32 randomised, controlled clinical trials were included in the meta-analysis, in total 1354 alveolar sockets1. The loss of volume, both horizontally and vertically, is lowest when xenogenic bone replacement materials are being used. In this case, only 1.3 mm in ridge width and 0.57 mm in ridge height are lost - instead of 2.79 mm or 1.74 mm, respectively, in spontaneous healing. By comparison: if an allograft, i.e. human bone material from tissue banks, is being used, 1.63 mm in ridge width and 0.58 mm in ridge height are lost on average, with synthetic bone material even 2.13 mm in ridge width and 0.77 in height.
Only studies with flapless tooth extraction included
In the meta-analysis of Jambhekar et al., only studies were included in which teeth were extracted with a flapless approach. As this is the gentlest form of tooth extraction, it minimises volume shrinkage, even if nothing is done to compensate it. That's why in this analysis, volume loss in case of spontaneous healing is smaller compared to other meta-analyses. So, in this case, the effects of Ridge Preservation are really additional effects under otherwise "ideal conditions".
- Jambhekar S, et al.: J Prosthet Dent. 2015; 113(5): 371-82.