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Which statement correctly describes osseointegration, as the term is used for pure titanium in dental implants and similar devices?

  1. AA state in which bone and the implant surface are in direct contact without intervening fibrous tissue and can transfer load
  2. BA state in which the implant gradually dissolves and is resorbed in the body and is replaced by new bone formed by osteoblasts
  3. CA state in which the gap between the implant and bone is filled with PMMA bone cement, fixing them by mechanical interlocking
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Answer: A. A state in which bone and the implant surface are in direct contact without intervening fibrous tissue and can transfer load

Osseointegration is a phenomenon discovered by Brånemark with titanium, and it refers to a state in which living bone and the implant surface are in direct contact without intervening fibrous connective tissue and can transfer load. The titanium surface is covered by a TiO₂ passive film a few nm thick that is stable in body fluids, so bone forms along that surface. Moderately roughening the surface helps bone interlock with it and speeds fixation. The term mainly expresses direct contact with bone, as distinct from chemical bonding such as that of hydroxyapatite. Being resorbed in the body and replaced by bone is a property of bioresorbable materials such as β-TCP, and fixation with bone cement is a different method called cemented fixation.

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