title: CAD-CAM-generated hydroxyapatite scaffold to replace the mandibular condyle in sheep: preliminary results.
abstract: In this study, rapid CAD-CAM prototyping of pure hydroxyapatite to replace temporomandibular joint condyles was tested in sheep. Three adult animals were implanted with CAD-CAM-designed porous hydroxyapatite scaffolds as condyle substitutes. The desired scaffold shape was achieved by subtractive automated milling machining (block reduction). Custom-made surgical guides were created by direct metal laser sintering and were used to export the virtual planning of the bone cut lines into the surgical environment. Using the same technique, fixation plates were created and applied to the scaffold pre-operatively to firmly secure the condyles to the bone and to assure primary stability of the hydroxyapatite scaffolds during masticatory function. Four months post-surgery, the sheep were sacrificed. The hydroxyapatite scaffolds were explanted, and histological specimens were prepared. Different histological tissues penetrating the scaffold macropores, the sequence of bone remodeling, new apposition of bone and/or cartilage as a consequence of the different functional anatomic role, and osseointegration at the interface between the scaffold and bone were documented. This animal model was found to be appropriate for testing CAD-CAM customization and the biomechanical properties of porous, pure hydroxyapatite scaffolds used as joint prostheses.
authors.affiliation: Department of Oral Science, Alma Mater Studiorum University of Bologna, Bologna, Italy. leonardo.ciocca@unibo.it
authors.forename: Leonardo
authors.initials: L
authors.lastname: Ciocca
authors.forename: Davide
authors.initials: D
authors.lastname: Donati
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Fantini
authors.forename: Elena
authors.initials: E
authors.lastname: Landi
authors.forename: Adriano
authors.initials: A
authors.lastname: Piattelli
authors.forename: Giovanna
authors.initials: G
authors.lastname: Iezzi
authors.forename: Anna
authors.initials: A
authors.lastname: Tampieri
authors.forename: Alessandro
authors.initials: A
authors.lastname: Spadari
authors.forename: Noemi
authors.initials: N
authors.lastname: Romagnoli
authors.forename: Roberto
authors.initials: R
authors.lastname: Scotti
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry / Q000627:therapeutic use*; D017076:Computer-Aided Design; D017886:Durapatite / Q000737:chemistry / Q000627:therapeutic use*; D008335:Mandibular Condyle / Q000473:pathology / Q000601:surgery*; D016062:Porosity; D019651:Plastic Surgery Procedures / Q000379:methods; D012756:Sheep / Q000601:surgery*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D018786:Bone Substitutes; D017886:Durapatite