State of the art on biomaterials for soft tissue augmentation in the oral cavity. Part I: Natural polymers-based biomaterials

Oral soft tissue thickening or grafting procedures are often necessary to cover tooth recession, re-establish an adequate width of keratinized tissue, correct mucogingival deformities improving esthetics, prepare a site for an implant or prosthetics, for ridge preservation procedures, and soft tissue contouring around dental implants. Gingival recession and root or implant exposure are commonly associated and have led to mucogingival deficiencies that have traditionally been treated with free gingival grafts and autogenous soft tissue grafts. The latter represents the gold standard in acquiring a functionally adequate zone of keratinized attached gingiva. However, soft tissue substitutes are more usually employed because they lessen morbidity and abbreviate surgical time. This review is aimed at assessing oral soft tissue augmentation techniques and biomaterials used from existing literature, principally concerning scaffolds from both human and animal-based tissue derivatives matrices. In order to avoid the use of human donor tissue, the xenogenic collagen matrices are proposed for soft tissue augmentation. In general, all of them have provided the remodeling processes and enhanced the formation of new connective tissue within the matrix body.