An orthodontic appliance covering device for shielding an orthodontic appliance from view and for mimicking a set of teeth includes a shell, which has a plurality of cavities positioned therein. Each cavity is complementary to at least one of a tooth and a portion of an orthodontic appliance. The shell has a first face, which is open for insertion of a set of teeth having the orthodontic appliance engaged thereto. Each cavity has an associated at least one of a tooth and a portion of an orthodontic appliance positioned therein. A plurality of protrusions is engaged to and extends from a front face of the shell. The plurality of protrusions is shaped complementarily to the set of teeth. The protrusions are substantially opaque and white and thus mimic the set of teeth and shield both the set of teeth the orthodontic appliance from view.

An offset gingival overlay denture is provided. An offset gingival overlay denture may include a denture core and a gingival overlay extending over a portion of the denture core. The denture core may provide support to artificial dentition structures, such as teeth, and a gingival overlay may simulate natural mucosa, such as gum tissue.

The present disclosure belongs to the field of biological materials, and particularly relates to a multilayer zirconia ceramic with uniform transition and a method for preparing the same. The specific technical solution of the present disclosure is as follows: a zirconia ceramic with a formula comprising, in percentage by mass, 0-3% of lanthana, 1.5-16% of yttria, 0-2.5% of silicon carbide nano-whiskers, and 0-1.5% of a coloring agent, the balance being zirconia. Correspondingly provided are a multi-layer zirconia ceramic with uniform transition prepared using the formula and a method for preparing the same. By using the method of the present disclosure, multilayer zirconia ceramics with good and uniformly transitioning core properties can be quickly and conveniently prepared, meeting the requirements of patients with dental disorders on the use and esthetics of dentures.

A zirconia sintered body comprises zirconia and multiple different areas, including at least one upper area and at least one lower area having a different chemical composition and a different strength. The sintered body has a translucency and a strength with an inverse relationship. The translucency increases in one direction across the multiple different areas and the strength decreasing in the same direction across the multiple different areas. At least part of the sintered body has a total light transmittance of at least 35% and less than 53% to light with a wavelength at least at a point between 400 nm and 600 nm, and at least 51% and less than 57% to light with a wavelength at least at a point between 600 nm and 800 nm, at a thickness of 0.6 mm. At least a part of the sintered body has a strength of at least 925 Mpa.

Dental instrumentation for use in guiding a cutting tool to remove tooth structure from a working tooth is prepared. A digital model of cutting guide shell structure for placement around a portion of the tooth to be treated is combined with preset tool movements to be made by the cutting tool by one or more processors to define final cutting guide data corresponding to final cutting guide structure for guiding the cutting tool. A digital model of a fixation instrument configuration for fixing the dental instrumentation to an adjacent tooth to the working tooth is combined with the final cutting guide data by one or more processors to define final instrument configuration data corresponding to a final instrument configuration for releasably fixing the dental instrumentation to the adjacent tooth and for guiding the cutting tool in the removal of the tooth structure from the tooth to be treated.

The invention relates to a porous zirconia article in particular for use in the dental or orthodontic field, the porous zirconia article comprising ZrO.sub.2: 80 to 87 wt. %, Y.sub.2O.sub.3: 3 to 5 wt. %, Al.sub.2O.sub.3: 10 to 14 wt. %, wt. % with respect to the weight of the porous zirconia article, the porous zirconia article being characterized by a BET surface from 15 to 100 m.sup.2/g. The invention also relates to a sintered zirconia article in particular for use in the dental or orthodontic field, the sintered zirconia article comprising ZrO.sub.2: 80 to 87 wt. %, Y.sub.2O.sub.3: 3 to 5 wt. %, Al.sub.2O.sub.3: 10 to 14 wt. %, wt. % with respect to the weight of the porous zirconia article, the sintered zirconia article being characterized by a corundum crystal phase content of 7 to 12 wt. % and a flexural strength of at least 2,000 MPa.

A partial connection full arch artificial connects and fixes in an appropriate occlusal relationship in advance and appropriately defines a region that should be separated and a region that may be standardized, appropriately defines a combination of regions of adjacent surfaces constituting a contact region, an angle of the denture with respect to the virtual occlusal plane, and an area thereof in a region where artificial teeth are brought into contact with each other.

A composition for forming artificial teeth, a method for producing artificial teeth, and artificial teeth produced using the technique are disclosed. The disclosed composition for forming artificial teeth includes 100 parts by weight of a first photocurable compound illustrated in Chemical Formula 1 below, 5 to 20 parts by weight of a second photocurable compound represented by Chemical Formula 2 below, 25 to 50 parts by weight of a third photocurable compound depicted by Chemical Formula 3 below, and 1 to 10 parts by weight of a fourth photocurable compound shown by Chemical Formula 4 below.

##STR00001##

A dental implant has an implant body made of diamond material, the implant body being provided with a bore hole that has at least one lateral dimension and a depth dimension, the lateral dimension and the depth dimension being mm sized. The bore hole is substantially formed by laser light being directed at the implant body to form said bore hole by softening said diamond material at an intended location of said bore hole. The bore hole is further defined by utilizing at least one metallic drilling tool to remove more of the diamond material after initial formation of the bore hole by said laser light. Preferably, the drilling tool has a cone shaped drilling head or a rectangular drilling head.

The present disclosure relates to the field of dental material treatment, and particularly to a dental zirconia treatment technology. The specific technical solution is as follows: a zirconia treatment method, mainly involving color masking the zirconia, surface roughening the zirconia, coloring the zirconia, surface protection treatment and additional protective film treatment. Based on this treatment method, a brand-new color masking liquid, coloring liquid and adhesive solution are proposed. The present zirconia treatment technology not only meets the individualized requirements of patients for teeth, but also meets the requirements of dentists for convenient operation, so that it is of great value in application and popularization on the market.