When the alveolus has a defect that needs to be regenerated, graft materials should be used for this. Hard tissue grafts maintain the long-term soft tissue architecture and esthetics, and soft tissue coverage is necessary for hard tissue grafts to heal.
Hard Tissue Grafts
Autologous bone grafts may retain the matrix, with its bone inductive properties and undifferentiated cells. It is the only osteoinductive material available, it has a long history of use, and is considered the gold standard of graft materials. Intraorally, small amounts of autologous bone chips or blocks can be harvested from the neighboring bone, and large amounts from the ramus/angle of the mandible and from the chin.
Allografts [demineralized freeze-dried bone allograft (DFDBA), mineralized freeze-dried bone allograft (MFDBA)] and xenografts [bovine-derived hydroxyapatite (BdHA)] are only osteoconductive.
It seems that the closer the localized site augmentation is to the bone crest, the more important it is to use gold-standard graft materials. The further away it is, the less important is the graft material used for regenerating the bone defect.
Soft Tissue Grafts
A connective tissue graft prevents the membrane from exposure, improves esthetics, and enlarges the attached gingival strip around the implant neck. This is important for the long-term maintenance of the bone crest profile and hygiene around the implant.
In a single immediate implant, soft tissue coverage can be achieved by a free gingival graft (see the discussion later on submerged implants and socket seal surgery) or by a pediculated graft rotated from the palate. With multiple immediate implants, the whole flap can be displaced to cover the membrane, so no free gingival graft will be necessary.
The periodontium phenotype should be considered too. A type I phenotype with a thin, highly scalloped gingival margin is less resistant to surgical trauma or restorative procedures and is more prone to recession, in comparison to the type II phenotype with a thick, flat gingival margin.