Research Dossier

Nanometer-scale CaP Enhances Early Implant-Bone Fixation In AnAnimal ModelJames N. Kenealy, PharmD, Bruce Berckmans, Renée M. Stach, DDS, BIOMET 3i, Palm Beach Gardens,Florida, USAEuropean Association ForOsseointegration15th Annual Meeting (October 5–7, 2006, Zurich, Switzerland)IntroductionThis study used an established rabbit tibia pull-out modelto demonstrate early bone fixation of implants treated witha discrete crystalline deposition (DCD) of nano-scale calciumphosphate (CaP) on a dual-acid-etched (DAE) surface.Materials And MethodsTwenty six-month-old New Zealand white rabbits wereassigned to two treatment groups. Control implants were3.3mmx4mm Ti-6Al-4V-alloy with the DAE surface. Testimplants were of the same design with the addition of DCDnano-scale CaP. One of each implant was surgically placedin the right antereomedial tibia of each rabbit 15mm apart,alternating medial and distal sites between animals.Radiographs were obtained to demonstrate uniformity ofimplant placement. The first treatment group was sacrificedafter two weeks and the second group after three weeks.Each tibia was dissected in whole, mounted and stabilizedin a precision alignment apparatus. A standard Instronmachine (Model #TTMBL)was attached to applytensile forces along thelong axis of the implant.The peak pull-out force todetach the implant frombone was electronicallymeasured and recorded.Results And DiscussionMean peak pull-out forcesfor Test implants were94.0±33.6 N at two weeks17016015014013012011010090807060504030Mean Peak Pull-Out ForcesTestControlTwo WeeksThree Weeksand 145.6±19.8 N at three weeks. Mean forces for Controlimplants are 53.2±24.1 N at two weeks and 93.2±44.9 N atthree weeks and P