title: Osseointegration of dental implants in extraction sockets preserved with porous titanium granules - an experimental study.
abstract: OBJECTIVE
  This study investigated osseointegration of dental implants inserted in healed extraction sockets preserved with porous titanium granules (PTG).
  
  
  METHODS
  Three adult female minipigs (Gøttingen minipig; Ellegaard A/S, Dalmose, Denmark) had the mandibular teeth P2, P3 and P4 extracted. The extraction sockets were preserved with metallic PTG (Tigran PTG; Tigran Technologies AB, Malmö, Sweden) n = 12, heat oxidized white porous titanium granules (WPTG) (Tigran PTG White) n = 12 or left empty (sham) n = 6. All sites were covered with collagen membranes (Bio-Gide; Geistlich Pharma, Wolhausen, Switzerland) and allowed 11 weeks of healing before implants (Straumann Bone Level; Straumann, Basel, Switzerland) were inserted. The temperature was measured during preparation of the osteotomies. Resonance frequency analysis (RFA, Osstell; Osstell AB, Gothenburg, Sweden) was performed at implant insertion and at termination. After 6 weeks of submerged implant healing, the pigs were euthanized and jaw segments were excised for microCT and histological analyses.
  
  
  RESULTS
  In the temperature and RFA analyses no significant differences were recorded between the test groups. The microCT analysis demonstrated an average bone volume of 61.7% for the PTG group compared to 50.3% for the WPTG group (P = 0.03) and 57.1% for the sham group. Histomorphometry demonstrated an average bone-to-implant contact of 68.2% for the PTG group compared to 36.6% for the WPTG group and 60.9% for the sham group (n.s). Eight out of ten implants demonstrated apical osseous defects in the WPTG group, but similar defects were observed in all groups.
  
  
  CONCLUSIONS
  PTG preserved extraction sockets demonstrate a similar outcome as the sham control group for all analyses suggesting that this material potentially can be used for extraction socket preservation prior to implant installment. Apical osseous defects were however observed in all groups including the sham group, and a single cause could not be determined.
authors.affiliation: Department of Biomaterials, Institute of Clinical Odontology, University of Oslo, Oslo, Norway.
authors.forename: Anders
authors.initials: A
authors.lastname: Verket
authors.forename: Ståle P
authors.initials: SP
authors.lastname: Lyngstadaas
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Rønold
authors.forename: Johan C
authors.initials: JC
authors.lastname: Wohlfahrt
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000494:pharmacology*; D003094:Collagen / Q000494:pharmacology; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D005260:Female; D020007:Implants, Experimental; D008334:Mandible / Q000601:surgery; D016348:Osseointegration / Q000502:physiology*; D016062:Porosity; D013552:Swine; D013556:Swine, Miniature; D014025:Titanium / Q000494:pharmacology*; D014081:Tooth Extraction; D020390:Tooth Socket / Q000601:surgery*; D014945:Wound Healing / Q000502:physiology; D055114:X-Ray Microtomography
chemical_list: C106416:Bio-Gide; D018786:Bone Substitutes; D015921:Dental Implants; D003094:Collagen; D014025:Titanium