title: Long-term outcomes after vestibuloplasty with a porcine collagen matrix (Mucograft®) versus the free gingival graft: a comparative prospective clinical trial.
abstract: OBJECTIVE
  Porcine collagen matrices are proclaimed being a sufficient alternative to autologous free gingival grafts (FGG) in terms of augmenting the keratinized mucosa. The collagen matrix Mucograft®(CM) already showed a comparable clinical performance in the early healing phase, similar histological appearance, and even a more natural appearance of augmented regions. Predictability for long-term stability does not yet exist due to missing studies reporting of a follow-up >6 months.
  
  
  METHODS
  The study included 48 patients with atrophic edentulous or partially edentulous lower jaw situations that had undergone an implant treatment. In the context of implant exposure, a vestibuloplasty was either performed with two FGGs from the palate (n = 21 patients) or with the CM (n = 27 patients). Surgery time was recorded from the first incision to the last suture. Follow-up examinations were performed at the following time points: 10, 30, 90, and 180 days and 1, 2, 3, 4, and 5 years after surgery. The width of keratinized mucosa was measured at the buccal aspect of each implant, and augmented sites were evaluated in terms of their clinical appearances (texture and color).
  
  
  RESULTS
  The groups showed similar healing with increased peri-implant keratinized mucosa after surgery (FGG: 13.06 mm ± 2.26 mm and CM: 12.96 mm ± 2.86 mm). The maximum follow-up was 5 years (5 patients per group). After 180 days, the width of keratinized mucosa had decreased to 67.08 ± 13.85% in the FGG group and 58.88 ± 14.62% in the CM group with no statistically significant difference. The total loss of the width of keratinized mucosa after 5 years was significant between the FGG (40.65%) and the CM group (52.89%). The CM group had significantly shorter operation times than the FGG group. Augmented soft tissues had a comparable clinical appearance to adjacent native gingiva in the CM group. FGGs could still be defined after 5 years.
  
  
  CONCLUSIONS
  The FGG and the CM are both suitable for the regeneration of the peri-implant keratinized mucosa with a sufficient long-term stability. With the CM, tissue harvesting procedures are invalid, surgery time can be reduced, and regenerated tissues have a more esthetic appearance.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Erlangen, Germany. Christian.Schmitt@uk-erlangen.de.
authors.forename: Christian M
authors.initials: CM
authors.lastname: Schmitt
authors.affiliation: Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Tobias
authors.identifier: http://orcid.org/0000-0002-3763-3122
authors.initials: T
authors.lastname: Moest
authors.affiliation: Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Rainer
authors.identifier: http://orcid.org/0000-0003-0199-9437
authors.initials: R
authors.lastname: Lutz
authors.affiliation: Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Falk
authors.initials: F
authors.lastname: Wehrhan
authors.affiliation: Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Friedrich W
authors.initials: FW
authors.lastname: Neukam
authors.affiliation: Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Karl Andreas
authors.initials: KA
authors.lastname: Schlegel
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D003094:Collagen; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D005260:Female; D005881:Gingiva / Q000637:transplantation*; D005893:Gingivoplasty / Q000379:methods*; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods*; D006801:Humans; D008297:Male; D008334:Mandible / Q000601:surgery*; D008567:Membranes, Artificial; D008875:Middle Aged; D061646:Operative Time; D011446:Prospective Studies; D013552:Swine; D014182:Transplantation, Autologous; D016896:Treatment Outcome; D014727:Vestibuloplasty / Q000379:methods*; D014945:Wound Healing / Q000502:physiology
chemical_list: D015921:Dental Implants; D008567:Membranes, Artificial; C000623317:Mucograft; D003094:Collagen
keywords: Mucograft®; dental implants; free gingival graft; keratinized mucosa; porcine collagen matrix; soft tissue augmentation; vestibuloplasty