CN105078598B - Digital preparation method of individualized impression trays for edentulous jaws - Google Patents

Abstract

The invention relates to a digital preparation method of an edentulous individualized impression tray, which comprises the steps of preparing an initial impression, which can be poured into a plaster model; scanning the initial impression or scanning the plaster model; transferring the scanned data into reverse engineering software, and intercepting The point cloud data of the tissue surface of the initial impression of the jaw; obtain the point cloud data of the surface of the alveolar ridge without undercut; along the normal direction of the surface of the alveolar ridge, enlarge the surface of the alveolar ridge uniformly by 1‑2 mm to obtain the inner surface of the virtual tray; Uniformly thicken the inner surface of the virtual tray by 2mm along the normal direction; design the upper jaw virtual tray handle, and lower jaw virtual tray handle design; fuse and save the data boundaries of the virtual tray inner surface, outer surface and handle in STL format, import and 3D print The computer system connected to the equipment, through the 3D printing equipment, makes the personalized impression tray of the edentulous jaw made of PMMA. The present invention uses digitally designed and manufactured individualized impression trays for edentulous jaws to replace traditional manual production.

Description

Digital preparation method of individualized impression trays for edentulous jaws

technical field

The invention relates to the production of an edentulous jaw impression tray, in particular to a digital preparation method of an edentulous jaw personalized impression tray.

Background technique

1. At present, the production technology of individual trays of manual complete dentures in clinical application at home and abroad

There are 4 key steps in making a complete denture: impression, model, collar relationship (including occlusal balance), tooth arrangement and base shape. Among them, impressions and models are the basis. Only with accurate impressions and models can complete dentures be well retained. However, it is feasible to take an impression with the help of a public tray for removable partial dentures. For complete dentures, the public tray is roughly similar to the edentulous oral tissue of a specific patient, and the distance between the two parts is uneven. , the gap between the edge and the mucosal refraction line is not equal, and it is impossible to obtain an accurate model for taking an impression. The individual trays made by the secondary method and the multiple-time method can make the pressure on each part very uniform, the thickness of the impression material is uniform, and the error caused by polymerization shrinkage is reduced. In particular, the margins can be aligned almost exactly with the mucosal reflexion line, so accurate impressions can be obtained. And for the edentulous patients with poor condition of the remaining alveolar ridge, the one-time method of taking the impression with the finished tray often fails to meet the requirements, while the second impression method is very practical to make the edentulous impression with individual trays, which is the best choice for edentulous patients. The most basic and commonly used clinical key operation technology in the complete denture restoration treatment of jaw patients is to use individual trays to make impressions and accurately obtain the morphological characteristics of the patient's oral tissues, which is the ideal and goal pursued by the stomatological community at home and abroad.

At present, individual trays can be formed by adding red paste to finished trays, but the clinical application process is cumbersome, requiring high manual operation skills, and unskilled operations are prone to failure in impression making. It is difficult for junior doctors and medical students to master it in a short period of time, which leads to the consumption of a lot of time and energy in the process of making clinical edentulous jaw impressions, which often takes half a day or even a whole day for a patient. In recent years, the method of using self-curing photocurable resin materials to make individual trays on the original model has gradually been accepted clinically, but the operation process is still relatively complicated, and the operation time has not been reduced. Moreover, this method is to make individual trays with self-curing or light-curing resin materials on the initial model. The edges should be stretched correctly, and the position and shape of the handles should not interfere with the surrounding soft tissue activities. The width of the alveolar ridge avoids interference with the movement of the floor of the mouth, resulting in low accuracy and efficiency when making clinical impressions, and it is difficult to achieve relevant standards. However, the process of making individual trays is completely done by hand, which requires a certain amount of time, requires the patient to return to the clinic, and has a great dependence on the experience level of the technician, and it is difficult to achieve a three-dimensional space with a uniform thickness for the final impression by manual operation. , unable to meet the purpose of efficient, convenient and accurate preparation of individual pallets. Therefore, it is urgent to develop a new, automated and intelligent digital preparation technology for clinical individual trays to replace the traditional manual mode!

2. Digital design technology of individual trays for complete dentures

The clinical digital design technology or computer-aided design (CAD) technology of dental restoration consists of three-dimensional planning of the restoration, design software program and computer hardware carrying it. Today’s commonly used CAD software program allows the operator to interact at various stages and angles design to meet the individual needs of restorations. In recent years, non-contact 3D scanners represented by structured light (grating), line laser and 3D stereo photography technology have gradually become the mainstream. Their outstanding features are high efficiency, high resolution and more humanized operation interface, which can Provide a better application platform for extraoral model scanning. Extraoral scanning technology has been widely used in clinical oral cavity to obtain 3D data of gypsum models for making full crowns and facial 3D image data, and has been successfully used in clinical diagnosis and treatment. still belongs to a new field.

3. Digital production technology of individual trays for complete dentures

At present, some digital manufacturing technologies have appeared at home and abroad and have been applied to dental clinical diagnosis and treatment. The basic principle is to accurately manufacture virtual restorations into physical objects, requiring good suitability and minimizing the workload of technicians for secondary processing. There are three types of commonly used technologies: CNC milling and grinding machines are automatically processed into pre-material blocks, prosthetics are directly fabricated on plaster models, and rapid prototyping (RP) technology. At present, 3D printing technology in rapid prototyping technology and its application in the field of oral cavity are also developing rapidly. 3D printing is a kind of direct digital manufacturing (Direct Digital Manufacturing). Products can be directly manufactured from 3D solid CAD models, reducing or omitting blanks. Prepare intermediate processes such as parts processing and assembly, and can maximize the characteristics of materials to reduce material waste. Therefore, the use of 3D printing technology to realize the digital production of individual trays of complete dentures has the characteristics of fast, accurate, efficient, convenient and timely, but there are no related reports at home and abroad.

Contents of the invention

The purpose of the present invention is to provide a digital preparation method for individualized edentulous impression trays, which can replace traditional manual production with digitally designed and produced individualized impression trays for edentulous jaws, so as to realize the automatic production of complete dentures in clinical oral cavity. The goal of individualized dental impression trays can effectively improve the level of clinical treatment and operation skills of grassroots doctors in a short period of time, and improve the efficiency and quality of diagnosis and treatment.

In order to achieve the above object, the present invention has the following technical solutions:

A digital preparation method of an edentulous individualized impression tray of the present invention comprises the following steps:

1. A digital preparation method for an edentulous personalized impression tray, comprising the following steps:

1) Use impression paste or alginate to make an initial impression, which can be poured into a plaster model;

2) Directly scan the initial impression or plaster model with a 3D scanner for edentulous jaws to obtain the 3D data of the tissue surface morphology of the initial impression or plaster model of the edentulous jaw;

3) Import the scanned data into the reverse engineering software, extract the fold line of the tissue surface mucosa of the edentulous primary impression as the edge line, and use the edge line as the boundary to intercept the point cloud data of the tissue surface of the edentulous primary impression;

4) In the reverse engineering software platform, corresponding to the virtual tray of the initial impression of the edentulous jaw in step 3), select a |occlusal|gingival orientation, and fill in the alveolar ridges inside all the marginal lines in this direction For the undercut area on the buccal and lingual sides, the point cloud data of the alveolar ridge surface without undercut is obtained;

5) Enlarge the alveolar ridge surface by 1-2mm evenly along the normal direction of the alveolar ridge surface, reserve a uniform and consistent three-dimensional space for the final edentulous personalized impression tray, and obtain the inner surface of the virtual tray;

6) Thicken the inner surface of the virtual pallet by 2 mm evenly along the normal direction, and then design a plane perpendicular to the direction of virtual pallet insertion and tangent to the inner surface as the outer surface of the virtual pallet;

7) The upper jaw virtual tray handle is designed as a handle with a rectangular stem and an arc-shaped end; the lower jaw virtual tray handle is designed as a handle with a rectangular stem and a triangular end;

8) The data boundaries of the inner surface, outer surface and handle of the virtual tray are fused to obtain the complete shape data of the virtual tray of the individualized initial impression of the edentulous jaw, which is saved in STL format;

9) Import the STL data described in step 8) into the computer system connected to the 3D printing device, and use the 3D printing device to make a personalized impression tray of the edentulous jaw made of PMMA material. Wherein, the step 5) uniformly enlarges the alveolar ridge surface by 1-2mm along the normal direction of the alveolar ridge surface.

The advantages of the present invention are:

Using digitally designed and produced personalized impression trays for edentulous jaws to replace traditional manual production, to reserve a uniform and consistent three-dimensional space for the final impression materials, and to realize the automatic production of personalized impression trays for complete dentures and edentulous jaws in oral clinical practice Objective, the present invention can effectively improve the clinical treatment operation technical level of grass-roots doctors in a short period of time, and improve the efficiency and quality of diagnosis and treatment.

Description of drawings

Fig. 1 is the schematic diagram of the initial impression of edentulous jaw plaster of the present invention;

Fig. 2 is a schematic diagram of an edentulous individualized impression tray of the present invention;

Fig. 3 is an enlarged schematic view of the undercut area of the edentulous gypsum initial impression of the present invention.

In the figure, 1. The fold line of the mucous membrane of the lower edentulous plaster initial impression; 2. The mucosal refraction line of the upper edentulous plaster initial impression; 3. |occlusal|gingival orientation; 4. Alveolar ridge; 5. The undercut area; 6. The inner surface of the tray; 7. The outer surface of the tray; 8. The handle; 9. The intersection of the mucosal reflex line and the direction of the seating path. The direction of the insertion path refers to the insertion route of the denture when the denture is worn.

detailed description

The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Referring to Fig. 1, a digital preparation method of an edentulous individualized impression tray of the present invention comprises the following steps:

1. A digital preparation method for an edentulous personalized impression tray, comprising the following steps:

1) Use impression paste or alginate to make an initial impression, which can be poured into a plaster model;

2) Directly scan the initial impression or plaster model with a 3D scanner for edentulous jaws to obtain the 3D data of the tissue surface morphology of the initial impression or plaster model of the edentulous jaw;

3) Import the scanned data into the reverse engineering software, extract the fold line of the tissue surface mucosa of the edentulous primary impression as the edge line, and use the edge line as the boundary to intercept the point cloud data of the tissue surface of the edentulous primary impression;

4) In the reverse engineering software platform, corresponding to the virtual tray of the initial impression of the edentulous jaw in step 3), select a |occlusal|gingival orientation, and fill in the alveolar ridges inside all the marginal lines in this direction For the undercut area on the buccal and lingual sides, the point cloud data of the alveolar ridge surface without undercut is obtained;

5) Enlarge the alveolar ridge surface by 1-2mm evenly along the normal direction of the alveolar ridge surface, reserve a uniform and consistent three-dimensional space for the final edentulous personalized impression tray, and obtain the inner surface of the virtual tray;

6) Thicken the inner surface of the virtual pallet by 2 mm evenly along the normal direction, and then design a plane perpendicular to the direction of virtual pallet insertion and tangent to the inner surface as the outer surface of the virtual pallet;

7) The upper jaw virtual tray handle is designed as a handle with a rectangular stem and an arc-shaped end; the lower jaw virtual tray handle is designed as a handle with a rectangular stem and a triangular end;

8) The data boundaries of the inner surface, outer surface and handle of the virtual tray are fused to obtain the complete shape data of the virtual tray of the individualized initial impression of the edentulous jaw, which is saved in STL format;

9) Import the STL data described in step 8) into the computer system connected to the 3D printing device, and use the 3D printing device to make a personalized impression tray of the edentulous jaw made of PMMA material.

Wherein, the step 5) uniformly enlarges the alveolar ridge surface by 1-2mm along the normal direction of the alveolar ridge surface.

The occlusal model scanner can be Smart Optics 880 Dental Scanner from Germany: the model is Smart Optics scanner.

The 3D reverse engineering software can use Geomagic Studio 2012 version software from Raindrop Geomagic Company in the United States.

As described above, the present invention can be more fully realized. The above description is only a comparatively reasonable implementation example of the present invention, and the scope of protection of the present invention includes but is not limited thereto. Any non-essential modification changes based on the technical solutions of the present invention are included in the scope of the present invention. within range.

Claims (1)

1. A digital preparation method of an edentulous personalized impression tray, characterized in that it comprises the following steps: 1) Use impression paste or alginate to make an initial impression, which can be poured into a plaster model; 2) Directly scan the initial impression or plaster model with a 3D scanner for edentulous jaws to obtain the 3D data of the tissue surface morphology of the initial impression or plaster model of the edentulous jaw; 3) Import the scanned data into the reverse engineering software, extract the fold line of the tissue surface mucosa of the edentulous primary impression as the edge line, and use the edge line as the boundary to intercept the point cloud data of the tissue surface of the edentulous primary impression; 4) In the reverse engineering software platform, corresponding to the point cloud data of the tissue surface of the edentulous initial impression in step 3), select a |occlusal|gingiva direction in place, and fill in all the internal edge lines in this direction For the buccal and lingual undercut areas of the alveolar ridge, obtain the point cloud data of the alveolar ridge surface without undercut; 5) The alveolar ridge surface is evenly enlarged by 1-2mm along the normal direction of the alveolar ridge surface, and a uniform and consistent three-dimensional space is reserved for the final edentulous personalized impression tray to obtain the inner surface of the virtual tray; 6) Thicken the inner surface of the virtual pallet by 2 mm evenly along the normal direction, and then design a plane perpendicular to the direction of virtual pallet insertion and tangent to the inner surface as the outer surface of the virtual pallet; 7) The upper jaw virtual tray handle is designed as a handle with a rectangular stem and an arc-shaped end; the lower jaw virtual tray handle is designed as a handle with a rectangular stem and a triangular end; 8) The data boundaries of the inner surface, outer surface and handle of the virtual tray are fused to obtain the complete shape data of the virtual tray of the individualized initial impression of the edentulous jaw, which is saved in STL format; 9) Import the STL data described in step 8) into the computer system connected to the 3D printing device, and use the 3D printing device to make a personalized impression tray of the edentulous jaw made of PMMA material.