In some cases, the patient has periodontal defects (damaged or poor bone structure) which hinder osseointegration. Guided tissue and/or bone regeneration may be necessary before the bone can osseointegrate with the dental implant. In this case a combination of barrier membranes, bone tacks, and supplemental autogenous bone may be required to promote proper osseointegration. In addition, implant surface modification has been studied and now integrated, thus promoting an optimal tissue-implant interface (i.e. osseointegration, implant-gingival seal).
Osseoincorporation
Hair cloning
Exon shuffling
Exon skipping
Fragmentation 
Bromism
Gene duplication
Somatic hypermutation