title: Histopathological observations of a polylactic acid-based device intended for guided bone/tissue regeneration.
abstract: BACKGROUND
  Barrier devices have been shown to support alveolar bone and periodontal regeneration, a procedure also known as guided bone/tissue regeneration (GBR/GTR). Popular demand and clinical convenience have raised an interest in bioresorbable barrier devices. Tissue reactions to such bioresorbable devices are, however, generally not well explored.
  
  
  OBJECTIVE
  The objective of this study was to evaluate short- and long-term tissue reactions following implantation of a bioresorbable polylactic acid (PLA)-based barrier device using a rat model.
  
  
  METHODS
  Twenty-one young adult male Sprague-Dawley rats were used. The animals were divided into three groups including 15 animals receiving the PLA device and animals serving as sham surgery (five) or nonoperated (one) controls. Using aseptic techniques, the PLA device was surgically implanted in direct contact with the calvarial bone. Animals receiving the PLA device were sacrificed at 3, 5, 7, and 12 months postsurgery to provide longitudinal histopathological observations of tissue and biomaterials reactions. Control animals were sacrificed at 3 months.
  
  
  RESULTS
  Animals were maintained without adverse events. Sham surgery and nonoperated control animals showed no signs of new bone formation or resorption, or signs of inflammatory reactions in adjoining soft tissues. In contrast, extensive amounts of residual biomaterial with evidence of foreign body reactions and bone resorption were observed in animals receiving the PLA device over 12 months.
  
  
  CONCLUSIONS
  The results suggest that the PLA device may induce bone resorbing foreign body reactions. Importantly, the PLA device does not resorb within a 12-month healing interval. These biomaterials properties may influence new bone formation and maintenance when applying the device for GBR/GTR.
authors.affiliation: Laboratory for Applied Periodontal & Craniofacial Regeneration, Medical College of Georgia, School of Dentistry, Augusta, GA 30912, USA.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Polimeni
authors.forename: Ki-Tae
authors.initials: KT
authors.lastname: Koo
authors.forename: Gordon A
authors.initials: GA
authors.lastname: Pringle
authors.forename: Alexis
authors.initials: A
authors.lastname: Agelan
authors.forename: Fayez F
authors.initials: FF
authors.lastname: Safadi
authors.forename: Ulf M E
authors.initials: UM
authors.lastname: Wikesjö
mesh_terms: D020341:Absorbable Implants / Q000009:adverse effects*; D000818:Animals; D001862:Bone Resorption / Q000139:chemically induced* / Q000473:pathology; D005549:Foreign-Body Reaction / Q000139:chemically induced* / Q000473:pathology; D048091:Guided Tissue Regeneration / Q000009:adverse effects / Q000379:methods; D019344:Lactic Acid / Q000009:adverse effects*; D008137:Longitudinal Studies; D008297:Male; D008567:Membranes, Artificial; D016348:Osseointegration / Q000187:drug effects; D011091:Polyesters; D011108:Polymers / Q000009:adverse effects*; D051381:Rats; D017208:Rats, Wistar; D012886:Skull / Q000187:drug effects / Q000473:pathology / Q000601:surgery; D013997:Time Factors
chemical_list: D008567:Membranes, Artificial; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide)