the load duration time has larger influence than the load strength. The periodontal ligament exists between the natural tooth root and the alveolar bone, and can sense external force and make corresponding feedback regulation, so that the periodontal ligament has good protectiveness, can prevent wounds caused by excessive lateral force, has good protectiveness, and the pseudo-tooth root implant is rigidly connected with bone tissue, and has no regulation effect. Therefore, the artificial tooth root implant should ensure that no larger or smaller bifurcation degree exists between the tooth roots and the inward concave or outward expansion of the tooth roots as much as possible when being implanted, thereby avoiding the undesirable complications such as uneven stress distribution of bone tissues around the implant, loosening and falling of the implant and the like caused by excessive lateral force. Therefore, the present embodiment needs to determine and repair the bifurcation degree between the roots of the obtained three-dimensional model M1 and the concave degree or the expansion degree of the roots.

The single tooth root of the anterior tooth is normal, can be straight or slightly inclined, is easy to implant during implantation, and has no problem of difficult implantation of molar. Whereas molar teeth having more than two roots 103 are more prone to irregular shapes of the roots and too large or too small a bifurcation between the roots. As shown in fig. 6, the tooth roots 103 of the molars are generally two, three or four, and not only the chewing mechanical pattern of the teeth is complicated, but also the irregular inclined structure a is easily generated. For example, the root 103 may curve toward one side, possibly concave inward or convex outward, making implantation difficult. In this regard, after the three-dimensional model is obtained, it is necessary to analyze the root of the affected tooth to determine whether the irregular inclined structure a exists.

Referring to fig. 7, a plurality of two-dimensional images (i.e., cross-sectional images) of the affected tooth may be obtained by CBCT scanning. And along the coronal direction, each of the two-dimensional images corresponds to a planar image of a respective layer in the three-dimensional model. The three-dimensional model M1 can be reconstructed by superimposing a certain number of the two-dimensional images in the chemicals software. It will be appreciated that in CBCT scanning, the affected teeth are automatically layered, and each layer of planar information of the affected teeth is scanned layer by layer and stored as a two-dimensional image. Via a plurality of said two-dimensional images, a three-dimensional model M1 of the affected tooth can be reproduced. The plurality of two-dimensional images obtained via CBCT scan can be understood as dividing the three-dimensional model M1 of the affected tooth into a plurality of layers along the axial direction z.

Further, according to the three-dimensional model M1, the plurality of layers of two-dimensional images and the direct positional relationship of the two-dimensional images, the projection lines of the central connecting lines of every two adjacent layers on the coronal plane and the sagittal plane are sequentially calculated from the layer closest to the dental crown in the dental root, and the included angle between the projection line of the first two layers on the coronal plane or the sagittal plane and the projection line of the second two layers on the corresponding plane in every three continuous layers is calculated. When the included angle is larger than or equal to 5 degrees, the tooth root does not meet the set requirement; and when all the included angles are smaller than 5 degrees, the tooth root meets the set requirement. The central connecting line of two adjacent layers is based on the contour line of the single two-dimensional image, the center point of gravity of the central connecting line is used as a central point, the coordinate value of the central point is obtained, and the central connecting line can be obtained by connecting the central points of the two-dimensional image contours of the adjacent layers. The calculation of each two adjacent layers in turn means that the first layer and the second layer are calculated first, then the second layer and the third layer are calculated, then the third layer and the fourth layer are calculated, and so on, starting from the layer closest to the crown in the root of the tooth and facing away from the crown. When the three-dimensional model M1 has a plurality of roots 103, it is necessary to make a judgment for each of the roots 103.

When the included angle is greater than or equal to 5 °, the root 103 needs to be flattened. The middle layer of the three successive layers having the included angle of 5 ° or more is taken as the inflection layer O. When judging whether the tooth root 103 of the affected tooth meets the set requirement layer by layer along the coronal root direction, when the first inflection layer O appears, the judgment can be stopped, and no matter whether other inflection layers O exist in the rest of the tooth root 103, the judgment is not needed. Since the other inflection layers O have no reference value, only the two-dimensional image corresponding to the first inflection layer O needs to be acquired. Taking the coronal plane projection as an example, fig. 7 in this embodiment shows an inflection layer O, and uses the inflection layer O as a boundary layer, where a projection line of the boundary layer and a central connection line of a layer adjacent thereto, which is close to the gum penetrating portion 102, on the coronal plane is a projection line a, and a projection line of the boundary layer and a central connection line of a layer adjacent thereto, which is far from the gum penetrating portion 102, on the coronal plane is a projection line b. Therefore, the projection line of the central axis of the part of the tooth root on the coronal plane after passing through the inflection point layer O along the coronal direction is changed from a to b, so that the tooth root 103 has an inverted concave shape, which is not beneficial to bearing stress, wherein the included angle α formed by the projection line a and the projection line b is the included angle required to be determined. The sagittal projection is similar to the coronal projection and will not be described in detail herein.

Referring to fig. 8, after the two-dimensional image corresponding to the inflection point layer O is extracted, a radial contour line of the root 103 in the two-dimensional image is taken as a start contour line S0. According to the initial contour S0, equidistant processing is performed in the direction toward the root of the tooth with the center connecting line of the inflection layer O and a layer adjacent to the inflection layer O and close to the direction of the crown 101 as a reference axis a to obtain at least one equidistant contour. As shown in fig. 8 and 9, the starting contour S0 is referenced and equidistant from the negative half-axes toward the reference axis a to form at least one equidistant contour. Wherein fig. 8 shows one equidistant contour S1 and fig. 9 shows four equidistant contours. The specific number of equidistant contours may be determined according to the length of the root. That is, when the inflection layer O is located at the middle position of the root 103 and is longer from the lowest position of the other roots 103, a plurality of equidistant contour lines may be equidistantly disposed, and when the inflection layer is close to the tip of the root 103, only one equidistant contour line may be disposed. Wherein the last of said equidistant contours is denoted as termination contour S1.

Further, as shown in fig. 9, during the equidistant processing, all the equidistant contour lines are sequentially reduced equidistantly in the radial direction. Wherein, the size range of each reduction is: 0.1 mm-0.8 mm, alternatively 0.1 mm, 0.5 mm or 0.8 mm. And the smallest diameter of the last equidistant contour, i.e. the ending contour S1, is greater than or equal to 0.3 mm. The equidistant contour lines are usually irregular plane closed curves, all points on the curves can be moved inwards by the same distance at the same time, so that the plane closed curves are scaled down, or the plane closed curves can be fitted into ellipses, and the minor diameter of the ending contour line S1 of the ellipses is larger than or equal to 0.3 millimeter, so that the bottom of the tooth root 103 subjected to the flattening treatment is curved instead of contact points, and the bearing of biting force is facilitated. Further, the axial distance between the start contour line S0 and the end contour line S1 is in the range of: 0.1 mm-8 mm. Preferably, the position of the termination contour S1 is flush with the lowest point of the other roots 103 in the affected tooth.

Referring to fig. 10, after the equidistant processing is completed, a basic lofting operation is performed on the starting contour S0 and all the equidistant contours, that is, all the contours are sequentially connected to form a solid model, thereby completing the flattening processing of the root 103. Then, as shown in fig. 11, the flattened root 103 is replaced with the root 103 having the original irregular inclined structure a. The flattened root 103 does not have undercut or expansion, so that the difficulty of implantation is reduced, the stress distribution of the pseudo-root implant is uniform, and the initial and long-term stability of the implant is improved.

Further, when determining whether the three-dimensional model M1 meets the set requirement, the method further includes: as shown in fig. 12, the three-dimensional model M1 is calculated to obtain a bifurcation angle β between two or more of the roots 103. The method for acquiring the bifurcation angle beta comprises the following steps: and acquiring projection lines of the central axis of each tooth root on the coronal plane and the sagittal plane in the three-dimensional model, and calculating an included angle between the projection lines of the central axes of every two tooth roots on the coronal plane or the sagittal plane, namely, a bifurcation angle beta. When the bifurcation angle beta is smaller than 5 degrees or larger than 15 degrees, the bifurcation angle beta does not meet the set requirement. When the bifurcation angle is larger than or equal to 5 degrees and smaller than or equal to 15 degrees, the bifurcation angle beta meets the set requirement. Because the bifurcation angle β directly affects the uniformity of stress distribution, and when the bifurcation angle β is too large, it also affects the implantation of the pseudo-root implant, and the bifurcation angle β is too small, which is not beneficial to the initial stability of the implantation, when the bifurcation angle β of the three-dimensional model M1 does not meet the set requirement, the bifurcation angle β needs to be adjusted.

The method for adjusting the bifurcation angle beta provided by the embodiment is as follows: taking the central axis of the tooth root 103 meeting the set requirement, or taking the central axis of the tooth root 103 after the flattening treatment as a reference axis, taking the central axis of a target tooth root to be treated as a target axis, projecting the reference axis and the target axis onto a coronal plane and a sagittal plane, taking the coronal plane projection as an example, referring to fig. 12, projecting the reference axis and the target axis onto the coronal plane to obtain a projection line c and a projection line d, forming an intersection e by the projection line c and the projection line d, and rotating the projection line d around the intersection e until an included angle beta between the projection line d and the projection line c meets the set requirement; and the tooth root 103 is set according to the processed target axis with the rotated projection line as the processed target axis. It can be understood that the furcation angle beta is adjusted by taking the crossing point e as a rotation datum point to reduce or enlarge the furcation angle beta so as to enable the furcation angle beta to meet the requirement of 5-15 degrees.

After the flattening process and/or the separation angle β process are performed on the root 103 in the three-dimensional model M1, a reference model M2 of the pseudo-root implant system shown in fig. 11 is obtained, and the reference model M2 is used as a standard reference for the subsequent design.

Further, in straightening the root 103 and adjusting the bifurcation angle β, it is necessary to consider the thickness of the bone wall around the affected area. Since the distance between the root itself and the bone wall is very small, excessive angle or excessive adjustment amplitude may cause bone windowing during adjustment of the bifurcation angle β or flattening. Therefore, when preparing the cavity, the labial bone wall of at least 2mm in the anterior tooth area and the buccal bone wall of at least 1mm in the posterior tooth area are generally required to be ensured, the bone wall of 1-1.5 mm is reserved on the jaw side, the distance between the bone wall and the adjacent tooth is 1.5-2 mm, and the distance between the bone wall and the similar type of pseudo-tooth root implant or other types of implant is more than 3 mm.

Step three S30: referring to fig. 13-49, a coating model M4 sleeved on the outer surface of the root 103 is obtained at least according to the root 103 in the reference model M2; and obtaining a bone grafting bin model M6 according to part or all of the single tooth root 102 in the reference model M2 or according to a three-dimensional area between more than two tooth roots in the coating model M4 so as to form a tooth-planning implant system with a coating and a bone grafting bin on the tooth-planning root.

Because the front teeth of the natural teeth are generally single tooth root and flat; molar teeth typically have two or three roots to achieve stress relief of the bite. Therefore, in designing the pseudo-root implant system, this embodiment requires separate design of a single root and more than two roots. When the reference model M2 has a single root 103, the bone grafting bin model M6 needs to be designed first, and then the coating model M4 needs to be designed. The coating model M4 is designed later because the coating model M4 needs to cover part of both the root 103 and the bone grafting cartridge model M6. When the reference model M2 has more than two tooth roots 103, the coating model M4 and then the bone grafting bin model M6 need to be designed. Since the coating model M4 only needs to cover part of the root 103, the bone grafting bin model M6 is located outside the coating model M4, the bone grafting bin model M6 is designed later.

As shown in fig. 13-14, when the reference model M2 has a single root, the bone graft bin model M6 may be located on opposite sides of the root 103. Because the single tooth root is generally flat, the thickness of the tooth root 103 along the X direction is greater than the thickness of the tooth root 103 along the Y direction, so that a sufficient connection area is reserved to ensure stable connection, and the bone grafting bin is generally arranged on the plane in the X direction. And the number of the bone grafting bins can be one, two or three or the like on two side surfaces. Alternatively, the number of the bone grafting bins on two sides may be different, for example, one side is provided and the other side is provided with two. Accordingly, the present embodiment does not limit the number of the bone graft compartment models M6 when the reference model M2 has a single root. In addition, when the reference model M2 has a single root, the bone graft compartment model M6 may replace part of the root 103. As shown in fig. 15-16, the bone graft compartment model M6 is provided as part of the root 103.

Referring to fig. 13-14, when the reference model M2 has a single root 103, the placement area of the bone grafting bin model M6 is selected first, and may be located on the outer surface of the root 103 or may be connected to a portion of the root 103 as a part of the root 103. As shown in fig. 13-14, when the bone grafting bin model M6 is to be located on the outer surface of the tooth root 103, the outer surface of the tooth root 103 corresponding to the placement area is used as a reference surface, and the reference surface is stretched along the radial direction of the tooth root 103 and towards the side far from the tooth root 103, so as to obtain the bone grafting bin solid model. It can be understood that the designed bone grafting bin needs to be attached to the outer surface of the tooth root, and when the bone grafting bin model M6 is designed, an attaching surface, namely a reference surface, needs to be selected first, and then the bone grafting bin solid model is obtained through stretching. The surface of the bone graft compartment solid model in contact with the root 103 is still the selected reference surface.

15-16, when the bone grafting bin model M6 is to replace a portion of a single tooth root 103, a portion of the tooth root 103 in the reference model M2 is first truncated, and a portion of the tooth root 103 is used as a bone grafting bin solid model. Wherein, taking part of the tooth root 103 as a bone grafting bin solid model can lead the bone grafting bin model M6 which is designed later to be well connected with the rest part of the tooth root, and no gap exists in the middle, thereby ensuring the integrity of the tooth root 103.

After the bone grafting bin solid model is obtained, the bone grafting bin solid model is subjected to inward shell drawing so as to obtain the bone grafting bin shell with set thickness. When the inward shell drawing command is executed, the original shape is required to be maintained, the bone grafting bin shell after shell drawing still maintains the outermost outline dimension, but the middle part is evacuated to form a cavity. Finally, a porosification process (see a process of coating shell porosification) is performed on the bone graft compartment shell to obtain the bone graft compartment model M6 disposed on the outer surface of the root 103 or replacing a portion of the root 103.

After the bone grafting cartridge model M6 is designed, the coating model M4 needs to be designed. When the reference model M2 has a single root 103 and the bone grafting bin model M6 is disposed on the outer surface of the root 103, the root 103 in the reference model M2 is first truncated. And then, carrying out Boolean joint operation on the bone grafting bin solid model positioned on the outer surface of the tooth root 103 and the intercepted tooth root 103, so that the bone grafting bin solid model and the intercepted tooth root 103 are synthesized into a whole to be used as a coating solid model. Next, as shown in fig. 17, the exterior drawing is performed on the coating solid model to obtain a coating case M3 having a set thickness. When the shell-out command is executed, the original shape of the coating solid model is required to be reserved, so that the obtained inner surface of the coating shell M3 is consistent with the outer surface of the coating solid model. Finally, a porosification process is performed on the coating housing M3 to obtain the coating model M4.

When the reference model M2 has a single root 103 and the bone grafting bin model M6 replaces a part of the root 103, the bone grafting bin model M6 may be designed first or the coating model M4 may be designed first, because no influence is exerted on the outer surface of the root 103. The design method of the coating model M4 is the same as the design method of the coating model M4 when two or more of the tooth roots 103 are used, and specifically includes the following steps:

the root 103 in the reference model M2 is first truncated as a coating solid model. Then, as shown in fig. 17 or 18, the exterior drawing is performed on the coating solid model to obtain a coating shell M3 having a set thickness. Also, when the shell-out command is executed, the original shape of the coating solid model needs to be maintained, so that the obtained inner surface of the coating shell M3 is consistent with the outer surface of the coating solid model. In other words, the outward extraction refers to the root 103 to be intercepted, leaving only the outer surface, the interior empty. And the outer surface of the root 103 is extended by a certain thickness toward the outside of the root 103. Finally, as shown in fig. 20, a porosification process is performed on the coating housing M3 to obtain the coating model M4.

Wherein, the porous treatment is carried out on the coating shell M3 and the bone grafting bin shell, and the difference is only the porosity and the pore size range. The process of porosification of the coating shell M3 is:

as shown in fig. 19, a plurality of bracket unit bodies B are selected, and the plurality of bracket unit bodies B are arranged in an array type infinite manner in a three-dimensional space. Further, the shape of the bracket unit body B includes, but is not limited to, a rhombic dodecahedron, a regular hexahedron, a honeycomb shape, or the like. The plurality of bracket unit bodies B are connected and are arranged in an array type infinite way in a three-dimensional space, so that the coating or the bone grafting bin forms a porous structure. Further, the array may be an ordered array or an unordered array, mimicking the trabecular bone structure. The porosity and pore size range can be set by adjusting the size and shape of the stent unit body B. Furthermore, the bracket unit body B comprises a bracket structure by a plurality of rods, and micropores can be formed on the surfaces of the rods through micro-arc oxidation so as to increase the surface area of the coating or the bone grafting bin and play a role in improving the drug loading rate.

Referring to fig. 20, the plurality of stent units B and the coating housing M3 are stacked (e.g. by boolean operations) to form a porous structure of the coating housing M3, so as to obtain the coating model M4. Likewise, the bone grafting bin model M6 also adopts the method to form a porous structure. The arrangement of the porous structure is favorable for bone tissue to climb into the implant body from the implant body outer phase, so that long-term biological fixation is formed. In addition, the porous design of the bone grafting bin is also beneficial to the diffusion of medicines in the bone grafting bin and the promotion of the bone tissue to grow from the implant body to the outside of the implant body by utilizing the self tooth tissue, so that the short-term and long-term planting stability is provided. Wherein the porosity of the coating model M4 ranges from 30% to 80%, and the pore size ranges from 100 micrometers to 1000 micrometers. Preferably, the porosity is 67% and the pore size is 650 microns. The bone graft compartment model M6 has a porosity ranging from 80% to 90%, and a pore size ranging from 1000 microns to 1400 microns, preferably 85% and 1200 microns.

Further, as shown in fig. 21 to 22, when designing the coating model M4, an axial distance h between a plane of the coronal most side of the root 103 in the reference model M2 and a plane of the coronal most side of the root 103 in the reference model M2 is: 0.1 mm-1 mm. It will be appreciated that the axial length of the coating model M4 obtained is smaller than the axial length of the root 103. The purpose is that the coating formed according to the design forms a platform transfer similar to the traditional implant with the top surface of the tooth root, so that the profile surface of the top surface of the coating is lower than the top surface of the tooth root, bone resorption occurs in the alveolar bone after implantation, and finally the top surface of the coating is leveled with the top surface of the alveolar bone. And, after implantation gum tissue and the laminating of platform shift, form soft tissue and seal, avoid food residue, bacterium etc. to get into the root of a tooth through the gap for the pseudo-root implant system is more firm, and can also reduce the butterfly bone absorption of the alveolar bone around the implant platform.

Further, the thickness of the coating shell M3 is determined by the periodontal ligament of the affected tooth. The thicknesses of periodontal membranes on the buccal side, lingual side, mesial side and distal side of the affected tooth are obtained from the oral data, and an average value is calculated as a reference thickness of the coating case M3. Since the thickness (interference) of the coating case M3 is set in consideration of the stress influence of the thickness on the alveolar bone at the time of implantation. Only if the stress developed is in a certain range will bone remodeling occur in the alveolar bone. Therefore, the thickness of the coating case M3 is slightly larger than the average value. For example, the average value of the periodontal ligament of the affected tooth is 0.34mm, and the thickness of the coating case M3 is optionally 0.5mm or 0.75mm. Preferably, to ensure the combination of the coating and the implant, an outer casing can be provided by drawing 0.5mm outwards to form an outer coating casing, and an inner casing can be provided by drawing 0.25mm inwards to form an inner bonding layer. The inner bonding layer is used for being overlapped with the implant, bonding strength is increased, and finally the coating shell with the wall thickness of 0.75mm is obtained. As shown in fig. 21, g is the outline of the outer coating shell, i is the outer outline of the tooth root, and f is the outline of the inner coating shell, then the thickness of the coating shell M3 is the thickness between the outline g and the outline f. In order to avoid damage to the tooth socket caused by too thick coating or poor initial stabilization effect of implantation caused by too thin coating, the thickness of the coating shell is preferably in the range of: 0.2 mm-2 mm.

The theoretical method of stress analysis in the design process of the coating model M4 is finite element analysis. Of course, the alveolar bone stress can be evaluated by performing some animal experiments or clinical trials. However, in the actual custom design manufacturing process, due to the time relationship, the stress influence of the interference magnitude of the implantation process on the alveolar bone is generally obtained through finite element calculation. The coating is designed to be in interference connection with the tooth extraction socket, so that initial stability after planting is facilitated.

Further, for the coating model M4 having a single root, an opening (not shown) is also provided on the coating model M4. The openings are used for exposing at least part of the bone grafting bin model M6 when the reference model M2 and the bone grafting bin model M6 are nested in the coating model M4, so that the placement and the diffusion of medicines in the bone grafting bin formed by design are facilitated. The number of the openings is not limited in this embodiment, and may be one, two, three, or the like.

22-25, for the reference model M4 with more than two tooth roots 103, the bone grafting chamber model M6 is designed after the coating shell M3 is obtained. The method comprises the following steps:

As shown in fig. 22, the root 103 of the reference model M2 is first nested into the coating model M4. Then, as shown in fig. 23, the reference model M2 and the coating model M4 are converted into a point cloud format using a convex hull algorithm, and all points are connected to each other to obtain a minimum envelope surface C. Next, as shown in fig. 24, the minimum envelope surface C and the reference model M2 sleeved with the coating model M4 are subjected to boolean subtraction operation, and the remaining minimum envelope surface is the bone grafting bin solid model M5. And then, performing inward shell extraction on the bone grafting bin solid model M5 to obtain a bone grafting bin shell with a set thickness. Namely, the outer surface of the bone grafting bin solid model M5 is reserved, the inside of the bone grafting bin solid model M5 is empty, and a certain thickness is extended inwards according to the outer surface of the bone grafting bin solid model M5, so that the bone grafting bin shell with the set thickness is formed. Wherein, the set thickness range of the bone grafting bin shell is 0.3 mm-0.7 mm, and is preferably 0.5 mm. Finally, as shown in fig. 25, the bone grafting chamber shell is subjected to a porosification treatment by adopting the same porosification treatment method for forming the coating model M4, so as to obtain the bone grafting chamber model M6. Wherein, fig. 25 is a sectional view taken along the line D-D' in fig. 24, and the outer shell of the bone grafting cartridge model M6 is porous and has a cavity formed therein. The purpose is that the extracted affected teeth are crushed together with the alveolar bone stripped by the prepared hole after glaze removal, cleaning and disinfection, and the mixed dental bone powder or some medicines with the growth anti-inflammatory effect are plugged into the cavity of the bone grafting bin which is designed to form, so that the bone tissue growth after the implantation is facilitated, and meanwhile, the autologous bone implantation can reduce rejection reaction and improve the initial stability after the implantation.

After the coating model M4 and the bone grafting cartridge model M6 are prepared, the design method further includes designing a crown model.

Referring to fig. 26, to ensure a stable connection of the crown model, the abutment 106 in the pseudo-root implant body model M7 needs to be designed to be connected to the crown model. In this regard, the present embodiment provides three schemes of designing the base station.

The first design method of the base station comprises the following steps: as shown in fig. 27, crowns in the reference model M2 are removed so that the crowns of the rest of the reference model M2 form a planting platform. Wherein, the method in the step one S10 can be adopted to obtain the rest of the reference model M2, namely, the combined model of the gum penetrating portion 102 and the root portion 103. As shown in fig. 27, a region is selected at the center of the implant platform and stretched toward the crown with the region being located, to form a abutment 106 protruding from the implant platform. It will be appreciated that a small piece of surface is selected as a reference surface on the surface of the implant platform centered on the center point of the implant platform's contour, and stretched toward the crown side to obtain the abutment 106 shown in fig. 22. Further, the abutment 106 has an axial length less than the axial length of the crown. Preferably, the axial length of the coronal side of the abutment 106 from the coronal side of the dental crown is 2mm. The abutment 106 has a radial length that is less than the radial length of the crown. Preferably, the abutment 106 has a radial length that is less than 2mm of the radial length of the crown. Further, the shape of the abutment 106 needs to be adjusted so that the included angle between the projection line of the sidewall of the abutment on the coronal plane or the sagittal plane and the cross section meets the set requirement, and optionally: 90-150 deg.. Thereby, the abutment 106 and the remaining reference model M2 can be obtained to form the pseudo-root implant body model M7.

The second design method of the base station comprises the following steps: as shown in fig. 28 to 32, the crown 101 in the reference model M2 is obtained by the method in step one S10. By pulling the crown 101 inward by 2mm, a reduced version of the second crown 1011 can be obtained. The coronal surface of the second crown 1011 is the coronal surface of the abutment 106. Because the side wall of the dental crown 101 is in a circular arc shape or an irregular arc shape, if the second dental crown 1011 is directly used as the abutment 106, the side wall of the abutment 106 is also in a circular arc shape or an irregular arc shape, which is not beneficial for the subsequent formation of the dental crown model to be sleeved on the abutment 106. Therefore, the side wall of the second crown 1011 needs to be adjusted. Specifically, a crown axis, that is, a central axis of the second crown is obtained by fitting the obtained second crown 1011. As shown in fig. 30, a plane perpendicular to the crown axis is made to intersect the second crown 1011, thereby obtaining a minimum intersecting contour line L1 and a maximum intersecting contour line L2. Referring to fig. 31, the minimum intersecting contour line L1 is taken as a reference plane, and is stretched along the coronal axis toward the root of the tooth, so that the intersecting contour line L3 is obtained at the intersection of the coronal plane where the gingiva penetrating portion 102 is located, thereby obtaining the abutment 106 shown in fig. 31 and 32.

The third base station design method performs the lofting basic operation based on the minimum intersecting contour line L1 and the maximum intersecting contour line L2 obtained in the second method, that is, using the minimum intersecting contour line L1 as a start contour line and the maximum intersecting contour line L2 as a stop contour line, as shown in fig. 30. After the lofting substrate treatment, the substrate 106 shown in fig. 33 can be obtained.

The side wall of the abutment 106 obtained by the second abutment design method is perpendicular to the surface (the coronal plane of the gingival part) where the planting platform is located, and the included angle between the projection line of the side wall of the abutment obtained by the third abutment design method on the coronal plane or sagittal plane and the cross section meets the set requirement, which is selected from the following: 90-150 deg.. Thus, through the three schemes described above, the pseudo-root implant body model M7 with the abutment 106 can be obtained.

Referring to fig. 34, after the pseudo-root implant body model M7 is obtained, the crown in the reference model M2 is extracted inward. Wherein in executing the shell extraction command, the outer contour of the crown 101 (i.e., the crown in the reference model) is set to be preserved to obtain a first porcelain model (not shown). That is, the outer surface of the first crown 101 is left, the interior of the crown 101 is hollow, and the first porcelain model having a set thickness is formed by extending a certain thickness inward according to the outer surface of the crown 101. Among these, the porcelain is designed to obtain a better aesthetic effect of the crown. Namely, the color difference is modified by adopting a porcelain bushing to be arranged on the base crown because the formed base crown is over abrupt. Further, the thickness of each area of the first porcelain model is equal, so that stress on each part of the porcelain formed according to the design and the base crown is balanced, and cracking caused by uneven stress is avoided. In executing the shell extraction command, it is set not to retain the outer contour of the dental crown 101 to obtain a first basic crown model M8. That is, the outer surface of the crown 101 is not maintained in size, and the outer surface of the crown 101 is entirely reduced inward, and the reduced thickness is equal to the thickness of the first porcelain model so that the first porcelain model can be fitted over the outer surface of the first basic crown model M8.

The first basal crown model M8 is subjected to a boolean subtraction operation with the abutment 106 to obtain a second basal crown model. That is, a groove having the same contour as the outer contour of the abutment 106 is formed in the first crown model M8 by boolean subtraction.

Referring to fig. 35-37, a portion of the first porcelain mold having a set thickness is cut toward the crown with the bottom surface of the first porcelain mold as a reference plane to serve as a neck ring mold M9. The neck ring is designed for supporting the decorative porcelain, so that the compressive resistance of the dental crown is improved. Wherein, the setting thickness range of the neck ring model M9 is: 0.3 mm-3 mm. And the thickness of the collar at the molars is preferably 2 mm. After the neck ring model M9 is obtained, the neck ring model M9 and the first porcelain model are subjected to boolean subtraction operation to obtain a second porcelain model M10. The crown model is thus obtained, wherein the crown model comprises a second basic crown model M11, a second porcelain model M10 and a neck ring model M9. The second porcelain model M10 and the neck ring model M9 are both sleeved on the outer surface of the second base crown model M11, and the neck ring model M9 is connected with the bottom surface of the second porcelain model M10. In order to facilitate the later preparation, the neck ring model M9 and the second crown model M11 may be further subjected to boolean operations to obtain a third crown model M12. That is, the neck ring model M9 and the second crown model M11 are combined into a single body, and the crown model includes a third crown model M12 and the second porcelain model M10. The second porcelain model M10 is sleeved on the outer surface of the third crown base model M12.

After the crown model is designed to be completed, a model of an pseudo-root implant as shown in fig. 25 has been completed, including: the second porcelain model M10, the second basal crown model M11, the neck ring model M9, the pseudo-root implant body model M7, the coating model M4 and the bone grafting bin model M6. However, in actual planting, the implant needs to be fixed, and the pseudo-root implant system further comprises a fixing structure.

Further, screw fixation, maryland fixation or snap ring fixation may be selected depending on the age, oral condition and bone quality of the patient. Thus, a maryland bridge model or a clasp model, or a screw model, connected to the second porcelain model M10 may be designed according to the dentition data of the patient. The maryland bridge model and the snap ring model are designed as conventional models, and an existing model can be selected and adaptively adjusted, which is not described herein.

The design process of the screw model is specifically described below. The screw is used as a fixing structure, and is more aged or worse in bone quality, so that specific conditions of the affected tooth position are required to be acquired according to the dentition data of the patient, the axial length and the placement position of the screw are determined, and the screw designed to be placed in the buccal lingual direction or the screw placed in the coronal direction is determined. In this embodiment, the screw model is described by taking the reference model M2 of more than two tooth roots as an example, and the reference model M2 having a single tooth root can refer to the method.

In designing the screw placed in the buccal lingual direction or the screw placed in the coronal direction, it is necessary to use a screw-like model to obtain a screw channel formed in the designed implant model. As shown in fig. 39-40, the position E of the simulated screw model placed in the coronal direction or the position F of the simulated screw model placed in the buccal lingual direction is first determined. In order to ensure the stability of connection and the balance of stress everywhere, the position E of the simulated screw model placed along the coronal direction can be selected as the position along the coronal central axis of the implant, and the position F of the simulated screw model placed along the buccal lingual direction can be selected as the position along the buccal lingual central axis of the bone grafting bin.

Further, referring to fig. 41, after the position E of the screw-like model placed in the coronal direction is selected, the screw-like model M14 is selected to be placed in the coronal direction. The rod part of the screw-like model M14 is hollow cylindrical, i.e. the rod part of the screw-like model M14 is not provided with threads. The purpose is to form a larger range of screw channels later, so that the screws formed according to the design can be screwed into the screw channels conveniently. Then, as shown in fig. 38 and 41 to 44, the roots of the pseudo-root implant body model M7 are nested into the coating model M4, and the bone graft compartment model M6 is placed between the corresponding roots of the coating model M4. Secondly, placing the simulated screw model M14 in the pseudo-root implant body model M7 along the coronal direction, enabling the simulated screw model M14 to coincide with the central axis L0 of the pseudo-root implant body model M7, enabling the top end of the simulated screw model M14 to be positioned in the base 106, and enabling the rod portion of the simulated screw model M14 to penetrate through the coating model M4 and the bone grafting bin model M6. And carrying out Boolean intersection operation on the screw simulation model M14, the pseudo-tooth root implant body model M7, the coating model M4 and the bone grafting bin model M6, so that a screw channel D is formed in the pseudo-tooth root implant body model M7, a through hole is formed in the coating model M4, and two guide ring models M13 which are opposite along the coronal direction are formed in the bone grafting bin model M6. The thickness of the guide ring model M13 is the wall thickness of the hollow cylinder of the screw-like model M14, and preferably, the thickness of the guide ring model M13 is 0.3 mm. As shown in fig. 25, the bone grafting chamber model M6 is shown in a sectional view along D-D', and the two guide ring models M13 are opposite to each other along the coronal direction.

45-47, when designing a screw for buccal-lingual placement, the simulated screw model M15 is passed through the bone graft compartment model M6 in the buccal-lingual direction. And performing Boolean intersection operation on the screw-like model M14 and the bone grafting bin model M6 to form two guide ring models M13 in the bone grafting bin model M6, wherein the two guide ring models are opposite along the cheek-tongue direction. The guide ring designed according to the guide ring model M13 is designed to guide the extended position of the screw, and also has a fixing function on the screw. In addition, the guide ring model M13 and the screw channel D may be further provided with threads on the inner wall as required to improve the retention effect on the screw.

After forming the guide ring model M13, the design method further includes: a screw model M16 disposed in the coronal direction and a screw model M17 disposed in the buccal-lingual direction are designed. Referring to fig. 48-49, the shaft portions of the screw models M16, M17 are provided with self-tapping threads, and the maximum diameter of the shaft portions of the screw models M16, M17 is equal to the inner diameter of the shaft portion of the screw-like model, so as to ensure that the screws formed according to the screw models M16, M17 can be screwed into the corresponding screw channels, through holes and guide rings.

As shown in fig. 49, the screw model M17 provided in the cheek-tongue direction is also fitted with a nut model M18 and a washer model M19. The gasket model M19 is sleeved with the rod part of the screw model M17 and is connected with the head end of the screw model M17. Wherein, the head outline of the screw model M17 is arc-shaped. The screw that the design formed runs through the alveolar bone and both ends wear out the outside soft tissue of alveolar bone to fixed implant and be convenient for install the nut, simultaneously the both ends of screw are designed to convex head profile can reduce soft tissue's friction, reduce food stopper and inlay. The surface of the head of the screw model M17, which is in contact with the spacer model M19, is a circular surface, and the surface of the head of the screw model M17, which is close to the spacer model M19, is also a circular surface. Because the spacer prepared according to the spacer model M19 is used for connecting the head of the screw and the side wall of the alveolar bone, in order to avoid the foreign body sensation after implantation, a side surface of the spacer model M19 away from the head end of the screw model M17 needs to be fitted with the surface of the side wall of the alveolar bone, so that a side surface of the spacer model M19 away from the head end of the screw model M17 can conform to the side wall of the alveolar bone, avoiding protrusion or depression, similar to the anatomy shown in fig. 49. The head contour of the nut pattern M18 is in the shape of a circular arc, which is close to one side of the head end of the screw pattern M18, and, likewise, is fitted through the side surface of the part of the alveolar bone at the affected part so as to conform to the side wall of the alveolar bone and avoid bulge or dent.

In conclusion, the design of the pseudo-root implant system is completed. Wherein, the design model of the pseudo root implant system comprises: the second porcelain model M10, the second basal crown model M11, the neck ring model M9, the pseudo-root implant body model M7, the coating model M4, the bone grafting bin model M6 and the model of the fixed structure, and the model of the fixed structure comprises: the coronal screw model M16 or the buccal lingual screw model M17, the nut model M18 and the gasket model M19 are either Maryland bridge models or clasp models. Furthermore, the simulated tooth root implant body model M7 is designed according to a three-dimensional model of the affected tooth, and the simulated tooth root implant body has strong anti-rotation performance by simulating the stress conduction characteristic of the natural molar and the stress distribution characteristic of the tooth root. In addition, the tooth roots in the pseudo-tooth root implant body model M7 are all in a straight state, so that implantation difficulty is reduced. The coating formed according to the coating model M4 contributes to the formation of a stable interference connection between the implant and the socket. And, the bone grafting bin model M6 and the coating model M4 are both porous structures, which is helpful for the diffusion of the medicine in the bone grafting bin and the bone growth after implantation. In addition, in the case of the optical fiber, the present embodiment provides a variety of fixed structure models: the coronal screw model M16, the buccal lingual screw model M17, the nut model M18, the gasket model M19, the Maryland bridge model and the clasp model are used for meeting the individual fixing requirements of patients.

Further, the auxiliary computer program used in the design method includes, but is not limited to: computer aided design and fabrication techniques (computer aided design/CAD/CAM), computed tomography techniques (computed tomography, CT), finite element simulation techniques (finite element analysis, FEA), and medical image control systems (materials's interactive medical image control system, micrometers).

Based on the same inventive concept, the embodiment also provides a preparation method of the pseudo-root implant system, which comprises the following steps: and preparing the pseudo-tooth root implant system designed by the design method of the pseudo-tooth root implant system by adopting a 3D printing technology.

Further, the pseudo-tooth root implant body model M7, the coating model M4 and the bone grafting bin model M6 are integrally printed by adopting a titanium alloy material. Because the 3D printing technology is inconvenient for replacing materials in the middle, the coating model M4 can be printed by adopting a shape memory material, the pseudo-tooth root implant body model M7 and the bone grafting bin model M6 are printed by adopting a titanium alloy material, and the obtained coating model M4 is an elastic coating. The elastic coating has deformability, so that the difficulty of the artificial tooth root implant body entering the tooth extraction socket can be reduced during implantation, and the damage of the traditional interference connection to the tooth extraction socket is avoided. And after the artificial tooth root implant body reaches the target position, the elastic coating recovers the elastic deformation quantity and is abutted with the tooth extraction socket, so that the initial stability of implantation is improved. After being printed respectively, the pseudo-tooth root implant body model M7, the coating model M4 and the bone grafting bin model M6 are combined into a whole through welding, bonding and other modes. Among them, there are two more suitable methods of welding: the first is laser welding, only the area of the contact surface is welded, and the interior is not required to be treated; and the second is resistance welding, and all contacted parts are fused and welded through heating by current. Wherein the pseudo-root implant body model M7 and the coating model are preferably resistance welded.

Further, the pseudo-root implant body model M7, the coating model M4 and the bone grafting bin model M6 may also be printed using metal additive manufacturing techniques (Metal additive manufacturing technology, AM). The laser melting technique (selective laser melting, SLM) or electron beam melting technique (Electron Beam Melting, EBM) may be specifically selected.

The material of the second base crown and the neck ring is preferably zirconia, and the material of the second decoration porcelain is preferably feldspar glass ceramic, lithium disilicate glass ceramic or lithium disilicate glass ceramic. The second crown molding machine M11, the second porcelain molding machine M10 and the neck ring molding machine M9 can be respectively printed using different materials using a 3D printing technique, the preformed ceramic blocks can also be cut into a base crown and a neck ring according to the second base crown model M11 and the neck ring model M9 by adopting CAD/CAM technology, then the low-melting ceramic powder is attached on the base crown and the neck ring, and the decorative ceramic is formed by sintering. Further, the porcelain, the collar and the crown base may be bonded using a resin cement to form the crown.

After printing, the pseudo-root implant body, the coating and the bone grafting bin are subjected to heat treatment. After heat treatment, the internal residual stress is reduced, and the sample has higher strength and plasticity. And then removing the supporting piece in the forming process, and polishing the bottom of the support by using files, sand paper and the like until the bottom meets the requirements. Then, after sand blasting, cleaning and sterilization, the preparation of the pseudo-root implant system is completed.

Further, the coronal screw, the buccal screw, the nut, the gasket, the Maryland bridge and the snap ring can adopt a 3D printing technology, a CNC (Computerized Numerical Control, computer numerical control technology, namely, processing by using a numerical control lathe) technology or a combination of the two technologies.

In summary, in the design method of the pseudo-tooth root implant system and the preparation method thereof provided in the embodiment, the three-dimensional model M1 of the affected tooth obtained by scanning is used as the basis of the design, and is closer to the real tooth, so that the force transmission characteristic of the natural molar and the stress distribution characteristic of the tooth root are simulated, and the occlusion stress is dispersed by the arrangement of multiple tooth roots, thereby having stronger anti-rotation performance. In addition, when the three-dimensional model M1 does not meet the set requirement, the present embodiment may perform the straightening process and/or the parting angle process on the root 103 of the three-dimensional model M1, so that the designed root 103 is easier to locate in the extracted socket, thereby avoiding the excessive or insufficient parting angle and reducing the implantation difficulty. In addition, the embodiment also designs a coating model M4 and the bone grafting bin model M6. The coating model M4 is sleeved on the outer surface of the tooth root 103 of the reference model M2, and can be in interference connection with the tooth extraction socket during planting, so that initial stability after planting is facilitated. The bone grafting bin model M6 is a shell model, can contain anti-inflammatory and growth promoting medicines therebetween, and is beneficial to the short-term and long-term stability after planting. Wherein, the coating model M4 and the bone grafting bin model M6 are both subjected to porosification treatment, which is beneficial to the diffusion of the medicine. Therefore, the artificial tooth root implant system formed by adopting the embodiment not only can simulate the stress characteristic of natural tooth grinding and disperse the occlusal stress so as to improve the stability of the implant, but also can reduce implantation difficulty by flattening treatment and bifurcation angle treatment of the tooth root 103.

It should also be appreciated that while the present invention has been disclosed in the context of a preferred embodiment, the above embodiments are not intended to limit the invention. Many possible variations and modifications of the disclosed technology can be made by anyone skilled in the art without departing from the scope of the technology, or the technology can be modified to be equivalent. Therefore, any simple modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A design method of a pseudo-root implant system, which is characterized in that the pseudo-root implant system is used for planting at a suffering tooth; the design method comprises the following steps:

2. The method for designing a pseudo-dental implant system according to claim 1, wherein the process of acquiring oral data and acquiring a three-dimensional model of an affected tooth comprises:

3. A method of designing a pseudo-dental implant system according to claim 2, wherein when the crown of the affected tooth is missing or defective, from the dentition data, a result is obtainedTaking the pair of the suffering teeth

A crown of a tooth or a symmetric tooth is used as a crown of the three-dimensional model of the affected tooth.

4. The method of designing a pseudo-root implant system according to claim 2, wherein a plurality of cross-sectional images of the affected tooth are obtained by CBCT scanning; and along the coronal direction, each of said cross-sectional images corresponds to a planar image of a corresponding layer in said three-dimensional model;

and when all the included angles are smaller than 5 degrees, the tooth root meets the set requirement.

5. The method of designing a pseudo-dental implant system according to claim 4, wherein the three-dimensional model of the affected tooth comprises at least two roots;

6. A method of designing a pseudo-root implant system according to claim 4, wherein the method of flattening the roots of the teeth in the three-dimensional model comprises:

7. The method of designing a pseudo-root implant system according to claim 6, wherein during the performing of the equidistant treatment, all equidistant contour lines are sequentially equally reduced in radial direction; wherein each reduction has a size ranging from 0.1 mm to 0.8 mm and the smallest diameter of the last said equidistant profile is greater than or equal to 0.3 mm; the axial distance between the starting contour and the last of the equidistant contours ranges from 0.1 mm to 8 mm.

8. The method of designing a pseudo-root implant system according to claim 5, wherein the step of processing the classification angle further comprises:

9. The method of designing a pseudo-root implant system according to claim 1, wherein the process of forming the bone graft compartment model from a portion of the roots in the reference model comprises:

10. A method of designing a pseudo-dental implant system according to claim 9, wherein the process of obtaining a coating model for placement over the outer surface of the root of a tooth based at least on the root of the tooth in the reference model comprises:

11. A method of designing a pseudo-dental implant system according to claim 9, wherein the process of obtaining a coating model for placement over the outer surface of the root of a tooth based at least on the root of the tooth in the reference model comprises:

12. The method of designing a pseudo-dental implant system according to claim 11, wherein the process of obtaining a bone graft compartment model from a three-dimensional region between two or more of the roots in the coating model comprises:

nesting the root of the reference model into the coating model;

13. The method for designing a pseudo-root implant system according to any one of claims 9 to 12, wherein the porosification process includes:

14. The method for designing a pseudo-dental implant system according to claim 10 or 11, wherein the plane of the coronal side of the coating model is located on a side of the plane of the coronal side of the dental root in the reference model, which is far away from the dental crown, and the axial distance between the plane of the coronal side of the coating model and the plane of the coronal side of the dental root in the reference model is: 0.1 mm-1 mm.

15. A method of designing a pseudo-dental implant system according to claim 10 or 11, wherein when the reference model has a single said root, an opening is formed in the coating model for exposing at least part of the bone graft compartment model when the reference model and the bone graft compartment model are nested in the coating model.

16. A method of designing a pseudo-dental implant system according to claim 10 or 11, wherein the porosity of the coating model is in the range of 30% -80% and the pore size is in the range of 100-1000 microns.

17. The method of designing a root-planning implant system according to claim 10 or 11, wherein the set thickness of the coating shell ranges from: 0.2 mm-2 mm.

18. A method of designing a pseudo-dental implant system according to claim 9 or 12, wherein the bone graft compartment model has a porosity in the range of 80% -90% and a pore size in the range of 1000-1400 microns.

19. The method of designing a pseudo-dental implant system according to claim 9 or 12, wherein the set thickness of the bone graft compartment shell ranges from 0.3 mm to 0.7 mm.

20. The method of designing a root-planning implant system according to claim 1, further comprising:

21. The method of designing a root-planning implant system according to claim 1, further comprising:

22. A method of designing a pseudo-dental implant system according to claim 20 or 21, wherein the axial length of the abutment is less than the axial length of the crown; the radial length of the abutment is less than the radial length of the crown; the set requirement range of the included angle between the projection line of the side wall of the base station on the coronal plane or the sagittal plane and the cross section is as follows: 90-150 deg..

23. A method of designing a pseudo-root implant system according to claim 20 or 21, wherein the method of designing further comprises:

24. The method of designing a root-planning implant system according to claim 23, wherein the set thickness range of the neck ring model is: 0.3 mm-3 mm.

25. The method of designing a root-planning implant system of claim 23, further comprising: and selecting a Maryland bridge model or a clasp model connected with the second decorative porcelain model according to the oral cavity data.

26. The method of designing a root-planning implant system of claim 22, further comprising:

when the screw-imitating model is arranged along the coronal direction, carrying out Boolean subtraction operation on the screw-imitating model, the pseudo-tooth root implant body model and the coating model, and carrying out Boolean intersection operation on the screw-imitating model and the bone grafting bin model, so that a screw channel is formed in the pseudo-tooth root implant body model, a through hole is formed in the coating model, and two guide ring models which are opposite along the coronal direction are formed in the bone grafting bin model;

27. The method of designing a root-planning implant system of claim 26, further comprising: designing a screw model arranged along the coronal direction and a screw model arranged along the buccal-lingual direction; wherein, the rod part of the screw model is provided with self-tapping threads, and the maximum diameter of the stem of the screw model is equal to the inner diameter of the stem of the simulated screw model;

28. A method for preparing a pseudo-root implant system, characterized in that the pseudo-root implant system designed by the method for designing a pseudo-root implant system according to any one of claims 1 to 27 is prepared by adopting a 3D printing technology and/or a CNC technology.

29. The method of preparing a pseudo-root implant system according to claim 28, wherein the coating and the bone grafting cartridge are each independently made of a titanium alloy material or a shape memory material.