KR101612846B1

KR101612846B1 - Preform for plastic dental positioning appliance and method for producing the same

Info

Publication number: KR101612846B1
Application number: KR1020150059195A
Authority: KR
Inventors: 박철규; 순영미; 오윤종
Original assignee: 주식회사 메디오션
Priority date: 2015-04-27
Filing date: 2015-04-27
Publication date: 2016-04-15

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a preform used for manufacturing a plastic orthodontic appliance. According to the present invention, there is provided a method of manufacturing a preformed body of a plastic orthodontic appliance, comprising the steps of: (a) securing three-dimensional image data (A image data) indicating a tooth arrangement before calibration; (b) rearranging the teeth using the A image data to form three-dimensional image data (C image data) representing the tooth arrangement after calibration; (c) creating a three-dimensional image data set (B image data set) representing a series of successive tooth arrays going from the pre-calibration tooth alignment to the post-calibration tooth alignment; (d) creating three-dimensional image data (D image data) comprising a union of images of the C image data and the B image data set; (e) making a preform by using the D image data. A method of manufacturing a preform of a plastic orthodontic appliance is provided. Since the preform according to the present invention is provided with the cavity formed in consideration of the tooth arrangement state of the patient, it is possible to partially improve the thickness of the orthodontic appliance during the process of manufacturing the orthodontic appliance through thermoforming have.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a plastic dental orthodontic appliance,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an orthodontic appliance for calibrating teeth using a transparent reinforced plastic frame, and more particularly to a preform used for manufacturing a plastic orthodontic appliance.

Occlusion refers to the state in which the teeth of the upper and lower jaws mesh with each other when their mouths are closed. Malocclusion refers to an occlusal relationship in which the teeth are not aligned due to a certain cause, or the state of the up-and-down engagement is out of the normal position, resulting in aesthetic and functional problems.

The major causes of malocclusion are known to be genetic influences. Malocclusion is caused by various causes such as tooth shape, size, environmental effects, bad habits, wrong postures, dental caries, and congenital disorders such as cleft lip and cleft .

If malocclusion occurs, teeth arrangement is not uniform and food residue is likely to remain between the teeth. Because it is not easy to maintain clean with accurate brushing, it increases the plaque in the mouth, and it is easy to progress to gum disease such as dental caries or gingival inflammation. In addition, if there is a tooth that deviates much from the normal dentition or if the position of the jaw is abnormal, there is a high possibility that the teeth are damaged, such as a tooth fracture, when an external shock is applied.

Treating such malocclusion is orthodontic treatment or orthodontic treatment. Orthodontic treatment uses the property that the tooth moves when it receives some force. Treatment of malocclusion uses a variety of devices and methods depending on the cause and timing of treatment. A device designed to remove habit, a device for suppressing or enhancing the development of the upper and lower jawbone, and a device for slowly moving the tooth to a desired position, and a removable device that can be inserted and removed in the oral cavity. It can also be divided into removable fixed devices.

Currently, most commonly used is a fixed treatment that attaches a device called a bracket to the teeth and moves the teeth using the elasticity of the wires and the rubber band. It is often used for malocclusion of any kind. Brackets are usually made of metal, which has a noticeable disadvantage during treatment.

Currently, most commonly used is a fixed treatment that attaches a device called a bracket to the teeth and moves the teeth using the elasticity of wires and rubber strips, and is often used for malocclusion of any kind. Brackets are usually made of metal, which has a noticeable disadvantage during treatment.

In order to overcome these disadvantages, orthodontics using clear aligner method has been proposed. Transparent correction is a procedure to make clear orthodontic appliances that change step by step from the state of the tooth before correction to the state of the tooth after correction, and correcting the dentition by changing it to the teeth. The orthodontic appliance used for transparent correction is made of transparent plastic, so it has a good sense of aesthetics. Japanese Patent Application Laid-Open No. 10-0657724 discloses an orthodontic appliance used for transparent correction.

The orthodontic appliance used for transparent correction is made by a vacuum molding method in which a mold is made by drawing a bone of a tooth, a transparent plastic sheet of about 1 mm is placed on the mold, and heat is applied to the mold while negative pressure is applied to the mold. The thickness of the molded orthodontic appliance differs depending on the bending of the tooth shape.

One of the biggest problems of the orthodontic appliance is that the thickness of the orthodontic appliance becomes too thin in part during the molding process. The thickness of the plastic sheet is uniform, and the shape of the teeth is not considered at all. Therefore, the portion where the teeth are located during the molding process becomes very thin. Such thinned portions can easily be torn when worn, and the correction force is reduced. The part of the tooth that gives the orthodontic force is a part that stretches much during molding and is thinner than the average thickness. In the transparent correction, the orthodontic force by the orthodontic appliance depends on the elastic restoring force generated when the orthodontic appliance is elastically deformed. The elastic restoring force is determined by the thickness and deformation amount of the plastic material and the orthodontic appliance, which are materials of the orthodontic appliance . Therefore, as the thickness becomes thinner, the correction force decreases.

It is preferable to use a thick transparent plastic sheet to increase the corrective force. However, when the thickness is increased, the feeling of fit is lowered, the portion that is not stretched during vacuum molding becomes too thick, and the problem of overbite occurs.

Patent Registration No. 10-0657724

SUMMARY OF THE INVENTION It is an object of the present invention to provide a preform for manufacturing a orthodontic appliance having a high correction force without deteriorating the wearing comfort of the orthodontic appliance and a method of manufacturing the same.

According to the present invention, there is provided a method of manufacturing a preformed body of a plastic orthodontic appliance, comprising the steps of: (a) securing three-dimensional image data (A image data) indicating a tooth arrangement before calibration; (b) rearranging the teeth using the A image data to form three-dimensional image data (C image data) representing the tooth arrangement after calibration; (c) creating a three-dimensional image data set (B image data set) representing a series of successive tooth arrays going from the pre-calibration tooth alignment to the post-calibration tooth alignment; (d) creating three-dimensional image data (D image data) comprising a union of images of the C image data and the B image data set; (e) making a preform by using the D image data. A method of manufacturing a preform of a plastic orthodontic appliance is provided.

According to another aspect of the present invention, there is provided a tooth comprising: a cavity formed by a tooth arrangement configuration of a combination of a set of teeth arranged successively between a tooth arrangement after calibration and a tooth arrangement before calibration and a tooth arrangement after calibration A preform of a calibrating device is provided.

Wherein a cavity is formed that includes a shape obtained by smoothing a tooth arrangement shape of a union of consecutive tooth array sets between a tooth arrangement after calibration and a tooth arrangement before calibration and a tooth arrangement after calibration Is provided.

Since the preform according to the present invention is provided with the cavity formed in consideration of the tooth arrangement state of the patient, it is possible to partially improve the thickness of the orthodontic appliance during the process of manufacturing the orthodontic appliance through thermoforming have. Therefore, it is possible to manufacture an orthodontic appliance having excellent wearing comfort and corrective force.

1 is a flowchart showing a procedure of a method of manufacturing a preform of a plastic orthodontic appliance according to the present invention.
Fig. 2 shows a state in which teeth of a tooth shape are obtained in a method of manufacturing a preformed body of a plastic orthodontic appliance according to the present invention.
Fig. 3 shows a three-dimensional image of the tooth condition after calibration made during the method of manufacturing the preform of the plastic orthodontic appliance according to the present invention.
4 is a view for explaining a step of smoothing a three-dimensional image of a tooth condition before calibration in a method of manufacturing a preform of a plastic orthodontic appliance according to the present invention.
FIG. 5 is a view for explaining a step of creating one overlapped three-dimensional image data in a method of manufacturing a preform of a plastic orthodontic appliance according to the present invention.
FIG. 6 shows a state in which a mold having a smoothed tooth arrangement is obtained in a method of manufacturing a preformed body of a plastic orthodontic appliance according to the present invention.
FIG. 7 shows a state in which a preform is obtained in a method of manufacturing a preformed body of a plastic orthodontic appliance according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings. The embodiments described below can be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. In the drawings illustrating embodiments of the present invention, the same reference numerals in the drawings denote the same elements.

1 is a flowchart showing a procedure of a method of manufacturing a preform of a plastic orthodontic appliance according to the present invention. Referring to FIG. 1, a method of manufacturing a preform of a plastic orthodontic appliance according to the present invention starts with step S1 of securing three-dimensional image data (A image data) representing the tooth arrangement before calibration.

The step of securing the A image data includes providing a tooth-shaped mold representing the tooth arrangement state of the patient before calibration, and scanning the mold to secure three-dimensional image data.

In the step of providing the mold, a specialist such as a dentist uses a tray on which an impression material such as alginate is placed to obtain an impression of a malocclusion tooth by floating the patient's teeth. Then, the obtained impression is filled with plastic or ceramic or the like to produce a tooth-like mold 1 as shown in Fig.

In the step of securing the three-dimensional image data, the mold 1 of the tooth shape is scanned by using a device such as a laser to secure three-dimensional digital image data. The obtained data can be represented as an image on a computer system equipped with appropriate software.

Next, the teeth are rearranged using the A image data, and three-dimensional image data (C image data) indicating the tooth arrangement after calibration is created (S2). 3 shows a three-dimensional image of the tooth condition after calibration made during the method of manufacturing the orthodontic appliance according to the present invention. The three-dimensional image data (C) representing the tooth arrangement after calibration can be obtained by rearranging teeth while a person having a professional knowledge such as a dentist observes the image. It is also possible to automatically rearrange using software provided with an algorithm to help rearrange the teeth.

Next, a three-dimensional image data set (B image data set) representing a series of successive tooth arrays running from the tooth arrangement before calibration to the tooth arrangement after calibration is created (S3). At this stage, the number of teeth arrays included in the B image data set differs depending on the patient's tooth condition. When the tooth condition is comparatively good, it includes about ten steps, and generally includes about 30 to about 40 steps. A set of B image data representing a series of successive tooth arrays is generated based on the tooth arrangement before calibration and the tooth arrangement after calibration.

The B image data set representing a series of consecutive tooth arrangements is determined by determining the shortest path to move from the initial position to the final position by separating each tooth of the tooth array before calibration and determining the rate of movement along the path . If a collision or interference occurs between teeth separated on the movement path, a shortest path that can move while avoiding collision or interference is set. This step can be done automatically by software with a detection algorithm that can set the shortest hardness taking into account the collision or interference between teeth.

Next, all the images of the C image data and the B image data set are smoothed (S4). Fig. 4 is a view for explaining a step of smoothing a three-dimensional image of a tooth condition before correction in a manufacturing method of the orthodontic appliance according to the present invention. Fig. 4 (a) shows the cross-sectional state of the tooth surface before smoothing, Fig. 4 (b) shows three low-frequency components in the trigonometric function obtained through the fast Fourier transform, Represents the sum of three low-frequency components in the trigonometric function.

Smoothing is performed by Fourier transform, wavelet transform, etc., which are used to convert complex wave signals into simpler components.

The Fourier transform will be described below as an example.

The three-dimensional image data (B image data set, C image data) representing the tooth arrangement representing each step is very complex in shape as shown in FIG. 4 (a). 4 (a) shows an image of C image data indicating a tooth arrangement after calibration. Such complex three-dimensional image data can be represented by the sum of simple trigonometric functions as shown in FIG. 4 (b) using Fourier transform, and when the trigonometric functions are summed together, the three- Can be obtained. These trigonometric functions include a low-frequency component and a high-frequency component. By adding only the low-frequency components to the complex three-dimensional image data, as shown in FIG. 4C, It is possible to obtain an approximate simple curved line C '.

Next, as shown in Fig. 5, three-dimensional image data (C 'image data) representing a tooth arrangement after smoothing after Fourier transformation and a three-dimensional image data set (B' image data set) Dimensional image data (D 'image data) including the union of images of the three-dimensional image. At this time, the data are overlapped on the basis of points where the position is not changed throughout the tooth correction process in the tooth (S5).

Next, the D 'image data, which is the three-dimensional image data including the union, is smoothed again (S6). This step can also use Fourier transform. If only the low frequency component is selected from the data obtained through the Fourier transform except for the high frequency component, a smooth curve (E) reflecting the tooth arrangement state of all the teeth can be obtained.

Next, the mold 2 of the smoothed tooth arrangement is manufactured as shown in Fig. 6 by using the three-dimensional image data (E image data) including the smoothed union. The mold 2 is manufactured using a stereolithography technique (S7). Optical fabrication technology is a three-dimensional printing technique that irradiates light to a photo-curing resin to continuously cure and laminate a photo-curing resin into a thin layer of several micrometers in thickness. E image data is used to generate the cross-sectional information, and the thin layer is continuously formed by irradiating light to the photo-curing resin using the cross-sectional information thus generated to prepare the mold 2 having the smoothed tooth arrangement. The produced mold 2 is separated from the uncured photocurable resin. In this mold 2, unlike actual teeth, teeth of a smooth curve are arranged.

Finally, the preform 3 of the plastic orthodontic appliance having the cavities of the tooth arrangement arranged in a smoothed shape is heated by placing the plastic sheet on the mold 2 (S8). This step is carried out by vacuum molding. Vacuum molding is a type of thermoforming in which a plastic sheet is molded into a three-dimensional form by applying heat and pressure. Vacuum forming is a well-known forming method and will be briefly described. First, the mold 2 is placed on a vacuum plate, a plastic sheet is placed thereon, and the plastic sheet is heated to a temperature not lower than the softening point of the plastic sheet to soften the plastic sheet. Then, a vacuum is formed under the mold 2 so that the softened plastic sheet is brought into close contact with the mold, thereby forming the preform 3 having the cavities of the smoothed tooth arrangement.

The plastic sheet may have a circular or square shape depending on the vacuum forming apparatus, and the thickness thereof is about 1 mm. PC, PET, and poly-urethane are mainly used. Next, the preform 3 is separated from the mold 2 to obtain a preform 3 in which a cavity having a smoothed tooth array shape having the same shape as the tooth shape of the mold as shown in Fig. 7 is formed.

Although the preferred embodiments of the present invention have been described above, it is apparent that various modifications can be made without departing from the scope of the present invention.

For example, it has been described that a mold having a tooth shape is first made and then scanned using a laser to acquire three-dimensional image data indicating a tooth arrangement before treatment. However, by X-ray image and computed tomography (CAT scan) It is possible to acquire three-dimensional image data representing the tooth arrangement before treatment by a conventional technique of digitizing an image created, magnetic resonance tomography (MRI), and the like.

In addition, although the image of the three-dimensional image data (B image data set and C image data) indicating the tooth arrangement representing each step is first smoothed and then the union is smoothed again, the tooth arrangement (B image data set, C image data) representing the three-dimensional image data.

Further, it is also possible to directly use the union of the three-dimensional image data including the union of the images of the three-dimensional image data (B image data set and C image data) representing the teeth arrangement representing each step without smoothing the three-dimensional image data have.

In addition, although the preform 3 is thermoformed using the mold 2 after the mold 2 is manufactured by using the stereolithography technique, the preform may be directly manufactured using the stereolithography, The preform may be produced by another molding method such as injection molding.

1: Mold
2: Mold of smoothed tooth arrangement
3: preform

Claims

A method of manufacturing a preform of a plastic orthodontic appliance,
(a) securing three-dimensional image data (A image data) representing a tooth arrangement before calibration;
(b) rearranging the teeth using the A image data to form three-dimensional image data (C image data) representing the tooth arrangement after calibration;
(c) creating a three-dimensional image data set (B image data set) representing a series of successive tooth arrays going from the pre-calibration tooth alignment to the post-calibration tooth alignment;
(d) creating three-dimensional image data (D image data) comprising a union of images of the C image data and the B image data set;
(e) making a preform using the D image data. < RTI ID = 0.0 > 8. < / RTI >

The method according to claim 1,
The step (e)
(e-1) fabricating a tooth array using the D image data; And
(e -2) thermoforming a preform of a plastic orthodontic appliance in which a plastic sheet is placed on the mold and heated to form a cavity having a tooth array shape &Lt; / RTI >

The method according to claim 1,
Further comprising the step of smoothing the D image data to form smoothed three-dimensional image data (E image data) after the step (d)
Wherein the step (e) is a step of preparing a mold having a smoothed tooth arrangement using the E image data.

The method of claim 3,
Wherein the smoothing step is a step of smoothing by a Fourier transform or a Wavelet transform. &Lt; Desc / Clms Page number 19 >

The method according to claim 1,
The step (a)
And scanning the three-dimensional model of the patient's teeth.

The method according to claim 1,
After the step (c)
(C 'image data) and a smoothed image data set (B' image data set) by smoothing the C image data and the B image data set, respectively,
The step (d)
Dimensional image data (D 'image data) including the union of the images of the C' image data and the B 'image data set,
The step (e)
And the step of forming the preform using the D 'image data.

In a preform of a plastic orthodontic appliance,
Wherein a cavity is formed which includes a tooth array configuration of a combination of a tooth array after calibration, a tooth array before tooth calibration, and a set of teeth array continuous between teeth after calibration.

In a preform of a plastic orthodontic appliance,
Wherein a cavity is formed which includes a shape obtained by smoothing a tooth arrangement shape of a union of consecutive teeth array sets between a tooth arrangement after calibration and a tooth arrangement before calibration and a tooth arrangement after calibration Shaped body.