title: Influence of collar design on peri-implant tissue healing around immediate implants: A pilot study in Foxhound dogs.
abstract: OBJECTIVE
  The study aims to assess the soft tissue level (STL) and crestal bone level (CBL), of titanium dental implants with different mixed collar abutments configurations.
  
  
  METHODS
  This study included 48 implants with the same dimensions. They were divided into two groups of 24 implants each one: implants with a polished collar of 2 mm plus a roughened area of 0.8 mm (CONTROL) and implants with a polished collar of 0.8 mm plus a micro-threated and roughened area of 2 mm (TEST). The implants were inserted randomly in the post-extraction sockets of P2, P3, P4, and M1 bilaterally in the lower jaw of six foxhound dogs. STL and CBL were evaluated after 8 and 12 weeks by histology and histometry.
  
  
  RESULTS
  All implants were clinically and histologically osseointegrated. Healing patterns examined microscopically at 8 and 12 weeks for both groups yielded similar qualitative findings for the STL evaluation, without significant differences between groups (P > 0.05). CBL was significantly higher in the buccal side in comparison with the lingual side for both groups (P < 0.05); the comparison between groups at 8 weeks showed IS-B (distance from the implant shoulder to the top of the bony crest) and IS-C (distance from the implant shoulder to the first bone-to-implant contact) values significantly higher for control group in comparison with test (P < 0.05). At 12 weeks, CBL showed increased values for both groups that were higher in controls group in comparison with test (P < 0.05).
  
  
  CONCLUSIONS
  Bony crest resorption could not be avoided both at test and control sites. However, the neck conformation at the test sites reduced the buccal bone resorption. Soft tissue dimensions were similar both at the test and control sites.
authors.affiliation: Faculty of Medicine and Dentistry, University of Murcia, Murcia, Spain.
authors.forename: José Luis
authors.identifier: http://orcid.org/0000-0002-9860-5416
authors.initials: JL
authors.lastname: Calvo-Guirado
authors.affiliation: Faculty of Medicine and Dentistry, University of Murcia, Murcia, Spain.
authors.forename: Patricia Jara
authors.initials: PJ
authors.lastname: López-López
authors.affiliation: Faculty of Medicine and Dentistry, University of Murcia, Murcia, Spain.
authors.forename: José Eduardo
authors.initials: JE
authors.lastname: Maté Sánchez de Val
authors.affiliation: Faculty of Dentistry, International University of Catalonia, Barcelona, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Mareque-Bueno
authors.affiliation: School of Dental Medicine, Stony Brook University, Stony Brook, NY, USA.
authors.forename: Rafael Arcesio
authors.identifier: http://orcid.org/0000-0003-1721-0509
authors.initials: RA
authors.lastname: Delgado-Ruiz
authors.affiliation: School of Dental Medicine, Stony Brook University, Stony Brook, NY, USA.
authors.forename: Georgios E
authors.initials: GE
authors.lastname: Romanos
mesh_terms: D000818:Animals; D015921:Dental Implants; D017267:Dental Prosthesis Design; D004285:Dogs; D005881:Gingiva / Q000502:physiology* / Q000601:surgery; D057893:Immediate Dental Implant Loading; D020007:Implants, Experimental; D008297:Male; D008334:Mandible / Q000601:surgery; D016348:Osseointegration / Q000502:physiology; D010865:Pilot Projects; D013499:Surface Properties; D014025:Titanium; D020390:Tooth Socket / Q000601:surgery; D014945:Wound Healing / Q000502:physiology*
chemical_list: D015921:Dental Implants; D014025:Titanium
keywords: collar design; crestal bone; immediate implant placement; soft tissue