Long-term outcomes after vestibuloplasty with a porcine collagen matrix (Mucograft®) versus the free gingival graft: a comparative prospective clinical trial

ObjectivesPorcine 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((R)) (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 >6months. Material and methodsThe 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 180days and 1, 2, 3, 4, and 5years 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). ResultsThe groups showed similar healing with increased peri-implant keratinized mucosa after surgery (FGG: 13.06mm2.26mm and CM: 12.96mm +/- 2.86mm). The maximum follow-up was 5years (5 patients per group). After 180days, 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 5years 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 5years. ConclusionsThe 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.