title: Observations on healing of human tooth extraction sockets implanted with bioabsorbable polylactic-polyglycolic acids (PLGA) copolymer root replicas: a clinical, radiographic, and histologic follow-up report of 8 cases.
abstract: OBJECTIVE
  The objective was to conduct a clinical, radiographic, and histologic follow-up of alveolar socket healing in 8 human cases in which the extraction sockets of the involved teeth were treated with biodegradable root replicas before metallic implants were placed.
  
  
  METHODS
  Chair side prepared solid and porous forms of root replicas made out of polylactic-polyglycolic acids (PLGA) copolymer were utilized. Five patients were treated with the solid form and 3 with the porous form of the replicas. The cases were followed up at regular intervals postoperatively, and standardized photographs and radiographs were taken. The cylindrical core of biopsies that were removed with trephine for placement of titanium implants were processed and examined by light and transmission-electron microscopy.
  
  
  RESULTS
  Both forms of the root replicas were well tolerated and biodegraded by the body. There were no histologically observable pathological tissue reactions at the time of implant application. However, the solid form seemed to cause an initial decalcification of the bone surrounding the extraction sockets that was subsequently repaired along with the bone healing of the extraction sockets. Such initial decalcification of the alveolar process was not observed in the cases that were treated with the porous form of root replicas. There was wide variation in the osseous component of the trephine-harvested biopsies in both treatment groups that suggests inconsistency in bone healing of the alveolar sockets.
  
  
  CONCLUSIONS
  The 2 forms of root replicas under investigation were found to be biocompatible and biodegradable. But the compact solid form may cause an initial temporary lactic acid induced decalcification of the alveolar process, which makes it unsuitable for regular clinical application as compared to the granular porous form. The observed inconsistent and unpredictable bone regeneration calls for further research to develop more optimal replica materials.
authors.affiliation: Institute of Oral Biology, Section of Oral Structures and Development, University of Zurich Center of Dental and Oral Medicine, Switzerland. nair@zzmk.unizh.ch
authors.forename: P n Ramachandran
authors.initials: Pn
authors.lastname: Nair Pn
authors.forename: Jens
authors.initials: J
authors.lastname: Schug
mesh_terms: D020341:Absorbable Implants; D000328:Adult; D000368:Aged; D000539:Alveolar Process / Q000000981:diagnostic imaging / Q000473:pathology; D001672:Biocompatible Materials / Q000737:chemistry / Q000627:therapeutic use*; D001706:Biopsy; D001861:Bone Regeneration / Q000502:physiology; D003649:Decalcification, Pathologic / Q000000981:diagnostic imaging / Q000473:pathology; D015921:Dental Implants; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry / Q000627:therapeutic use*; D008297:Male; D008854:Microscopy, Electron; D011100:Polyglycolic Acid / Q000737:chemistry / Q000627:therapeutic use*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry / Q000627:therapeutic use*; D016062:Porosity; D011859:Radiography; D013499:Surface Properties; D014025:Titanium; D014081:Tooth Extraction; D020390:Tooth Socket / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D014945:Wound Healing / Q000502:physiology
chemical_list: D001672:Biocompatible Materials; D015921:Dental Implants; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D014025:Titanium