title: Titanium implant osseointegration with calcium pyrophosphate in rabbits.
abstract: The objective of this study was to characterize calcium pyrophosphate material, evaluate its in vitro cytotoxicity, and assess its ability to induce bone formation. X-ray diffraction (XRD) was used to determine crystallinity and phases present in material. Serial dilutions of extracts, from 10-day dissolution tests in modified Eagle's medium, were exposed for 24 h to mouse fibroblasts and cytotoxicity assessed via viable staining. In vivo performance was determined by placing Ti screws with and without calcium pyrophosphate agglutinated with marrow adipose tissue in the tibiae of eight rabbits. New bone formation around test and control implants was evaluated histomorphometrically by using three fluorochrome labels: alizarin, calcein, and tetracycline. After 8 postoperative weeks, the animals were killed and specimens were retrieved and processed for fluorescence and light microscopic analysis. Calcium pyrophosphate showed no cytotoxicity and the XRD showed that the main phase of the analyzed sample corresponded to beta-calcium pyrophosphate. The largest fluorochrome labeling area occurred during the fourth and fifth postoperative weeks, in both control and experimental groups. Histologically, the bone neoformation occurred in regions where the calcium pyrophosphate was resorbed. The morphometric analysis showed implants placed with calcium pyrophosphate resulted in smaller polyfluorochrome labeling area (p < 0.05).
authors.affiliation: Center for Implantology, School of Dental Medicine, Boston University, 100 East Newton St., Suite G308, Boston, Massachusetts 02118, USA. samuelkoo@yahoo.com
authors.forename: Samuel
authors.initials: S
authors.lastname: Koo
authors.forename: Bruno
authors.initials: B
authors.lastname: König
authors.forename: Sérgio
authors.initials: S
authors.lastname: Allegrini
authors.forename: Marcelo
authors.initials: M
authors.lastname: Yoshimoto
authors.forename: Marcelo José
authors.initials: MJ
authors.lastname: Carbonari
authors.forename: Fábio Franceschini
authors.initials: FF
authors.lastname: Mitri-Luiz
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism*; D016025:Bone Transplantation; D001842:Bone and Bones / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D002131:Calcium Pyrophosphate / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D005456:Fluorescent Dyes / Q000378:metabolism; D006801:Humans; D020007:Implants, Experimental; D008422:Materials Testing; D051379:Mice; D016348:Osseointegration; D011817:Rabbits; D014025:Titanium / Q000737:chemistry / Q000378:metabolism*; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D005456:Fluorescent Dyes; D014025:Titanium; D002131:Calcium Pyrophosphate