CN112809023A

CN112809023A - 3D printing-based sleeve crown and manufacturing method thereof

Info

Publication number: CN112809023A
Application number: CN202110014026.1A
Authority: CN
Inventors: 周小锋
Original assignee: Chengdu Dengte Dental Technology Development Co ltd
Current assignee: Chengdu Dengte Dental Technology Development Co ltd
Priority date: 2021-01-06
Filing date: 2021-01-06
Publication date: 2021-05-18
Anticipated expiration: 2041-01-06
Also published as: CN112809023B

Abstract

The invention belongs to the field of oral cavity repair and repair processes, and discloses an integrated sleeve crown based on 3D printing and a manufacturing method thereof. According to the manufacturing method of the coping, the full crown form is generated through the set parameters of the secondary crown, and then the secondary crown is formed through back cutting, so that the porcelain layers on the secondary crown and the follow-up secondary crown have enough thickness and better form, the accuracy and stability of combination of the primary crown and the secondary crown are ensured, the pre-designed full crown form is also beneficial to follow-up processing and manufacturing, and the final coping finished product can better exert the normal function of teeth; the design of the second-level crown is designed firstly and then the telescopic crown support is designed, so that the accuracy of the relative position of the telescopic crown support and the second-level crown and the connection stability can be ensured.

Description

3D printing-based sleeve crown and manufacturing method thereof

Technical Field

The invention belongs to the field of oral cavity repair and repair processes, and particularly relates to an integrated sleeve crown based on 3D printing and a manufacturing method thereof.

Background

Tooth body defect is a common problem in the field of oral cavity repair, and the tooth row defect destroys the integrity of the tooth row of the oral cavity, so that periodontal tissues of the remaining teeth bear extra force and are further destroyed, thereby generating new tooth row defect, and therefore the defect position needs to be controlled. The coping process is one of the most important treatment methods for repairing the dentition defect, and is widely applied to clinical oral repair treatment due to the advantages of comfort, attractiveness and the like. The sleeve crown is composed of an inner crown and an outer crown, the inner crown is bonded on the abutment, the outer crown is sleeved on the inner crown, and the outer crown and the inner crown are closely bonded and embedded to form a fixing force to provide a fixing effect for the movable false teeth.

The manufacturing of the traditional sleeve crown is carried out by separating an inner crown, an outer crown and a support, and the steps of taking an impression, pouring gypsum, manufacturing a wax pattern, embedding and casting, grinding and polishing, sand blasting and the like are carried out according to design requirements respectively, so that the working procedures are quite complex, and the working procedures relate to a plurality of aspects such as materials, manufacturing processes and equipment. In particular, during the investment casting process, defects such as incomplete casting and bubble generation are easily caused due to the precise complexity of the sleeve crown, and the repair is often failed.

The 3D printing technology is also called additive manufacturing technology, and has been widely used in industries such as personalized medical care, aerospace, mold manufacturing, jewelry production, and the like. The field of oral restoration directly acts on human bodies, and compared with other industries, the field of oral restoration has high requirements on individuation, complication, high difficulty, refinement and customization, and the 3D printing technology is adopted, so that key process parameters more suitable for oral restoration need to be developed.

Patent application publication No. CN106580496A discloses a concurrent fixed-movable combined repairing method, which comprises the following steps:

1. directly scanning and acquiring the three-dimensional shape of soft and hard tissues related to the mouth of a dentition defect patient by using a scanning measuring instrument, or indirectly scanning and acquiring the three-dimensional shape of a corresponding impression prepared by a conventional method or a plaster model copied by the impression, and reconstructing the three-dimensional shape into a digital model which is consistent with the oral cavity missing tooth condition and the abutment tooth condition in software, namely an A model for short;

2. adopting computer aided design software to complete the corresponding artificial tooth configuration design of the abutment or the preparation body thereof and the implant abutment required by the removable partial denture design on the model A, which is called B configuration for short;

3. the configuration B is aligned and placed on the original position of the model A in computer aided design software, and on the basis, the configuration design of the removable partial denture metal substrate or bracket, namely C1 configuration for short, is completed; or the corresponding artificial tooth design in the edentulous area is finished simultaneously on the basis of the C1 configuration, which is called C2 configuration for short; or on the basis, the novel configuration design of the composite removable partial denture, which is called C3 configuration for short, is finished through a dental prosthesis CAD/CAM/SLM-3D printing composite system.

4. Inputting the data of the B configuration into a numerical control cutting machine tool, selecting and obtaining oral ceramic, metal and resin blank materials permitted by national medical certification, and cutting a corresponding artificial tooth, namely a D structure;

meanwhile, C1 configuration data are input into a 3D printer, metal powder materials meeting national medical material permission are selected, a 3D printing process of a selective laser melting technology (SLM) is used for manufacturing a corresponding metal substrate or support, and the manufacturing of the removable partial denture, namely an E1 structure, is completed through a conventional craftsman room process; or inputting the C2 configuration data into a 3D printer to directly manufacture the metal removable partial denture integrating the artificial tooth and the bracket by the process, which is called an E2 structure for short; the novel composite removable partial denture can be manufactured by a CAD/CAM/SLM-metal 3D printing composite system, which is called as an E3 structure for short;

5. the D structure is firstly bonded or cemented on the corresponding abutment in the patient mouth, and the E1, E2 and E3 structures can be worn by the patient after the D structure is completed.

The method is completed by adopting laser 3D printing additive manufacturing, the material waste is very little, the complex steps of wax shape, embedding, casting, spot welding and the like in the traditional manufacturing mode can be replaced, and the operation of a technician is simpler and easier, so the method is far higher than the common process technology in the aspect of usability, the manufacturing efficiency is higher, the forming time is shorter, and the part precision is higher. If the method is applied to the sleeve crown repair technology, the abutment is the inner crown of the sleeve crown, the B configuration designed on the abutment and the D structure manufactured based on the B configuration are respectively a digital and physical sleeve crown inner crown, and E1, E2 and E3 are movable parts of the sleeve crown comprising an outer crown and a bracket. By utilizing the mode, the problems of complex process, long time period, low finished product strength, high operation difficulty and the like of the traditional sleeve crown can be well solved. However, this patent application is mainly directed to the design of removable denture from clasp retainer, and the socket crown retainer has a more complicated structure, so there still exist some problems in designing and manufacturing by this method, the most important of which is that the socket crown not only plays the role of retention by the combination of inner and outer crowns, ensures the stability and position accuracy of denture, but also bears the normal function of teeth, and the design method for removable denture from clasp retainer cannot take both these two aspects into consideration.

Disclosure of Invention

The invention aims to provide a 3D printing-based socket crown and a manufacturing method thereof, so that the accuracy of integral positioning of a false tooth is ensured, and the socket crown has good tooth functions.

The invention discloses a 3D printing-based sleeve crown manufacturing method, which comprises the following steps:

primary crown treatment: acquiring a three-dimensional digital model containing primary crowns, and determining a common in-place path of all the primary crowns, wherein the three-dimensional digital model comprises a digital working model, a jaw-to-jaw model and an occlusion relation;

designing a secondary crown: setting secondary crown related parameters;

generating a full crown form with a natural tooth form on the primary crown according to the set related parameters of the secondary crown, and ensuring that the full crown form has enough back cutting thickness on the basis of the secondary crown;

adjusting the shape of the whole crown according to the occlusion relation between the working model and the jaw model;

under the condition that the shape of the whole crown is kept with the set thickness of the secondary crown, back cutting is carried out to form a digital secondary crown;

designing a sleeve crown support: designing a digital sleeve crown support according to the three-dimensional digital model and the designed digital secondary crown; 3D printing: carry out the data processing that 3D printed to digital second grade hat and digital sleeve crown support, data processing puts, adds support and section processing including the position, then prints out second grade hat and sleeve crown support through the 3D printer.

Preferably, when designing the secondary crown, setting the secondary crown related parameters includes:

editing a primary crown shoulder line as a secondary crown edge line;

generating a gap space between the secondary crown and the primary crown;

and setting the minimum thickness of the secondary crown axial surface, the edge thickness of the secondary crown and the thickness transition angle.

Preferably, when designing the secondary crown, the designed digital secondary crown connects adjacent and unconnected secondary crowns together by using a connecting rod;

when the sleeve crown support is designed, the digital secondary crown and the digital sleeve crown are connected with each other to form an integrated digital sleeve crown;

when 3D prints, print out integral type telescopic crown through 3D based on the digital telescopic crown of integral type.

Preferably, during the primary crown treatment, the initial primary crown is positioned on the working model of the entity, the primary crown is ground and polished, so that all the primary crowns have a common positioning channel, and the ground and polished primary crown is positioned on the model to be scanned in three dimensions and converted into a three-dimensional digital model.

Preferably, when designing the secondary crown, the working model of the three-dimensional digital model is adjusted to the shoulders and all surfaces of all the primary crowns which can be seen by naked eyes in a rotating way, and then the current view direction is defined as the initial positioning path of the sleeve crown;

and calculating undercut areas by using the initial in-place tracks, ensuring that no undercut area exists on all the primary crowns, determining that the common in-place tracks are correct, and performing subsequent design on the basis of the determined common in-place tracks.

Preferably, when the primary crown is processed, the grinding needles grind the inverted concave surface of the primary crown to form a common locating channel, and the grinding needles are selected as follows:

if the abutment is loosened once, a 4-degree grinding machine needle is used;

if the abutment is loosened for the second time, a 6-degree grinding machine needle is used;

if the abutment is not loosened, a grinding needle with the angle of 2 degrees is used;

if the abutment is below 4mm, a 2 ° reduced grinding needle is used under the above conditions.

Preferably, during the first-level crown treatment, after the ground and polished first-level crown is put on the model, the upper jaw model and the lower jaw model are respectively subjected to three-dimensional scanning to obtain a digital working model and a jaw model;

after biting and fixing the upper jaw model and the lower jaw model, carrying out three-dimensional scanning to obtain a digital occlusion model;

and respectively aligning the digitized working model and the contra-jaw model to the digitized occlusion model to obtain a three-dimensional digitized model for subsequent design.

Preferably, designing the collet cap holder comprises: and designing a base support net, a large connector and a small connector, and synchronously drawing the small connector to be in contact with the digital secondary crown gap side and simultaneously to be in contact with the base support net when drawing the large connector.

Preferably, when designing the large and small connectors, the oral situation and corresponding design requirements are as follows:

upper jaw general requirements: under the condition of ensuring the connection strength, the width of the large connector is reduced as much as possible;

the small connector divided from the large connector is directly connected with the second-level coronal tooth arrangement lacuna side;

the large connecting body avoids the lingual side of the abutment;

maxillary bilateral posterior tooth loss: the large connector is connected with two sides across the faucial pillars, the thickness is not less than 0.5mm, and the width is not less than 5 mm;

maxillary anterior and posterior tooth loss: the large connector is designed by adopting a U-shaped plate, a U-shaped plate and a back palate plate or only the back palate plate, the thickness is not less than 0.5mm, and the width is not less than 5 mm;

lower jaw requirements: the large connecting body of the tongue rod is connected with the second-level crown tooth arrangement lacuna side through the small connecting body; the large tongue plate connector is directly connected with the second-level crown tongue side and the tooth arrangement metal base;

if the mouth bottom depth is not less than 6mm and the anterior tooth area has no tooth arrangement missing tooth area, the tongue rod is designed to have the thickness of 2-3mm and the width of 3-4 mm;

if the depth of the mouth bottom is less than 6mm or the anterior tooth area is a missing tooth to be arranged and repaired, the mouth bottom is designed to be a tongue plate, namely, the large connector is considered to be connected with the metal base at the alveolar ridge.

Preferably, when the large connector is designed, the glue filling termination line is placed 2mm away from the tongue side of the large connector and is higher than the large connector by 1-2mm, and the glue filling termination line is in angle transition of 30 degrees and is used for glue filling in the later period.

Preferably, before data processing of 3D printing, left and right anterior lingual abutments, the center of the large connector and lingual sides of the middle positions of the anterior teeth are respectively marked on the integral digital sleeve crown, and then each point is connected in pairs to form a stable triangle.

Preferably, the integral digital sleeve crown tissue is placed face up and the anatomical face down while in position for 3D print data processing.

Preferably, when the 3D printing data processing position is placed, the integrated digital sleeve crown is rotated to enable the front dental arch to be vertical to the scraper direction of the 3D printer.

Preferably, when adding support for 3D printing data processing, a cross support is added below the digitized sleeve crown support, a fence structure with a strip-shaped edge is added at the edge of the whole cross support area, the fence and forming plate contact area is a tooth-shaped structure, and a tooth-shaped structure is arranged at the outer side of the digitized secondary crown (i.e. the opposite side of the connection side of the digitized secondary crown and the digitized sleeve crown support).

The invention also discloses a 3D printing-based sleeve crown and a 3D printing-based sleeve crown manufacturing method.

The invention has the beneficial effects that: according to the manufacturing method of the coping, the full crown form is generated through the set parameters of the secondary crown, and then the secondary crown is formed through back cutting, so that the porcelain layers on the secondary crown and the follow-up secondary crown have enough thickness and better form, the accuracy and stability of combination of the primary crown and the secondary crown are ensured, the pre-designed full crown form is also beneficial to follow-up processing and manufacturing, and the final coping finished product can better exert the normal function of teeth; the design of the second-level crown is designed firstly and then the telescopic crown support is designed, so that the accuracy of the relative position of the telescopic crown support and the second-level crown and the connection stability can be ensured.

Drawings

FIG. 1 is a schematic representation of a three-dimensional digital model of the present invention;

FIG. 2 is a schematic representation of the secondary crown and telescopic crown stent design of the present invention;

FIG. 3 is a schematic view of an integrated digitized coping of a secondary coping and a coping holder included in the present invention;

fig. 4 is a schematic view of a 3D printed integral digitizing coping.

FIG. 5 is a schematic view of a cross support;

FIG. 6 is a schematic view of a fence structure;

FIG. 7 is a schematic view of the tooth-like structure of the contact area of the fence and the forming plate;

fig. 8 is a schematic view of the structure of the enclosure of an equilateral triangle of a cross support range.

Detailed Description

The present invention is further described below.

designing a secondary crown: editing a primary crown shoulder line as a secondary crown edge line;

generating a gap space between the secondary crown and the primary crown;

setting the minimum thickness of the secondary crown axial surface, the edge thickness of the secondary crown and a thickness transition angle;

generating a full crown form with a natural tooth form on the primary crown according to the set parameters of the secondary crown, and ensuring that the full crown form has enough back cutting thickness on the basis of the secondary crown;

designing a sleeve crown support: the digital sleeve crown bracket is designed according to the three-dimensional digital model and the designed digital secondary crown, the accuracy of the relative form and position of the digital secondary crown and the digital sleeve crown is ensured,

3D printing: carry out the data processing that 3D printed to digital second grade hat and digital sleeve crown support, data processing puts, adds support and section processing including the position, then prints out second grade hat and sleeve crown support through the 3D printer.

Wherein, the first-level crown is an inner crown of the collet crown, the second-level crown is a basal crown of the outer crown, before the invention is implemented, the initial first-level crown is designed only according to the existing mode, then the specific treatment of the collet crown is carried out to form a three-dimensional digital model which comprises the first-level crown and is shown in figure 1, the three-dimensional digital model at least comprises a digital working model, a jaw-facing model and a bite relation, the working model is a model of the side where the collet crown is positioned, the jaw model is a relative model of the other side, according to the difference of the actual situation, the upper jaw model can be a working model, the lower jaw model can be a working model, the upper jaw model and the lower jaw model can be both working models and can be a jaw-facing model, the bite relation is the contraposition relation between the working model and the jaw-facing model, because the collet crown comprises a plurality of first-level, in order to ensure smooth wearing, it is necessary to determine that all primary crowns have a common positioning channel, so that all secondary crowns can be positioned on the primary crown in the same direction.

After preparing the three-dimensional digital model, can carry out the design of second grade crown and sleeve crown support on it, although can carry out the design of second grade crown or design second grade crown and sleeve crown simultaneously after sleeve crown support design is accomplished, but, consider that this place is the maintenance that utilizes second grade crown and one-level crown to combine to realize, therefore the design of second grade crown is carried out to the priority, carry out the design of sleeve crown support again, in second grade crown design, determine second grade crown relevant parameter earlier, concrete parameter can be according to the parameter setting mode of current outer crown basement crown, mainly include the parameter of second grade crown such as the thickness of each position of second grade crown and the cooperation parameter of second grade crown and one-level crown such as cooperation clearance. In a preferred embodiment of the present invention, setting the secondary crown related parameters comprises: editing a primary crown shoulder line as a secondary crown edge line; generating a gap space between the secondary crown and the primary crown; and setting the minimum thickness of the secondary crown axial surface, the edge thickness of the secondary crown and the thickness transition angle.

Under the condition of determining the related parameters of the secondary crown, generating a full crown form with a natural tooth form on the primary crown, adjusting the full crown form through the occlusion relation after the full crown form is formed, simultaneously ensuring that the secondary crown, a ceramic layer manufactured on the subsequent secondary crown and the whole full crown form have better configurations, and then obtaining the digital secondary crown through back cutting. Can carry out the sleeve crown support after the formation of digital second grade hat, because wear the location and rely on one-level hat and second grade hat to combine, carry out sleeve crown support design based on the second grade hat that has designed, can guarantee the accuracy and the stability of sleeve crown support position, make sleeve crown support obtain better mechanics framework simultaneously.

After the design of the secondary crown and the sleeve crown support is finished, the existing 3D printing technology is adopted for printing, the file formats of 3D printing such as STL, OBJ, AMF and the like are generally required to be converted into, then the position of the file formats is placed, data processing such as support generation and slicing processing is carried out, and the data processing is carried out through a 3D printer. Because the secondary crown and the sleeve crown support are mostly made of metal materials, the laser selective melting technology is preferably adopted for printing, after printing is finished, post-treatment such as stress removal and polishing can be carried out, finally, operations such as melting and adhering of the crown, glue filling and the like are carried out according to the traditional sleeve crown manufacturing process, the manufactured primary crown is adhered to the abutment in the mouth of the patient, and then the movable part is worn.

Generally speaking, in the traditional processing of the sleeve crown, the secondary crown and the designed sleeve crown bracket are connected by spot welding after being manufactured separately, but the spot welding can only weld the surface, and the spot welding position has large brittleness and easy stress concentration, thereby having great influence on the overall strength. Because the invention adopts 3D printing for processing, complex and precise components can be formed, so that the secondary crown and the sleeve crown bracket are considered to be integrally manufactured, and the specific mode is that as shown in figure 2, when the secondary crown is designed, the adjacent unconnected secondary crowns are connected together by a connecting rod in the designed digital secondary crown; as shown in fig. 3, when designing the coping holder, the digital secondary crown and the digital coping are connected to each other to form an integrated digital coping; when 3D prints, print out integral type telescopic crown through 3D based on the digital telescopic crown of integral type. 3D prints integrated into one piece, and high compactness is unified, can not form the stress concentration of specific position, and intensity is high, difficult rupture, can not appear because the spot welding stress takes one's place repeatedly contact area between the secondary crown that leads to and the primary crown reduce, frictional force descends, long-term frictional force loses fast scheduling problem. The digital second-level crown is connected together through the connecting rod, and then the second-level crown is connected through the sleeve crown support, so that the integrity can be enhanced, and the subsequent processing and manufacturing are facilitated.

In the treatment of the primary crowns, all the primary crowns are ensured to have a common in-place way, and the specific mode can be that the three-dimensional shape of the oral cavity is obtained through oral cavity three-dimensional scanning, then an initial primary crown is designed on the oral cavity three-dimensional shape, and then the common in-place way is treated, or the primary crown is designed on a plaster model. In the preferred embodiment of the invention, the latter mode is adopted, when the primary crown is processed, the initial primary crown is positioned on the working model of the entity, the primary crown is ground and polished, all the primary crowns have a common positioning channel, and the ground and polished primary crown is positioned on the model to be scanned in three dimensions and converted into a three-dimensional digital model. The method can simultaneously obtain the formed primary crown of the object, and can save the working procedures to a certain extent.

Because the in-place path grinding is carried out on the working model of the entity, in order to ensure that the three-dimensional digital model is in-place path, when designing the secondary crown, the working model of the three-dimensional digital model is firstly rotated and adjusted to the shoulder and each surface of all the primary crowns which can be seen by naked eyes, and then the current view direction is defined as the initial in-place path of the sleeve crown; and calculating undercut areas by using the initial in-place tracks, ensuring that no undercut area exists on all the primary crowns, determining that the common in-place tracks are correct, and performing subsequent design on the basis of the determined common in-place tracks. If there is a undercut in the adjustment, the primary crown is re-made and the scan is repeated.

The primary crown can be ground by a grinding machine needle to the inverted concave surface of the primary crown to form a common locating channel, and the grinding machine needle is selected as follows: if the abutment is loosened once, a 4-degree grinding machine needle is used; if the abutment is loosened for the second time, a 6-degree grinding machine needle is used; if the abutment is not loosened, a grinding needle with the angle of 2 degrees is used; if the abutment is below 4mm, a 2 ° reduced grinding needle is used under the above conditions, i.e. if the abutment is below 4mm and is once loose, a 2 ° grinding needle is used, and so on. The more the angle, the larger the inclination of the primary crown ground by the grinding machine needle, the more convenient the wearing, the retention effect is correspondingly reduced, the changeability of the loose abutment is larger, and the larger angle is needed so as to facilitate the subsequent wearing, the position of the loose abutment is stable, the wearing is easy, and the retention effect is needed to be enhanced. Abutment height is low, wearing is easier, and retention is relatively low, thus requiring a smaller angle grinding needle.

The three-dimensional digital model comprises a digital working model, a jaw alignment model and an occlusion relation, and in order to ensure accuracy, when the primary crown is processed, the ground and polished primary crown is put on the model, and then the upper jaw model and the lower jaw model are respectively subjected to three-dimensional scanning to obtain the digital working model and the jaw alignment model; after biting and fixing the upper jaw model and the lower jaw model, carrying out three-dimensional scanning to obtain a digital occlusion model; and respectively aligning the digitized working model and the contra-jaw model to the digitized occlusion model to obtain a three-dimensional digitized model for subsequent design. The upper jaw model and the lower jaw model can be respectively scanned to obtain better precision

The face details, the upper jaw model and the lower jaw model can be fixed and stabilized by gluing and the like, then the occlusion model is obtained by scanning, and finally the three are combined to obtain a high-precision three-dimensional digital model for subsequent design.

Designing a telescopic crown stent generally comprises: design metal base and hold in the palm net, design big connector and little connector, during design big connector and little connector, in order to realize the counterpoint of sleeve crown support and second grade crown, when drawing big connector, draw little connector and digital second grade crown lacuna side and contact in step, contact with the base net of holding in the palm simultaneously.

The oral situation and corresponding design requirements are as follows:

generally, the subsequent need of the sleeve crown support is filled with glue, in order to conveniently fill glue subsequently, when a large connector is designed, a glue filling termination line is placed 2mm on the tongue side of the large connector, is 1-2mm higher than the large connector, and is in transition at an angle of 30 degrees and used for later glue filling.

In view of the problems that in the integrated digital socket crown, the socket crown support is mainly connected with the digital secondary crown by the small connector, and bending deformation and the like are easy to occur in the later manufacturing process, in a preferred embodiment of the invention, before 3D printed data are processed, left and right front tongue side abutments, the center of the large connector and the tongue side of the middle position of the front teeth are respectively marked on the integrated digital socket crown, and then each point is connected in pairs to form a stable triangle, so that the stability of the whole structure is ensured, deformation in the subsequent manufacturing process is prevented, and certainly, the connections need to be removed after the false tooth is manufactured.

In 3D printing, the printing precision of the face up is generally higher, while the printing precision of the face down is relatively lower, so that when the 3D printing data processing position is put, the integrated digital sleeve crown tissue is placed face up and the anatomy face down, as shown in FIG. 4. The tissue surface is the surface of the integral sleeve cap contacting with the alveolar ridge, the upper jaw and the like, the precision of the tissue surface is required to be higher, and the anatomical surface is the surface opposite to the tissue surface, and the precision of the tissue surface is required to be relatively lower. Thus, higher printing accuracy and printing quality can be achieved by facing the integral digital sleeve crown tissue upwards.

When the scraper of 3D printer spreads the powder, certain friction may take place with the part of having printed, in order to furthest reduce the negative effect of friction to printing, when the position of 3D printing data processing was put, rotatory integral type digital sleeve crown, made its anterior dental arch perpendicular relative 3D printer's scraper direction. The movement direction of the front dental arch relative to the direction of the scraper is parallel, so that the friction width between the front dental arch and the scraper can be reduced, and the deformation resistance of the front dental arch is improved.

Because the height difference of a section of thick bamboo hat support and second grade hat is huge, when 3D print data processing's interpolation supports, add the cross support in the below of digital sleeve hat support, be the schematic diagram that the cross supported as shown in fig. 5, the cross supports the bearing structure that is two slice structures and is the cross and form, on this basis, as shown in fig. 6, the banding rail structure in edge is increased at the edge of whole cross support region, guarantee the stability of supporting, as shown in fig. 7, rail and profiled sheeting contact area are dentate structure, prevent that expend with heat and contract with cold and arouse the rail and warp, guarantee simultaneously that the rail is connected on the profiled sheeting steadily. And a toothed structure is arranged on the outer side edge of the digital secondary crown, namely the opposite side of the connecting side of the secondary crown and the sleeve crown bracket. As shown in fig. 8, an equilateral triangular enclosure structure similar to the edge fence is designed in the cross support range. The overall stability can be further improved through the fence structural support, and the printing quality is guaranteed.

While the above description of the preferred embodiments has been briefly made separately, the method of the present invention is described below in its entirety by a preferred embodiment to facilitate understanding by those skilled in the art.

Grinding and polishing primary and secondary crowns

(1) The initial primary crown is placed on the working model.

(2) And placing the working model on a parallel grinding instrument, and adjusting the working model in-place channel through the parallel grinding instrument to minimize the undercut of the primary crown.

(3) According to the abutment condition, a grinding vehicle is selected to grind the inverted concave surface of the primary crown, so that all the primary crowns have a common in-place channel, and a uniform polymerization degree is formed at the same time, if a 0-degree grinding vehicle needle is adopted, a uniform and consistent axial surface is ground, and the height of the axial surface is regulated to be not less than 4 mm.

(4) For reasons of post-laser printing efficacy, oral health, and abutment stability, the following grinding needle usage rules are specified:

A. once the abutment is loosened, a 4-degree grinding machine needle is used;

B. loosening the abutment tooth for the second time, and using a 6-degree grinding machine needle;

C. the abutment is not loosened, and a grinding needle with the angle of 2 degrees is used;

D. the abutment is below 4mm and under the above conditions a 2 ° reduced grinding needle is used.

(5) On a parallel grinding instrument, a rubber cylindrical machine needle polishes a primary crown to a mirror surface effect, and a new undercut cannot be formed.

Two, scanning

(1) And (3) placing the ground and polished primary crown on the model, then respectively placing the upper model and the lower model into a three-dimensional scanner with the precision within 5 microns, collecting surface data of the entity, converting the surface data into a three-dimensional digital model in a computer, and obtaining a virtual 3D working model and a jaw alignment model.

(2) Biting the upper and lower jaw models, applying hot melt adhesive to the positions of middle incisors and molars of the biting models by using a hot melt adhesive gun, fixing the biting relationship of the upper and lower jaw models, connecting the upper and lower jaw models by using a small stick, and then putting the upper and lower jaw models into a scanner for scanning.

(3) And after scanning is finished, respectively aligning the virtual 3D working model and the opposite jaw model, so that the virtual 3D working model and the opposite jaw model obtain a jaw biting relation consistent with the oral cavity, and storing the data in an STL triangular patch format.

Thirdly, designing a second-level crown of the sleeve crown

(1) Loading the data of the second step into the dental three-dimensional design software.

(2) The working die is rotationally adjusted to the shoulders and all sides of all the primary crowns which can be seen from the screen by naked eyes, and then the current view direction is defined as the initial positioning path of the sleeve crown.

(3) And (3) calculating the undercut area by the computer according to the initial seating track in the step (2). Whether the inverted concave area with the mark exists on the primary crown is checked through rotation of the mouse, if the inverted concave area with the mark exists on the primary crown, the axial direction of the positioning channel can be adjusted in each direction, and therefore positioning is changed, and the optimal positioning is achieved when the inverted concave area does not exist on all the primary crowns. If there is a undercut in the adjustment, the primary crown is re-made and the scan is repeated.

(4) Editing a primary crown shoulder line, namely the position of an edge line of a secondary crown, wherein the edge can not cover the shoulder towards the root.

(5) Generating a gap space, wherein the shoulder gap is 0-0.05mm, and the coronal gap is 0-0.05 mm.

(6) The minimum thickness of the secondary crown axial surface is set to be 0.5mm, the thickness of the secondary crown edge is set to be 0.1mm, and the thickness transition angle is set to be 60 degrees.

(7) A full crown with the natural tooth morphology is generated on the primary crown according to the above parameters.

(8) The full crown shape is adjusted according to the relation of the jaw and the jaw.

(9) If the gap tooth position between the first-level crowns is too small or is positioned in the front tooth area, the full crown shape of the missing tooth can be directly generated at the gap tooth position, and the full crown shape is adjusted according to the jaw teeth.

(10) And under the condition of ensuring the basic thickness of 0.5mm, cutting back all the full crown forms to the thickness of 1.5mm, thereby forming the basic crown.

(11) If wanting to be made into metal

When the face or the metal tongue face is used, the whole crown can be kept

The face or tongue side is not cut back.

(12) All adjacent teeth without un-designed missing teethThe undercut crowns are connected together by a connecting rod, the buccal-labial abduction gap of which is open and the cross-sectional area of which is not less than 6mm². Thus, the design of the secondary crown is completed.

Fourthly, design the support of the sleeve crown

(1) Designing a metal-based supporting net: the base support net adopts a circular mesh, the single space is designed, and the base support net is positioned at the tooth arrangement gap position and has a gap of 0.6mm with the model.

(2) Designing a large connector: the large connector position is drawn on the model by mouse as required in the previous table:

(3) when the large connecting body is drawn, the small connecting body is synchronously drawn to be contacted with the second-level coronal lacuna side in the third step and simultaneously contacted with the base support net, and the lower jaw tongue plate can be directly contacted with the second-level coronal tongue side in the third step.

(4) Generating a large connector and a small connector according to the drawn range and the parameters required in the table, wherein the gap is designed to be 0-0.05 mm;

(5) and (3) placing a glue filling termination line 2mm away from the tongue side on the large connector in consideration of the later tooth arrangement position, wherein the glue filling termination line is 1-2mm higher than the large connector and is in transition at 30 degrees, so that later glue filling is facilitated.

(6) And combining the secondary crown in the third step and the sleeve crown support in the fourth step into a whole, and smoothly processing a joint to obtain a final sleeve crown movable part, and exporting the final sleeve crown movable part into an STL file.

Laser printing

(1) And (3) importing the STL integrated digital socket crown data obtained in the fourth step into software such as Magics, exocad and the like, respectively marking left and right anterior lingual abutments, the center of the large connector and the lingual side of the middle position of the anterior teeth on the movable part of the STL socket crown, and then connecting every two points to form a stable triangle so as to keep the stability of post-processing.

(2) With the digital sleeve crown work piece tissue face of integral type down, dissect the face downwards, minimum highly places to reduce the printing time and support the degree of difficulty when guaranteeing to print the precision.

(3) And vertically rotating the front dental arch of the integrated digital sleeve crown workpiece relative to the direction of the scraper to strengthen deformation resistance.

(4) And ensuring that the distance between the lowest point and the forming plate is 1.5-2.5mm to generate support.

(5) The support is basically supported by a cross, the cross is a sheet structure with the width of 1mm and the thickness of 0.1mm, and the centers of the two sheets are crossed to form the cross.

(6) The fence structure is added at the edge of the whole cross supporting area and is an edge strip-shaped fence, the contact area of the fence and the forming plate is a tooth-shaped structure, and the gap of the tooth-shaped structure is 1mm wide and 2-3mm high; the same tooth-like structure is also used on one side of the integral digital collet crown workpiece.

(7) And generating a fence structure of a 10mm equilateral triangle within the range of the cross support, wherein the parameters are the same as those of the edge fence.

(8) And slicing the integrally-arranged digital sleeve crown workpiece into a slice file with the layer thickness of 0.03-0.09mm, and then exporting the slice file.

(9) And (4) importing the slice file into a 3D metal printer for direct printing and molding to obtain an integrated sleeve crown semi-finished product, and finally further processing according to the existing manufacturing mode.

Claims

1. The manufacturing method of the sleeve crown based on 3D printing is characterized by comprising the following steps:

designing a secondary crown: setting secondary crown related parameters;

2. The method for manufacturing a 3D-printing-based collet crown according to claim 1, wherein the setting of secondary crown related parameters comprises:

editing a primary crown shoulder line as a secondary crown edge line;

generating a gap space between the secondary crown and the primary crown;

3. The method of manufacturing a 3D printing-based collet cap of claim 1,

when the secondary crown is designed, adjacent and unconnected secondary crowns in the designed digital secondary crown are connected together by a connecting rod;

4. The 3D printing-based method for manufacturing a coping as recited in claim 1, wherein in the primary coping process, an initial primary coping is positioned on a working model of a solid, the primary coping is ground and polished to have a common positioning channel for all the primary coping, and the ground and polished primary coping is positioned on the model to be scanned in three dimensions and converted into a three-dimensional digital model.

5. The 3D printing-based telescopic crown manufacturing method according to claim 4, wherein when designing the secondary crown, the working model of the three-dimensional digital model is adjusted to be rotated to the shoulders and the faces of all the primary crowns which can be seen by naked eyes, and then the current view direction is defined as an initial positioning path of the telescopic crown;

6. The 3D printing-based sleeve crown manufacturing method according to claim 4, wherein during the primary crown processing, the grinding needles grind the inverted concave surface of the primary crown to form a common positioning channel, and the grinding needles are selected as follows:

if the abutment is loosened once, a 4-degree grinding machine needle is used;

7. The method for manufacturing a 3D printing-based collet crown according to claim 4, wherein in the primary crown processing, after the ground and polished primary crown is put on the model, the upper jaw model and the lower jaw model are respectively scanned in three dimensions to obtain a digitized working model and a pair jaw model;

8. The 3D printing-based method for making a coping of claim 1, wherein: designing a coping bracket includes: and designing a base support net, a large connector and a small connector, and synchronously drawing the small connector to be in contact with the digital secondary crown gap side and simultaneously to be in contact with the base support net when drawing the large connector.

9. The 3D printing-based method for making a coping of claim 8, wherein: when designing a large connector and a small connector, the oral conditions and corresponding design requirements are as follows:

the large connecting body avoids the lingual side of the abutment;

10. The 3D printing-based method for making a coping of claim 8, wherein: when the large connector is designed, the glue filling stop line is placed 2mm on the tongue-biased side of the large connector and is 1-2mm higher than the large connector, and the glue filling stop line is in 30-degree angle transition and is used for glue filling in the later period.

11. The 3D printing-based method for making a collet cap of claim 3, wherein: before the data processing of 3D printing, left and right anterior lingual abutment, the center of a large connector and the lingual side of the middle position of the anterior teeth are respectively marked on an integrated digital sleeve crown, and then each point is connected in pairs to form a stable triangle.

12. The 3D printing-based method for making a collet cap of claim 3, wherein: when the 3D printing data processing position is placed, the integrated digital sleeve crown tissue is placed upwards and the dissection surface is placed downwards.

13. The 3D printing-based method for making a collet cap of claim 3, wherein: when the 3D printing data processing position is placed, the integrated digital sleeve crown is rotated, and the front dental arch of the integrated digital sleeve crown is perpendicular to the scraper direction of the 3D printer.

14. The 3D printing-based method for making a coping of claim 12, wherein: when the 3D printing data is processed to add and support, add the cross support in the below of digital sleeve crown support, the banding rail structure in edge is increased at the edge of whole cross support region, and rail and profiled sheeting contact area are dentate structure, sets up dentate structure in the outside limit of digital second grade crown.

15. Sleeve crown based on 3D prints, its characterized in that: method of making a 3D printing based collet cap according to any of claims 1 to 14.