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Different patterns of bone fixation with hydroxyapatite and resorbable CaP coatings in the rabbit tibia at 6, 12, and 52 weeks
Author(s) -
Reigstad Ole,
Johansson Carina,
Stenport Victoria,
Wennerberg Ann,
Reigstad Astor,
Røkkum Magne
Publication year - 2011
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.31866
Subject(s) - fixation (population genetics) , resorption , tibia , implant , materials science , bone resorption , dentistry , coating , bone healing , medicine , surgery , composite material , pathology , population , environmental health
Applying bioactive coatings on orthopedic implants can increase the fixation and long‐term implant survival. In our study, we compared a resorbable electrochemically deposited calcium phosphate coating (Bonit ® ) to a thin (40 μm) plasma‐sprayed hydroxyapatite (HA) coating, applied on grit‐blasted screw‐shaped Ti‐6Al‐4V implants in the cortical region of rabbit tibia, implanted for 6, 12, and 52 weeks. The removal torque results demonstrated stronger bone‐to‐implant fixation for the HA than Bonit‐coated screws at 6 and 12 weeks. After 52 weeks, the fixation was in favor of the Bonit‐coated screws, but the difference was statistically insignificant. Coat flaking and delamination of the HA with multinucleated giant cell activity and bone resorption observed histologically seemed to preclude any significant increase in fixation comparing the HA implants at 6 versus 12 weeks and 12 versus 52 weeks. The Bonit‐coated implants exhibited increasing fixation from 6 to 12 weeks and from 12 to 52 weeks, and the coat was resorbed within 6 weeks, with minimal activity of multinucleated giant cells or bone resorption. A different fixation pattern was observed for the two coatings with a sharper but time limited increase in fixation for the HA‐coated screws, and a slower but more steadily increasing fixation pattern for the Bonit‐coated screws. The side effects were more serious for the HA coating and limiting the expected increase in fixation with time. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.