Background: Ensuring a minimum peri-implant keratinized mucosa width (PIKM-W) is critical
for maintaining dental implant health, as inadequate PIKM-W is associated with increased
risks of plaque accumulation, mucosal inflammation, and peri-implantitis. While epithelialized
connective tissue grafts (ECTGs) are considered the gold standard for soft tissue
augmentation, they often lead to significant patient morbidity. Xenogeneic dermal
matrices (XDMs) offer a less invasive alternative, but are prone to shrinkage, particularly
in the mandible. The aim of this study was to evaluate a new surgical method to overcome
these limitations with the combination of a narrow band of ECTG (autogenous strip
graft, ASG) and an XDM to augment the PIKM-W in the posterior mandible. Methods: Twelve
patients with a PIKM-W of less than 2 mm in the mandible underwent peri-implant soft
tissue augmentation using this combined approach. Changes in the PIKM-W were measured
preoperatively; immediately postoperatively; and at 1, 3, 6, 9, and 12 months. Graft
remodeling (shrinkage or contraction) and PIKM thickness (PIKM-T) were also evaluated
over time. Results: Preoperatively, the mean PIKM-W was 0.39 +/- 0.40 mm and the PIKM-T
was 1.36 +/- 0.43 mm. At 6 months, the mean PIKM-W was 4.93 +/- 0.98 mm and the PIKM-T
was 2.88 +/- 0.80 mm, with shrinkage of 39.2 +/- 14.1%. By 12 months, the mean PIKM-W
stabilized at 4.58 +/- 1.28 mm and the PIKM-T stabilized at 2.83 +/- 0.65 mm, with
shrinkage of 42.2% +/- 16.8%. Conclusions: There were statistically significant differences
in clinical parameters between the baseline and 6 and 12 months (p < 0.05). This technique
demonstrated the potential for stable augmentation of PIKM-W and PIKM-T over time,
with manageable shrinkage. However, further studies with larger sample sizes are needed
to confirm its clinical efficacy as an alternative for mandibular keratinized mucosa
augmentation around implants.
