【考案の詳細な説明】[Detailed explanation of the idea]
本考案は熱可塑性樹脂を材料として用い圧縮成
形法により義歯床を作製する場合に使用するため
の特定の形状を有する成形用材料に関する。
従来、熱可塑性樹脂による義歯床の製造法とし
て、射出成形法が知られているが、圧縮成形法は
未知である。
本考案者は上記圧縮成形法を開発しさきに特許
出願を行なった。（特願昭56−99892号）。
その方法は、下部フラスコ内の石膏型の上に義
歯床用熱可塑性樹脂をのせ、恒温加熱槽に入れ熱
風で軟化させた後、上部フラスコ内の石膏型を合
わせ圧縮成形を行ない、義歯床を得る方法であ
る。
この方法で使用される石膏型の断面図を第１図
に示す。
図において、上フラスコ１内に、人工歯２が内
蔵された石膏型３が入っている。下フラスコ４内
に石膏模型７が埋設された石膏型５が入ってい
る。
上下の石膏型間に形成される型窩（キャビテ
ィ）６内で義歯床が成形される。線８は上下のフ
ラスコおよび石膏型の分割線である。
第１図からわかるように、上記石膏型の型窩は、
凹凸が激しく一様でなく、しかも石膏面の歯槽堤
凸部部分の上石膏型部分に人工歯が内蔵され、か
つこの部分が義歯床では一番肉厚になっている、
また上顎口蓋部では食物の味覚、温度を感じる必
要から肉薄になっているというように複雑な様相
を呈している。
本考案者は、研究の結果、上記成形法において
下石膏型の上に仕込む熱可塑性樹脂材料が、従来
一般に圧縮成形法で使用されている粉状ないし粒
状のものでは良好な義歯床が得られないことを知
った。
すなわち、粉状ないし粒状樹脂では型上にのせ
たとき凹部に集まり熱風が届きにくく成形するの
が困難であることがわかった。
又、上記の材料が板状のものは熱風で軟化させ
ることは出来るが厚みが一様に軟化するかともす
ると凸部で軟化された熱可塑性樹脂は流れて薄く
なってしまう場合が多い。この状態で圧縮成形す
ると人工歯の下部で充填不足になって人工歯脱落
の原因となることがわかった。
本考案の目的は、上記圧縮成形法において良好
な結果、すなわち、人工歯が強固に植えられ、ひ
けがない義歯床が得られる熱可塑性樹脂材料を提
供することである。
本考案者は、研究の結果、上記熱可塑性樹脂材
料の形状が歯列弓に近似のＵ字状又は周縁に歯列
弓に近似のＵ字状の肉厚部を有する板状の場合に
好結果が得られることを見出し本考案に到達し
た。
すなわち、本考案は、歯列弓に近似のＵ字状の
熱可塑性樹脂成形品又は周縁に歯列弓に近似のＵ
字状の肉厚部を有する板状の熱可塑性樹脂成形品
からなる圧縮成形用の義歯床成形用材料である。
本考案の材料の形状を図面によって説明する。
第２図はＵ字状であって横断面が方形の成形品の
例の斜視図である。第３図はＵ字状であって横断
面が台形の成形品の例の斜視図である。
第４図は周縁にＵ字状の肉厚部を有する板状で
あって、Ｕ字部の横断面が方形の成形品の例の斜
視図である。第５図は周縁にＵ字状の肉厚部を有
する板状であって、Ｕ字部の横断面が台形の成形
品の例の斜視図である。
本考案の材料のＵ字部の横断面の形状は、これ
らの角形に限らず、三角形、円形、楕円形、かま
ぼこ形あるいはその他の形状でもよい。
本考案の材料におけるＵ字状又は周縁にＵ字状
の肉厚部を有する板状の形状は、それらの肉厚部
が人の歯槽堤に近似している。このためこれを下
石膏型の上で加熱軟化させ、樹脂が流れ出した場
合でも、歯槽堤凸部の石膏面に大部分の熱可塑性
樹脂が残存するので、これに上石膏型が下降して
嵌合したとき、上石膏型内の人工歯と初期に接触
し、人工歯の根元で樹脂不足が起ることがなく、
義歯に人工歯を強固に植えることができる。
Ｕ字部の横断面を方形や台形等の角形にする
と、熱風によって軟化される様子を角部の変形に
よって観察しやすいので、圧縮成形のタイミング
を適確に側ることができるので好ましい。
本考案において使用される熱可塑性樹脂として
は、該成形方法で熱的に劣化を起さず、かつ適度
な粘度を有し、良好な賦型性をもち、歯肉に近似
した色に着色が可能で、適度な剛性と耐湿性を有
し、かつ使用時にストレスクラックを起さない強
靭性を備えた樹脂であることが要求される。した
がって、ポリスチレン、ポリメチルメタクリレー
ト、ポリメチルペンテン−１、透明ナイロン、ポ
リエチレンテレフタレート、ポリカーボネート、
ポリアリレート、ポリエステルカーボネート、透
明ABS樹脂、ポリサルホン系樹脂などが使用さ
れるが、特にポリサルホン、ポリエーテルサルホ
ンなどポリサルホン系の樹脂が耐湿性、剛性、耐
ストレスクラッキング性などにすぐれており、好
ましい。
本考案では好ましい態様として使用されるポリ
サルホン系樹脂はアリーレン単位がエーテルおよ
びスルホン結合と共に無秩序にまたは秩序正しく
位置するポリアリーレンポリエーテルポリサルホ
ンとして定義される。たとえば、
の構造を有するUCC製ポリサルホンUdel
や
The present invention relates to a molding material having a specific shape for use in producing a denture base by compression molding using a thermoplastic resin as a material. Conventionally, injection molding is known as a method for manufacturing denture bases using thermoplastic resin, but compression molding is unknown. The inventor filed a patent application immediately after developing the above-mentioned compression molding method. (Special Application No. 1983-99892). The method is to place thermoplastic resin for denture bases on top of the plaster mold in the lower flask, place it in a constant temperature heating tank and soften it with hot air, then fit it with the plaster mold in the upper flask and perform compression molding to form the denture base. This is the way to get it. A cross-sectional view of the plaster mold used in this method is shown in FIG. In the figure, an upper flask 1 contains a plaster mold 3 containing an artificial tooth 2 therein. A lower flask 4 contains a plaster mold 5 in which a plaster model 7 is embedded. A denture base is molded within a mold cavity 6 formed between the upper and lower plaster molds. Line 8 is the dividing line between the upper and lower flasks and the plaster mold. As can be seen from Figure 1, the mold cavity of the above plaster mold is
The unevenness is severe and uneven, and the artificial tooth is built into the plaster mold part above the convex part of the alveolar ridge on the plaster surface, and this part is the thickest part of the denture base.
In addition, the maxillary palate has a complex aspect, as it is thin because it needs to sense the taste and temperature of food. As a result of research, the inventor of the present invention found that in the above molding method, a good denture base could not be obtained with the powdered or granular thermoplastic resin material used in the compression molding method. I learned that there isn't. In other words, it has been found that powdered or granular resin is difficult to mold because it collects in the recesses when placed on a mold, making it difficult for hot air to reach. Further, if the above-mentioned material is in the form of a plate, it is possible to soften it with hot air, but even if the thickness is uniformly softened, the softened thermoplastic resin in the convex portions often flows and becomes thin. It was found that compression molding in this state resulted in insufficient filling in the lower part of the artificial tooth, causing the artificial tooth to fall out. The object of the present invention is to provide a thermoplastic resin material that provides good results in the above-mentioned compression molding method, that is, a denture base in which an artificial tooth is firmly implanted and which has no sink marks. As a result of research, the present inventor found that it is preferable that the thermoplastic resin material has a U-shape similar to a dental arch, or a plate having a thick U-shaped part similar to a dental arch on the periphery. We found that results could be obtained and arrived at the present invention. That is, the present invention provides a U-shaped thermoplastic resin molded product that approximates the dental arch, or a U-shaped thermoplastic resin molded product that approximates the dental arch at the periphery.
This is a denture base molding material for compression molding consisting of a plate-shaped thermoplastic resin molded product having a letter-shaped thick wall portion. The shape of the material of the present invention will be explained with reference to the drawings.
FIG. 2 is a perspective view of an example of a molded product that is U-shaped and has a rectangular cross section. FIG. 3 is a perspective view of an example of a molded product that is U-shaped and has a trapezoidal cross section. FIG. 4 is a perspective view of an example of a plate-shaped molded product having a U-shaped thick portion at the periphery, and the U-shaped portion has a rectangular cross section. FIG. 5 is a perspective view of an example of a plate-shaped molded product having a U-shaped thick portion at the periphery, and the cross section of the U-shaped portion is trapezoidal. The cross-sectional shape of the U-shaped portion of the material of the present invention is not limited to these rectangular shapes, but may be triangular, circular, oval, semicylindrical, or other shapes. In the material of the present invention, the U-shape or the plate-like shape having a U-shaped thick wall portion on the periphery resembles a human alveolar ridge in that thick wall portion. For this reason, even if this is heated and softened on the lower plaster mold and the resin flows out, most of the thermoplastic resin remains on the plaster surface of the alveolar ridge convexity, so the upper plaster mold descends and fits into this. When the resin is assembled, it makes initial contact with the artificial tooth in the upper plaster mold, preventing resin shortage at the root of the artificial tooth.
Artificial teeth can be firmly implanted into dentures. It is preferable to make the cross section of the U-shaped part into a rectangular shape such as a square or a trapezoid because it is easy to observe the softening by hot air by the deformation of the corners, and the timing of compression molding can be accurately determined. The thermoplastic resin used in this invention does not undergo thermal deterioration through the molding method, has an appropriate viscosity, has good moldability, and can be colored to resemble the color of the gums. Therefore, the resin is required to have appropriate rigidity and moisture resistance, as well as toughness that does not cause stress cracks during use. Therefore, polystyrene, polymethyl methacrylate, polymethylpentene-1, transparent nylon, polyethylene terephthalate, polycarbonate,
Polyarylate, polyester carbonate, transparent ABS resin, polysulfone resin, etc. are used, and polysulfone resins such as polysulfone and polyethersulfone are particularly preferred because they have excellent moisture resistance, rigidity, and stress cracking resistance. In the present invention, the polysulfone resin used as a preferred embodiment is defined as a polyarylene polyether polysulfone in which arylene units are located in a disordered or ordered manner together with ether and sulfone bonds. for example, UCC polysulfone Udel with the structure
【式】の構造を有す
るICI製のポリエーテルサルホンVictrex
が挙
げられる。
本考案において、歯列弓に近似のＵ字状又は周
縁に歯列弓に近似のＵ字状の肉厚部を有する板状
の成形品は、射出成形法、圧縮成形法等の公知の
方法によってつくることができる。
本考案の材料のＵ字部のサイズは、第２図の例
で示すならば、たて(a)４〜７cm、よこ(b)５〜８
cm、厚さ(c)0.5〜1.5cm程度が好ましい。
本考案の熱可塑性樹脂製義歯成形用材料は、成
形後裸で空気中に放置すると水分を吸収し、後の
成形の際発泡を起こすため、予備乾燥が必要とな
る場合があるので、水分を通さない材料で包装す
ることが好ましい。
本考案の熱可塑性樹脂製義歯歯床成形用材料は
次のような効果を有する。
(1) 圧縮成形時、樹脂が人工歯の周囲の細かい部
分に初期に圧入され、保圧されることにより、
樹脂と人工歯との密着性が良い製品ができる。
(2) 上部フラスコより下部フラスコの温度が高い
ため、溶融樹脂は人工歯部分から冷却硬化され
過剰熱可塑性樹脂は下部フラスコ石膏面に添っ
て押し出され、圧力が均一に付加されるため成
形品にひけを生じさせない。
(3) フラスコ一個に本考案の材料一個使用すれば
よいので材料の計量等の繁雑な作業がなくな
る。
(4) 異物の混入、予備乾燥の不足等トラブルがな
くなる。One example is polyether sulfone Victrex manufactured by ICI, which has the structure of [Formula]. In the present invention, the plate-shaped molded product having a U-shape approximating the dental arch or having a thick U-shape portion approximating the dental arch on the periphery can be manufactured using known methods such as injection molding, compression molding, etc. It can be created by As shown in the example in Figure 2, the size of the U-shaped part of the material of this invention is 4 to 7 cm in length (a) and 5 to 8 cm in width (b).
cm, and the thickness (c) is preferably about 0.5 to 1.5 cm. The thermoplastic resin denture molding material of the present invention will absorb moisture if it is left exposed in the air after molding, causing foaming during subsequent molding, which may require preliminary drying. Preferably, it is packaged in impermeable material. The thermoplastic resin denture base molding material of the present invention has the following effects. (1) During compression molding, the resin is initially press-fitted into the small areas around the artificial tooth and the pressure is maintained.
A product with good adhesion between resin and artificial teeth can be created. (2) Since the temperature of the lower flask is higher than that of the upper flask, the molten resin is cooled and hardened from the artificial tooth part, and the excess thermoplastic resin is extruded along the plaster surface of the lower flask, and the pressure is evenly applied to the molded product. Does not cause sink marks. (3) Since it is only necessary to use one material of the present invention for one flask, complicated work such as measuring materials is eliminated. (4) Problems such as foreign matter contamination and insufficient pre-drying are eliminated.
【図面の簡単な説明】[Brief explanation of drawings]
第１図は、義歯床成形用の石膏型の断面図であ
る。第２図〜第５図は、本考案の義歯床成形用材
料の例の斜視図である。第１図において１は上フ
ラスコ、２は人工歯、３は上石膏型、４は下フラ
スコ、５は下石膏型、６は型窩、７は石膏模型、
８は分割線である。
FIG. 1 is a sectional view of a plaster mold for molding a denture base. 2 to 5 are perspective views of examples of the denture base molding material of the present invention. In Figure 1, 1 is the upper flask, 2 is the artificial tooth, 3 is the upper plaster mold, 4 is the lower flask, 5 is the lower plaster mold, 6 is the mold cavity, 7 is the plaster model,
8 is a dividing line.