Allografts and Xenografts for Periodontal Plastic Surgical Procedures

Abstract

The selection of surgical techniques and grafting materials is undoubtedly a critical component in the treatment of gingival recession defects. In order to provide top quality care, dental professionals are always in pursuit of treatment modality that provides maximal efficacy and predictability with minimal patient morbidity. The subepithelial connective tissue graft procedure, the gold standard, has been consistently proven to show excellent root coverage, but limited palatal tissue availability and potential morbidity associated with the harvesting process push dental practitioners to seek an alternative. The same holds true for peri-implant tissues—while autogenous grafts have served our purpose well, alternatives that can achieve similar results while avoiding a second intraoral wound (the donor sites) are preferred. The purpose of this review of recent studies is to evaluate the effectiveness and predictability of allografts and xenografts for root coverage procedures and around dental implants. The electronic database search was limited to the past 5 years and to the studies addressing root coverage procedures in the Miller class I and II gingival recession (even though the 2017 International Workshop suggested a new classification, the majority of research projects use the classic Miller classification). Search was also made for studies addressing soft tissue treatment around implants that were published during the same period. A total of 30 human clinical trials involving allografts (mainly acellular dermal matrix and placental membranes) and xenografts (porcine-derived collagen matrix) for treatment of gingival recession and a total of 19 clinical studies using allografts and xenografts to improve soft tissue quality around implants were selected. Based on the selected studies, acellular dermal matrix in combination with various flap designs appears to produce results similar to autogenous grafts in terms of mean root coverage and width of keratinized tissue. Other grafting materials, while less effective compared to autogenous grafts, still show some promise especially in patient-centered outcomes. For soft tissue quality improvement around implant sites, allografts and xenografts in general provide satisfactory clinical results. Multicenter, randomized clinical studies with large numbers of individuals and long-term outcomes may provide the most realistic answer for this topic.