Fate of root shell after pontic/socket shield techniques, is it better to extract the whole tooth?

Figure 2 Techniques to compensate for the loss of socket wall post extraction. A: Tooth in socket; B: Empty socket after the tooth is extracted; C: Socket grafting (with lots of different biomaterials) to preserve the alveolar bone; D: Buccal bone grafting with GTR (guided tissue regeneration) to increase the thickness of buccal bone; E: Placement of immediate implant (with/without grafting the jumping space); F: Retaining only a part of root in contact with the buccal bone plate (socket-shield).