PROBLEM TO BE SOLVED: To provide a plastic impression tray for an upper jaw, which enables an impression to be taken with a high degree of accuracy by preventing lift or separation from a tray for an impression material after curing.SOLUTION: An outer wall 2 and a bulge portion 3 for closing a U-shaped space between bottoms 1 are provided on the outside including an U-shaped end of the bottom 1 forming a plane assuming a U-shape with an expanded section between ends and having almost the same width. A rim 4 with a specific height is provided on the side of the bottom 1 along an upper end of the outer wall 2. On the outer wall 2, a slot-like through-hole 5 with a specific width, which reaches the bottom 1 from directly below the rim 4 in such a manner as to be perpendicular to the rim 4, is provided in the outer wall 2, which does not include the U-shaped end, in such a manner that an adjacent gap is specific times wider than the through-hole 5. A similar slot-like through-hole 6 is also provided in the bulge portion 3. A circular through-hole 7 with a specific diameter is provided in the center of the adjacent interval of the slot-like through-hole 5, which is provided in the outer wall 3, in the bottom 1. Furthermore, slot-like end-side through-holes 8 with a specific width and a specific length are provided at the U-shaped end, on a line connecting bottom-side ends of the respective slot-like through-holes 5 and 6 positioned nearest to the U-shaped end sides of the outer wall 2 and the bulge portion 3 or on the end side with respect to the line and on the end side of the center of the bulge portion 3, respectively.COPYRIGHT: (C)2014,JPO&INPIT【課題】硬化後の印象材のトレーから浮き上がりや剥離を防止することで精度の高い印象採得が可能なプラスチック製の上顎用の印象用トレーを提供する。【解決手段】端部間が拡がるU字状で略同一幅の平面を成す底部1のU字状の端部を含む外側に外壁2と底部1間のU字状の空間を閉塞する膨隆部3とを有し、外壁2の上端に沿って底部1側に特定高さのリム4を、U字状の端部を含まない外壁2にリム4に対して直角にリム4の直下から底部1に達する特定幅の長穴状の貫通穴5を隣接する間隙を貫通穴5の幅の特定倍に、且つ膨隆部3にも同様な長穴状の貫通穴6を、底部1には外壁2に設けられている長穴状の貫通穴5の隣接する間隔の中央に特定直径の円形貫通穴7を、更にU字状の端部であって外壁2と膨隆部3
