JP7699779B2

JP7699779B2 - Dental laboratory working model and dowel pin used therewith

Info

Publication number: JP7699779B2
Application number: JP2022203878A
Authority: JP
Inventors: 直仁齊藤
Original assignee: 有限会社齋藤歯研工業所
Priority date: 2022-12-21
Filing date: 2022-12-21
Publication date: 2025-06-30
Anticipated expiration: 2042-12-21
Also published as: JP2024088865A

Description

本発明は、歯科治療などにおいて用いられる歯科技工用作業模型及びこれに用いるダウエルピンに関する。 The present invention relates to a dental laboratory working model used in dental treatment and the like, and a dowel pin used therewith.

一般に、歯科治療などにおいて用いられる歯科技工用作業模型は、歯形模型が固定される固定用プレートと、固定用プレートに植設された複数のダウエルピンと、固定用プレートを支持するための支持基台と、を備えており、この固定用プレートの上面に、歯形模型が固定される（例えば、特許文献１の図５参照）。支持基台は合成樹脂から形成され、その上面にはダウエルピンを挿入するための複数の挿入孔が設けられ、これら挿入孔は支持基台に間隔を置いて配設される。 Generally, a dental laboratory working model used in dental treatment etc. comprises a fixing plate to which a dental cast is fixed, a number of dowel pins embedded in the fixing plate, and a support base for supporting the fixing plate, and the dental cast is fixed to the upper surface of the fixing plate (see, for example, FIG. 5 of Patent Document 1). The support base is made of synthetic resin, and its upper surface is provided with a number of insertion holes for inserting dowel pins, which are arranged at intervals on the support base.

この支持基台の上面の一側縁には第１係合突部が設けられ、この第１係合突部の内側部に、複数の第１突状部及び複数の第１凹状部が交互に設けられ、またその他側縁には第２係合突部が設けられ、この第２係合突部の内側部に、複数の第２突状部及び第２凹状部が設けられている。 A first engaging protrusion is provided on one side edge of the upper surface of the support base, and a plurality of first protrusions and a plurality of first recesses are alternately provided on the inner side of the first engaging protrusion, and a second engaging protrusion is provided on the other side edge, and a plurality of second protrusions and a second recess are provided on the inner side of the second engaging protrusion.

一方、固定用プレートは石膏から形成され、その下面の両側縁には、支持基台側の第１及び第２係合突部に対応して、第１及び第２係合凹部が設けられ、この第１係合凹部の内側部に、支持基台側の複数の第１突状部及び複数の第１凹状部に対応して、複数の第１凹状部及び複数の第１突状部が設けられ、また第２係合凹部の内側部に、支持基台側の複数の第２突状部及び複数の第２凹状部に対応して、複数の第２凹状部及び複数の第２突状部が設けられている。 On the other hand, the fixing plate is made of gypsum, and first and second engagement recesses are provided on both side edges of the underside thereof in correspondence with the first and second engagement protrusions on the support base side, and a plurality of first recesses and a plurality of first protrusions are provided on the inner side of the first engagement recess in correspondence with the plurality of first protrusions and a plurality of first recesses on the support base side, and a plurality of second recesses and a plurality of second protrusions are provided on the inner side of the second engagement recess in correspondence with the plurality of second protrusions and a plurality of second recesses on the support base side.

このような歯科技工用作業模型においては、固定用プレート側の複数のダウエルピンを支持基台側の複数の挿入孔に挿入して固定用プレートを支持基台に載置すると、支持基台側の第１及び第２係合突部が固定用プレート側の第１及び第２係合凹部に係合され、また支持基台側の複数の第１及び第２突状部並びに複数の第１及び第２凹状部が固定用プレート側の複数の第１及び第２凹状部並びに複数の第１及び第２突状部に係合され、これによって、固定用プレートを支持基台に確実に載置支持することができる。 In such a dental laboratory working model, when the multiple dowel pins on the fixing plate are inserted into the multiple insertion holes on the support base and the fixing plate is placed on the support base, the first and second engaging protrusions on the support base engage with the first and second engaging recesses on the fixing plate , and the multiple first and second protrusions and multiple first and second recessed portions on the support base engage with the multiple first and second recessed portions and multiple first and second protrusions on the fixing plate , thereby allowing the fixing plate to be securely placed and supported on the support base.

特開２０１３－２２６４５５号公報JP 2013-226455 A

しかしながら、このような歯科技工用作業模型においては、支持基台の各挿入孔の内周面は、先端側に向けて外径が漸減する細長い円錐状に形成され、これに対応して、各ダウエルピンのピン本体部の外径も先端側に向けて細長い円錐状に形成され、この挿入孔の内周面の全域に対応するダウエルピン（ピン本体部）の外周面が接触支持されるように構成されている。このように構成されているので、支持基台側の挿入孔とダウエルピンとの接触長さが長くなると、この挿入孔の内径を大きくする必要が生じ、これによって、これに挿入されるダウエルピンも外径が太いものを用いるようになる。従って、ダウエルピンとして太い材料を使用するために、その材料費が高くなり、加えて高精度に加工しなければならない領域（挿入孔と接触する領域）が長くなるために、この領域の加工に長い加工時間を要し、加工費も高くなる。 However, in such a dental laboratory working model, the inner peripheral surface of each insertion hole of the support base is formed in an elongated cone shape with the outer diameter gradually decreasing toward the tip side, and correspondingly, the outer diameter of the pin body of each dowel pin is also formed in an elongated cone shape toward the tip side, and the outer peripheral surface of the dowel pin (pin body) corresponding to the entire inner peripheral surface of this insertion hole is configured to be contacted and supported. Because of this configuration, if the contact length between the insertion hole on the support base side and the dowel pin becomes long, it becomes necessary to increase the inner diameter of this insertion hole, and as a result, the dowel pin inserted therein also has a large outer diameter. Therefore, since a thick material is used for the dowel pin, the material cost is high, and in addition, since the area that must be machined with high precision (the area in contact with the insertion hole) is long, it takes a long processing time to process this area, and the processing cost is also high.

また、このような歯科技工用作業模型においては、ダウエルピンの基端部は、ピン本体部の基端から同じ太さで延びている。作業模型を形成する際には、支持基台の挿入孔にダウエルピンを挿入し、かく挿入した状態で支持基台の上部に枠体を装着し、そして、この枠体内に石膏を流し込んで石膏を固めている。その後、固定用プレートに歯形模型が所望の通りに固定されるように、その表面を研削してきれいな平らな状態になるように形成している。 In addition, in such dental laboratory working models, the base end of the dowel pin extends with the same thickness from the base end of the pin body. When forming the working model, the dowel pin is inserted into the insertion hole of the support base, and in this inserted state, a frame is attached to the top of the support base, and plaster is poured into this frame and allowed to harden. After that, the surface of the dental model is ground to a clean, flat state so that it can be fixed to the fixing plate as desired.

このとき、固定用プレートの厚さを均一にするために、ダウエルピンの基端面に当接する（換言すると、基端面が露出する）まで研削しているが、ここまで研削すると、研削作業の大きな負荷が作業者の手に伝わり、作業者の作業負担が大きくなる。 At this time, in order to make the thickness of the fixing plate uniform, it is ground until it abuts against the base end face of the dowel pin (in other words, the base end face is exposed), but grinding to this extent transfers a large load to the worker's hands, increasing the worker's workload.

本発明の目的は、ダウエルピンの材料を少なく抑えるとともに、その加工時間も短縮して加工費も抑えることができる歯科技工用作業模型及びこれに用いるダウエルピンを提供することである。 The object of the present invention is to provide a dental laboratory working model and a dowel pin for use therewith that can reduce the amount of material used for the dowel pin, as well as shorten the processing time and reduce processing costs.

本発明の歯科技工用作業模型は、歯形模型が固定される固定用プレートと、前記固定用プレートに植設された複数のダウエルピンと、前記固定用プレートを支持するための支持基台と、を備えた歯科技工用作業模型であって、
前記支持基台の上面には、前記複数のダウエルピンを挿入するための複数の挿入孔が設けられ、前記複数の挿入孔の少なくとも挿入側開口部は、先端側に向けて内径が漸減する円錐状に形成されており、
前記複数のダウエルピンは、前記支持基台の複数の挿入孔に支持されるピン本体部と、前記ピン本体部から先端側に延びる先端側部と、前記ピン本体部から基端側に延びる基端側部とを有し、前記複数のダウエルピンの前記ピン本体部は、前記支持基台側の前記複数の挿入孔の前記挿入側開口部に対応して、先端側に向けて外径が漸減する円錐状に形成され、前記複数のダウエルピンの前記基端側部は、前記固定プレートに埋設されており、
前記複数のダウエルピンを前記複数の挿入孔に挿入して前記固定用プレートを前記支持基台に載置すると、前記複数のダウエルピンの前記ピン本体部の外周面が、前記支持基台側の前記複数の挿入孔の前記挿入側開口部の内周面に支持され、この載置状態においては、前記複数のダウエルピンの先端側部は、前記支持基台側の前記複数の挿入孔の内周面に実質上支持されないことを特徴とする。 The present invention provides a working model for dental laboratory comprising a fixing plate to which a dental model is fixed, a plurality of dowel pins embedded in the fixing plate, and a support base for supporting the fixing plate,
A plurality of insertion holes for inserting the plurality of dowel pins are provided on the upper surface of the support base, and at least an insertion side opening of the plurality of insertion holes is formed in a conical shape whose inner diameter gradually decreases toward a tip side,
the plurality of dowel pins have a pin body portion supported in the plurality of insertion holes of the support base, a tip side portion extending from the pin body portion toward the tip side, and a base side portion extending from the pin body portion toward the base side, the pin body portions of the plurality of dowel pins are formed in a conical shape whose outer diameter gradually decreases toward the tip side in correspondence with the insertion side openings of the plurality of insertion holes on the support base side, and the base side portions of the plurality of dowel pins are embedded in the fixing plate,
When the multiple dowel pins are inserted into the multiple insertion holes and the fixing plate is placed on the support base, the outer peripheral surfaces of the pin main body portions of the multiple dowel pins are supported by the inner peripheral surfaces of the insertion side openings of the multiple insertion holes on the support base side, and in this placed state, the tip side portions of the multiple dowel pins are not substantially supported by the inner peripheral surfaces of the multiple insertion holes on the support base side.

また、本発明のダウエルピンは、固定用プレートを支持するための支持基台に設けられた挿入孔に挿入支持されるダウエルピンであって、
前記支持基台の前記挿入孔に支持されるピン本体部と、前記ピン本体部から先端側に延びる先端側部と、前記ピン本体部から基端側に延び且つ前記固定用プレートに埋設される基端側部とを有し、前記ピン本体部は、前記挿入孔の挿入側開口部の形状に対応するように、先端側に向けて外径が漸減する円錐状に形成され、前記ピン本体部を前記挿入孔の前記挿入側開口部に装着した状態において、前記先端側部は前記挿入孔の内周面に実質上支持されないように構成されていることを特徴とする。 The dowel pin of the present invention is a dowel pin that is inserted and supported in an insertion hole provided in a support base for supporting a fixing plate,
The pin has a pin main body portion supported in the insertion hole of the support base, a tip side portion extending from the pin main body portion toward the tip side, and a base side portion extending from the pin main body portion toward the base end and embedded in the fixing plate, and the pin main body portion is formed in a conical shape whose outer diameter gradually decreases toward the tip side to correspond to the shape of the insertion side opening of the insertion hole, and is configured so that when the pin main body portion is attached to the insertion side opening of the insertion hole, the tip side portion is substantially not supported by the inner surface of the insertion hole.

このような歯科技工用作業模型（及びダウエルピン）においては、ダウエルピンのピン本体部の軸方向の長さを１．２～５．０ｍｍとすることが望ましく、このような長さにすることによって、ダウエルピンの外径を小さくすることが可能となり、これによって、その材料を少なくして材料費を抑えることができるとともに、高精度に加工しなければならない部位の長さを短くすることができる。 In such dental laboratory working models (and dowel pins), it is desirable to set the axial length of the pin body of the dowel pin to 1.2 to 5.0 mm. This length makes it possible to reduce the outer diameter of the dowel pin, which in turn reduces the amount of material used and keeps material costs down, while also shortening the length of the area that must be machined with high precision.

また、このような歯科技工用作業模型（及びダウエルピン）においては、ダウエルピンの基端側部の端部を、その端面の外径が基端側部の他の部位に比して小さくなるように円錐状又は円段状に、或いは基端側部を細い円柱状に形成するのが好ましく、このように形成することにより、その基端側部の端面の外径が小さくなり、研削作業においてダウエルピンの基端側部を研削しても作業負荷が小さくなり、作業者の負担を少なくすることができる。 In addition, in such a dental laboratory working model (and dowel pin), it is preferable to form the end of the base side of the dowel pin in a conical or stepped shape, or to form the base side into a thin cylindrical shape, so that the outer diameter of the end face is smaller than the other parts of the base side. By forming it in this way, the outer diameter of the end face of the base side becomes smaller, and the workload when grinding the base side of the dowel pin in the grinding operation becomes lighter, reducing the burden on the worker.

また、このような歯科技工用作業模型では、支持基台の上面における少なくとも一側縁の一部に上方に突出する第１係合突部を設け、この第１係合突部の内側部に複数の第１突状部及び複数の第１凹状部を交互に設けるとともに、固定用プレートの下面における少なくとも一側縁の一部に第１係合凹部を設け、また固定用プレート側の第１係合凹部の内側部に複数の第１凹状部及び複数の第１突状部を交互に設けるのが好ましく、このように構成することにより、支持基台側の複数の挿入孔に固定用プレート側の複数のダウエルピンを挿入してこの固定用プレートを支持基台の上面に確実にガタなく載置支持することができる。 Furthermore, in such a dental laboratory working model, it is preferable to provide a first engagement protrusion protruding upward from at least a portion of one side edge on the upper surface of the support base, and to provide multiple first protrusions and multiple first concave portions alternately on the inner portion of this first engagement protrusion, and to provide a first engagement recess on at least a portion of one side edge on the lower surface of the fixing plate , and to provide multiple first concave portions and multiple first protrusions alternately on the inner portion of the first engagement recess on the fixing plate side.By configuring in this manner, the fixing plate can be reliably placed and supported on the upper surface of the support base without any play by inserting multiple dowel pins on the fixing plate side into multiple insertion holes on the support base side.

このような係合突部（第１及び第２係合突部）を支持基台の上面の両側縁の一部に設け、また、このような係合凹部（第１及び第２係合凹部）を固定用プレートの下面の両側縁の一部に設けるようにしてもよく、このように構成することにより、固定用プレートを支持基台の上面により確実にガタなく載置支持することができる。 Such engaging protrusions (first and second engaging protrusions) may be provided on part of both side edges of the upper surface of the support base, and such engaging recesses (first and second engaging recesses) may be provided on part of both side edges of the lower surface of the fixing plate. By configuring it in this way, the fixing plate can be reliably placed and supported on the upper surface of the support base without any rattle.

このような歯科技工用作業模型においては、支持基台の上面における一側縁と複数の挿入孔との間の内側領域に複数の小突部を設けるとともに、これらの小突部に対応して、固定用プレートの下面に複数の小凹部を設けるようにしてもよく、このように構成しても、固定用プレートを支持基台の上面に確実にガタなく載置支持することができる。 In such a dental laboratory working model, multiple small protrusions may be provided in the inner region between one side edge of the upper surface of the support base and the multiple insertion holes, and multiple small recesses may be provided on the lower surface of the fixing plate corresponding to these small protrusions. Even with this configuration, the fixing plate can be reliably placed and supported on the upper surface of the support base without any backlash.

本発明の歯科技工用作業模型（及びダウエルピン）によれば、支持基台の挿入孔に挿入されるダウエルピンのピン本体部は、支持基台側の挿入孔の挿入側開口部に対応して、先端側に向けて外径が漸減する円錐状に形成されているので、このピン本体部が挿入孔の挿入側開口部に接触支持され、これによって、ピン本体部（即ち、挿入孔に支持される円錐状部）の軸方向の長さが従来に比して短くなり、その結果、高精度に加工すべき部位の長さが短くなって加工時間及び加工費用の低減を図ることができる。また、ピン本体部の軸方向の長さが短くなるので、ダウエルピン自体の外径を細くすることが可能となり、これによって、材料を少なく抑えて材料費用の低減をも図ることができる。また、支持基台に固定用プレートを載置した状態においてはダウエルピンの先端側部が支持基台側の挿入孔の内周面に支持されないので、このダウエルピンはピン本体部で支持されるようになり、これにより、ダウエルピンをガタなく確実に支持することができる。 According to the dental laboratory working model (and dowel pin) of the present invention, the pin body of the dowel pin inserted into the insertion hole of the support base is formed in a cone shape with an outer diameter gradually decreasing toward the tip side in correspondence with the insertion side opening of the insertion hole on the support base side, so that this pin body is supported in contact with the insertion side opening of the insertion hole, and thus the axial length of the pin body (i.e., the cone-shaped part supported by the insertion hole) is shorter than in the past, and as a result, the length of the part to be machined with high precision is shortened, and it is possible to reduce the machining time and machining costs. In addition, since the axial length of the pin body is shortened, it is possible to make the outer diameter of the dowel pin itself thinner, and thus it is possible to reduce the material and reduce the material costs. In addition, when the fixing plate is placed on the support base, the tip side of the dowel pin is not supported by the inner peripheral surface of the insertion hole on the support base side, so that the dowel pin is supported by the pin body, and thus the dowel pin can be reliably supported without any backlash.

本発明に従う歯科技工用作業模型の第１の実施形態を示す斜視図。FIG. 1 is a perspective view showing a first embodiment of a dental laboratory working model according to the present invention. 図１の歯科技工用作業模型において、固定用プレートを支持基台から取り外して示す斜視図。FIG. 2 is a perspective view showing the dental laboratory working model of FIG. 1 with a fixing plate removed from a support base. 図１の歯科技工用作業模型において、支持基台の上面及び固定用プレートの下面を示す図。2 is a diagram showing the upper surface of the support base and the lower surface of the fixing plate in the dental laboratory working model of FIG. 1 . 図１におけるIV－IV線による断面図。4 is a cross-sectional view taken along line IV-IV in FIG. 1. 図１の歯科技工用作業模型に用いられたダウエルピン（本発明に従うダウエルピン）の一実施形態を拡大して示す正面図。FIG. 2 is an enlarged front view showing an embodiment of a dowel pin (a dowel pin according to the present invention) used in the dental laboratory working model of FIG. 1 . 固定用プレートの製作工程において、支持基台の上部に成型用基枠を装着する前の状態を示す斜視図。13 is a perspective view showing a state before a molding base frame is attached to the upper part of a support base in a manufacturing process of the fixing plate. FIG. 支持基台の上部に成型用基枠を装着した状態を示す断面図。FIG. 4 is a cross-sectional view showing a state in which a molding base frame is attached to the upper part of the support base. 注入空間内に石膏を注入した状態を示す断面図。FIG. 4 is a cross-sectional view showing a state in which gypsum is injected into the injection space. 図９（ａ）～（ｃ）は、ダウエルピンの他の実施形態を拡大して示す正面図。9(a) to 9(c) are enlarged front views showing other embodiments of the dowel pin. 本発明に従う歯科技工用作業模型の第２の実施形態における支持基台の上面及び固定用プレートの下面を示す図。13 is a view showing the upper surface of a support base and the lower surface of a fixing plate in a second embodiment of a dental laboratory working model according to the present invention. FIG. 本発明に従う歯科技工用作業模型の第３の実施形態における支持基台を示す平面図。FIG. 11 is a plan view showing a support base in a third embodiment of a dental laboratory working model according to the present invention. 本発明に従う歯科技工用作業模型の第４の実施形態における支持基台を示す平面図。FIG. 13 is a plan view showing a support base in a fourth embodiment of a dental laboratory working model according to the present invention.

以下、添付図面を参照して、本発明に従う歯科技工用作業模型及びこれに用いるダウエルピンの各種実施形態について説明する。 Various embodiments of the dental laboratory working model and the dowel pins used therein according to the present invention will be described below with reference to the attached drawings.

まず、図１～図９を参照して、第１の実施形態の歯科技工用作業模型及びこれに用いるダウエルピンについて説明する。図１～図４を参照して、図示の歯科技工用作業模型２は、歯形模型４が固定される固定用プレート６と、固定用プレート６に植設された複数（この形態では、５本）のダウエルピン８と、固定用プレート６を支持するための支持基台１０と、を備えている。 First, a dental laboratory working model and a dowel pin used therein according to a first embodiment will be described with reference to Figures 1 to 9. With reference to Figures 1 to 4, the illustrated dental laboratory working model 2 includes a fixing plate 6 to which a dental model 4 is fixed, a plurality of dowel pins 8 (five in this embodiment) embedded in the fixing plate 6, and a support base 10 for supporting the fixing plate 6.

支持基台１０は支持基台本体１２を備え、この支持基台本体１２は、例えばポリエチレン樹脂やポリプロピレン樹脂、ナイロン樹脂、ウレタン樹脂などの合成樹脂から形成される。この支持基台本体１２は、横長且つ筒状の周側壁１４と、この周側壁１４の上側を覆う横長の上壁１６とを有している。上壁１６の上面（支持基台１０の上面を規定する）には、その長手方向（図２及び図３において左右方向）に間隔を置いて５個の挿入孔１８が設けられている。 The support base 10 includes a support base body 12, which is formed from a synthetic resin such as polyethylene resin, polypropylene resin, nylon resin, or urethane resin. The support base body 12 has a horizontally long, cylindrical peripheral wall 14 and a horizontally long upper wall 16 that covers the upper side of the peripheral wall 14. The upper surface of the upper wall 16 (which defines the upper surface of the support base 10) has five insertion holes 18 spaced apart in the longitudinal direction (left-right direction in Figures 2 and 3).

この周側壁１４の内側に形成された空間２０には、各挿入孔１８に対応して上壁１６の下面から下方に延びる筒状突部２２が設けられており、各挿入孔１８はこの筒状突部２２の内部を貫通して設けられている（図４参照）。これら挿入孔１８は、筒状突部２２の上端部から下端部に向けて内径が漸減する円錐状に（即ち、断面形状が細くなるテーパ状に）形成されている。尚、各挿入孔１８は、後の記載から理解されるように、その全長にわたって円錐状（断面テーパ状）にする必要はなく、この挿入孔１８の挿入側開口部（後に説明するダウエルピン８のピン本体部を接触支持する部位）を円錐状にすればよい。 In the space 20 formed inside the peripheral side wall 14, cylindrical protrusions 22 are provided corresponding to the respective insertion holes 18 and extending downward from the lower surface of the upper wall 16, and the respective insertion holes 18 are provided penetrating the interior of the cylindrical protrusions 22 (see FIG. 4). The insertion holes 18 are formed in a conical shape with an inner diameter gradually decreasing from the upper end to the lower end of the cylindrical protrusions 22 (i.e., a tapered shape with a narrower cross section). As will be understood from the description below, each insertion hole 18 does not need to be conical (tapered in cross section) over its entire length, and it is sufficient that the insertion side opening of the insertion hole 18 (a portion that contacts and supports the pin body of the dowel pin 8 described later) is conical.

この支持基台１０（支持基台本体１２）の上壁１６の相互に対向する両側縁には一対の係合突部、即ち第１及び第２係合突部２４，２６が設けられ、これら係合用突部２４，２６はそれぞれ、上方に突出するとともに上壁１６の長手方向に延びている。この実施形態では、第１及び第２係合突部２４，２６は、上壁１６の長手方向中間部に設けられ、その両端部には設けられていない。第１及び第２係合突部２４，２６の上壁１６からの突出高さは、例えば１．５ｍｍ程度に設定されている。 A pair of engaging protrusions, i.e., first and second engaging protrusions 24, 26, are provided on both opposing edges of the top wall 16 of this support base 10 (support base main body 12), and these engaging protrusions 24, 26 each protrude upward and extend in the longitudinal direction of the top wall 16. In this embodiment, the first and second engaging protrusions 24, 26 are provided in the longitudinal middle portion of the top wall 16, and not at either end. The protruding height of the first and second engaging protrusions 24, 26 from the top wall 16 is set to, for example, about 1.5 mm.

第１及び第２係合突部２４，２６の内側部には複数の第１及び第２突状部２８，３０が間隔を置いて設けられ、また複数の第１及び第２突状部２８，３０の間にはそれぞれ第１及び第２凹状部３２，３４が設けられている（図２及び図３参照）。即ち、上壁１６の片側縁には第１係合突部２４が設けられ、この第１係合突部２４の長手方向に第１突状部２８及び第１凹状部３２が交互に設けられている。また上壁１６の他側縁には第２係合突部２６が設けられ、この第２係合突部２６の長手方向に第２突状部３０及び第２凹状部３４が交互に設けられている。 A plurality of first and second protrusions 28, 30 are provided at intervals on the inner side of the first and second engagement protrusions 24, 26, and first and second recessed portions 32, 34 are provided between the plurality of first and second protrusions 28, 30, respectively (see Figures 2 and 3). That is, a first engagement protrusion 24 is provided on one side edge of the upper wall 16, and the first protrusions 28 and first recessed portions 32 are alternately provided in the longitudinal direction of the first engagement protrusion 24. A second engagement protrusion 26 is provided on the other side edge of the upper wall 16, and the second protrusions 30 and second recessed portions 34 are alternately provided in the longitudinal direction of the second engagement protrusion 26.

第１及び第２突状部２８，３０には、内側に向けて下り傾斜する傾斜面が形成され、また第１及び第２凹状部３２，３４にも、内側に向けて下り傾斜する傾斜面が形成されている。第１及び第２突条部２８，３０の傾斜面は、それらの傾斜が第１及び第２凹状部３２，３４の傾斜面よりも緩やかになるように形成されており、このように構成することにより、第１及び第２突状部２８，３０は、第１及び第２凹状部３２，３４よりも内側に突出している（図３及び図４参照）。 The first and second protrusions 28, 30 are formed with inclined surfaces that slope downward toward the inside, and the first and second recessed portions 32, 34 are also formed with inclined surfaces that slope downward toward the inside. The slopes of the first and second protrusions 28, 30 are formed so that they are more gentle than the slopes of the first and second recessed portions 32, 34. With this configuration, the first and second protrusions 28, 30 protrude more inward than the first and second recessed portions 32, 34 (see Figures 3 and 4).

また、支持基台１０（支持時代本体１２）の周側壁１４の外周面には、各挿入孔１８に対応して（換言すると、固定用プレート６のダウエルピン８に対応して）位置決め用突部３６が設けられ、この位置決め用突部３６は、挿入孔１８を挟んでそれらの両側にそれぞれ配設されている。 In addition, positioning protrusions 36 are provided on the outer peripheral surface of the peripheral side wall 14 of the support base 10 (support base body 12) in correspondence with each insertion hole 18 (in other words, in correspondence with the dowel pins 8 of the fixing plate 6), and these positioning protrusions 36 are disposed on both sides of the insertion hole 18.

支持基台１０に載置される固定用プレート６は石膏から形成され、支持基台本体１２の上壁１６の形状に対応した横長の形状を有している。この固定用プレート６には、支持基台本体１２の各挿入孔１８に対応してダウエルピン８が植設されている。このダウエルピン８は、図５に示すように、ピン本体部３８、このピン本体部３８から先端側（図５において下側）に延びる先端側部４０及びこのピン本体部３８から基端側（図５において上側）に延びる基端側部４２を有し、この基端側部４２が後述するようにして固定用プレート６に植設される。このダウエルピン８については、後に詳述する。 The fixing plate 6 placed on the support base 10 is made of gypsum and has a horizontally elongated shape corresponding to the shape of the upper wall 16 of the support base body 12. Dowel pins 8 are implanted in the fixing plate 6 in correspondence with each insertion hole 18 of the support base body 12. As shown in FIG. 5, the dowel pin 8 has a pin body portion 38, a tip side portion 40 extending from the pin body portion 38 to the tip side (lower side in FIG. 5), and a base side portion 42 extending from the pin body portion 38 to the base side (upper side in FIG. 5), and the base side portion 42 is implanted in the fixing plate 6 as described below. The dowel pin 8 will be described in detail later.

次に、固定用プレート６について説明すると、この固定プレート６の下面（即ち、ダウエルピン８が突出する側の面）の両側縁には、支持基台１０（支持基台本体１２）側の第１及び第２係合突部２４，２６に対応して、一対の係合凹部、即ち第１及び第２係合凹部４４，４６が設けられている。第１及び第２係合凹部４４，４６はそれぞれ、上方に窪んでいるとともに固定用プレート６の長手方向に延びている。 Next, the fixing plate 6 will be described. On both side edges of the underside of the fixing plate 6 (i.e., the side from which the dowel pin 8 protrudes), a pair of engagement recesses, i.e., first and second engagement recesses 44, 46, are provided in correspondence with the first and second engagement protrusions 24, 26 on the support base 10 (support base main body 12). The first and second engagement recesses 44, 46 are each recessed upward and extend in the longitudinal direction of the fixing plate 6.

第１及び第２係合凹部４４，４６の内側部には、支持基台１０側の第１及び第２突状部２８，３０に対応して第１及び第２凹状部４８，５０が設けられているとともに、支持基台１０側の第１及び第２凹状部３２，３４に対応して第１及び第２突状部５２，５４が設けられている。即ち、固定用プレート６の片側縁には、基台本体１０側の第１係合突部２４に対応して第１係合凹部４４が設けられ、この第１係合凹部４４には、基台本体１０側の第１突状部２８及び第１凹状部３２に対応して第１凹状部４８及び第１突状部５２が交互に設けられている。また、固定用プレート６の他側縁には、基台本体１０側の第２係合突部２６に対応して第２係合凹部４６が設けられ、この第２係合凹部４６には、基台本体１０側の第２突状部３０及び第２凹状部３４に対応して第２凹状部５０及び第２突状部５４が交互に設けられている。 On the inner side of the first and second engagement recesses 44, 46, first and second concave portions 48, 50 are provided corresponding to the first and second protrusions 28, 30 on the support base 10 side, and first and second protrusions 52, 54 are provided corresponding to the first and second concave portions 32, 34 on the support base 10 side. That is, on one side edge of the fixing plate 6, a first engagement recess 44 is provided corresponding to the first engagement protrusion 24 on the base body 10 side, and this first engagement recess 44 is alternately provided with first concave portions 48 and first protrusions 52 corresponding to the first protrusions 28 and first concave portions 32 on the base body 10 side. In addition, a second engagement recess 46 is provided on the other side edge of the fixing plate 6 in correspondence with the second engagement protrusion 26 on the base body 10 side, and this second engagement recess 46 is provided with second recesses 50 and second protrusions 54 alternately in correspondence with the second protrusions 30 and second recesses 34 on the base body 10 side.

この実施形態では、第１及び第２凹状部５０，５２の傾斜面は、基台本体１０側の第１及び第２突状部２８，３０の傾斜面に対応して、それらの傾斜が緩やかになるように形成され、第１及び第２突状部５２，５４の傾斜面は、基台本体１０側の第１及び第２凹状部３２，３４の傾斜面に対応して、それらの傾斜が急になるように形成されている。 In this embodiment, the inclined surfaces of the first and second recessed portions 50, 52 are formed so that their inclination is gentle in correspondence with the inclined surfaces of the first and second protruding portions 28, 30 on the base body 10 side, and the inclined surfaces of the first and second protruding portions 52, 54 are formed so that their inclination is steep in correspondence with the inclined surfaces of the first and second recessed portions 32, 34 on the base body 10 side.

この固定用プレート６の上面には、図１、図２及び図４に示すように、石膏から形成された歯形模型４（本実施形態では、部分タイプのもの）が固定される。この固定用プレート６は、ダウエルピン８を対応する挿入孔１８に着脱自在に挿入することにより、支持基台１０（支持基台本体１２）の上壁１６に着脱自在に支持される。この支持状態では、支持基台１０（支持基台本体１２）の第１及び第２係合用突部２４，２６と固定用プレート６側の第１及び第２係合凹部４４，４６とが着脱自在に係合し、また支持基台１０側の第１及び第２突状部２８，３０と固定用プレート６側の第１及び第２凹状部４８，５０とが着脱自在に係合するとともに、支持基台１０側の第１及び第２凹状部３２，３４と固定用プレート６側の第１及び第２突状部５２，５４とが着脱自在に係合される（図４参照）。 As shown in Figures 1, 2 and 4, a dental cast 4 (partial type in this embodiment) made of gypsum is fixed to the upper surface of the fixing plate 6. The fixing plate 6 is detachably supported on the upper wall 16 of the support base 10 (support base body 12) by detachably inserting the dowel pins 8 into the corresponding insertion holes 18. In this supported state, the first and second engagement protrusions 24, 26 of the support base 10 (support base body 12) and the first and second engagement recesses 44, 46 on the fixing plate 6 side are detachably engaged, the first and second protrusions 28, 30 on the support base 10 side and the first and second recesses 48, 50 on the fixing plate 6 side are detachably engaged, and the first and second recesses 32, 34 on the support base 10 side and the first and second protrusions 52, 54 on the fixing plate 6 side are detachably engaged (see Figure 4).

次に、図５を参照して、図示のダウエルピン８について説明する。このダウエルピン８のピン本体部３８は、支持基台１０の挿入孔１８の挿入側開口部の形状に対応して円錐状に形成され、その外径は先端側に向けて漸減されており、このピン本体部３８が支持基台１０の挿入孔１８の挿入開口部に挿入支持される。 Next, the illustrated dowel pin 8 will be described with reference to Fig. 5. The pin body 38 of this dowel pin 8 is formed in a conical shape corresponding to the shape of the insertion side opening of the insertion hole 18 of the support base 10, and the outer diameter thereof gradually decreases toward the tip side.

このピン本体部３８の長さは、ダウエルピン８を安定して支持できる長さに設定され、その軸方向の長さＬ（図５）は１．２～５．０ｍｍの範囲に設定され、１．５～３．５ｍｍに設定するのが好ましい。この長さＬが１．２ｍｍ未満になると、ダウエルピン８を安定して支持することが難しくなり、またこの長さＬが５．０ｍｍを超えると、ダウエルピン８として外径の大きい材料を用いるようになり、材料費などが高くなる。 The length of the pin body 38 is set to a length that can stably support the dowel pin 8, and its axial length L (Figure 5) is set in the range of 1.2 to 5.0 mm, and preferably set to 1.5 to 3.5 mm. If this length L is less than 1.2 mm, it becomes difficult to stably support the dowel pin 8, and if this length L exceeds 5.0 mm, a material with a large outer diameter will be used for the dowel pin 8, which will increase material costs, etc.

このダウエルピン８を支持基台１０の挿入孔１８に装着した状態では、図４に示すように、そのピン本体部３８が挿入孔１８の挿入側開口部に隙間無く嵌まり込むとともに、このピン本体部３８の上面（環状上面）が支持基台１０の上壁１６と同一平面を規定するようになり、このように構成することにより、固定用プレート６の製作時に挿入孔１８内に石膏が流入するのを防止することができる。 When this dowel pin 8 is attached to the insertion hole 18 of the support base 10, as shown in Figure 4, the pin main body 38 fits snugly into the insertion side opening of the insertion hole 18, and the upper surface (annular upper surface) of the pin main body 38 defines the same plane as the upper wall 16 of the support base 10. By configuring it in this manner, it is possible to prevent gypsum from flowing into the insertion hole 18 when the fixing plate 6 is manufactured.

ダウエルピン８の先端側部４０は、このピン本体部３８の先端側端面から直線状に延びており、その外径はピン本体部３８の先端側端面の外径よりも小さく、細長い円筒状に形成されている。ダウエルピン８の装着状態においては、その先端側部４０は支持基台１０の挿入孔１８の内周面に実施上接触支持されることはなく、このピン本体部３８の外周面が挿入孔１８の内周面に接触支持される。 The tip side portion 40 of the dowel pin 8 extends linearly from the tip end face of the pin body 38, and its outer diameter is smaller than the outer diameter of the tip end face of the pin body 38, and is formed into a long, thin cylinder. When the dowel pin 8 is attached, the tip side portion 40 is not actually supported in contact with the inner peripheral surface of the insertion hole 18 of the support base 10, but the outer peripheral surface of the pin body 38 is supported in contact with the inner peripheral surface of the insertion hole 18.

この支持状態においては、図４に示すように、ダウエルピン８の先端側部４０の先端部が支持基台１０の筒状突部２２から下方に突出するようになり、このように突出させることによって、先端側部４０の突出した部位を下側から押し上げることにより、支持本体１０から固定用プレート６（又は固定用プレート６の切断した一部）を容易に取り外すことができる。 In this supported state, as shown in FIG. 4, the tip of the tip side portion 40 of the dowel pin 8 protrudes downward from the cylindrical protrusion 22 of the support base 10. By protruding in this manner, the protruding portion of the tip side portion 40 can be pushed up from below, making it easy to remove the fixing plate 6 (or the cut part of the fixing plate 6) from the support body 10.

このダウエルピン８の基端側部４２は、このピン本体部３８の基端側端面から直線状に延びており、その外径はピン本体部３８の基端側端面の外径よりも小さく、先端側部４０と同様に、細長い円筒状に形成されている。この基端側部４２には環状突部６２が設けられており、このように環状突部６２を設けることにより、ダウエルピン８の固定用プレート６からの離脱を防止することができる。 The base end side portion 42 of the dowel pin 8 extends linearly from the base end face of the pin body 38, has an outer diameter smaller than the outer diameter of the base end face of the pin body 38, and is formed in an elongated cylindrical shape, similar to the tip side portion 40. The base end side portion 42 is provided with an annular protrusion 62, and providing the annular protrusion 62 in this manner can prevent the dowel pin 8 from coming off the fixing plate 6.

この実施形態では、更に、ダウエルピン８の基端側部４２の先端部６４が先端に向けて外径が漸減する円錐状に形成されており、このように形成することにより、この先端部６４の先端面の外径が基端側部４２のその他の部位に比して小さくなり、その先端面の面積が小さくなる。このように構成することにより、固定用プレートを製作する際の切削加工のとき（即ち、ダウエルピン８の基端側部４２の先端面が露出するまで切削加工するとき）の作業負荷を小さく抑え、作業者の作業負担を少なくすることができる。 In this embodiment, the tip 64 of the base end side portion 42 of the dowel pin 8 is further formed into a cone shape with an outer diameter gradually decreasing toward the tip. By forming it in this manner, the outer diameter of the tip surface of the tip 64 is smaller than the other portions of the base end side portion 42, and the area of the tip surface is reduced. By configuring it in this manner, the workload during cutting when manufacturing the fixing plate (i.e., when cutting is performed until the tip surface of the base end side portion 42 of the dowel pin 8 is exposed) can be kept small, and the workload of the worker can be reduced.

次に、図６～図８を参照して、上述した歯科技工用作業模型２の製造方法について説明する。この歯科技工用作業模型２を製作するに際し、歯型（図示せず）に石膏を流し込んで歯形模型４を製作し、また、合成樹脂による射出成型によって支持基台１０（支持基台本体１２）を製造する。そして、図６に示すように、支持基台本体１２の各挿入孔１８にダウエルピン８を先端側から着脱自在に挿入する（ピン挿入工程）。このように挿入すると、ダウエルピン８のピン本体部３８が支持基台本体１２の挿入孔１８の挿入側開口部に挿入支持され、その基端側部４２が上壁１６の上面から上方に所定長さ（例えば、約４ｍｍ程度）だけ突出する（図７参照）。 Next, a method for manufacturing the above-mentioned dental laboratory working model 2 will be described with reference to Figures 6 to 8. When manufacturing the dental laboratory working model 2, gypsum is poured into a dental mold (not shown) to manufacture a dental cast 4, and a support base 10 (support base body 12) is manufactured by injection molding with synthetic resin. Then, as shown in Figure 6, the dowel pins 8 are detachably inserted from the tip side into each insertion hole 18 of the support base body 12 (pin insertion process). When inserted in this manner, the pin body portion 38 of the dowel pin 8 is inserted and supported in the insertion side opening of the insertion hole 18 of the support base body 12, and the base end side portion 42 protrudes upward from the upper surface of the upper wall 16 by a predetermined length (for example, about 4 mm) (see Figure 7).

その後、図６及び図７に示すように、支持基台本体１２の上部に成型用基枠７２を着脱自在に装着する（枠装着工程）。ここで、枠装着工程で用いる成型用基枠７２について説明すると、成型用基枠７２は全体として略矩形状の外形を有し、例えばシリコンゴムや合成ゴムなどのゴム材料から形成されている。成型用基枠７２の内側には上下に貫通する開口７４が設けられ、この開口７４は、支持基台本体１２の上部の形状に対応した形状を有している。 After that, as shown in Figures 6 and 7, a molding base frame 72 is detachably attached to the top of the support base main body 12 (frame attachment process). The molding base frame 72 used in the frame attachment process will be described. The molding base frame 72 has a generally rectangular outer shape overall, and is made of a rubber material such as silicone rubber or synthetic rubber. An opening 74 is provided inside the molding base frame 72, penetrating it from top to bottom, and this opening 74 has a shape that corresponds to the shape of the top of the support base main body 12.

成型用基枠７２を支持基台本体１２の上部に装着すると、支持基台本体１２の上壁１６及び周側壁１４の上端部が開口７４の下端部に挿入され、成型用基枠７２の内周面が周側壁１４の外周面に密着するようになる。このとき、成型用基枠７２の下端部が支持基台本体１２の位置決め用突部３６に支持されることにより、成型用基枠７２が支持基台本体１２に対して位置決めされる。この装着状態では、成型用基枠７２は、支持基台本体１２の上壁１６から上方に所定高さ（例えば、８ｍｍ程度）だけ突出するようになり、支持基台本体１２の上面及び成型用基枠７２の内周面によって注入空間７６が規定される。 When the molding frame 72 is attached to the top of the support base body 12, the upper end of the top wall 16 and the peripheral side wall 14 of the support base body 12 are inserted into the lower end of the opening 74, and the inner peripheral surface of the molding frame 72 comes into close contact with the outer peripheral surface of the peripheral side wall 14. At this time, the lower end of the molding frame 72 is supported by the positioning protrusion 36 of the support base body 12, so that the molding frame 72 is positioned relative to the support base body 12. In this attached state, the molding frame 72 protrudes upward from the upper wall 16 of the support base body 12 by a predetermined height (for example, about 8 mm), and the upper surface of the support base body 12 and the inner peripheral surface of the molding frame 72 define the injection space 76.

その後に、図８に示すように、固定用プレート６を成型するための石膏７８を注入空間７６に注入する（プレート成型工程）。この石膏７８は、ダウエルピン８の基端側部４２が石膏７８に完全に浸漬されるまで注入される。このとき、支持基台本体１２の上壁１６の両端部には第１及び係合突部２４，２６が設けられていないので、注入した石膏７８が上壁１６の両端部に流れるようになり、石膏７８を上壁１６の全域にほぼ均一に注入することができる。そして、注入空間７６に注入した石膏７８が硬化することにより、ダウエルピン８が植設された固定用プレート６が成型される。このとき固定用プレート６の下面には、支持基台本体１２の第１及び第２係合突部２４，２６に対応して第１及び第２係合凹部４４，４６が形成され、また支持基台本体１２の第１及び第２突状部２８，３０に対応して第１及び第２凹状部４８，５０が形成されるとともに、支持基台本体１２の第１及び第２凹状部３２，３４に対応して第１及び第２突状部５２，５４が形成される。 8, plaster 78 for forming the fixing plate 6 is injected into the injection space 76 (plate molding process). The plaster 78 is injected until the base end side 42 of the dowel pin 8 is completely immersed in the plaster 78. At this time, since the first and engaging protrusions 24, 26 are not provided at both ends of the upper wall 16 of the support base body 12, the injected plaster 78 flows to both ends of the upper wall 16, and the plaster 78 can be injected almost uniformly over the entire upper wall 16. Then, the plaster 78 injected into the injection space 76 hardens, forming the fixing plate 6 with the dowel pin 8 implanted therein. At this time, first and second engagement recesses 44, 46 are formed on the underside of the fixing plate 6 in correspondence with the first and second engagement protrusions 24, 26 of the support base body 12, and first and second recessed portions 48, 50 are formed in correspondence with the first and second protrusions 28, 30 of the support base body 12, and first and second protrusions 52, 54 are formed in correspondence with the first and second recessed portions 32, 34 of the support base body 12.

その後、成型用基枠７２を支持基台本体１２の上部から取り外し、固定用プレート６の上面に例えば研削加工を施して厚さが均一に且つ平坦となるように加工する（加工工程）。この加工は、固定用プレート６を支持基台本体１２の上面に支持させた状態で行われ、ダウエルピン８の基端面が外部に露出するまで行う。 Then, the molding frame 72 is removed from the top of the support base body 12, and the upper surface of the fixing plate 6 is processed, for example by grinding, so that the thickness is uniform and flat (processing step). This processing is performed while the fixing plate 6 is supported on the upper surface of the support base body 12, and is continued until the base end surface of the dowel pin 8 is exposed to the outside.

この研削作業においては、石膏は柔らかく、研削が容易であるが、ダウエルピン８はステンレス鋼などの金属材料から形成されて硬く、研削が容易でなく、このダウエルピン８の基端側部４２の端面に到達するまで研削すると作業負荷が急激に増大するために、作業者はダウエルピン８が露出するまで研削したことを知ることができる。この実施形態では、ダウエルピン８の基端側部４２の先端部６４が円錐状に形成され、その端面の面積が小さくなっているので、研削作業中にダウエルピン８の基端側部４２の端面に到達しても作業負荷の急激な増大を抑えることができ、これによって、作業者の作業負荷を少なくすることができる。 In this grinding operation, gypsum is soft and easy to grind, but the dowel pin 8 is made of a metal material such as stainless steel and is hard and not easy to grind. When grinding until the end face of the base end side portion 42 of the dowel pin 8 is reached, the workload increases rapidly, so the worker can know that the dowel pin 8 has been ground until it is exposed. In this embodiment, the tip portion 64 of the base end side portion 42 of the dowel pin 8 is formed in a cone shape and the area of the end face is small, so that even if the end face of the base end side portion 42 of the dowel pin 8 is reached during the grinding operation, a sudden increase in the workload can be suppressed, and the workload of the worker can be reduced.

その後、研削加工を施した固定用プレート６の上面に歯形模型４を接着剤等を用いて固定し（模型固定工程）、このようにして図１及び図２に示す歯科技工用作業模型２を製作することができる。 Then, the dental model 4 is fixed to the upper surface of the grinding-processed fixing plate 6 using adhesive or the like (model fixing process), and in this way the dental laboratory working model 2 shown in Figures 1 and 2 can be produced.

この歯科技工用作業模型２を用いて所定の作業を行うときには、固定用プレート６を支持基台本体１２の上面に支持させた状態で、図１に一点鎖線で示すように、例えば歯形模型４の所望部位を切断線８０に沿って固定プレート６とともに切断工具（図示せず）を用いて切断する（切断工程）。このように切断することによって、歯形模型４の切断した部位を固定用プレート６及びダウエルピン８とともに残りの部位から取り出すことができる。尚、支持基台本体１２には各挿入孔１８に対応して位置決め用突部３６が設けられているので、歯形模型４を切断する際に、この位置決め用突部３６を目印とすることにより、ダウエルピン８の配設箇所を容易に認識することができる。 When performing a predetermined operation using this dental laboratory working model 2, the fixing plate 6 is supported on the upper surface of the support base body 12, and as shown by the dashed line in FIG. 1, the desired portion of the dental model 4 is cut along the cutting line 80 together with the fixing plate 6 using a cutting tool (not shown) (cutting process). By cutting in this manner, the cut portion of the dental model 4 can be removed together with the fixing plate 6 and the dowel pins 8 from the remaining portion. In addition, since the support base body 12 is provided with positioning protrusions 36 corresponding to each insertion hole 18, when cutting the dental model 4, the position of the dowel pins 8 can be easily identified by using the positioning protrusions 36 as a marker.

この切断した歯形模型４を用いた所要の作業（例えば、歯冠補綴物の製作など）は、切断した固定用プレート６を支持基台本体１２の上面に支持させた状態で行われる。この歯科技工用作業模型２では、上述のように、支持基台１０側の第１及び第２係合突部２４，２６と固定プレート６側の第１及び第２係合凹部４４，４６とが相互に係合され、また支持基台１０側の第１及び第２突状部２８，３０と固定用プレート６側の第１及び第２凹状部４８，５０とが相互に係合されるとともに、支持基台１０側の第１及び第２凹状部３２，３４と固定用プレート６側の第１及び第２突状部５２，５４とが相互に係合されるので、固定用プレート６と支持基台本体１２との水平方向の係合強度を高めることができ、切断した固定用プレート６の支持基台本体１２に対する回転やぐらつきなどを確実に防止することができる。 The required work using this cut dental cast 4 (for example, the production of a crown prosthesis, etc.) is performed with the cut fixing plate 6 supported on the upper surface of the support base body 12. In this dental laboratory working model 2, as described above, the first and second engagement protrusions 24, 26 on the support base 10 side and the first and second engagement recesses 44, 46 on the fixing plate 6 side are engaged with each other, the first and second protrusions 28, 30 on the support base 10 side and the first and second recesses 48, 50 on the fixing plate 6 side are engaged with each other, and the first and second recesses 32, 34 on the support base 10 side and the first and second protrusions 52, 54 on the fixing plate 6 side are engaged with each other. This increases the horizontal engagement strength between the fixing plate 6 and the support base body 12, and reliably prevents the cut fixing plate 6 from rotating or wobbling relative to the support base body 12.

第１の実施形態では、模型固定工程において、固定用プレート６の上面に歯形模型４を接着剤などを用いて固定するようにしているが、成型前の固定用プレート６（即ち、硬化前の石膏７８）に歯形模型４を押し付け、石膏７８の硬化により固定用プレート６の上面に歯形模型４を固定するようにしてもよい。 In the first embodiment, in the model fixing process, the dental model 4 is fixed to the upper surface of the fixing plate 6 using an adhesive or the like, but it is also possible to press the dental model 4 against the fixing plate 6 before molding (i.e., the plaster 78 before hardening) and fix the dental model 4 to the upper surface of the fixing plate 6 by hardening the plaster 78.

例えば、上述した実施形態では、支持基台１０（支持基台本体１２）の両側縁に一対の係合突部（第１及び第２係合突部２４，２６）を設け、これに対応して、固定用プレート６の両側縁に一対の係合凹部（第１及び第２係合凹部４４，４６）を設けているが、このように一対の係合突部及び係合凹部を必ず設ける必要はなく、これのいずれか一方、例えば第１係合突部２４及び第１係合凹部４４（又は第２係合突部２６及び第２係合凹部４６）を設けるようにしてもよい。 For example, in the above-described embodiment, a pair of engaging protrusions (first and second engaging protrusions 24, 26) are provided on both side edges of the support base 10 (support base main body 12), and a pair of engaging recesses (first and second engaging recesses 44, 46) are provided on both side edges of the fixing plate 6 corresponding to the pair of engaging protrusions and engaging recesses in this manner. However, it is not necessary to provide a pair of engaging protrusions and engaging recesses in this manner, and it is also possible to provide only one of them, for example, the first engaging protrusion 24 and the first engaging recess 44 (or the second engaging protrusion 26 and the second engaging recess 46).

例えば、支持基台本体１２側に第１係合突部２４（又は第２係合突部２６）を設け、固定用プレート６側に第１係合凹部４４（又は第２係合凹部４６）を設けた場合、支持基台本体１２側の第１係合突部２４（第２係合突部２６）に設けられた第１突状部２８（又は第２突状部３０）及び第１凹状部３２（又は第２凹状部３４）と固定用プレート６側に設けられた第１凹状部４８（又は第２凹状部５０）及び第１突状部５２（又は第２突状部５４）とが相互に着脱自在に係合されるようになる。 For example, if the first engaging protrusion 24 (or the second engaging protrusion 26) is provided on the support base body 12 side and the first engaging recess 44 (or the second engaging recess 46) is provided on the fixing plate 6 side, the first protrusion 28 (or the second protrusion 30) and the first recess 32 (or the second recess 34) provided on the first engaging protrusion 24 (second engaging protrusion 26) on the support base body 12 side and the first recess 48 (or the second recess 50) and the first protrusion 52 (or the second protrusion 54) provided on the fixing plate 6 side are detachably engaged with each other.

ダウエルピンとしては、上述した形態のものに代えて、例えば、図９（ａ）～（ｃ）に示す形態のものを用いることができる。尚、以下の実施形態において、上述した実施形態と同様の部材（部位）には同一の参照番号を付し、その説明を省略する。 Instead of the above-mentioned configuration, the dowel pin may be, for example, one of the configurations shown in Figures 9(a) to (c). In the following embodiment, the same reference numbers are used for the same members (parts) as those in the above-mentioned embodiment, and their description will be omitted.

第１の変形形態を示す図９（ａ）において、このダウエルピン８Ａにおいては、ピン本体部３８から基端側に延びる基端側部４２Ａに複数（この形態では、２つ）の環状突部６２Ａがその軸方向に間隔をおいて設けられている。この環状突部６２Ａは、軸方向に３つ以上設けるようにしてもよく、これら環状突部６２Ａに代えて、ローレット加工を施すようにしてもよい。 9(a) showing a first modified embodiment, in this dowel pin 8A, a plurality of (two in this embodiment) annular protrusions 62A are provided at intervals in the axial direction on the base end side portion 42A extending from the pin main body 38 toward the base end side. Three or more annular protrusions 62A may be provided in the axial direction, and instead of these annular protrusions 62A, knurling may be performed.

第２の変形形態を示す図９（ｂ）において、このダウエルピン８Ｂにおいては、ピン本体３８から基端側に延びる基端側部４２Ｂの先端部６４Ｂが円段状に形成され、この先端部６４Ｂの外径が基端側部４２Ｂのその他の部位に比して外径が小さくなっている。このようにこの先端部６４Ｂを小径部に加工することによっても、この基端側部４２Ｂの端面の面積を小さくすることができ、上述したと同様に、固定用プレートを研削加工するときの作業負荷を小さくすることができる。 In FIG. 9(b) showing the second modified form, in this dowel pin 8B, the tip 64B of the base end side portion 42B extending from the pin body 38 toward the base end side is formed in a stepped shape, and the outer diameter of this tip 64B is smaller than the outer diameter of the other parts of the base end side portion 42B. By machining this tip 64B into a small diameter portion in this way, the area of the end face of this base end side portion 42B can also be reduced, and as described above, the workload when grinding the fixing plate can be reduced.

第３の変形形態を示す図９（ｃ）において、このダウエルピン８Ｃにおいては、ピン本体３８から基端側に延びる基端側部４２Ｃの全体が細い円柱状に形成され、基端側部４２Ｃの外径が小さくなっている。この基端側部４２の外径ｄは、ピン本体部３８の基端側端面の外径Ｄの２／５～４／５（２Ｄ／５≦ｄ≦４Ｄ／５）程度に形成される。このように構成したときには、この基端部側部４２Ｃに例えば２つの環状突部６２Ｃが設けられる。尚、この環状突部６２Ｃは、１つ又は３つ以上設けるようにしてもよい。 In FIG. 9(c) showing the third modified form, in this dowel pin 8C, the entire base end side portion 42C extending from the pin body 38 to the base end side is formed in a thin cylindrical shape, and the outside diameter of the base end side portion 42C is small. The outside diameter d of this base end side portion 42 is formed to be about 2/5 to 4/5 (2D/5≦d≦4D/5) of the outside diameter D of the base end side face of the pin body portion 38. When configured in this way, for example, two annular protrusions 62C are provided on this base end side portion 42C. Note that one or three or more annular protrusions 62C may be provided.

歯科技工用作業模型としては、図１０～図１２に示す形態のものにも同様に適用することができる。尚、図１０～図１２においては、歯科技工用作業模型の全体を示すのではなく、図１０に示す第２の実施形態においては、その支持基台及び固定用プレートを示し、図１１及び図１２に示す第３及び第４の実施形態においては、それらの支持基台のみを示している。 The dental laboratory working model can be similarly applied to those shown in Figures 10 to 12. Note that Figures 10 to 12 do not show the entire dental laboratory working model, but show its support base and fixing plate in the second embodiment shown in Figure 10, and show only the support base in the third and fourth embodiments shown in Figures 11 and 12.

第２の実施形態の歯科技工用作業模型を示す図１０において、この支持基台１０Ｄ（支持基台本体１２Ｄ）には第１及び第２係合突部２４，２６に加えて、複数の小突部８２が設けられている。この実施形態では、複数の小突部８２は、支持基台１０Ｄ（支持基台本体１２Ｄ）の上壁１６Ｄにおける複数の挿入孔１８と第２係合突部２６との間の内側領域Ｓに、支持基台１０Ｄの長手方向に沿って実質上等間隔で設けられている。 In FIG. 10 showing the dental laboratory working model of the second embodiment, the support base 10D (support base main body 12D) is provided with a plurality of small protrusions 82 in addition to the first and second engagement protrusions 24, 26. In this embodiment, the plurality of small protrusions 82 are provided at substantially equal intervals along the longitudinal direction of the support base 10D in the inner region S between the plurality of insertion holes 18 and the second engagement protrusions 26 in the upper wall 16D of the support base 10D (support base main body 12D).

支持基台１０Ｄ側の複数の小突部８２に対応して、固定用プレート６Ｄの下面には、その長手方向に間隔をおいて複数の小凹部８４が設けられ、これら小凹部８４に対応する小突部８２が着脱自在に係合される。上述したダウエルピン８（８Ａ～８Ｃ）は、このような形態の歯科技工用作業模型にも同様に適用することができる。この第２の実施形態のその他の構成は、上述の第１の実施形態と同様である。 The underside of the fixing plate 6D has a number of small recesses 84 spaced apart in the longitudinal direction to correspond to the small protrusions 82 on the support base 10D, and the small protrusions 82 corresponding to these small recesses 84 are removably engaged. The dowel pins 8 (8A-8C) described above can also be applied to dental laboratory working models of this type. The other configurations of this second embodiment are the same as those of the first embodiment described above.

この第２の実施形態においても、固定用プレート６Ｄ側の複数のダウエルピン８の先端側を支持基台１０Ｄ側の複数の挿入孔１８に挿入してこの固定用プレート６Ｄが支持基台１０Ｄの上壁１６Ｄに載置支持される。この支持状態においては、上述した記載から理解されるように、支持基台１０Ｄ側の第１及び第２係合突部２４，２６と固定用プレート６Ｄ側の第１及び第２係合凹部４４，４６とが相互に係合され、また支持基台１０Ｄ側の第１及び第２突状部２８，３０と固定用プレート６Ｄ側の第１及び第２凹状部４８，５０とが相互に係合されるとともに、支持基台１０側の第１及び第２凹状部３２，３４と固定用プレート６Ｄ側の第１及び第２突状部５２，５４とが相互に係合される。加えて、支持基台１０Ｄ側の複数の小突部８２と固定用プレート６Ｄ側の複数の小凹部８４が相互に係合される。この第２の実施形態ではこのように係合されるので、固定用プレート６と支持基台１０（支持基台本体１２）との水平方向の係合強度を更に高めることができ、切断した固定用プレート６の支持基台本体１２に対する回転やぐらつきなどを一層確実に防止することができる。 In this second embodiment, the tip sides of the multiple dowel pins 8 on the fixing plate 6D side are inserted into the multiple insertion holes 18 on the support base 10D side, and the fixing plate 6D is placed and supported on the upper wall 16D of the support base 10D. In this supported state, as can be understood from the above description, the first and second engagement protrusions 24, 26 on the support base 10D side and the first and second engagement recesses 44, 46 on the fixing plate 6D side are engaged with each other, the first and second protrusions 28, 30 on the support base 10D side and the first and second recesses 48, 50 on the fixing plate 6D side are engaged with each other, and the first and second recesses 32, 34 on the support base 10 side and the first and second protrusions 52, 54 on the fixing plate 6D side are engaged with each other. In addition, the multiple small protrusions 82 on the support base 10D side and the multiple small recesses 84 on the fixing plate 6D side are engaged with each other. In this second embodiment, the engagement is performed in this manner, which further increases the horizontal engagement strength between the fixing plate 6 and the support base 10 (support base body 12), and more reliably prevents the cut fixing plate 6 from rotating or wobbling relative to the support base body 12.

この第２の実施形態においては、複数の小突部８２が支持基台１０Ｄ（支持基台本体１２Ｄ）側の複数の挿入孔１８と第２係合突部２６との間に設けられているので、このように構成した場合には、第２係合突部２６（並びに第２突状部３０及び第２凹状部３４）を省略するようにしてもよい。或いは、このような構成に代えて、これら小突部８２を支持基台１０Ｄ（支持基台本体１２Ｄ）側の第１係合突部２４と複数の挿入孔１８との間の内側領域に設けるようにしてもよく、この場合、第１係合突部２４（並びに第１突状部２８及び第１凹状部３２を省略するようにしてもよい。 In this second embodiment, the multiple small protrusions 82 are provided between the multiple insertion holes 18 on the support base 10D (support base main body 12D) side and the second engagement protrusion 26, so in this configuration, the second engagement protrusion 26 (as well as the second protrusion 30 and the second recessed portion 34) may be omitted. Alternatively, instead of this configuration, these small protrusions 82 may be provided in the inner region between the first engagement protrusion 24 on the support base 10D (support base main body 12D) side and the multiple insertion holes 18, in which case the first engagement protrusion 24 (as well as the first protrusion 28 and the first recessed portion 32) may be omitted.

第３の実施形態の歯科技工用作業模型を示す図１１において、この支持基台１０Ｅ（支持基台本体１２Ｅ）には、複数（この形態では、５つ）の挿入孔１８ａ，１８ｂが２列に設けられている。即ち、片方の列の挿入孔１８ａは、第１係合突部２４の内側に、支持基台１０Ｅの長手方向に沿って間隔をおいて設けられ、他方の列の挿入孔１８ｂは、第２係合突部２６の内側に、支持基台１０Ｅの長手方向に沿って間隔をおいて設けられ、片方の列の各挿入孔１８ａと他方の列の各挿入孔１８ｂとは、相互に対抗するように配置されている。 In FIG. 11 showing the dental laboratory working model of the third embodiment, the support base 10E (support base main body 12E) has a plurality of (five in this embodiment) insertion holes 18a, 18b in two rows. That is, the insertion holes 18a in one row are spaced apart along the longitudinal direction of the support base 10E on the inside of the first engaging protrusion 24, and the insertion holes 18b in the other row are spaced apart along the longitudinal direction of the support base 10E on the inside of the second engaging protrusion 26, with each insertion hole 18a in one row and each insertion hole 18b in the other row being disposed opposite each other.

支持基台１０Ｅ（支持基台本体１２Ｅ）のこのような構成に対応して、固定用プレート６Ｅの下面には、図示していないが、２列の挿入孔１８ａ，１８ｂに対応して、ダウエルピンが固定用プレートの長手方向に沿って２列に設けられる。上述したダウエルピン８（８ａ～８Ｄ）は、このような形態の歯科技工用作業模型においても同様に適用することができる。第３の実施形態のその他の構成は、上述の第１の実施形態と同様である。 In response to this configuration of the support base 10E (support base main body 12E), dowel pins (not shown) are provided in two rows along the longitudinal direction of the fixing plate on the underside of the fixing plate 6E, corresponding to the two rows of insertion holes 18a, 18b. The above-mentioned dowel pins 8 (8a-8D) can also be applied to this type of dental laboratory working model. The other configurations of the third embodiment are the same as those of the first embodiment described above.

この第３の実施形態においては、固定用プレート６Ｄ側の２列の複数のダウエルピンの先端側を支持基台１０Ｅ側の対応する２列の複数の挿入孔１８ａ，１８ｂに挿入してこの固定用プレート６Ｅが支持基台１０Ｅの上壁１６Ｅに載置支持される。この支持状態においては、上述した記載から理解されるように、支持基台１０Ｅ側の第１及び第２係合突部２４，２６と固定用プレート側の第１及び第２係合凹部とが相互に係合され、また支持基台１０Ｅ側の第１及び第２突状部２８，３０と固定用プレート側の第１及び第２凹状部とが相互に係合されるとともに、支持基台１０Ｅ側の第１及び第２凹状部３２，３４と固定用プレート側の第１及び第２突状部とが相互に係合される。 In this third embodiment, the tip sides of the two rows of multiple dowel pins on the fixing plate 6D side are inserted into the corresponding two rows of multiple insertion holes 18a, 18b on the support base 10E side, and the fixing plate 6E is placed and supported on the upper wall 16E of the support base 10E. In this supported state, as can be understood from the above description, the first and second engagement protrusions 24, 26 on the support base 10E side and the first and second engagement recesses on the fixing plate side are engaged with each other, the first and second protrusions 28, 30 on the support base 10E side and the first and second recesses on the fixing plate side are engaged with each other, and the first and second recesses 32, 34 on the support base 10E side and the first and second protrusions on the fixing plate side are engaged with each other.

第４の実施形態の歯科技工用作業模型を示す図１２において、この支持基台１０Ｆ（支持基台本体１２Ｆ）の上壁１６Ｆは、上歯全体（又は下歯全体）の歯形模型（図示せず）に対応して略円弧状に形成されている。このような形態の歯科技工用作業模型は全顎タイプと称される。この支持基台１０Ｆ（支持基台本体１２Ｆ）の上壁１６Ｆの内側には略半楕円状の支持用凹部９２が設けられる。尚。図１２では、支持基台本体１２Ｆの周側壁１４Ｆの外周面に設けられる位置決め用突部３は省略している。 In FIG. 12, which shows the dental laboratory working model of the fourth embodiment, the upper wall 16F of the support base 10F (support base main body 12F) is formed in a generally arc shape to correspond to a dental model (not shown) of the entire upper teeth (or entire lower teeth). A dental laboratory working model of this type is called a full-arch type. A generally semi-elliptical support recess 92 is provided on the inside of the upper wall 16F of the support base 10F (support base main body 12F). Note that in FIG. 12, the positioning protrusion 3 provided on the outer circumferential surface of the peripheral side wall 14F of the support base main body 12F is omitted.

この第４の実施形態の歯科技工用作業模型では、支持基台１０Ｆ（支持基台本体１２Ｆ）の上壁１６Ｆには、この上壁１６Ｆ（即ち、支持基台本体１２Ｆ）の長手方向に沿って１４個の挿入孔１８Ｆが設けられ、これら挿入孔１８Ｆと第２係合突部２６Ｆとの間の内側領域Ｓに、上述の第２の実施形態と同様に、複数の小突部８２Ｆが設けられている。 In the dental laboratory working model of this fourth embodiment, the upper wall 16F of the support base 10F (support base body 12F) has 14 insertion holes 18F along the longitudinal direction of the upper wall 16F (i.e., the support base body 12F), and in the inner region S between these insertion holes 18F and the second engaging protrusion 26F, multiple small protrusions 82F are provided, similar to the second embodiment described above.

この第４の実施形態では、支持基台１０Ｆ側の複数（この形態では、１４個）の挿入孔１８Ｆに対応して、図示していないが、固定用プレートの下面にその長手方向に沿って１４本のダウエルピンが上述したようにして設けられる。また、支持基台１０Ｆ側の第１及び第２係合突部２４Ｆ，２６Ｆに対応して、図示していないが、固定用プレートの下面の両側縁に第１及び第２係合凹部が設けられる。また、支持基台１０Ｆ側の第１及び第２突状部２８Ｆ，３０Ｆに対応して、図示していないが、固定用プレートの下面に第１及び第２凹状部が設けられるとともに、支持基台１０Ｆ側の第１及び第２凹状部３２Ｆ，３４Ｆに対応して、図示していないが、皇帝用プレートの下面に第１及び第２突状部が設けられる。上述したダウエルピン８（８Ａ～８Ｃ）は、このような全顎タイプのものにも同様に適用することができる。この第４の実施形態のその他の構成は、上述した第２の実施形態と同様でよい。 In this fourth embodiment, 14 dowel pins are provided on the lower surface of the fixing plate along its longitudinal direction in the manner described above, corresponding to the multiple (14 in this embodiment) insertion holes 18F on the support base 10F side, although not shown. Also, first and second engagement recesses are provided on both side edges of the lower surface of the fixing plate, although not shown, corresponding to the first and second engagement protrusions 24F, 26F on the support base 10F side. Also, first and second recesses are provided on the lower surface of the fixing plate, although not shown, corresponding to the first and second protrusions 28F, 30F on the support base 10F side, and first and second protrusions are provided on the lower surface of the emperor plate, although not shown, corresponding to the first and second recesses 32F, 34F on the support base 10F side. The above-mentioned dowel pins 8 (8A to 8C) can be applied to such full-jaw type in the same manner. The other configurations of this fourth embodiment may be the same as those of the above-mentioned second embodiment.

以上、本発明に従う歯科技工用作業模型及びこれに用いるダウエルピンの各種実施形態について説明したが、本発明はこれら実施形態に限定されるものではなく、本発明の範囲を逸脱することなく種々の変形乃至修正が可能である。 Various embodiments of the dental laboratory working model and the dowel pins used therein according to the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and alterations are possible without departing from the scope of the present invention.

２歯科技工用作業模型
４歯形模型
６，６Ｄ固定用プレート
８，８Ａ，８Ｂ，８Ｃダウエルピン
１０，１０Ｄ，１０Ｅ，１０Ｆ支持基台
１２，１２Ｄ，１２Ｅ，１２Ｆ支持基台本体
１８，１８ａ，１８ｂ、１８Ｆ挿入孔
２４，２４Ｆ，２６，２６Ｆ係合突部
２８，２８Ｆ，３０，３０Ｆ，５２，５４突状部
３２，３２Ｆ，３４，３４Ｆ，４８，５０凹状部
３８ピン本体部
４０先端側部
４２，４２Ａ，４２Ｂ，４２Ｃ基端側部
８２，８２Ｆ小突部
８４小凹部

2 Dental laboratory working model 4 Tooth model 6, 6D Fixing plate 8, 8A, 8B, 8C Dowel pin 10, 10D, 10E, 10F Support base 12, 12D, 12E, 12F Support base body 18, 18a, 18b, 18F Insertion hole 24, 24F, 26, 26F Engagement protrusion 28, 28F, 30, 30F, 52, 54 Protrusion 32, 32F, 34, 34F, 48, 50 Concave portion 38 Pin body 40 Tip side 42, 42A, 42B, 42C Base side 82, 82F Small protrusion 84 Small recess

Claims

A dental laboratory working model comprising: a fixing plate to which a dental model is fixed; a plurality of dowel pins embedded in the fixing plate; and a support base for supporting the fixing plate,
A plurality of insertion holes for inserting the plurality of dowel pins are provided on the upper surface of the support base, and at least an insertion side opening of the plurality of insertion holes is formed in a conical shape whose inner diameter gradually decreases toward a tip side,
the plurality of dowel pins have a pin body portion supported in the plurality of insertion holes of the support base, a tip side portion extending from the pin body portion toward the tip side, and a base side portion extending from the pin body portion toward the base side, the pin body portions of the plurality of dowel pins are formed in a conical shape whose outer diameter gradually decreases toward the tip side in correspondence with the insertion side openings of the plurality of insertion holes on the support base side, and the base side portions of the plurality of dowel pins are embedded in the fixing plate,
a plurality of dowel pins are inserted into the plurality of insertion holes and the fixing plate is placed on the support base, the outer peripheral surfaces of the pin main bodies of the plurality of dowel pins are supported by the inner peripheral surfaces of the insertion side openings of the plurality of insertion holes on the support base side, and in this placed state, the tip sides of the plurality of dowel pins are not substantially supported by the inner peripheral surfaces of the plurality of insertion holes on the support base side.

The dental laboratory working model according to claim 1, characterized in that the axial length of the pin body of the multiple dowel pins is 1.2 to 5.0 mm.

The dental laboratory working model according to claim 1, characterized in that the end of the base end of each of the dowel pins is formed in a cone or step shape so that the outer diameter of the end face is smaller than the other parts of the base end, or the base end is formed in a thin cylindrical shape.

a first engagement protrusion protruding upward from at least one side edge of the upper surface of the support base, and a plurality of first protruding portions and a plurality of first recessed portions are alternately provided on an inner side of the first engagement protrusion;
Furthermore, a first engagement recess is provided on at least one side edge of the lower surface of the fixing plate in correspondence with the first engagement protrusion on the support base side, and a plurality of first concave portions and a plurality of first protrusion portions are alternately provided on an inner side of the first engagement recess on the fixing plate in correspondence with the plurality of first protrusion portions and the plurality of first concave portions on the support base side,
2. The dental laboratory working model according to claim 1, characterized in that, when the plurality of dowel pins are inserted into the plurality of insertion holes and the fixing plate is placed on the support base, the first engagement protrusion on the support base side is engaged with the first engagement recess on the fixing plate side, and the plurality of first protrusions and the plurality of first concave portions on the support base side are engaged with the plurality of first concave portions and the plurality of first protrusions on the fixing plate side.

a first engaging protrusion and a second engaging protrusion protruding upward are provided on a portion of both side edges of the upper surface of the support base, and a plurality of first protruding portions and a plurality of first concave portions are alternately provided on an inner side of the first engaging protrusion, and a plurality of second protruding portions and a plurality of second concave portions are alternately provided on an inner side of the second engaging protrusion,
Furthermore, first and second engagement recesses are provided on parts of both side edges of the lower surface of the fixing plate in correspondence with the first and second engagement protrusions on the support base side, and a plurality of first concave portions and a plurality of first protrusion portions are alternately provided on the inner side of the first engagement recess on the fixing plate in correspondence with the plurality of first protrusion portions and the plurality of first concave portions on the support base side, and a plurality of second concave portions and a plurality of second protrusion portions are alternately provided in correspondence with the plurality of second protrusion portions and the plurality of second concave portions on the support base side,
2. The dental laboratory working model according to claim 1, characterized in that, when the plurality of dowel pins are inserted into the plurality of insertion holes and the fixing plate is placed on the support base, the first engaging protrusion and the second engaging protrusion on the support base side are engaged with the first engaging recess and the second engaging recess on the fixing plate side, and the plurality of first protrusions and the plurality of second protrusions as well as the plurality of first concave portions and the plurality of second concave portions on the support base side are engaged with the plurality of first concave portions and the plurality of second concave portions as well as the plurality of first protrusions and the plurality of second protrusions on the fixing plate side.

a plurality of small protrusions are provided in an inner region between one side edge of the upper surface of the support base and the plurality of insertion holes, and a plurality of small recesses are provided on a lower surface of the fixing plate in correspondence with the plurality of small protrusions on the support base side;
2. The dental laboratory working model according to claim 1, wherein when the plurality of dowel pins are inserted into the plurality of insertion holes and the fixing plate is placed on the support base, the plurality of small protrusions on the support base side engage with the plurality of small recesses on the fixing plate side.

A dowel pin is inserted and supported in an insertion hole provided in a support base for supporting a fixing plate,
a tip side portion extending from the pin body portion toward the tip side, and a base side portion extending from the pin body portion toward the base side and embedded in the fixing plate, the pin body portion being formed in a conical shape whose outer diameter gradually decreases toward the tip side so as to correspond to the shape of an insertion side opening of the insertion hole, and the tip side portion being configured so that when the pin body portion is attached to the insertion side opening of the insertion hole, the tip side portion is not substantially supported by the inner surface of the insertion hole.

The dowel pin according to claim 7, characterized in that the axial length of the pin body is 1.2 to 5.0 mm.

The dowel pin according to claim 7, characterized in that the end of the base end portion is formed in a conical or stepped shape so that the outer diameter of the end face is smaller than the outer diameter of the other parts of the base end portion.