Abstract: The techniques described herein relate to additively manufactured orthodontic appliances. An example custom metal orthodontic bracket includes a body, a plurality of tie-wings, and a base. The base includes a base surface that is contoured to a shape of a tooth of a patient to which the custom metal orthodontic bracket is to be bonded, and a plurality of retentive structures, wherein at least one of a portion of the base is not polished or only partially polished, or a portion of at least one of the plurality of retentive structures is not polished or only partially polished. An example method for manufacturing a custom orthodontic bracket includes measuring dentition data of a patient, constructing a three-dimensional (3D) model of at least one tooth of the patient, designing a 3D model of the bracket, preparing feedstock, building the bracket, removing the feedstock, hardening the bracket, and polishing the bracket.

Abstract: A friction spacer adapted to be interposed between two mechanical components in order to transfer a force between the two mechanical components, the friction spacer including a flat part having two opposite surfaces defining a thickness, and a plurality of protuberances projecting from at least one of the surfaces, the protuberances of the plurality of protuberances extending from the at least one of the opposite surfaces by a determined average height. The flat part and the protuberances are produced from the same metal material, and the same metal material continuously extends between the flat part and the protuberances.

Abstract: A friction spacer adapted to be interposed between two mechanical components in order to transfer a force between the two mechanical components, the friction spacer including a flat part having two opposite surfaces defining a thickness, and a plurality of protuberances projecting from at least one of the surfaces, the protuberances of the plurality of protuberances extending from the at least one of the opposite surfaces by a determined average height. The flat part and the protuberances are produced from the same metal material, and the same metal material continuously extends between the flat part and the protuberances.