title: The impact of dis-/reconnection of laser microgrooved and machined implant abutments on soft- and hard-tissue healing.
abstract: OBJECTIVE
  To (i) investigate the influence of different extensions of a laser microgrooved abutment zone on connective tissue attachment and (ii) assess the impact of a repeated abutment dis-/reconnection on soft- and hard-tissue healing.
  
  
  METHODS
  Titanium implants were inserted epicrestally in the lower jaws of six dogs. Healing abutments with either partially (LP) or completely (LC) laser microgrooved margins or machined surface margins (M) were randomly allocated either to a single (1×)/repeated (2×) dis-/reconnection at 4 and 6 weeks (test), respectively, or left undisturbed (control). At 6 and 8 weeks, histomorphometrical (e.g. most coronal level of bone in contact with the implant [CBI], subepithelial connective tissue attachment [STC]) and immunohistochemical (Collagen Type-I [CI]) parameters were assessed.
  
  
  RESULTS
  At control sites, LP/LC groups revealed lower mean CBL (8 weeks, 0.95 ± 0.51 vs. 0.54 ± 0.63 vs. 1.66 ± 1.26 mm), higher mean STC (8 weeks, 82.58 ± 24.32% vs. 96.37 ± 5.12% vs. 54.17 ± 8.09%), but comparable CI antigen reactivity. A repeated abutment manipulation was associated with increased mean CBL (8 weeks, 1.53 ± 1.09 vs. 0.94 ± 0.17 vs. 1.06 ± 0.34 mm), decreased STC (8 weeks, 57.34 ± 43.06% vs. 13.26 ± 19.04% vs. 37.76 ± 37.08%) and CI values.
  
  
  CONCLUSIONS
  It was concluded that (i) LC>LP abutments enhanced subepithelial connective tissue attachment and preserved crestal bone levels, (ii) repeated abutment dis-/reconnection during the initial healing phase (4-6 weeks) may be associated with increased soft- and hard-tissue changes and (iii) LP and LC should be considered using a one abutment, one time approach.
authors.affiliation: Department of Oral and Maxillofacial Surgery, George-Augusta-University, Göttingen, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Iglhaut
authors.forename: Kathrin
authors.initials: K
authors.lastname: Becker
authors.forename: Vladimir
authors.initials: V
authors.lastname: Golubovic
authors.forename: Henning
authors.initials: H
authors.lastname: Schliephake
authors.forename: Ilja
authors.initials: I
authors.lastname: Mihatovic
mesh_terms: D000818:Animals; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D017267:Dental Prosthesis Design; D004285:Dogs; D007124:Immunoenzyme Techniques; D007834:Lasers; D008297:Male; D008334:Mandible / Q000601:surgery; D011897:Random Allocation; D013499:Surface Properties; D014025:Titanium; D014945:Wound Healing / Q000502:physiology*
chemical_list: D015921:Dental Implants; D014025:Titanium