Abstract: A tray for taking a dental impression from a jaw having mobile and immobile gum tissues separated at an action line. The tray is formed of a body formed with a U-shaped outer wall having an edge formed as a thickened bead, a U-shaped inner wall spaced inwardly from the outer wall and defining therewith a U-shaped cavity adapted to fit over the jaw with the edge projecting past the action line, a plurality of throughgoing slots on the outer wall immediately adjacent the outer-wall edge and extending generally parallel to the outer-wall edge.

Abstract: A bead of a high-viscosity impression material is applied along the entire edge of an imperforate tray forming a U-shaped recess and an endless edge extending all around the recess and the tray is fitted, before the material cures, over a patient's dental arch with the bead on the edge engaging and deformed by the patient's mobile mucosa outward of the linear action boundary. The deformed bead of high-viscosity material is cured to form the tray and the cured bead of high-viscosity material into a custom tray which is then filled with a body of a low-viscosity impression material and again pressed over the patient's dental arch to press the cured bead on the tray edge into tight engagement against the mobile mucosa outward of the linear action boundary to form between the tray and the dental arch a substantially closed and generally constant-section chamber hydraulically confining the low-viscosity impression material.

Abstract: A model of a maxilla is marked with the location of the patient's lip line and with the location of the patient's ear-nose plane. Then the incisor portion of the model is shaped to have a lower edge lying on the location of the lip line. A calibration plate having a posterior ridge engaging the tuberosity portion of the model, an anterior part engaging the shaped incisor portion of the model, and sides formed with slots aligned with the molar portions of the model is then positioned on the model. The plate extends substantially parallel to the ear-nose plane from shaped front of the model. The slots are filled around the molar portions of the model with wax and a mold fork is fitted flat to the underside of the calibration plate underneath the slots with the compound adhering to the mold fork. Thereafter the fork and the compound are separated from the plate and model and are fitted to the patient.

Abstract: A model of a maxilla is marked with the location of the patient's lip line and with the location of the patient's ear-nose plane. Then the incisor portion of the model is shaped to have a lower edge lying on the location of the lip line. A calibration plate having a posterior ridge engaging the tuberosity portion of the model, an anterior part engaging the shaped incisor portion of the model, and sides formed with slots aligned with the molar portions of the model is then positioned on the model. The plate extends substantially parallel to the ear-nose plane from shaped front of the model. The slots are filled around the molar portions of the model with wax and a mold fork is fitted flat to the underside of the calibration plate underneath the slots with the compound adhering to the mold fork. Thereafter the fork and the compound are separated from the plate and model and are fitted to the patient.

Abstract: An impression tray for a dentate human jaw having a mobile mucosa and a stationary mucosa with a linear action boundary between the mucosae, the tray having an envelope which in plan follows the U-shape of the dental arch of the jaw and which has a U-shaped trough cross-section near the dental arch, the envelope having a buccal edge and a lingual edge or a palatal edge, the buccal edge and the lingual or palatal edge terminating substantially in the region of the mobile mucosa, the envelope being fillable with an impression material and being pressable onto the jaw. The U-shaped trough cross-section of the envelope extends around the associated dental arch and the stationary mucosa at a distance from them of less than 5 mm, preferably approximately 1 mm. The buccal edge and the lingual edge or palatal edge are pressable onto the mobile mucosa as a sealing strip beyond the action boundary near the mobile mucosa at least with the mobile mucosa mobilized.

Abstract: Zero-degree posterior teeth for a lower and an upper denture, wherein opposite posterior teeth interact at least substantially in line contact. The contour at the level of the active surface of the posterior teeth closely resembles the contour of natural posterior teeth. In each pair of opposite posterior teeth the lingual or palatal contour section of one posterior tooth is provided with a line shaped masticatory rim and the buccal contour section of this posterior tooth is provided with a masticatory plane, while the palatal or lingual contour section of the opposite posterior tooth is provided with a masticatory plane and the buccal contour section of this opposite posterior tooth is provided with a line shaped masticatory rim. The posterior teeth are provided with evacuation channels in their active surface, which channels originate near the line contact between opposite posterior teeth, their depth gradually increasing towards their end at the contour.

Abstract: A perforated tray for taking an impression of an upper or a lower jaw, which may be dentulous or edentulous. In this tray all perforations are shaped as elongated slits. Further the slits may extend at least approximately transversely to the vestibular outline of the tray when viewed from above or from below. The part of the tray, which covers in situ the top of the crest of the jaw, or the masticatory surfaces of the teeth, may be left unperforated. In a tray for taking an impression of an upper jaw, the part of the tray which covers in situ the torus palatinus lying in the center of the palate, may be left unperforated.