title: Tissue regeneration in bone defects adjacent to endosseous implants: an experimental pilot study.
abstract: Extraction socket defects or alveolar ridge defects may limit or restrict placement of implants. The present study assessed the efficacy of inducing bone formation with demineralized freeze-dried bone (DFDB), osteoinduction with hydroxyapatite (HA), and guided bone regeneration with expanded polytetrafluoroethylene (e-PTFE) in bone defects adjacent to endosseous implants in an animal model. Twenty-four implants were placed in the long bones of 3 pigs. After preparation of 24 cylindric acute defects adjacent to the coronal 5 mm of each implant, 18 of the defects were treated by DFDB, HA, or e-PTFE. The 6 remaining defects healed spontaneously with no treatment (controls). In each pig, one tibia received 4 commercially pure titanium screw implants (3.75 mm x 15 mm), while the contralateral tibia received 4 HA-coated cylindric implants (3.25 mm x 15 mm). Bone formation in response to the 3 treatments and control cases was evaluated using computer-assisted densitometric image analysis. The results showed that a higher density of tissue formed under e-PTFE membranes. A significantly greater increase in bone density was noticed in bone defects treated with an e-PTFE membrane vs DFDB (P = 0.04), in e-PTFE vs control sites (P = 0.04), and in defects treated with HA vs DFDB (P = 0.04) in HA-coated implants. In titanium implants the differences observed were not significant. It was also observed that bone regeneration in defects treated with HA differs with the type of implant used (titanium vs HA-coated implants), but such differences were not significant.
authors.affiliation: Departamento de Cirugia-Escuela de Estomatologia, Universidad de Oviedo, C/Julián Clavería s/n, 33006 Oviedo, Spain. jvicente@correo.uniovi.es
authors.forename: J C
authors.initials: JC
authors.lastname: De Vicente
authors.forename: E
authors.initials: E
authors.lastname: López-Arranz
authors.forename: J S
authors.initials: JS
authors.lastname: López-Arranz
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015519:Bone Density; D001861:Bone Regeneration; D001862:Bone Resorption / Q000209:etiology / Q000601:surgery; D016025:Bone Transplantation / Q000379:methods; D020099:Coated Materials, Biocompatible; D003648:Decalcification Technique; D017886:Durapatite; D005612:Freeze Drying; D048091:Guided Tissue Regeneration / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D020007:Implants, Experimental / Q000009:adverse effects; D008297:Male; D008567:Membranes, Artificial; D023421:Models, Animal; D010865:Pilot Projects; D011138:Polytetrafluoroethylene; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D013552:Swine; D013977:Tibia / Q000601:surgery; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D008567:Membranes, Artificial; D011138:Polytetrafluoroethylene; D017886:Durapatite; D014025:Titanium