Aim: This study aims to examine the composition of lining and masticatory mucosa at the pre- and post-soft tissue augmentation procedures with a volume-stable cross-linking collagen matrix (VCMX) in humans.
Materials and methods: In 12 patients, single implant sites were augmented with a VCMX. Biopsies were obtained including masticatory (MM) and lining (LM) mucosa before augmentation and at 12 weeks post-augmentation procedures. Rete pegs density (RPD), length (RPL), and blood vessel density (BVD) were histomorphometrically analyzed at both time points. Picrosirius red staining under polarized light microscopy was used to evaluate collagen fiber organization. The effects of time and tissue type were evaluated by ANOVA with repeated measures.
Results: Both MM and LM areas demonstrated an increase in mean RPL following augmentation, 382.6 µm ± 95.1 vs. 290.5 µm ± 79.3 and 335.6 µm ± 94.2 vs. 292.9 µm ± 77.0, respectively (p < .05). There was a significant difference in the numbers of RP per 1 mm length (RPD) between the MM (9.2 ± 1.7) and LM (6.1 ± 2.8) mucosa but not between the pre- and post-VCMX augmentation time points. The mean BVD in the LM was greater than in the MM (5.5 ± 2.4 and 6.3 ± 2.4 vs. 3.4 ± 3.3 and 3.7 ± 1.8, respectively, p < .05) but not between time points. The collagen fiber arrangements pre- and post-augmentation were not significantly different.
Conclusion: Augmentation with VCMX did not alter the composition of lining and masticatory mucosa at implant sites.
Clinical relevance: A thick soft tissue phenotype around the implant neck is an important factor to maintain peri-implant health. A non-autogenous cross-linking collagen matrix is proposed as an alternate graft substitute in soft tissue augmentation procedures in order to improve implant soft tissue phenotype.
Keywords: Collagen fibers; Collagen matrix; Connective tissue; Mucosal thickness; Soft tissue augmentation.
© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.