JP2018192197A - Scan body and dental implant impression taking method using the same - Google Patents

Abstract

To provide a scan body that gives a clear three-dimensional image in digital impression acquisition.SOLUTION: A scan body is used for digital impression acquisition for denture preparation, with at least its edge composed of resin and the other portions composed of metal.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a measurement member (so-called scan body) used for taking a denture digital impression and a denture digital impression taking method using the same.

  Artificial objects embedded in the body that replace or assist biological organs or tissues are called implants. Known implants include cardiac pacemakers and artificial joints, cosmetic silicone agents, and dental implants. In this context, dental implants refer to dentures and their accessories that are implanted in the jaw bone instead of lost teeth, and its history is relatively new. The clinical application of dental implants started in the 1960s, and rapid improvement has been promoted since the 1980s, and its clinical results are rapidly improving.

  An example of dental implant treatment is shown in FIGS. FIG. 1 shows the course of dental implant treatment to make up for a lost tooth. In this case, the fixture (implant body) (3) is embedded in the portion (2) where the teeth of the gingiva (1) are lost, and the denture (4) is connected to the fixture (3). As shown in FIG. 2, the fixture (3) and the denture (4) are connected by a part called an abutment (5). The abutment (5) is fixed to the fixture (3) with a screw (6) (actually inside the abutment 5 and the fixture 3).

  The size, shape, and inclination of the teeth, and the thickness and inclination of the jawbone and root that support the teeth are different for each person. For this reason, in a dental implant, the lost teeth must be reproduced with the alignment and meshing with the surrounding teeth in a normal state adapted to individual patient differences. Moreover, once a dental implant is created, it is not easy to replace the whole. Therefore, in dental implant treatment, it is necessary to design a dental implant structure including a fixture, an abutment, and a denture with high accuracy in accordance with a patient-specific state.

  At the beginning of the development of dental implants, molds were taken in the patient's mouth for the design of dentures. However, the burden placed on the patient by the mold-taking work was great, and fine adjustment of the dentures created from the molds was complicated. There was a problem that. However, with the development and advancement of CAD (computer-aided design), so-called prosthetics such as dentures and bridges are designed using optical data obtained by three-dimensional scanning of a patient's intraoral dentition. Digital dental (digital dentistry) technology has greatly reduced the burden on the patient and design effort (Non-patent Document 1, Non-patent Document 2, and Non-patent Document 3). In recent dental implant treatments, the oral cavity of a patient with an embedded fixture is optically scanned three-dimensionally, and the resulting optical scan data virtually reproduces the denture shape and meshing state (digital impression) Based on the above, customized dentures are created for each patient (Patent Documents 1 and 2).

  FIG. 14 shows how the digital impression is taken. In digital impression collection, the fixture (3) is first embedded in the jaw bone (7) regenerated with the patient's normal jaw bone or artificial object, and a part of the fixture (3) is placed on the inner surface of the patient's gum (1). Open. Next, a scan body (an implant position detection member readable by optical scanning) (16) is connected to the end of the fixture (3) coming out of the gingiva (1). A three-dimensional optical scan of the vicinity of the scan body (16) is performed to obtain three-dimensional data of the patient's dental implant placement site, and a virtual data is reflected in this data to create a three-dimensional model of the entire dental implant including the denture. create.

  In order to collect such a digital impression, it is necessary to accurately measure the denture height by bringing the fixture and the scan body into close contact with each other without any gap. For this reason, the scan body is made of metal such as stainless steel or titanium so that the scan body can be screwed to the fixture with high torque. However, the metal scan body has a problem that halation occurs during optical scanning, and a three-dimensional image corresponding to the actual object cannot be obtained. Therefore, if the scan body is made of a matte material, for example, white plastic containing a large amount of filler, it is easy to obtain a fine three-dimensional image, but the scan body is poor in strength when screwed to the fixture. There is a problem that is easily damaged. Thus, it is difficult to achieve both the accuracy of the digital impression and the strength of the scan body.

  However, prior art documents including the above-described patent documents and non-patent documents have not attempted to solve such problems. A scan body that can be firmly connected to the fixture and can provide clear optical scan data has not been found.

“Special Feature: Paradigm Shift in Dental Medicine“ Digital Dentistry ”Digital Dentistry Transforms Prosthetic Clinic” Journal of Showa University Vol. 75, No. 1, pp. 38-45 2015 "Talking about the near future dentistry-Toward the digital dentistry era" Journal of Japanese Dental Society Vol. 33, p. 5-37, 2014 "From CAD / CAM to Digital Denstry-The Forefront of Dental Treatment Applying Computers-Transition and Prospects of Digital Prosthodontics," Prosthodontic Society Vol. 4, No. 2, pages 123-131 (2012)

JP 2008-142528 A JP 2006-107059 A

  Accordingly, the present invention has eagerly sought for a scan body that can be firmly connected to a fixture and can provide clear optical scan data when taking a digital impression necessary for dental implant design.

As a result, at least a part of the part protruding from the patient's gingiva during the optical scan of the scan body is made of resin that gives clear optical scan data, and the other part is made of durable metal, thereby solving the above-mentioned problems. Settled. That is, the present invention is as follows.
(Invention 1) A scan body used for acquiring a denture digital impression, wherein at least an end portion is made of resin and the other portion is made of metal.
(Invention 2) The scan body according to Invention 1, wherein the resin is made of polyetheretherketone and the metal is made of stainless steel and / or a titanium alloy.
(Invention 3) The scan body of Invention 1 or 2, wherein the resin is colored in a color tone ranging from white to beige.
(Invention 4) A step of optically scanning the scan body of any one of Inventions 1, 2, and 3 to create three-dimensional image data, and a step of creating a virtual denture image using the obtained optical scan data Including denture digital impression collection method.

  The scan body of the present invention can be firmly fixed to the fixture with a metal screw, and a high-definition digital impression can be obtained by the three-dimensional optical scan.

The figure seen from the tooth | gear which shows typically the preparation process of a dental implant. 1 schematically shows a cross section of a dental implant. Sectional drawing which shows typically the state by which one example of the scan body of this invention was fixed to the fixture. An example of the scan body of the present invention is shown typically. An example of the scan body of the present invention is shown typically. An example of the scan body of the present invention is shown typically. Sectional drawing which shows typically the state by which one example of the scan body of this invention was fixed to the patient's oral cavity. A mode that optically scans a scan body by the present invention is shown typically. A mode that three-dimensional image data is created by this invention is shown typically. A mode that a virtual denture image is created by the present invention is shown typically. Scan bodies A, B, C, and D used in Examples and Comparative Examples. Three-dimensional image obtained by optical scanning of scan bodies A, B, C, D Three-dimensional image obtained by optical scanning of scan bodies A, B, C, D A conventional scan body used for digital impression collection is schematically shown.

(Scan body)
FIG. 3 shows a state in which the scan body (8, 9) of the present invention is fixed to the fixture (3) buried in the jawbone (7). FIG. 3 schematically shows a cross section passing through the central axis of the fixture (3) and the scan body (8, 9). The scan body of the present invention comprises a resin part (8) and a metal part (9). Of the scan body (8, 9), the resin part (8) and a part of the metal part (9) are exposed outside the patient's gingiva (1).

  As the resin, polyether ether ketone (PEEK) which is widely used as a dental resin material is preferable. PEEK does not cause halation during optical scanning and produces a clear impression. In order to obtain a clearer impression, the color tone of PEEK is set to a light whiteish color, generally a color tone corresponding to white to beige, preferably an ivory color. Such PEEK is available as, for example, VESTAKEEEP (registered trademark) manufactured by Daicel-Evonik, TPS (registered trademark) manufactured by Toray Plastic Seiko Co., Ltd., or VICTREX (registered trademark) manufactured by Victrex.

  In digital impression collection, the denture can be positioned by detecting the position of the scan body protruding outside the gingiva. When the scan body of the present invention is optically scanned, a clear and accurate impression is produced in which the resin portion outside the gum is aligned with the real thing. By using the obtained accurate impression, the position of the denture can be accurately predicted and determined.

  The ratio of the resin portion in the entire scan body of the present invention is not limited as long as the end of the scan body protruding outside the gingiva can be detected optically accurately. In general, a height of 0.5 mm to 10 mm from the end of a columnar scan body protruding out of the gingiva is made of resin. Generally, a PEEK product is cut into a predetermined size and shape by cutting, and the obtained PEEK piece is bonded to a metal part.

  In order to accurately reflect the orientation of the scan body in the impression, it is possible to provide a direction detection marker such as providing a cutout portion in the resin portion of the scan body of the present invention or a polygonal cross section of the end portion.

  As the metal constituting other than the resin portion of the scan body of the present invention, stainless steel or titanium alloy is preferable. Stainless steel and titanium alloy are selected without limitation from those used for medical and dental purposes.

  The overall shape of the scan body of the present invention is not limited as long as the resin portion and the metal portion are arranged so as to satisfy the above conditions. The height, diameter, etc. of the scan body of the present invention are variously adjusted according to the shape of the fixture.

  The metal part of the scan body of the present invention and the fixture are connected via a metal screw. It is desirable that the screw, the metal part of the scan body of the present invention, and the fixture are made of the same kind of metal. The screwing form of the scan body and the fixture of the present invention can be appropriately designed according to the shape of the fixture. A common form is a combination of a stainless steel pin and a titanium alloy screw. In this case, the stainless steel is widely used for bolts and nuts and has good workability, for example, JIS SUS303 is preferable, and the titanium alloy is widely used for medical use and has high strength, for example, JIS 60 type (so-called 6-4 titanium) is preferred.

  FIGS. 4, 5, and 6 show examples of the scan body of the present invention having various shapes. In the scan body shown in FIG. 6, a notch portion is provided in the resin portion for direction detection. In any case, the connecting parts of the scan body and the fixture are omitted.

(Digital impression collection)
The digital impression collection method of the present invention includes a step of optically scanning the scan body of the present invention to create three-dimensional image data, and a step of creating a virtual denture image using the obtained optical scan data It is.

  The digital impression collection method of the present invention will be described with reference to the drawings. First, as shown in FIG. 7, the scan body (8, 9) of the present invention having a shape corresponding to the fixture (3) embedded in the jawbone of the patient's tooth defect (12) is screwed. Then, the resin part (8) of the scan body is exposed to the outside of the gingiva. The invisible part of the gingiva is indicated by a dotted line. The screws inside the fixture (3) and the scan body (8, 9) are omitted.

  Next, as shown in FIG. 8, while moving the laser scanner (13), the scan body (8, 9) and its periphery are irradiated with laser light (14), and the scan body (8, 9) and its periphery are irradiated. Read the surface in three dimensions.

  The read position information is sent to the computer (14) as shown in FIG. 9, and is accumulated and output as three-dimensional image data of the scan body and its periphery. In this step, a fine image matching the actual shape is generated from the scan data of the resin portion of the scan body of the present invention. After the acquisition of the three-dimensional data is completed, the scan body (8, 9) is removed from the fixture (3).

  Furthermore, as shown in FIG. 10, based on the accumulated data, a virtual shape (15) of the denture is designed by computer processing. In this process, the virtual denture is designed to have an optimal structure based on actual three-dimensional information such as jaw bone, fixture inclination, and the position of surrounding teeth. A model is obtained. The designed denture shape is displayed as a three-dimensional image (digital impression) (15). This completes the collection of a digital impression for creating a denture. Dentures are created using appropriate materials so that the digital impression obtained is reproduced.

The following four types of scan bodies having different edge materials shown in FIG. 11 were laser-scanned, and the sharpness of the obtained three-dimensional impressions was compared.
-A (reference product) PEEK colored gray (darker than beige)
・ B (Invention) PEEK colored ivory
-Stainless steel (SUS303) with blasted C (control product) surface
・ D (control product) glossy stainless steel with no blasting treatment (SUS303)

  A three-dimensional image obtained by optical scanning of the scan bodies A, B, C, and D is shown in FIG. 12 (stereoscopic image from an oblique upper part) and FIG. 13 (stereoscopic image from right above). In A, the contour of the upper end is clear, but a part of the surface is not displayed. In B, both the contour and the surface are clear. In C, a part of the contour and a part of the surface are not displayed. In D, the shape of most parts was not reproduced.

  From this result, it can be understood that the scan body of the present invention is advantageous for obtaining a digital impression.

  With the scan body of the present invention, a highly accurate digital impression for creating a denture can be obtained. High quality dentures can be efficiently created by the digital impression acquisition method using the scan body of the present invention.

DESCRIPTION OF SYMBOLS 1 Gingival 2 The part where the tooth was lost 3 Fixture 4 Denture 5 Abutment 6 Screw 7 Jaw bone 8 Part made of resin of scan body 9 Part made of metal of scan body 10 Screw 11 Tooth 12 Tooth defect part 13 Scanner 14 Computer 15 Virtual three-dimensional image of denture (digital denture impression)
16 Conventional scan body

Claims (4)

Scan body used for acquiring denture digital impressions, with at least the edges made of resin and the other parts made of metal. The scan body according to claim 1, wherein the resin is made of polyetheretherketone, and the metal is made of stainless steel and / or a titanium alloy. The scan body according to claim 1 or 2, wherein the resin is colored in a color tone ranging from white to beige. A step of optically scanning the scan body according to any one of claims 1, 2, and 3 to generate three-dimensional image data, and a step of generating a virtual denture image using the obtained optical scan data Denture digital impression collection method.

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