Ceramic bodies having antimicrobial properties and methods of making the same

#Use of inorganic substances that form hydrogen cations in the presence of an aqueous medium for antimicrobial activity is known. U.S. Patent Publication No. 2010/0057199 teaches making active substances by incorporating composite metal oxide substances containing molybdenum and/or tungsten with resin. When the active substances are contacted with water, the formation of hydrogen ions causes the pH to lower in the aqueous medium. The composite metal oxide/resin may be formed as a layer on the surface of a substrate to achieve an antimicrobial effect in an aqueous medium.

#Zollfrank et al. tested antimicrobial activity on titanium rods coated with a nearly amorphous gel coating consisting of a mixture of molybdates containing [Mo3O10]−2 ions and hydrated MoO3. Coated titanium rods were annealed at about 300° C., transforming the gel layer into blue crystalline MoO3, and an antimicrobial effect was detected. However, upon annealing at 500° C., a significant decrease in antimicrobial activity occurred, and upon annealing coated titanium rods at 700° C. antimicrobial activity was no longer detected. (C. Zolifrank, et al. Materials Science and Engineering C (2011), doi: 10.1016/j.msec. 2011.09.010.)

#Ceramic, glass-ceramic, glass and bodies materials are provided that exhibit antimicrobial activity against harmful bacteria. A method for infiltrating a porous body with a liquid molybdenum-containing composition is also provided. In another embodiment, a method for incorporating a ceramic material comprising a molybdenum-containing component as a filler or second phase in a ceramic, glass-ceramic or glass body, is also provided. In a further embodiment, ceramic material comprising a molybdenum-containing component may be incorporated as a coating or glaze, for example, when making a porcelain body. The resulting structures have long term antimicrobial effectiveness, and are suitable for use in medical procedures having a risk of infection, such as joint replacement.

#FIG. 1. An illustration of an example of an implant installed in a jaw on which an abutment and a dental restoration crown are connected.

#FIG. 2a and FIG. 2b. Cross-sectional illustrations of one embodiment of a dental restoration crown.

#FIG. 3. Graph of percent reduction of S. mutans over time exposed to samples of treated sintered zirconia bodies.

#Ceramic, glass-ceramic and glass materials having antimicrobial properties are provided. In one method, a porous body, such as a green stage or bisque stage ceramic body is infiltrated with a molybdenum-containing composition prior to or during a sintering process. In another embodiment, a ceramic, glass or glass-ceramic body comprises a filler or second phase material, such as a ceramic that comprises a molybdenum-containing component. In another embodiment, a ceramic crown restoration or a porcelain body comprises a coating or glaze that contains a molybdenum-containing component, or a filler material comprising a molybdenum-containing component.

#A molybdenum-containing component is provided that comprises a source of molybdenum in the final body that imparts antimicrobial activity. The source of molybdenum may be organic, organo-metallic or inorganic. A molybdenum-containing component may be included in a polymer-molybdenum salt system and/or a molybdenum-containing resin system, including, but not limited to, dental/denture base resin systems, such as, polyurethane, acrylic systems, such as PMMA (polymethyl methacrylate), or PVA. Molybdenum-containing salts include, but are not limited to, molybdenum chloride (e.g., MoCl3 or MoCl4), including molybdenum (V) chloride (MoCl5), molybdenum-2-ethylhexanoate (Mo [OOCCH(C2H5)C4H9]4), ammonium heptamolybdate ((NH4)6Mo7O24·4H2O), cyclopentadienylmolybdenum(V) tetrachloride (C5H5C14Mo), and molybdenum(VI) oxide bis(2,4-pentanedionate) (C10H14MoO6).

#A molybdenum-containing component may be dispersed, dissolved or hydrolyzed in a liquid such as water, organic solvent, inorganic solvent, or combinations thereof, to form a molybdenum-containing composition. A liquid molybdenum-containing composition may be a solution, suspension or a colloidal dispersion. Liquid molybdenum-containing compositions may comprise 0.015 wt % to 5 wt % molybdenum-containing salt based to the total weight of the liquid molybdenum-containing composition. In other embodiments, the concentration of molybdenum-containing salt is between 0.02 wt % and 3 wt %, or between 0.02 wt % and 2.5 wt %, or between 0.02 wt % and 2 wt %, or between 0.02 wt % and 1 wt %, or between 0.02 wt % and 0.5 wt %, or between 0.02 wt % and 0.2 wt %, or between 0.02 wt % and 0.1 wt %, or between 0.015 wt % and 0.5 wt %, or between 0.015 wt % and 0.1 wt %, or at least 0.015 wt % and less than 0.1 wt %, or at least 0.02 wt % and less than 0.1 wt %, based on the total weight of the liquid molybdenum-containing composition.