Alveolar Ridge Preservation With a Xenograft (Bio-Oss® Collagen) and a Collagen Matrix (Mucograft® Seal) or a Free Connective Tissue Graft Versus Spontaneous Healing:A 5-year Follow up

Replacement of a single tooth in the esthetic zone is a demanding procedure. For optimal esthetic results, no deficiency in both bone and soft tissue is acceptable. Immediately after tooth extraction, the alveolar ridge undergoes horizontal and vertical bone loss. This negatively influences the soft tissue contours, and thus esthetic outcome. Although immediate placement of an implant after extraction leads to acceptable esthetic results, there is an increased risk of mucosal recession due to the lack of adequate soft tissue. Early implant placement, 4 to 8 weeks after extraction, may offer advantages in terms of soft and hard tissue preservation. The main goals when treating the extraction socket in the esthetic zone is to preserve as much as possible existing soft and hard tissue volume as possible for future implant placement. Landsberg described a modified ridge preservation technique called "socket seal surgery" where flap elevation is avoided and it combines both bone and soft tissue grafting prior to implant placement. Closing the extraction site from the oral cavity using a thick epithelized palatal graft enables optimal ridge preservation immediately after tooth extraction. Jung showed that the application of a slowly resorbing biomaterial (BioOss Collagen®, Geistlich) into an extraction socket, covered with an autogenous palatal soft tissue punch graft resulted in a high predictability and reliability for a good esthetic result for future (early) implant placement. Although a soft tissue graft is a relatively easy procedure, patient morbidity is often associated with the second surgical site. An artificial socket seal might prevent donor morbidity associated with soft tissue grafts. A critical determinant for stable esthetic long-term outcomes is integrity and stability of the facial bone wall. The application of a biomaterial into an extraction socket, covered with a collagen matrix or a soft tissue graft, resulted in less vertical and horizontal changes of the alveolar ridge 6 months after extraction. Although there seems to be no difference in the long term change of the buccal soft tissue contour and alveolar ridge between a collagen matrix and an autogenous soft tissue punch graft, there is a lack in data concerning the difference in esthetic outcome between these two methods in early implant placement. Therefore, we evaluated esthetic and clinical outcomes and patient satisfaction following single-tooth replacement in the anterior maxilla in patients treated with alveolar ridge preservation(ARP) with a xenograft (Bio-Oss® Collagen) and a collagen matrix (Mucograft® Seal) or a free connective tissue graft versus spontaneous healing up to 1 year after functional loading (MEC-2015-016;NL49965.078.14). This study showed that ARP using a xenogeneic bone substitute covered with a collagen matrix or a palatal graft, resulted in less bone resorption and fewer bone augmentation procedures at early implant placement compared to spontaneous healing. One year after functional loading, there was no difference in clinical and esthetical outcomes and similar PROMS between the three treatment modalities. In order to achieve optimal esthetic results, both the bone and soft tissue have to be preserved as good as possible. Not much is known about the long term stability of ARP compared to spontaneous healing and PROMs.