CN1215819C - Preparation method of laser three-dimensional forming of oral metal restoration - Google Patents

Abstract

The present invention discloses a laser stereo forming method for metal oral prostheses. The laser stereo forming technology is combined with the dental computer-assisted design and manufacture technology to establish a new technology for directly manufacturing metal oral prostheses from metal powder. The laser stereo forming method comprises the following steps: a three-dimensional CAD model of a prosthesis is generated in a computer, the model is sliced according to a certain thickness by layers so as to convert three-dimensional information into a series of two-dimensional outline information, and the metal powder material is accumulated layer by layer according to the outline trace by using the laser coating method so as to finally form the oral prosthesis only needing little processing. The present invention develops a novel method for manufacturing dental prostheses. The laser stereo forming method can be used for quickly accurately manufacturing prostheses in the fields of orthopaedics, cosmetic surgery, etc.

Description

The laser solid forming preparation method of oral cavity metal restoration

Technical field

The invention belongs to stomatology or biomedical engineering field, relate to oral artificial tooth or artificial tooth parts preparation method, particularly the laser solid forming preparation method of oral cavity metal restoration.

Background technology

Tooth body, defect of dentition are a kind of commonly encountered diseases and the frequently-occurring diseases of the department of stomatology, account for 24%--53% among the natural person, select fixed restoration to repair with manual indivedual production methods during morbidity usually.Casting method is adopted in the making of dummy, and technology is loaded down with trivial details, and speed is slow, and efficient is low, and patient goes to a doctor often, and the time is long.It is imperative to change traditional manufacture method.

Begin the eighties in last century, the CAD/CAM technology is introduced into the prosthetic dentistry field, France, Switzerland, Germany, the U.S. etc. develop dental CAD/CAM system in succession, wherein famous and universal with German CEREC--CAD/CAM system, sell more than 5000, can make ceramic inlay, veneer and complete crown.The revolutionary character that this technology is considered to the stomatology field breaks through.But, processing method loses the material milling mode because adopting, there are the following problems: first must prepare the machining materials that is complementary in advance, and the volume of machining materials must just can be reserved enough allowance greater than the cutting forming body, therefore certainly will cause a large amount of wastes of material in the course of processing; Second is subjected to the restriction of machining materials performance, can only make less and dummy simple shape, and as leaf-comb, simple fixation bridge, range of application is very limited; The 3rd, the machining materials material is single, perhaps is metal or is pottery, does not possess the ability of making the composite dummy.

Summary of the invention

In order to overcome shortcomings such as the poor performance, the stock utilization that exist in the prior art are low, the process-cycle is long, shaping form is simple, purpose of the present invention is intended to set up the laser solid forming preparation method of a kind of oral cavity metal restoration.This method is the manufacturing that advanced person's laser solid forming technology is applied to the oral cavity metal restoration, be expected to open up a kind of brand-new processing technique for the making of mouth mending material for replacing the conventional cast method or reforming existing mouth mending material area of computer aided manufacture method and establish the theory and technology basis.

To achieve these goals, technical solution of the present invention is, at first in computer, generate the three-dimensional CAD model of oral cavity metal restoration, and according to requirement on machining accuracy this model is carried out hierarchy slicing and handle, the 3 D stereo data transaction of oral cavity metallic prosthetic shape is become a series of two dimensional surface data; Then, determine the track of laser beam flying, generate processor, and it is passed to numerical control table, NC table according to the panel data of each layer; Realize that by numerical control table, NC table track while scan that laser beam determines according to processor in the enterprising line scanning of base material, simultaneously, sends into the metal/alloy powder by powder feeder, thereby obtain the coating consistent with this flat shape in laser molten pool; Behind the intact one deck of laser beam flying, laser head and powder-feeding nozzle are along the Z axle segment distance Δ Z (its numerical values recited equates with the thickness of CAD two dimension slicing model) that rises, track while scan according to following one deck scans again, after all planes have all been scanned, promptly obtain three-dimensional entity oral cavity metal restoration.(as Fig. 1).In the process of making, can adjust the size of different powder feeder powder sending quantities as required, make the different parts of oral cavity metal restoration have different compositions and tissue, realize the best collocation of material/performance/environment for use.

Method of the present invention will be opened up new manufacturing process with auxiliary make (CAD/CAM) for computer-aided design, meet every neither identical personalization of mouth mending material more and make requirement; And the multiple material of energy processing and fabricating, be expected to make the composite dummy; The material property of the dummy of processing will be far superior to current material; Can save expensive dental materials, compare with cutting working method etc., range of application is wider, and practical value is higher.Replace traditional typographical printing technology as modern laser phototypesetting technology, greatly improve the automaticity and the production efficiency of mouth mending material, satisfy vast dental defect patient and repair needs fast, this technology can be extended to simultaneously accurately making fast of subject dummy such as orthopaedics, department of plastic surgery and accurate medical apparatus and instruments, economic benefit and social benefit are huge.This method can be made the advantage that composite dummy and dummy physics and chemistry, mechanical property can artificially be controlled except that having economical with materials, can process the general characteristic of arbitrary shape, having more, and greatly widens kind and scope that area of computer aided is made dummy.

Description of drawings

Fig. 1 laser solid forming know-why sketch map;

Fig. 2 is experiment system for use in carrying sketch map; What number in the figure was represented is laser instrument 1, reflect focalization mirror 2, powder feeder 3, base material 5, laser molten pool 4, numerical control table, NC table 6.

Fig. 3 is a wax pattern three-dimensional reconstruction figure;

Fig. 4 is the SLC file that distributes by layer;

Fig. 5 is the SLFC hierarchical data file;

Fig. 6 shows that Rpdata handles the back and generates stl file;

The nichrome complete crown picture of Fig. 7 laser solid forming technology preparation.

The specific embodiment

The present invention is described in further detail below in conjunction with embodiment that accompanying drawing and inventor provide.

1. experimental facilities

Referring to Fig. 2, the Laser Processing experimental facilities comprises laser instrument 1, reflect focalization mirror 2, powder feeder 3, base material 5, laser molten pool 4, numerical control table, NC table 6.Data acquisition facility comprises four radium-shine scanning systems of CNC of Taiwan product, Intel PIV2.0G computer.Software: SURFACER 10.5, SDBC (StructuralDynamics Research Corporation) company; Cloud Date Process software is by the software of Xi'an Communications University's development and Design processing cloud data; MIMICS software, Belgian Materialise company; RP daba software, Xi'an Communications University's design, the model conversion that CAD is cut into slices is the STL format software.

2. experiment material

Select the Rene95 alloyed powder for use, its composition sees Table 1.Granularity is-200 orders～+ 300 orders, and powder particle is spherical in shape, and flowability will be got well.Manufacture and design micro-powder feeder, the powder sending quantity scope is 1.0--10g/min, powder pushing precision ± 3%.Selecting matrix is diameter 120mm, the discoid carbon steel of thick 8mm, and its light receiving surface is handled to increase absorptivity through melanism.

Table 1:Rene95 alloying component

C	Cr	Co	Al	Ti	Mo	W	Nb	Zr	B	Ni
											0.04～	12～14	7～	3.3～	2.3～	3.3～3.7	3.3～3.7	3.3～	0.03～0.07	0.006～0.015	Surplus
0.09		9	3.7	2.7			3.7

3. experimental technique

(1). carry out artificial complete crown tooth preparation by the prosthetic dentistry requirement, impression taking turns over system super hard gypsum model, utilizes plaster model to prepare detachable die.Make the complete crown wax pattern with inlay wax.With wax pattern evenly, placed dry tack free 10 minutes with the universal flaw detection developer spraying of HD-EV.Wax pattern is placed on the mechanical scanning platform, by moving of computer control machinery scanning platform, the mechanical scanning platform is in the translation of X-Y direction of principal axis, rotate in Z-direction, so that measure each surface of wax pattern, the laser beam emitting device of radium-shine scanning system produces laser beam, and incident laser is vertical with horizontal plane, and the receiving beam of two CCD and the angle of incident beam are 45 degree.Laser beam is that wire is launched, and after linear beam projected wax pattern surface and reflects, its reflected light was received and be input to computer by the pick off receiving system.Along with the continuous rotation of platform in Z-direction, progressively measure 360 degree profiles of wax pattern, obtain the total data of wax pattern, scanning step pitch 0.01mm.

The measured data of the radium-shine scanning system of Computer Processing are cloud data, SCN data format.These data can be formed wax shape three-dimensional reconstruction through the SURFACER software processes see Fig. 3.

Above SCN cloud data with Cloud Data Process software processes, is formed the SLC formatted file that distributes by layer.See Fig. 4.

With SLC file MIMICS software processes, become binary system SLFC file, this file is the rapid prototyping hierarchical data file.See Fig. 5.

With SLFC file Rpdata software processes, finally generate the STL formatted file.See Fig. 6.

By laser scanning measurement method realize the grinding one's teeth in sleep three-dimensional reconstruction of complete crown, obtain corona CAD physical model, file format is the STL form.

(2). equipment, material are prepared: preparation Rene95 alloy powder, granularity is-200 orders～+ 300 orders, and powder particle is spherical in shape, and flowability will be got well.Manufacture and design micro-powder feeder, the powder sending quantity scope is 1.0～10g/min, powder pushing precision ± 3%.

(3). with corona CAD physical model input laser solid forming equipment, this device software is cut into 0.1mm thickness sheet with corona CAD physical model, and every data transaction becomes the digital control processing instruction, the work of control laser solid forming equipment.

(4). laser beam 1 is through forming the laser molten pool 4 of certain size on base material 5 surfaces behind the reflect focalization mirror 2, and under the drive of numerical control table, NC table 6, the sweep trace digital control processing instruction according to step (3) is generated scans on base material 5 surfaces.In laser beam flying, powder feeder 3 is sent into the metal/alloy powder in laser molten pool 4, promptly carries out synchronous powder feeding system and applies, and obtains layer of material after the condensation.After having scanned one deck, laser beam 1 and powder feeder 3 (3) setting of being exported set by step apply layer of material down according to the sweep trace of one deck down again along the Z-direction distance, delta Z that rises.After all layer has all applied, just obtain Three-dimensional Entity Components.

(5). testing selected parameter is: laser power 3300w～4000w, scanning speed 5mm/s～10mm/s, powder sending quantity 1.0g/min～10g/min, shield gas flow rate 3.5l/min～6.5l/min.Each layer laser melting coating 6 roads, overlapping rate 40%.Obtain artificial corona, its precision is x-y direction ± 1mm/100mm, z direction ± 1mm/200mm.The mechanical property of material is: the room temperature yield strength reaches 850MPa, and hot strength reaches 950MPa, and percentage elongation surpasses 10%, and fatigue behaviour reaches the forged material level.

4. embodiment: use the laser solid forming technology and prepare oral cavity nichrome complete crown

Material: choose nichrome powder (Rene95 alloy powder, Beijing Iron and Steel Research Geueral Inst), its composition sees Table 1.

With reference to 3 experimental techniques, obtain the nichrome complete crown.As Fig. 7.

The present invention opens up new manufacturing process for computer-aided design and auxiliary make (CAD/CAM system), meets every neither identical personalization of mouth mending material more and makes requirement; And the multiple material of energy processing and fabricating, be expected to make the composite dummy; The material property of the dummy of processing will be far superior to current material; Can save expensive dental materials, compare with cutting working method etc., range of application is wider, and practical value is higher.Replace traditional typographical printing technology as modern laser phototypesetting technology, greatly improve the automaticity and the production efficiency of mouth mending material, satisfy vast dental defect patient and repair needs fast, this technology can be extended to simultaneously accurately making fast of subject dummy such as orthopaedics, department of plastic surgery and accurate medical apparatus and instruments, economic benefit and social benefit are huge.

This method can be made the advantage that composite dummy and dummy physics and chemistry, mechanical property can artificially be controlled except that having economical with materials, can process the general characteristic of arbitrary shape, having more, and greatly widens kind and scope that area of computer aided is made dummy.

Claims (1)

1. Preparation method of laser three-dimensional forming of oral metal restorations. Laser three-dimensional forming equipment includes laser, reflective focusing mirror, powder feeder, base material, laser melting pool, numerical control workbench, data acquisition equipment includes laser scanning system, computer and its Software; It is characterized in that, comprises the following steps: 1) Firstly, the artificial full crown tooth body was prepared according to the requirements of prosthodontics, the impression was taken, the superhard plaster model was made, the removable model was prepared using the plaster model, and the full crown wax model was made with inlay wax; the wax model was used HD-EV universal flaw detection imaging agent is sprayed evenly and left for 10 minutes to dry the surface; 2) Place the wax-up on the mechanical scanning platform, and control the movement of the mechanical scanning platform through the computer. The mechanical scanning platform translates in the direction of the X-Y axis and rotates in the direction of the Z-axis, so as to measure the various surfaces of the wax-up. The laser scanning system The laser emitting device generates a laser beam, and the incident laser is perpendicular to the horizontal plane. The angle between the receiving beam of the dual CCD and the incident beam is 45 degrees; the laser beam is projected in a linear form. The reflected light is received by the sensor receiving device and input to the computer; with the continuous rotation of the mechanical scanning platform in the Z-axis direction, the 360-degree contour of the wax-up is gradually measured, and all the data of the wax-up is obtained. The laser power is 3300w ~ 4000w, scanning Speed 5mm/s～10mm/s, scanning step 0.01mm; 3) Computer processing The data measured by the laser scanning system is point cloud data and SCN data format, and the data is processed by SURFACER software to form a wax-shaped 3D reconstruction; the 3D reconstruction of the molar crown is realized by laser scanning measurement method, and the crown is obtained CAD solid model; 4) Input the CAD solid model of the dental crown into the laser three-dimensional forming equipment, the equipment software cuts the CAD solid model of the dental crown into 0.1mm thick slices, and converts each piece of data into numerical control processing instructions to control the operation of the laser three-dimensional forming equipment; the laser three-dimensional forming equipment The laser beam forms a laser molten pool of specified size on the surface of the substrate after passing through the reflective focusing mirror, and is driven by the CNC workbench to scan the surface of the substrate according to the generated CNC machining instructions; 5) At the same time, the metal or alloy powder is fed into the laser molten pool through the powder feeder. The powder feeding range of the powder feeder is 1.0~10g/min, the powder feeding accuracy is ±3%, and the protective gas flow rate is 3.5l/min ~6.5l/min, so as to obtain a coating consistent with the shape of the plane; after the laser beam scans a layer, the laser head and the powder feeding nozzle rise along the Z axis for a distance ΔZ, and the value is 0.1mm; then follow the next step The scanning trajectory of each layer is scanned, and when all the planes are scanned, a three-dimensional solid oral metal restoration is obtained.

Images