title: Histologic and Histometric Analysis of Bone Repair at the Site of Mandibular Body Osteotomy and at the Bone-Screw Interface After Using a Biodegradable 2.0-mm Internal Fixation System.
abstract: The aim of the study was to evaluate histologically and histometrically the bone repair at the mandibular body osteotomy and at the bone-screw interface after using a biodegradable 2.0-mm internal fixation system. Six dogs were subjected to an osteotomy in the mandibular body, which was stabilized by applying a fixation device manufactured with poly-L-DL-lactic acid (70:30). The dogs were euthanized at 2 and 18 weeks. Each screw was sectioned along its long axis, and the osteotomy sites were divided into 3 parts: the upper part was labeled the tension third (TT); the lower part, compression third (CT); and the part between the TT and CT, intermediary third (IT). Histologic analysis showed areas of direct contact between the screw surface and the parent lamellar bone at 2 weeks. At 18 weeks, 3 microscopically distinct layers at the bone-screw interface were noted. At the osteotomy sites, union between the bone fragments was observed at 18 weeks. Statistically significant differences in the newly formed bone among TT, IT, and CT (P = 0.019) were observed. In conclusion, the biomechanical environment created by the biodegradable IF system used in this study facilitated bone repair at the osteotomy site.
authors.affiliation: *Department of Oral and Maxillofacial Surgery and Periodontology, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Sao Paulo †Department of Physiological Sciences, School of Medical and Health Sciences, Pontifical Catholic University of Sao Paulo, Sorocaba ‡Departament of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Cassio Edvard
authors.initials: CE
authors.lastname: Sverzut
authors.forename: Fernando Pando
authors.initials: FP
authors.lastname: de Matos
authors.forename: Alexandre Elias
authors.initials: AE
authors.lastname: Trivellato
authors.forename: Rogerio Bentes
authors.initials: RB
authors.lastname: Kato
authors.forename: Alexander Tadeu
authors.initials: AT
authors.lastname: Sverzut
authors.forename: Mario
authors.initials: M
authors.lastname: Taba Junior
authors.forename: Eliana Aparecida
authors.initials: EA
authors.lastname: de Rezende Duek
authors.forename: Paulo Tambasco
authors.initials: PT
authors.lastname: de Oliveira
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001860:Bone Plates; D001863:Bone Screws; D004195:Disease Models, Animal; D004285:Dogs; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D019344:Lactic Acid; D008297:Male; D008334:Mandible / Q000601:surgery*; D008337:Mandibular Fractures / Q000601:surgery*; D010027:Osteotomy / Q000295:instrumentation*; D011091:Polyesters; D011108:Polymers; D011474:Prosthesis Design
chemical_list: D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide)