title: The use of light/chemically hardened polymethylmethacrylate, polyhydroxylethylmethacrylate, and calcium hydroxide graft material in combination with polyanhydride around implants and extraction sockets in minipigs: Part II: histologic and micro-CT evaluations.
abstract: BACKGROUND
  This report is the second part of the previously published study on the impact of light/chemical hardening technology and a newly formulated composite graft material for crestal augmentation during immediate implant placement.
  
  
  METHODS
  A total of 48 implants were placed into the sockets of the mesial roots of freshly extracted mandibular premolar teeth in three minipigs. Crestal areas and intrabony spaces were randomly augmented with light-hardened graft materials including a composite graft consisting of polymethylmethacrylate, polyhydroxylethylmethacrylate, and calcium hydroxide (PPCH) plus polyanhydride (PA); PPCH graft; and PA graft, or left untreated. Distal sockets not receiving implants and the sockets of first molars (n = 60) were randomly treated with one of the graft materials or left empty. In addition, two molar sockets were treated with the original PPCH graft material. Quantitative microcomputed tomography (micro-CT) was used to assess alveolar bone structure and tissue compositions. Histologic evaluations included descriptive histology to assess the peri-implant wound healing, as well as histomorphometric measurements to determine bone-to-implant contact (BIC).
  
  
  RESULTS
  Both trabecular and cortical bone measurements by micro-CT did not reveal any significant differences among the groups. Sites augmented with PPCH+PA resulted in significantly greater BIC surface than PPCH alone and no-graft-treated implants (P <0.05) histologically. Stained ground sections showed complete bone formation between bone and implant surface in the PPCH+PA group, whereas sites without augmentation showed large gaps between bone and implant surfaces, indicating a slower bone apposition and less BIC surface compared to all other groups. Similar to implant sections, all materials showed positive outcome on trabecular and cortical bone formation in extraction sockets with an intact crestal cortical bone.
  
  
  CONCLUSIONS
  Histologic evaluations supported the previous findings on implant stability and function and confirmed that PPCH+PA provides a greater BIC with a well-organized implant-bone interface and is useful in crestal augmentation during immediate implant placement.
authors: Department of Applied Oral Sciences, Center for Periodontology, The Forsyth Institute, Cambridge, MA.
authors: Hatice
authors: H
authors: Hasturk
authors: Alpdogan
authors: A
authors: Kantarci
authors: Mazen
authors: M
authors: Ghattas
authors: Smit J
authors: SJ
authors: Dangaria
authors: Rima
authors: R
authors: Abdallah
authors: Elise F
authors: EF
authors: Morgan
authors: Thomas G H
authors: TG
authors: Diekwisch
authors: Arthur
authors: A
authors: Ashman
authors: Thomas
authors: T
authors: Van Dyke
mesh_terms: D000539:Alveolar Process / Q000473:pathology; D000540:Alveolar Ridge Augmentation / Q000379:methods; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000627:therapeutic use*; D015519:Bone Density / Q000502:physiology; D018786:Bone Substitutes / Q000627:therapeutic use*; D002113:Calcification, Physiologic / Q000502:physiology; D002126:Calcium Hydroxide / Q000737:chemistry*; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D057893:Immediate Dental Implant Loading; D055115:Light-Curing of Dental Adhesives; D008297:Male; D008334:Mandible / Q000601:surgery; D016348:Osseointegration / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology; D010512:Periodontal Index; D049388:Polyanhydrides / Q000737:chemistry*; D011102:Polyhydroxyethyl Methacrylate / Q000737:chemistry*; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D011897:Random Allocation; D013499:Surface Properties; D013552:Swine; D013556:Swine, Miniature; D020390:Tooth Socket / Q000473:pathology / Q000601:surgery*; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D015921:Dental Implants; D049388:Polyanhydrides; D011102:Polyhydroxyethyl Methacrylate; D019904:Polymethyl Methacrylate; D002126:Calcium Hydroxide
keywords: Alveolar ridge augmentation; dental implants; immediate dental implant loading