Implants osseointegrated

Dr. O Sullivan Volume Fractions Implant" Osseointegration New Bone in Available Space = Bone/(Soft tissue + Bone)... 

Allergic reactions to titanium can occur (13). Inflammatory reactions and contact sensitivity have been reported after insertion of titanium implants. Osseointegration of the implant tends to occur, but around the area there can be an intense inflammatory reaction and persistent irritation of soft tissues (SEDA-22, 250) (14,15). 

Gittens, R.A., Olivares-Navarrete, R., Schwartz, Z., and Boyan, B.D. (2014) Implant osseointegration and the role of microroughness and nanostructures lessons for spine implants. Acta Biomater., 10 (8), 3363-3371. 

Mavrogenis AF, Dimitriou R, Parvizi J, Babis GC. Biology of implant osseointegration. J Mnsculoskelet Neuronal Interact 2009 9(2) 61-71. Available from PM 19516081. 

Cheng Z, Guo C, Dong W, He FM, Zhao SF, Yang GL. Effect of thin nano-hydroxyapa-tite coating on implant osseointegration in ovaiiectomized rats. Oral Surg Oral Med Oral Pathol Oral Radiol 2012 113(3) e48-53. Available from PM 22669157. 

Subperiosteal. The subperiosteal implants are placed on the residual bony ridge and are not osseointegrated. This implant is most commonly used in the mandible but sometimes is used in the maxilla. Subperiosteal implants have been installed since the 1940s (311) and still have a success rate after five years of only 50 to 60%. A success rate of over 90% for five years and 50% for 15 years also has been quoted (312). Subperiosteal implants are fitted by casting, which is an individual procedure. The casting can be coated with a porous metal coating or other coating and then put in the patient. This may result in an improvement for these implants. 

Traditional materials for orthopedic and dental applications have been selected based on their mechanical properties and ability to remain inert in vivo this selection process has provided materials that satisfied physiological loading conditions but did not duplicate the mechanical, chemical, and architectural properties of bone. Most importantly, to date, failure of conventional orthopedic and dental implant materials is often due to insufficient bonding to juxtaposed bone (that is, insufficient osseointegration). 

Biomaterial scientists and engineers are currently investigating novel formulations and modifications of existing materials that elicit specific, timely, and desirable responses from surrounding cells and tissues to support the osseointegration of the next generation of orthopedic and dental biomaterials (Ratner, 1992). Enhanced deposition of mineralized matrix at the bone-implant interface provides crucial mechanical stability to implants. Proactive orthopedic and dental biomaterials could consist of novel formulations that selectively enhance osteoblast function (such as adhesion, proliferation and formation of calcium-containing mineral) while, at the same time, minimize other cell (such as fibroblast) functions that may decrease implant efficacy (e.g., fibroblast participation in callus formation and fibrous encapsulation of implants in vivo). 

In spite of these investigations, many reports in the literature demonstrate that these nanoapatite ceramics are not always osteoinductive and, furthermore, do not possess mechanical properties similar enough to bone for sustained osseointegration (Muller-Mai el al., 1995 Doremus, 1992 Du et al., 1999 Weng et al., 1997), criteria necessary for increased orthopedic and dental implant efficacy. Moreover, mechanisms of osteoinduction of calcium phosphate ceramics are not clear and seem to depend on specific nanoapatite material properties (such as surface properties and crystallinity) and the animal tested (i.e., dog versus rabbit). Undoubtedly, the incidental cases of calcium phosphate biomaterial-induced osteogenesis indicate promise in... 

Adhesion of osteoblasts to ceramic surfaces alone, however, is not adequate to achieve long-term osseointegration of orthopedic and dental implants subsequent osteoblast functions (such as proliferation, synthesis of... 

Due to their ability to selectively promote both osteoblast and osteoclast function, nanophase ceramics provide a preferable alternative to conventional orthopedic and dental implants that fail to integrate with surrounding bone it is undoubtedly highly desirable to minimize, if not avoid, clinical complications that necessitate removal of failed implants as a result of poor surface properties that lead to insufficient osseointegration. These results provide evidence that nanoceramics may be synthesized to match surface properties of bone and, thus, demonstrate strong promise and potential for their use in orthopedic and dental applications. 

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