title: Ceramic hydroxyapatite implants for the release of bisphosphonate.
abstract: Maintaining bone mass after extraction of teeth is a major problem in the prevention of oral disease. Maintenance theoretically could be enhanced by immediate implantation of submerged ceramic hydroxyapatite (HA) implants releasing the bone resorption-inhibiting agent bisphosphonate (P-C-P). Four different types of ceramic HA implants were designed as release systems for an in vitro study and assayed in saline at a temperature of 37 degrees C during 3 months. The implants were either rod- or tube-shaped, with densities of 3.104 g/cm3 and 1.408 g/cm3 (microporous) or 2.369 g/cm3 (macro/microporous). Loading of the implants with the P-C-P was done by adsorption into the ceramic (rod-shaped implants) or by filling the reservoir of the implant (tube-shaped implants). Despite the fact that P-C-P has a high bonding affinity to HA it appeared that the release of adsorbed P-C-P from the ceramic HA occurred steady, controlled and over a long period of time. The rod-shaped implants had much better release properties than the tube-shaped implants. Microporous ceramic HA rods sintered at 800 degrees C and macro/microporous rods sintered at 1300 degrees C are considered to be promising release systems for P-C-Ps.
authors.affiliation: Department of Implantology, Academic Center for Dentistry Amsterdam (ACTA), Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: Denissen
authors.forename: E
authors.initials: E
authors.lastname: van Beek
authors.forename: C
authors.initials: C
authors.lastname: Löwik
authors.forename: S
authors.initials: S
authors.lastname: Papapoulos
authors.forename: A
authors.initials: A
authors.lastname: van den Hooff
mesh_terms: D000327:Adsorption; D015519:Bone Density / Q000502:physiology*; D002516:Ceramics; D015921:Dental Implants; D004164:Diphosphonates / Q000737:chemistry / Q000378:metabolism*; D017886:Durapatite; D006358:Hot Temperature; D066298:In Vitro Techniques; D008854:Microscopy, Electron; D016062:Porosity
chemical_list: D015921:Dental Implants; D004164:Diphosphonates; D017886:Durapatite