**7. Future directions**

Undoubtedly, acoustic devices are useful tools to stimulate osteogenesis. Nevertheless, there is a wide list of topics that require further investigations: physical phenomena elicited by acoustic forces need to be proved in vivo, signalling molecules need to be assigned to specific signalling pathways, the control of cellular response to acoustic loads needs to be clarified, RPWT and piezoelectric ESWT influence on bone biology lack investigations, clinical protocols for ESWT and RPWT should be established and, finally, randomized controlled trials address‐ ing acoustic therapy should be performed. As a conclusion, a lot of research is expected within the next years to clarify the unanswered questions about the relationship of bone tissue and acoustic forces.
