Patent ID: 6910888

Claim:
A dental model tray for use in forming a dental model from casting material poured on said tray and wherein the resulting, hardened, dental model is retained on the tray with upstanding projections that extend into the hardened, dental model, said dental model tray comprising a substantially planar base wall that forms the floor upon which dental casting material is poured in forming a dental model, said base wall being formed from a polymeric material; a plurality of spaced apart, elongate projections extending upwardly from an upper face of said base wall so that an elongate central axis of each of said projections is substantially perpendicular to the upper face of said base wall, said projections being formed of polymeric material and having a base end that is formed integrally with and integrally connected to said base wall; said projections being arranged in two and only two, substantially parallel rows, with said two rows being oriented as an inner row and an outer row that together form the shape of a dental arch, with said projections in said inner row of said two rows being offset from corresponding projections in said outer row of said two rows so that any two adjacent projections in said inner row and a mutually corresponding projection in said outer row are oriented in a triangular configuration; each of said projections has an upstanding sidewall that tapers inwardly from said base end of each said projections toward said central axis of each of said projections so that the sidewall of each of said projections makes an angle of between about 82 to 88 degrees with said upper face of said base wall; each of said projections has a cross-sectional thickness at its said base end of between about 3 millimeters and 7 millimeters, with the projections positioned in a curved apex portion of said inner row having cross-sectional thicknesses at their base ends that are substantially smaller than corresponding cross-sectional thicknesses of projections that are positioned in a curved apex portion of said outer row; and said projections are spaced from each other so that the distance between said base ends of adjacent projections is between 0 millimeter and about 5 millimeters.