CN109446738B - Design method and implant of bone-surface-anchored dental implant with topology optimization structure - Google Patents

Abstract

A method for designing a bone-surface-anchored dental implant with a topology-optimized structure, comprising the following steps: 1) Obtaining a patient's oral and maxillofacial CT image, using medical image processing software to reconstruct a three-dimensional mandibular model of the patient, and the reconstructed model also includes mandibular The anatomical structure of the neural tube; 2) Measure and evaluate the tooth loss and the bone mass of the implant site in the medical image processing software, determine the position of the restoration abutment, and formulate a comprehensive restoration plan; determine the position and form of the implant: In places with sufficient or slightly insufficient bone, traditional cylindrical or tapered dental implants are implanted; in places with severe bone deficiency, bone surface-anchored implants are designed. The present invention provides a design method for a bone-surface-anchored dental implant with a topology-optimized structure and the implant, which are different from traditional subperiosteal implants and root-shaped implants and do not require bone augmentation operations.

Description

Design method of bone surface anchored dental implant with topology optimization structure and implant

technical field

The invention relates to a design method of a bone-surface anchored dental implant with topology optimization structure and the implant.

Background technique

At present, with the increasing development of society, people's pursuit of oral aesthetics is getting higher and higher. Tooth loss affects oral relationships and is also aesthetically pleasing. Dental implants have increasingly become the main choice for missing teeth due to their advantages of aesthetics, comfort, and high chewing efficiency. However, traditional root-shaped implants have higher requirements on bone mass, including bone height and bone width, which need to meet the requirements of implant surgery. If the alveolar bone volume is insufficient, there may be risks of failure in implant restoration, including insufficient bone width causing the implant side to protrude from the alveolar bone, insufficient bone height leading to implant exposure, and insufficient initial stability. Clinically, due to factors such as periodontal disease, jaw disease, trauma, and tumors, there are many cases of insufficient bone mass, which limits the application of dental implant restoration technology.

In order to increase the bone mass when implanting root-shaped implants, bone powder and periosteum coverage are often used to solve the problem of a small amount of bone deficiency in clinical practice, or to solve severe bone deficiency through surgical methods such as autologous bone grafting, surgical splitting, and distraction osteogenesis. problem, but these methods need to solve the problem of bone augmentation through surgery first, and then perform dental implant surgery after a period of recovery. The operation process is more complicated, and the number of operations increases, which increases the difficulty of dental implant restoration and the time of treatment. The cost is high, and there are also problems such as infection in the operation area and limited bone augmentation.

In fact, before the application of root-shaped (including cylindrical or tapered) implants based on the concept of osseointegration, a special scaffold-type implant based on subperiosteal bone surface fixation, that is, subperiosteal implants, had been developed in the 1930s. There are applications. But its production needs to expose the bone surface by operation and take an impression, then manufacture the support of the subperiosteal implant close to the bone surface by casting, and then implant it through the second operation. Due to the complicated operation, long manufacturing process and large surgical trauma, it was gradually eliminated after the emergence of root-shaped implants. However, it is directly fixed on the bone surface, which provides a solution to solve the problem of root-shaped implants in the face of insufficient bone mass. Especially in recent years, with the development and application of digital technologies such as medical image acquisition, three-dimensional reconstruction of maxillofacial tissue, digital precise design of surgical plan, titanium metal 3D printing and optimal design, and biomechanical finite element analysis, direct anchoring of bone surface The personalized subperiosteal dental implants are precisely designed and manufactured before surgery, and the implantation is completed through one-time surgery, which has high feasibility.

Contents of the invention

In order to solve the problem that multi-stage surgery must be performed for dental implant restoration in patients with severe bone deficiency, that is, to replenish bone mass before implanting the implant, the present invention provides a bone surface-anchored dental implant with a topology-optimized structure The design method and implants are different from traditional subperiosteal implants and root implants and do not require bone augmentation.

The technical solution adopted by the present invention to solve its technical problems is:

A method for designing a bone-surface-anchored dental implant with a topology-optimized structure, comprising the following steps:

1) Obtain the patient's oral and maxillofacial CT images, and use medical image processing software to reconstruct the three-dimensional model of the patient's mandible, including the anatomical structure of the mandibular canal;

2) Measure and evaluate the missing teeth and the bone mass of the dental implant implant site in the medical image processing software, determine the position of the restoration abutment, and formulate a comprehensive restoration plan; determine the position and form of the dental implant: when the bone mass is sufficient Or a small amount of insufficient position, implant the traditional cylindrical or tapered dental implant; in the position of severe bone deficiency, design the bone surface anchored dental implant;

3) According to the comprehensive restoration plan, determine the restoration position of the bone surface-anchored dental implant, that is, the position of the upper restoration abutment, and design a three-dimensional model of the restoration abutment with reference to the standard structure of the abutment;

4) Design the bone surface anchoring structure of the anchored dental implant with a topologically optimized structure:

(4.1) Determine the fixation area: including the action area and fixed position of the entire bone surface anchoring structure;

(4.2) Based on the fixed area of the bone surface, the initial anchoring plate is designed through the thickening function of the curved surface;

(4.3) Construct a biomechanical model of the mandible, load the occlusal force load on the abutment position, and use the finite element software to perform topology optimization on the anchoring structure of the bone surface to obtain the initial optimized structure of the anchoring structure;

(4.4) Standardize the design according to the initial optimized structure of the bone surface anchoring structure, and obtain the anchoring structure with fixation holes and regular structure;

5) The anchoring structure can be topologically optimized multiple times to obtain a bone surface anchoring structure with the best mechanical properties;

6) Perform Boolean operations on the bone surface anchoring structure and the 3D model of the abutment to obtain a complete 3D model of the bone surface anchoring dental implant with a topology optimized structure;

7) Use 3D printing technology to print and manufacture the designed bone surface-anchored dental implant, and the material can be titanium alloy or PEKK polymer material;

8) The bone-surface anchored dental implant is surface treated to obtain a bone-surface-anchored dental implant with a topology-optimized structure that can be applied clinically.

Furthermore, the design method also includes the following steps: in order to facilitate the doctor's operation, a personalized surgical guide can be designed for positioning during the operation, including determining the position of the fixation nail.

An implant constructed according to the design method of the bone-surface-anchored dental implant with a topology-optimized structure, comprising a prosthetic abutment for installing a denture and a bone-surface anchoring structure for supporting and fixing, the bone surface The anchoring structure includes a support unit for supporting the repair abutment and a fixation unit for fixing with the mandibular fixation area. The repair abutment is set at the center of the top of the support unit and the two are integrated. There are fixing units on both sides, and each fixing unit is provided with an installation through hole for fixing on the mandible, the upper end of each fixing unit is integrally formed with the support unit, and the lower end of each fixing unit is downward Extending, the bone surface anchoring structure is fixed to the mandibular fixation area through titanium nails.

Furthermore, both the repair abutment and the bone surface anchoring structure are made of titanium alloy or PEKK polymer material.

Still further, there are four fixing units, which are arranged in groups of two on the front and rear sides of the support unit, and each fixing unit is respectively provided with two installation through holes.

Further, the bone surface anchoring structure is topologically optimized multiple times to have the best mechanical properties, and the installation through-holes on the fixation unit avoid important anatomical structures in the fixation area.

The beneficial effects of the present invention are mainly manifested in: compared with traditional dental implants, the dental implants of the present invention are not limited by the amount of alveolar bone, and can be implanted without bone filling; The multi-stage operation can be simplified into one-stage operation to complete the expected dental implant, which can not only reduce the operation time but also reduce the economic burden of the patient, and has good practicability; the dental implant after topology optimization can meet both the strength requirement and the process Require.

Description of drawings

FIG. 1 is a schematic diagram of a skeletal model of an oral cavity.

Figure 2 is a schematic diagram of the preliminary position of the restoration abutment.

Fig. 3 is a schematic diagram of the structure of the initial anchoring plate.

Fig. 4 is a schematic diagram of the results after the first topology optimization.

Figure 5 is a schematic diagram of the standard anchoring structure.

Fig. 6 is a schematic diagram of a composite model of topology optimization for an example of planting position.

Fig. 7 is an implementation flow chart of performing multiple topology optimizations.

Fig. 8 is a schematic diagram of the bone surface anchoring structure after repeated topology optimization.

Fig. 9 is a schematic diagram of the dental implant of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

Referring to Figures 1 to 9, a design method for a bone-surface-anchored dental implant with a topology-optimized structure includes the following steps:

1) Obtain the patient's oral and maxillofacial CT image, and use medical image processing software such as Mimics to reconstruct the three-dimensional model of the patient's mandible 1. The reconstructed model also includes important anatomical structures such as the mandibular canal 11, as shown in Figure 1;

2) Using medical image processing software such as Mimics to measure and evaluate the edentulous situation and the bone mass of the dental implant implantation site, considering factors such as oral biomechanics, crown size, and position requirements with adjacent and opposing teeth, determine the Restoring the position of the abutment 2, formulating a comprehensive restoration plan; determining the position and form of the dental implant: in the position with sufficient or a small amount of insufficient bone, implant a traditional cylindrical or tapered dental implant; in the position with severe bone deficiency, Bone surface anchored dental implants are designed;

3) According to the comprehensive restoration plan, determine the restoration position of the bone surface-anchored dental implant, that is, the position of the upper restoration abutment, as shown in Figure 2, and design a three-dimensional model of the restoration abutment with reference to the standard structure of the abutment;

4) Design the bone surface anchoring structure of the anchored dental implant with a topologically optimized structure:

(4.1) Determination of the fixation area: According to the principles of biomechanics and considering the conditions of avoiding important anatomical structures such as the root of the tooth and the mandibular nerve canal, determine the fixation area, including the action area and fixed position of the entire bone surface anchoring structure;

(4.2) Based on the fixed area of the bone surface, the initial anchoring plate is designed through the thickening function of the curved surface, as shown in Figure 3;

(4.3) Build a biomechanical model of the mandible, load the occlusal load on the abutment, and use finite element software such as Abaqus to perform topology optimization on the bone surface anchoring structure. The results of topology optimization are shown in Figure 4, where 42 represents the stress The small area, 41 represents the area with large stress, and the initial optimized structure of the anchoring structure is obtained;

(4.4) Standardized design was carried out according to the initial optimized structure of the bone surface anchoring structure, and the anchoring structure with fixation holes and regular structure was obtained, as shown in Figure 5;

5) The anchoring structure can be topologically optimized multiple times. Take one of the implant positions as an example. The composite model for topology optimization is shown in Figure 6, and the implementation process is shown in Figure 7. The first step is mandible and bone surface The establishment of the anchoring structure model, the second step, the establishment of the finite element model, the third step, topology optimization design, the fourth step, the evaluation of the bone surface anchoring structure after topology optimization, if appropriate, the best mechanical properties The bone surface anchoring structure, as shown in Figure 8, if not suitable, continue to the third step, topology optimization design, until the bone surface anchoring structure with the best mechanical properties is obtained;

6) Perform Boolean operations on the bone-surface anchoring structure and the 3D model of the abutment to obtain a complete 3D model of the bone-surface-anchored dental implant with a topology-optimized structure, as shown in Figure 9.

7) Use 3D printing technology to print and manufacture the designed bone surface-anchored dental implant, and the material can be titanium alloy or PEKK polymer material;

8) After post-processing such as polishing, acid etching and other surface treatments on the bone-surface anchored dental implant, a bone-surface-anchored dental implant with a topology-optimized structure can be applied clinically;

In order to facilitate the doctor's operation, a personalized surgical guide can be designed for positioning during the operation, including determining the position of the fixation nail.

The implant constructed according to the design method of the bone-surface-anchored dental implant with topology optimization structure, including a prosthetic abutment 9 for installing a denture and a bone-surface anchoring structure 5 for supporting and fixing, the bone-surface anchoring structure 5 includes a support unit 51 for supporting the restoration abutment and a fixation unit 52 for fixing to the mandible fixation area, the support unit 51 is integrally formed with the restoration abutment 9, and the front and rear sides of the support unit 51 The fixing units 52 are all provided, and each fixing unit 52 is provided with an installation through hole 53 for fixing on the mandible, and the bone surface anchoring structure 5 is fixed to the mandible fixing area through titanium nails.

Both the repair abutment 9 and the bone surface anchoring structure 5 are made of titanium alloy or PEKK polymer material.

The fixing position of the fixing unit 52 , that is, the position of the installation through hole 53 avoids important anatomical structures in the fixing area.

The bone surface anchoring structure 5 is topologically optimized multiple times to meet the best mechanical properties.

The support unit 51 of the bone surface anchoring structure 5 is provided with two fixation units 52 on the front and rear sides respectively, and each fixation unit 52 is respectively provided with two installation through holes 53 . Each fixed unit 52 is further provided with strip-shaped hollows according to the results of multiple topology optimizations. Of course, the bone surface anchoring structure may not be fixed, that is, the number of fixing units 52 and installation through holes 53 is not unique, and the structure may be changeable according to different implant conditions and topology optimization results.

When using, put the personalized surgical guide plate in the patient's mouth first, then adjust the appropriate angle according to the position of the restoration abutment, place the bone-surface-anchored dental implant with a topology-optimized structure at a suitable position, and finally fix the dental implant with titanium nails. The implant is fixed to the mandible. It should be noted that the fixed position must avoid the important anatomical structure of the mandible.

The present invention can design a bone-surface-anchored dental implant directly anchored on the bone surface and having a topology-optimized structure according to the force of the tooth and surrounding tissues at the repaired position without multiple operations. And making full use of 3D printing technology will be able to effectively solve the problem of dental implant restoration with severe bone deficiency.

The content described in the embodiments of this specification is only an enumeration of the implementation forms of the inventive concept. The protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments. The protection scope of the present invention also includes those skilled in the art. Equivalent technical means conceivable according to the concept of the present invention.

Claims (6)

1. A method for designing a bone-surface-anchored dental implant with a topology-optimized structure, characterized in Yu: the design method comprises the following steps: 1) Obtain the patient's oral and maxillofacial CT images, and use medical image processing software to reconstruct the three-dimensional model of the patient's mandible, including the anatomical structure of the mandibular canal; 2) Measure and evaluate the missing teeth and the bone mass of the dental implant implant site in the medical image processing software, determine the position of the restoration abutment, and formulate a comprehensive restoration plan; determine the position and form of the dental implant: when the bone mass is sufficient Or a small amount of insufficient position, implant the traditional cylindrical or tapered dental implant; in the position of severe bone deficiency, design the bone surface anchored dental implant; 3) According to the comprehensive restoration plan, determine the restoration position of the bone surface-anchored dental implant, that is, the position of the upper restoration abutment, and design a three-dimensional model of the restoration abutment with reference to the standard structure of the abutment; 4) Design the bone surface anchoring structure of the anchored dental implant with a topologically optimized structure: (4.1) Determine the fixation area: including the action area and fixed position of the entire bone surface anchoring structure; (4.2) Based on the fixed area of the bone surface, the initial anchoring plate is designed through the thickening function of the curved surface; (4.3) Construct a biomechanical model of the mandible, load the occlusal force load on the abutment position, and use the finite element software to perform topology optimization on the anchoring structure of the bone surface to obtain the initial optimized structure of the anchoring structure; (4.4) Standardize the design according to the initial optimized structure of the bone surface anchoring structure, and obtain the anchoring structure with fixation holes and regular structure; 5) The anchoring structure can be topologically optimized multiple times to obtain a bone surface anchoring structure with the best mechanical properties; 6) Perform Boolean operations on the bone surface anchoring structure and the 3D model of the abutment to obtain a complete 3D model of the bone surface anchoring dental implant with a topology optimized structure; 7) Use 3D printing technology to print and manufacture the designed bone surface-anchored dental implant, and the material can be titanium alloy or PEKK polymer material; 8) The bone-surface anchored dental implant is surface treated to obtain a bone-surface-anchored dental implant with a topology-optimized structure that can be applied clinically. 2. The bone surface anchored dental implant design with topology optimization structure as claimed in claim 1 The method is characterized in that: the design method also includes the following steps: in order to facilitate the doctor's operation, a personalized surgical guide plate can be designed for positioning during the operation, including determining the position of the fixing nail. 3. A bone-surface-anchored dental implant with a topology-optimized structure according to claim 1 The implant constructed by body design method is characterized in that: the implant includes a prosthetic abutment for installing a denture and a bone surface anchoring structure for supporting and fixing, and the bone surface anchoring structure includes a prosthetic base for supporting The support unit of the table and the fixation unit used for fixing the mandible fixation area, the repair abutment is set at the center of the top of the support unit and the two are integrally formed, the support unit is provided with fixation units along the front and rear sides, and Each fixation unit is provided with an installation through hole for fixing on the mandible, the upper end of each fixation unit is integrally formed with the support unit, and the lower end of each fixation unit extends downward, and the bone surface anchoring structure It is fixed to the fixed area of the mandible with titanium nails. 4. The implant according to claim 3, wherein the restoration abutment and the bone surface anchoring structure are both made of titanium alloy or PEKK polymer material. 5. The implant as claimed in claim 3 or 4, characterized in that: there are four fixing units, which are arranged in groups of two on the front and rear sides of the supporting unit, and each fixing unit is respectively provided with two mounting holes. 6. The implant according to claim 3 or 4, characterized in that: multiple topological optimizations of the bone surface anchoring structure have the best mechanical properties, and the installation through holes on the fixation unit avoid the holes in the fixation area. important anatomical structures.

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