Dental implants are another biomedical application where ceramics are making significant inroads. With the success SINTX has had with the development of the Micro-composite ceramic (MC2) silicon nitride material for spinal implants, the company is looking to broaden the application of this unique material to other medical device applications. A key area of focus for the MC2 material is for dental implants.
Silicon Nitride material has the characteristics that may be beneficial for use in dental implants
While titanium is the “gold standard” for the fabrication of dental implants, ceramics (particularly zirconia) are making inroads. Ceramic implants are metal-free eliminating allergy concerns for patients.Silicon Nitride has been thoroughly tested to ISO 10993-01 standards  and has been shown to be highly biocompatible. As with all ceramics, Silicon Nitride is metal free and has no corrosion, no galvanism effect, no metallic taste, no electronic disturbances. Osman and Swain compared compare titanium vs. zirconia for this application  and concluded zirconia has many positive features but zirconia material is prone to cracking. Silicon nitride exhibits very high toughness for a ceramic.
Biomaterials that may resist bacterial colonization may offer a competitive solution in the dental implant market.  Silicon nitride material has been demonstrated in invitro experiments and animal studies to be effective against a wide variety of bacteria [4, 5] including P. Gingivalis , the bacteria implicated in gingivitis. The antibacterial properties of Silicon Nitride material are most likely related to favorable surface properties such as hydrophilicity, a net negative surface charge, and the fact that Si3N4 produces silicic acid and ammonia via hydrolysis upon exposure to water[7,16]. It is hypothesized that interfacial production of silicic acid and ammonia promotes local osteogenesis and leads to bacterial lysis [7,12].
Silicon nitride material has the ability to turn on bone-forming cells (osteoblasts) and suppress bone resorbing cells. A change to manufacturing of the material resulted in a near-200% increase in bone formation by cells exposed to silicon nitride . This finding could have implications and may speed up bone healing, bone fusion, and implant integration into the skeleton . Several other studies have demonstrated enhanced bone formation in invitro and in animal models [10-15]. These favorable results demonstrating anti-bacterial and bony ongrowth support the application and use of Si3N4 as a dental implant material.
Several different coating technologies have been developed and are transitioning from the laboratory to production. These technologies can confer the beneficial effects of silicon nitride onto metal components, such as titanium.
Silicon nitride may be an ideal material for dental implants. SINTX is continuing research and development and now looking to commercialize this technology. To learn more about dental implants a great resource is the American Academy of Implant Dentistry. https://www.aaid-implant.org/dental-implants/types-of-implants-and-techniques/
1. Internal data on file at SINTX.
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